tag:theconversation.com,2011:/au/topics/blood-cells-904/articlesBlood cells – The Conversation2024-02-05T13:30:15Ztag:theconversation.com,2011:article/2163412024-02-05T13:30:15Z2024-02-05T13:30:15ZWhat do your blood test results mean? A toxicologist explains the basics of how to interpret them<figure><img src="https://images.theconversation.com/files/570974/original/file-20240123-19-h34bd4.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2120%2C1414&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">From CBC to CMP and beyond, blood test panels provide essential information to health practitioners.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/workplace-of-laboratory-with-blood-tubes-samples-royalty-free-image/1389684965">angelp/iStock via Getty Images Plus</a></span></figcaption></figure><p>Your blood <a href="https://www.ncbi.nlm.nih.gov/books/NBK279392/">serves numerous roles</a> to maintain your health. To carry out these functions, blood contains a multitude of components, including red blood cells that transport oxygen, nutrients and hormones; white blood cells that remove waste products and support the immune system; plasma that regulates temperature; and platelets that help with clotting.</p>
<p>Within the blood are also numerous molecules formed as byproducts of normal biochemical functions. When these molecules indicate how your cells are responding to disease, injury or stress, scientists often refer to them as <a href="https://doi.org/10.1097/COH.0b013e32833ed177">biological markers, or biomarkers</a>. Thus, biomarkers in a blood sample can represent a snapshot of the current biochemical state of your body, and analyzing them can provide information about various aspects of your health.</p>
<p><a href="https://www.researchgate.net/profile/Brad-Reisfeld">As a toxicologist</a>, I study the effects of drugs and environmental contaminants on human health. As part of my work, I rely on various health-related biomarkers, many of which are measured using conventional blood tests.</p>
<p>Understanding what <a href="https://www.nhlbi.nih.gov/health/blood-tests">common blood tests</a> are intended to measure can help you better interpret the results. If you have results from a recent blood test handy, please follow along.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/4nYHPM7BHIM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Blood samples go through several processing steps after they’re drawn.</span></figcaption>
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<h2>Normal blood test ranges</h2>
<p><a href="https://theconversation.com/how-do-blood-tests-work-medical-laboratory-scientists-explain-the-pathway-from-blood-draw-to-diagnosis-and-treatment-196874">Depending on the lab</a> that analyzed your sample, the results from your blood test may be broken down into individual tests or collections of <a href="https://www.testing.com/tests/chemistry-panels/">related tests called panels</a>. Results from these panels can allow a health care professional to recommend preventive care, detect potential diseases and monitor ongoing health conditions.</p>
<p>For each of the tests listed in your report, there will typically be a number corresponding to your test result and a <a href="https://www.testing.com/articles/laboratory-test-reference-ranges/">reference range or interval</a>. This range is essentially the upper and lower limits within which most healthy people’s test results are expected to fall.</p>
<p>Sometimes called a normal range, a reference interval is based on <a href="https://webstore.ansi.org/preview-pages/CLSI/preview_CLSI+C28-A3.pdf">statistical analyses</a> of tests from a large number of patients in a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4975205/">reference population</a>. Normal levels of some biomarkers are expected to vary across a group of people, depending on their age, sex, ethnicity and other attributes. </p>
<p>So, separate reference populations are often created from people with a particular attribute. For example, a reference population could comprise all women or all children. A patient’s test value can then be appropriately compared with results from the reference population that fits them best.</p>
<p>Reference intervals <a href="https://doi.org/10.1001/archinternmed.2007.131">vary from lab to lab</a> because each may use different testing methods or reference populations. This means you might not be able to compare your results with reference intervals from other labs. To determine how your test results compare with the normal range, you need to check the reference interval listed on your lab report.</p>
<p>If you have results for a given test from different labs, your clinician will likely focus on test trends relative to their reference intervals and not the numerical results themselves.</p>
<h2>Interpreting your blood test results</h2>
<p>There are <a href="https://kidshealth.org/en/parents/blood-test-types.html">numerous blood panels</a> intended to test specific aspects of your health. These include panels that look at the cellular components of your blood, biomarkers of kidney and liver function, and many more.</p>
<p>Rather than describe each panel, let’s look at a hypothetical case study that requires using several panels to diagnose a disease.</p>
<p>In this situation, a patient visits their health care provider for fatigue that has lasted several months. <a href="https://www.merckmanuals.com/professional/special-subjects/nonspecific-symptoms/fatigue">Numerous factors and disorders</a> can result in prolonged or chronic fatigue.</p>
<p>Based on a physical examination, other symptoms and medical history, the health practitioner suspects that the patient could be suffering from any of the following: anemia, an underactive thyroid or diabetes.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/570977/original/file-20240123-21-rfgobx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close-up of a person holding gauze against the crook of their arm while another person holds up two heparin tubes of blood" src="https://images.theconversation.com/files/570977/original/file-20240123-21-rfgobx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570977/original/file-20240123-21-rfgobx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570977/original/file-20240123-21-rfgobx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570977/original/file-20240123-21-rfgobx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570977/original/file-20240123-21-rfgobx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570977/original/file-20240123-21-rfgobx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570977/original/file-20240123-21-rfgobx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Blood tests provide clinicians with more information to guide diagnoses and treatment decisions.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/female-nurse-holding-blood-collection-tubes-royalty-free-image/1463489972">FluxFactory/E+ via Getty Images</a></span>
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<p>Blood tests would help further narrow down the cause of fatigue.</p>
<p><a href="https://www.nhlbi.nih.gov/health/anemia">Anemia</a> is a condition involving reduced blood capacity to transport oxygen. This results from either lower than normal levels of red blood cells or a decrease in the quantity or quality of <a href="https://theconversation.com/why-do-we-bleed-a-hematologist-explains-how-the-body-prevents-blood-loss-after-injury-174581">hemoglobin</a>, the protein that allows these cells to transport oxygen. </p>
<p>A <a href="https://medlineplus.gov/lab-tests/complete-blood-count-cbc/">complete blood count panel</a> measures various components of the blood to provide a comprehensive overview of the cells that make it up. <a href="https://www.nhlbi.nih.gov/health/anemia/diagnosis">Low values</a> of red blood cell count, or RBC, hemoglobin, or Hb, and hematocrit, or HCT, would indicate that the patient is suffering from anemia.</p>
<p><a href="https://www.niddk.nih.gov/health-information/endocrine-diseases/hypothyroidism">Hypothyroidism</a> is a disorder in which the thyroid gland does not produce enough thyroid hormones. These include thyroid-stimulating hormone, or TSH, which stimulates the thyroid gland to release two other hormones: triiodothyronine, or T3, and thyroxine, or T4. The <a href="https://medlineplus.gov/thyroidtests.html">thyroid function panel</a> measures the levels of these hormones to assess thyroid-related health.</p>
<p><a href="https://www.cdc.gov/diabetes/basics/diabetes.html">Diabetes</a> is a disease that occurs when blood sugar levels are too high. Excessive glucose molecules in the bloodstream can bind to hemoglobin and form what’s called glycated hemoglobin, or HbA1c. A <a href="https://doi.org/10.4137/BMI.S38440">hemoglobin A1c test</a> measures the percentage of HbA1c present relative to the total amount of hemoglobin. This provides a history of glucose levels in the bloodstream over a period of about three months prior to the test.</p>
<p>Providing additional information is the <a href="https://medlineplus.gov/lab-tests/basic-metabolic-panel-bmp/">basic metabolic panel, or BMP</a>, which measures the amount various substances in your blood. These include:</p>
<ul>
<li>Glucose, a type of sugar that provides energy for your body and brain. Relevant to diabetes, the BMP measures the blood glucose levels at the time of the test.</li>
<li>Calcium, a mineral essential for proper functioning of your nerves, muscles and heart.</li>
<li>Creatinine, a byproduct of muscle activity.</li>
<li>Blood urea nitrogen, or BUN, the amount of the waste product urea your kidneys help remove from your blood. These indicate the status of a person’s metabolism, kidney health and electrolyte balance.</li>
</ul>
<p>With results from each of these panels, the health professional would assess the patient’s values relative to their reference intervals and determine which condition they most likely have.</p>
<p>Understanding the purpose of blood tests and how to interpret them can help patients partner with their health care providers and become more informed about their health.</p><img src="https://counter.theconversation.com/content/216341/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brad Reisfeld does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Your blood contains a wealth of information about the state of your health. Analyzing the levels of each component is an important part of diagnosis.Brad Reisfeld, Professor of Chemical and Biological Engineering, Biomedical Engineering, and Public Health, Colorado State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2051102023-08-07T12:43:56Z2023-08-07T12:43:56ZZebrafish are a scientist’s favorite for early-stage research – especially to study human blood disorders<figure><img src="https://images.theconversation.com/files/540000/original/file-20230728-23-tbljsp.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2048%2C1299&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">As an animal model, the zebrafish offers many advantages that save researchers time and money.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/wBu5Uz">Uri Manor/NICHD via Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Scientists have <a href="https://doi.org/10.7554/eLife.05959">relied on animal models</a> as an alternative to testing on human tissues and cells for decades. But not just any organism can adequately model how human cells behave. Researchers take into account how quickly the organism can mature, how many offspring it can produce and how often it can reproduce. When studying genetics and developmental biology, one of the most important qualities to consider is how similar the model organism’s genes are to human genes.</p>
<p>Although humans and fish certainly look very different, the zebrafish has proved to be an excellent model organism for scientists studying <a href="https://doi.org/10.1242%2Fdev.083147">hematopoiesis</a>, or the development of blood cells.</p>
<p>In the <a href="https://www.espinlab.com">Espín Lab</a> at Iowa State University, <a href="https://scholar.google.com/citations?user=O2ux60wAAAAJ&hl=en">we study</a> the early stages of blood development, particularly the birth of blood stem cells, which happens only once during embryonic development. We focus on a specific set of genes that play a significant but somewhat elusive role in the molecular pathways involved in this process. Although we want to understand how these genes work in the context of human blood development, testing on human embryos is obviously ethically impossible. To circumvent these challenges, we use zebrafish instead.</p>
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<a href="https://images.theconversation.com/files/540001/original/file-20230728-35025-grpb0x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scientist holding a small fish tank in a magenta-lit aisle of fish tanks filled with zebrafish" src="https://images.theconversation.com/files/540001/original/file-20230728-35025-grpb0x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/540001/original/file-20230728-35025-grpb0x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/540001/original/file-20230728-35025-grpb0x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/540001/original/file-20230728-35025-grpb0x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/540001/original/file-20230728-35025-grpb0x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/540001/original/file-20230728-35025-grpb0x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/540001/original/file-20230728-35025-grpb0x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The National Institute of Child Health and Human Development houses the largest zebrafish facility in the U.S. Each tank contains live zebrafish used in research.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/HJ4qwU">Ernesto del Aguila III/NHGRI via Flickr</a></span>
</figcaption>
</figure>
<h2>Zebrafish as a model organism</h2>
<p>Zebrafish have several traits that make them excellent model organisms.</p>
<p>For one, one female zebrafish can produce <a href="https://doi.org/10.1046/j.1365-2141.2003.04682.x">hundreds of embryos per week</a>. This is important to scientists because having larger sample numbers strengthens the accuracy of the data they collect in their experiments.</p>
<p>Zebrafish embryos are also able to develop quickly. One day of development in zebrafish is equivalent to approximately 90 days of human development. This means that researchers can save time and observe the different stages of development much sooner than with other organisms.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/BD4gqmGdFyY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This time-lapse video shows the first 22 hours of zebrafish development after fertilization, with blood vessels labeled green. Blood has already formed at this stage of development.</span></figcaption>
</figure>
<p>Another useful quality of zebrafish is that they are <a href="https://doi.org/10.1046/j.1365-2141.2003.04682.x">translucent during early development</a>. As soon as their embryos are fertilized, scientists can observe cells and tissues form and clearly see the effects of modifying different genes.</p>
<p>Perhaps the most important feature of zebrafish for scientists is their genetic makeup. Approximately <a href="https://doi.org/10.1038/nature12111">70% of zebrafish genes</a> have similar analogs in people, allowing researchers to study how certain genes work.</p>
<h2>Studying blood disorders with zebrafish</h2>
<p>Beyond sharing a significant percentage of genes with people, zebrafish are especially useful to blood development research because they produce the <a href="https://doi.org/10.1046/j.1365-2141.2003.04682.x">same types of blood cells</a>. Just like people, zebrafish have <a href="https://doi.org/10.1016/j.bcmd.2013.07.006">erythroid</a>, <a href="https://doi.org/10.1038/nri.2017.86">lymphoid</a> and <a href="https://doi.org/10.1016/j.biocel.2004.01.020">myeloid</a> cell types that are responsible for numerous roles in the body, like circulating oxygen and regulating inflammation and immunity. Mature blood cells are derived from blood stem cells. Therefore, studying how these stem cells are made would aid in developing treatment for numerous blood disorders that rely on blood stem cell therapies, such as leukemia, lymphoma and anemia.</p>
<p>Labs like ours use zebrafish to study how specific cell signaling pathways contribute to the birth, development and maturation of these blood stem cells. This knowledge provides context for how healthy cells work and communicate, because cells rely on signals from other cells to know which genes they need to turn on to produce specific proteins and molecules. </p>
<p>For example, we have previously shown how <a href="http://dx.doi.org/10.1016/j.cell.2014.10.031">inflammatory signaling pathways</a> are needed for zebrafish to properly develop the <a href="https://doi.org/10.15283/ijsc19127">hematopoietic stem cells</a> that produce multiple kinds of blood cells. We are currently exploring how these inflammatory pathways produce human blood stem cells. While most cells receive certain signals that trigger them to express certain genes, <a href="https://theconversation.com/triggering-cancer-cells-to-become-normal-cells-how-stem-cell-therapies-can-provide-new-ways-to-stop-tumors-from-spreading-or-growing-back-191559">stem cells</a> are capable of developing into multiple types of cells in an organism. Stem cells are undifferentiated, meaning that they are not yet limited to expressing or following only certain parts of the DNA like more mature, differentiated cells. </p>
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<a href="https://images.theconversation.com/files/540002/original/file-20230728-17-35i4pz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Microscopy image of blood cells flowing through the blood vessels on the yolk of a zebrafish embryo" src="https://images.theconversation.com/files/540002/original/file-20230728-17-35i4pz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/540002/original/file-20230728-17-35i4pz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=473&fit=crop&dpr=1 600w, https://images.theconversation.com/files/540002/original/file-20230728-17-35i4pz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=473&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/540002/original/file-20230728-17-35i4pz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=473&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/540002/original/file-20230728-17-35i4pz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=594&fit=crop&dpr=1 754w, https://images.theconversation.com/files/540002/original/file-20230728-17-35i4pz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=594&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/540002/original/file-20230728-17-35i4pz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=594&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This image shows blood cells (magenta) in blood vessels (yellow) on the yolk of a 2-day-old zebrafish embryo, which is roughly the size of a grain of rice.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/2j6TzAo">Daniel Castranova/National Institute of Child Health and Human Development, NIH via Flickr</a></span>
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</figure>
<p>For patients with blood-related disorders like leukemia, there are currently limited treatment options. <a href="https://theconversation.com/gut-bacteria-nurture-the-immune-system-for-cancer-patients-a-diverse-microbiome-can-protect-against-dangerous-treatment-complications-184427">Bone marrow transplants</a> are among these options. But there is a shortage of matching donors, and the procedure can be risky because of <a href="https://www.cancerresearchuk.org/about-cancer/coping/physically/gvhd/about">graft-versus-host disease</a>, in which the donor’s healthy immune cells attack the recipient’s body cells. </p>
<p>A possible solution is to use a special kind of stem cell called an <a href="https://doi.org/10.1038/cr.2008.309">induced pluripotent stem cell</a>. To make these cells, scientists use a special set of proteins called Yamanaka factors to turn on specific genes that revert a mature, differentiated cell into an immature, undifferentiated cell. From this point, the cells can be manipulated to express certain genes at specific times, told which part of their DNA to read or which signals to follow. </p>
<p>However, to properly direct these stem cells, researchers need a more complete understanding of the molecular signals involved and how they contribute to early blood development. To bridge these gaps, labs like ours rely on zebrafish to test their theories about the roles that certain genes and proteins play in development.</p>
<p>Model organisms like zebrafish are what allow scientists to get one step closer to solving real-world problems every day.</p><img src="https://counter.theconversation.com/content/205110/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Raquel Espín-Palazón receives funding from NIH, Carver Charitable Trust, Fundacion Seneca, American Heart Association, Iowa State University</span></em></p><p class="fine-print"><em><span>Gabrielle Dubansky does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Of the many qualities that make the zebrafish a model organism, the fact that it shares 70% of the genes humans have makes it an ideal candidate for developmental biology research.Gabrielle Dubansky, Master's Candidate in Molecular, Cellular and Developmental Biology, Iowa State UniversityRaquel Espín-Palazón, Assistant Professor of Genetics, Development and Cell Biology, Iowa State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1560602021-03-02T13:06:47Z2021-03-02T13:06:47ZParkinson’s disease: blood changes may occur years before diagnosis<figure><img src="https://images.theconversation.com/files/387223/original/file-20210302-13-1ywqh08.jpg?ixlib=rb-1.1.0&rect=54%2C0%2C6048%2C4001&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Patients had fewer lymphocytes in their blood.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/nurse-taking-blood-sample-patient-doctors-153078383">Alexander Raths/ Shutterstock</a></span></figcaption></figure><p>Although Parkinson’s disease affects around <a href="https://jnnp.bmj.com/content/62/1/10.long">1%-2% of people over the age of 65</a>, there is currently no cure. And by the time it is diagnosed – typically by identifying problems with movement, such as slower movements and tremors – the changes in the brain it causes are irreversible. So being able to identify Parkinson’s earlier will be important in finding ways to prevent and cure the disease. </p>
<p>In our latest study, my colleagues and I have identified changes in blood that occur years before a Parkinson’s diagnosis. This could lead to earlier diagnosis of the disease.</p>
<p>The causes of Parkinson’s aren’t completely understood, but clear links have been established with genetic and environmental risk factors – such as exposure to certain <a href="https://www.ncbi.nlm.nih.gov/books/NBK536721/pdf/Bookshelf_NBK536721.pdf">pesticides and solvents</a>. However, we do know that Parkinson’s disease causes the death of certain nerve cells in the brain, <a href="https://www.ncbi.nlm.nih.gov/books/NBK536721/pdf/Bookshelf_NBK536721.pdf">due to a combination</a> of abnormal protein accumulation in cells, problems with mitochrondia (the “power stations” of each cell), inflammation and changes in the immune system.</p>
<p>In <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/ana.26034">our study</a>, we set out to examine markers of inflammation that circulate in the blood of patients with Parkinson’s disease. We found people who later developed Parkinson’s disease had fewer lymphocytes – a type of white blood cell. We also found that this change may occur at least eight years before diagnosis and may contribute to the risk of being diagnosed with Parkinson’s.</p>
<p>Lymphocytes are one of five types of white blood cell that aid the body’s immune response. There are two distinct sub-types of lymphocytes: B cells and T cells. B cells produce antibodies that identify and neutralise harmful microbes, while T cells control how other immune cells respond to these microbes.</p>
<p>To conduct our study, we used data from the UK Biobank cohort. This project recruited approximately 500,000 participants between 2006 and 2010 to study how genetics and the environment impact a wide range of diseases. Blood was collected from participants at enrolment and they had ongoing follow-up appointments throughout. Any new health conditions they were diagnosed with appeared on their health care record, which could then be linked to their UK Biobank data.</p>
<p>From this cohort, we identified people who had been diagnosed with Parkinson’s during follow-up and compared them to people who had not been diagnosed with the disease. We looked at various markers of inflammation that circulate in the blood, such as the presence of certain proteins and immune cells. </p>
<h2>Lymphocytes</h2>
<p>In our first analysis of the data, we found several inflammatory markers were associated with a later diagnosis of Parkinson’s disease. But as we worked through further sub-analyses, we narrowed in on lower lymphocyte count as the main difference between those who did and didn’t develop the disease. </p>
<figure class="align-center ">
<img alt="A 3D depiction of a lymphocyte – a spherical particle covered in irregular bumps." src="https://images.theconversation.com/files/387224/original/file-20210302-15-ujtu99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/387224/original/file-20210302-15-ujtu99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/387224/original/file-20210302-15-ujtu99.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/387224/original/file-20210302-15-ujtu99.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/387224/original/file-20210302-15-ujtu99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/387224/original/file-20210302-15-ujtu99.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/387224/original/file-20210302-15-ujtu99.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Lymphocytes play an important role in the immune system.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/lymphocyte-3d-illustration-closeup-view-tcell-1437298838">Kateryna Kon/ Shutterstock</a></span>
</figcaption>
</figure>
<p>We then went on to examine whether changes in lymphocyte count might cause Parkinson’s, or were merely a result of the disease. To do this we used a method called <a href="https://www.bmj.com/content/362/bmj.k601">Mendelian randomisation</a>. This allows us to look at a person’s genetics, and infer whether changes are cause or effect. We found genetic evidence to support that lower lymphocyte count increases Parkinson’s disease risk, as opposed to simply being a sign of undiagnosed Parkinson’s disease.</p>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/22910543/">Previous studies</a> have shown that lymphocytes are on average lower in patients with Parkinson’s disease and that this could be driven by potential reductions in both B and T cells. However, once a diagnosis of Parkinson’s has been made and medication started, other factors – such as the effect of medication – may explain lower lymphocyte counts. Our research shows these changes occur before the disease develops. </p>
<p>Prior to our research, only <a href="https://onlinelibrary.wiley.com/doi/10.1002/ana.25614">one study</a> had shown that lymphocyte count may be lower prior to being diagnosed with Parkinson’s disease and may be a driver of the disease. Our study builds on this work and confirms that changes in lymphocyte count may be picked up on routine blood tests years before diagnosis, and may be linked to increased risk of Parkinson’s disease. However, we don’t yet know why lymphocyte count decreases.</p>
<p>There’s still a lot more work that needs to be done before the importance of this finding is fully known. For example, future research will need to investigate which lymphocyte types (B cells or T cells) are lower. Another important question is why lymphocytes are low. Is lymphocyte production slowed, their lifespan shortened, or are they moving out of the blood into a different part of the body (such as the brain)? Once further work has been done we might better know how to build on this knowledge to develop better treatments for Parkinson’s disease – and perhaps even methods to prevent it.</p><img src="https://counter.theconversation.com/content/156060/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alastair Noyce receives funding from the Barts Charity, Parkinson's UK and the Aligning Science Across Parkinson's initiative. </span></em></p>Our study found lower levels of one type of immune cell – which may even be seen years before a person develops the disease.Alastair Noyce, Reader in Neurology and Neuroepidemiology, Queen Mary University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1292002020-05-13T11:29:23Z2020-05-13T11:29:23ZSeven things you might not know about blood<figure><img src="https://images.theconversation.com/files/334639/original/file-20200513-156625-1nybj1k.jpg?ixlib=rb-1.1.0&rect=0%2C855%2C6709%2C3611&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Here's some facts you ought to know.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/top-view-hands-gloves-holding-blood-787103713">LightField Studios/ Shutterstock</a></span></figcaption></figure><p>Blood is fascinating. Many people learn at school that its function is to transport oxygen and nutrients around the body and remove waste products. But blood has <a href="https://www.ncbi.nlm.nih.gov/books/NBK279392/">many more functions</a>, including defence against pathogens, regulating our temperature, and keeping important internal chemicals and nutrients balanced.</p>
<p>Here are some other things you might not know about blood.</p>
<h2>1. Blood is both liquid and solid</h2>
<p>Blood is a connective tissue in the body. It has a multi-cellular component (made of red blood cells, white blood cells and platelets) and a liquid <a href="https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=90&ContentID=P02316">extracellular matrix</a>. </p>
<p>Unlike the other connective tissues in the body, blood is a liquid. The extracellular matrix, plasma, is liquid and suspends the cells in blood. But when tissues are damaged, by a cut for example, blood becomes a solid like other connective tissues. This is known as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4826570/">clotting</a>.</p>
<p>Clotting is activated by exposure to anything other than the smooth inner surface of a blood vessel, where a cascade commences to plug the wound. Platelets stick to the open wound, then soluble fibrinogen, a type of plasma protein, is converted to insoluble fibrin, which forms a “mesh” around the plug and prevents further blood loss. Over time, as this heals, the mesh and plug are broken down (or pulled off, if you pick scabs). </p>
<p>In most people, the blood is made up of about 45% cells – mainly red blood cells, only 1% are white blood cells – and 55% plasma. Too much or too little of any of these can cause disease, such as anaemia.</p>
<p>Blood cells are constantly produced and recycled. The body produces about <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4717490/">2 million</a> red blood cells a second, but this can be vastly increased in times of stress, such as at high altitudes, where less oxygen is available.</p>
<p><a href="https://www.nhs.uk/conditions/red-blood-count">On average</a>, men have between 4.7 to 6.1 million cells per microlitre, and women between 4.2 to 5.4 million cells per microlitre. There are 1,000 microlitres per millilitre.</p>
<h2>2. Volume is always changing</h2>
<p>The volume of blood in a person’s body changes over a <a href="https://www.jstage.jst.go.jp/article/jjphysiol1950/20/5/20_5_550/_pdf">24-hour</a> period. The body has its highest volume before lunch, as liquid is taken into the body. </p>
<p>A pregnant woman’s blood volume can <a href="https://www.ahajournals.org/doi/full/10.1161/circulationaha.114.009029">increase by up to 50%</a> during pregnancy. This is to support the uterus, which has the placenta and developing foetus in it. </p>
<p>But on average, men normally have between five to six litres of blood, and women have between <a href="https://www.ncbi.nlm.nih.gov/books/NBK526077/">four to five litres</a>. </p>
<h2>3. There are more than four blood types</h2>
<p>We inherit our blood type from our parents. We either have <a href="http://www.annclinlabsci.org/content/33/4/471.short">blood type</a> A, B, AB, or O. These groups determines what antigens you have, which means that depending on your blood type, blood from a person with an incompatible group cannot be transfused into another person. </p>
<p>But the other main blood group typing is Rhesus (Rh). People are either Rh+ or Rh- – meaning a person who is Rh+ has additional antigens, and cannot donate blood to someone who is Rh-, as this can cause an immune response. </p>
<h2>4. We’re always making more blood cells</h2>
<p>We constantly recycle blood cells and can make more blood cells when blood is lost. This means we can donate approximately 470 millilitres of blood at one time. The body takes about 12 weeks for men and 16 weeks for women to <a href="https://www.blood.co.uk/the-donation-process/after-your-donation/how-your-body-replaces-blood/">fully replenish</a> all the blood cells donated.</p>
<p>However, if we lose more than 40% of blood volume (a process known as <a href="https://www.ncbi.nlm.nih.gov/pubmed/29785654">exsanguination</a>), we die. If we lose around 10-20% of blood, the body goes into shock. While in shock, the body will try to fix the situation by increasing heart rate and breathing, and the body sweats and skin loses colour. </p>
<h2>5. Blood has a ‘use-by’ date</h2>
<p>It used to be that “whole” blood donations had to be used all at once. But now, the blood is separated into <a href="https://www.blood.co.uk/why-give-blood/how-blood-is-used/">its different components</a> – red blood cells, white blood cells, platelets and plasma – to make sure it is used as efficiently as possible, since a patient may only need one blood component. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334641/original/file-20200513-156645-1nr28p8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">After separation. Blood plasma is yellow in colour.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/preparing-plasmolifting-blood-tubes-two-layers-241407193">Iryna Kalamurza/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Blood, like all things, has a <a href="https://www.redcrossblood.org/donate-blood/blood-donation-process/what-happens-to-donated-blood.html">use-by date</a>. How quickly it must be used depends on the part of blood. Red blood cells can be stored for about six weeks. But platelets only last a few days so are constantly needed. Other parts, such as plasma, can be frozen for up to a year. White cells are usually filtered out of donations.</p>
<h2>6. Blood loss was medicine</h2>
<p>“Bloodletting,” which dates back at least <a href="https://www.bcmj.org/premise/history-bloodletting">3000 years</a>, used to be a popular treatment for many common ailments. Many cases of bloodletting used leeches, which can consume five to ten millilitres of blood at a time – about ten times its body weight.</p>
<p>Bloodletting is behind the <a href="https://www.history.com/news/why-are-barber-poles-red-white-and-blue">red-and-white poles</a> you see outside a barber’s shop. The red represents the blood, and the white represents bandages. Barbers used to perform common medical procedures, including bloodletting.</p>
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Read more:
<a href="https://theconversation.com/how-we-learned-to-keep-organs-alive-outside-the-body-a-horrible-history-132997">How we learned to keep organs alive outside the body: a horrible history</a>
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<p>Bloodletting is still used, even with <a href="https://www.ouh.nhs.uk/patient-guide/leaflets/files/32855Pleech.pdf">leeches</a> that are specially farmed, in cases of plastic or reconstructive surgery. They help to remove clotted blood in an area of tissue that requires healing or attachment. </p>
<p>Another form of bloodletting uses a needle to remove blood and reduce the amount of iron in the body to treat <a href="https://www.nhs.uk/conditions/haemochromatosis/treatment/">haemochromatosis</a> – where there’s too much iron in the body.</p>
<h2>7. Not all blood is red</h2>
<p>Human blood is red because of the <a href="https://www.ncbi.nlm.nih.gov/books/NBK310577/">presence of haemoglobin</a>. But not all animals bleed red.</p>
<p>Icefish have clear blood, and one species of skink (a type of lizard) has <a href="https://www.nationalgeographic.com/news/2015/03/150312-blood-antarctica-octopus-animals-science-colors/">green blood</a>. Peanut worms have purple blood, and many bugs and beetles have yellow blood. </p>
<p>The colour of blood is usually because of specific proteins in the blood. These proteins may also have some survival advantage depending on the environment in which the species lives. </p>
<p>Despite medical advances, one challenge scientists still face is being able to <a href="https://www.scientificamerican.com/article/how-do-scientists-make-ar/">produce artificial blood</a> that is as high quality and efficient at all the jobs human blood does.</p><img src="https://counter.theconversation.com/content/129200/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor is affiliated with the Anatomical Society. </span></em></p>We’re full of blood – around five litres, on average.Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/874972018-01-17T03:10:12Z2018-01-17T03:10:12ZHow rejuvenation of stem cells could lead to healthier aging<figure><img src="https://images.theconversation.com/files/198797/original/file-20171212-9389-cjsjns.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/group-senior-retirement-exercising-togetherness-concept-477077380?src=ZDmjg_uzXTaytUXq7fqnWg-1-5">Rawpixel.com/Shutterstock.com</a></span></figcaption></figure><p>“Rampant” and “elderly” are words rarely used in the same sentence, unless we are talking of the percentage of people over 65 years old worldwide. <a href="https://ourworldindata.org/life-expectancy/">Life expectancy</a> has considerably increased, but it is still unknown how many of those years are going to be lived in good health. </p>
<p>As a researcher of blood cancers and aging, I inevitably think about how in the next few decades a very large part of the population will deal with cancer treatments. Are we doing the best to manage the side effects, or even to manage aging itself? Could we accumulate just wisdom, instead of aches and pain?</p>
<p><a href="https://www.newscientist.com/article/mg22429894-000-everyday-drugs-could-give-extra-years-of-life/">Rejuvenation strategies</a> once sounded like science fiction, but they are becoming more and more promising. New research from my institute, Weill Cornell Medical College, suggests that transplantation of young blood vessel cells rejuvenates aged stem cells in mice, boosting older blood system function. It also shows signs that it could aid in recovery of the side effects of cancer therapy for humans. </p>
<h2>What happens to our blood system as we age?</h2>
<p>Of the over 7 billion people on Earth, more than <a href="http://www.who.int/world-health-day/2012/toolkit/background/en/">600 million are age 65</a> and older. This group, for the first time in human history, is expected by 2020 to be larger than the number of children below age 5. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4544764/">Aging is a risk factor</a> for many conditions, such as blood cancer, so we can foresee that aging countries should prepare to deal with the consequences in health care. </p>
<p>The blood system, also called <a href="https://theconversation.com/essays-on-blood-why-do-we-actually-have-it-75064">the hematopoietic system</a>, is responsible for producing blood cells throughout a person’s life. We know that, with age, its function declines. </p>
<p>All blood cells derive from a hierarchical system, with common ancestor cells, called hematopoietic stem cells, at its apex. Over the course of a person’s life, these cells will continuously supply all types of blood cells that we need, including different types of immune cells. </p>
<p>As we age, blood stem cells become less able to perform at the best of their capability. This results in a decreased ability to fight infections and <a href="http://news.cornell.edu/stories/2017/10/transplantation-young-blood-vessel-cells-boosts-aging-stem-cells">increased incidence of blood cancer</a> in the over-65 population. </p>
<p>Older patients are also frequently not good candidates for bone marrow transplant, the cure for many blood disorders. This is because of a higher degree of complications after transplant, which is also limited by having enough numbers of stem cells to reconstitute the hematopoietic system in an adult. Therefore, strategies to support blood stem cell recovery are needed to expand the pool of possible bone marrow transplant recipients.</p>
<h2>Blood vessel cells and how they work</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/198793/original/file-20171212-9396-y18q87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/198793/original/file-20171212-9396-y18q87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=481&fit=crop&dpr=1 600w, https://images.theconversation.com/files/198793/original/file-20171212-9396-y18q87.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=481&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/198793/original/file-20171212-9396-y18q87.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=481&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/198793/original/file-20171212-9396-y18q87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=605&fit=crop&dpr=1 754w, https://images.theconversation.com/files/198793/original/file-20171212-9396-y18q87.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=605&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/198793/original/file-20171212-9396-y18q87.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=605&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Aged blood vessel cells, shown in red and green, with blue nuclei, with an age-associated defect.</span>
<span class="attribution"><span class="source">Michael Gutkin</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Blood vessel cells, or <a href="https://www.ncbi.nlm.nih.gov/books/NBK26848/">endothelial cells</a>, are a particular cell type that lines the inside of blood vessels. They contribute to form arteries, veins and capillaries. For a long time, endothelial cells have been perceived as a passive conduit for blood. </p>
<p>However, in recent years, scientists have seen a new role for these cells. They discovered that blood vessel cells actively sustain nearby stem cells and guide organ regeneration. </p>
<p>So, instead of a pipe system, we can think of blood vessel cells more like active supporters lined up along a cyclist’s race. This dynamic role has been found to be true for many organs, including the one responsible for making new blood cells, the bone marrow. </p>
<p>In the marrow, blood stem cells are found in close contact with blood vessels cells, which provide many types of substances, such as <a href="https://www.cancer.gov/publications/dictionaries/cancer-terms?cdrid=632169">KIT ligand</a> that stem cells need to keep performing at their best. </p>
<p>As we get older, endothelial cell supportive function declines, and they become dysfunctional. They can still perform the basic function of architectural support for blood flow, but they are less able to support nearby stem cells. </p>
<p>A <a href="https://www.jci.org/articles/view/93940">recent study</a> from Weill Cornell Medical College shows that older blood vessel cells made young blood stem cells act old. Led by Dr. Jason Butler and Dr. Michael Poulos, the research isolated blood vessel cells from young or old mice and grew them in petri dishes with blood stem cells. </p>
<p>The young blood stem cells bias showed a tendency toward producing more of one type of immune cells, myeloid cells, which is a hallmark of aging. </p>
<p>In a complementary experiment in the study, the youngster cells rejuvenated the old ones. The team found out that the rejuvenated old cells were able to create a healthy blood system when transplanted back into mice.</p>
<p>The group then gave mice a strong dose of whole body radiation, similar to what patients undergo prior to <a href="https://bethematch.org/patients-and-families/about-transplant/what-is-a-bone-marrow-transplant-/">bone marrow transplant</a>. Then, they infused the mice with endothelial cells isolated from young mice. They found that the blood vessel infusions enhanced the recovery of the hematopoietic system and restored blood stem cell function in aged mice.</p>
<p>When the team modeled a bone marrow transplant on the mice, they even observed that mice infused with endothelial cells regained a healthy blood system, even if the number of blood stem cell transplanted was suboptimal.</p>
<h2>Benefits ahead?</h2>
<p>The study shows that young blood vessels can potentially rejuvenate blood stem cell functions, and mitigate the effects of medically induced stress, such as <a href="https://www.mayoclinic.org/tests-procedures/radiation-therapy/details/risks/cmc-20325837">radiation therapy</a>. The endothelial cells also protected other organs affected by radiation throughout the body, including the gut, skin, spleen and liver. </p>
<p>This global protection has many <a href="https://news.weill.cornell.edu/news/2017/10/transplantation-of-young-blood-vessel-cells-boosts-function-of-aging-stem-cells">potential benefits</a> for those undergoing cancer therapy, Butler explained in a statement. Those benefits include a shorter recovery time, less susceptibility to infections and lower the number of blood stem cells needed to achieve a successful transplant. The infusion of endothelial cells could thus lower the complication rates for elderly patients, Butler said.</p>
<p>At this time several groups are exploring endothelial cells as support strategy for blood stem cells, in <a href="http://www.bloodjournal.org/content/109/6/2365.long?sso-checked=true">mice</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5442761/">nonhuman primates</a>. </p>
<p>Researchers agree on two very relevant issues that will influence the clinical application of these findings. </p>
<p>First, the infused blood vessel cells stick around transiently, which means lower chances of any potential toxic or unwanted side effect. Second, the infusions would work as an adjunct therapy for clinical protocols already in place, a sort of upgrade on standard treatment. This could potentially speed up the clinical translation of these findings.</p>
<p>“The bullets are already there; this is a better one,” said Poulos.</p><img src="https://counter.theconversation.com/content/87497/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elisa Lazzari works for Weill Cornell Medical College.</span></em></p>As people’s bodies age, so do their blood cells. This affects immunity and an ability to withstand certain cancer treatments. A recent study in mice suggests that those cells can be rejuvenated.Elisa Lazzari, Postdoctoral Associate in Biomedical Sciences, Cornell UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/621792017-03-06T19:24:49Z2017-03-06T19:24:49ZExplainer: what are blood groups and why do they matter?<p>If you’ve ever needed a blood transfusion, or donated blood, you probably would have been asked your blood type. While it was once thought all blood was the same, we now know there are different types of blood, called blood groups. Transfusions between blood groups can be catastrophic, even deadly, so knowing the blood type of donors and recipients is of the utmost importance. </p>
<p>Our bodies contain trillions of red blood cells. Each is covered in an array of proteins and sugars, inherited from our parents, which determine our blood group. We can all be classified into group A, B, AB or O, based on which sugars coat our red blood cells. </p>
<p>We’re also classified as positive or negative, based on whether our blood cells carry a protein called the Rhesus D (RhD) antigen. These two blood group systems (ABO and Rh) give us the eight main blood types: O-, O+, B-, B+, A-, A+, AB-, AB+. </p>
<p><iframe id="tc-infographic-176" class="tc-infographic" height="720" src="https://cdn.theconversation.com/infographics/176/e0bc573a28765ef0177e50122a7960b9e2ce4d22/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>But there are also <a href="http://resources.transfusion.com.au/cdm/ref/collection/p16691coll1/id/863">more than 300 different antigens</a> – proteins and sugars that activate the immune system – expressed on red cells and 36 recognised blood group systems. And they’re just the ones we know about. </p>
<p>While most people know they are, for example, A+ or O-, few people will know (and never need to know) what their expression of other red cell antigens are.</p>
<h2>How were blood groups discovered?</h2>
<p>Transfusion has been practised intermittently <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2588804/pdf/yjbm00009-0056.pdf">since the 1660s</a>. But blood groups weren’t discovered until 1900, before which it was assumed that all blood was of the same type. </p>
<p>This led to some catastrophic transfusions of animal blood into humans in attempts to transfer certain qualities (for example, so the recipient would become meek like a lamb). There were also some fatal transfusions between humans. </p>
<p>For this reason, the practice was banned in the UK and France for more than 100 years.</p>
<p>In 1900, physician <a href="https://www.nobelprize.org/nobel_prizes/medicine/laureates/1930/landsteiner-facts.html">Karl Landsteiner</a>’s experiments showed that some people’s red cells “reacted” with plasma samples from other people, while others did not. This led to him describing the ABO system, the most important blood group system and the basis of safe modern transfusion. </p>
<p>After receiving the 1930 Nobel Prize for Medicine for this work, Landsteiner was experimenting with the blood of Rhesus monkeys when he discovered what is now known as the RhD antigen. </p>
<h2>Compatibility</h2>
<p>If we need to transfuse blood from one person to another, we want to give donor blood that is compatible with the recipient’s blood to minimise the chance of a transfusion reaction. </p>
<p>So if a person is group A, this means she can receive a red cell transfusion from either a group A or a group O donor. She should not receive group B or AB red cells, as she has naturally occurring antibodies (proteins formed as part of the immune response) that will likely cause a transfusion reaction, which may be serious – even <a href="http://www.transfusion.com.au/adverse_transfusion_reactions/classification_and_incidence">fatal</a>.</p>
<p>Around 31% of Australians are A+. It’s the second most common blood group after O+, which make up 40% of the <a href="http://www.donateblood.com.au/learn/about-blood">Australian population</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/135753/original/image-20160829-17872-xwxx3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/135753/original/image-20160829-17872-xwxx3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/135753/original/image-20160829-17872-xwxx3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/135753/original/image-20160829-17872-xwxx3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/135753/original/image-20160829-17872-xwxx3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/135753/original/image-20160829-17872-xwxx3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/135753/original/image-20160829-17872-xwxx3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">O negative people are universal donors.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-294586571/stock-photo-giving-blood-during-operation.html?src=lvi-MTLSLjTg1w8zL0DsQQ-1-2">www.shutterstock.com</a></span>
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<p>Group O negative people are called “universal donors”. Their red cells express neither group A nor B sugars, nor the RhD antigen, and so are unlikely to cause a reaction in recipients. </p>
<p>Emergency departments and some ambulances carry a stock of O negative blood, because in an emergency this is the safest blood to give a critically ill, bleeding patient of unknown blood type. Only 9% of the Australian population are O negative. </p>
<p>The Australian Red Cross Blood Service needs a diverse group of blood donors to meet the needs of our increasingly diverse patient population. </p>
<h2>What are blood groups for?</h2>
<p>It is likely all of the molecules that cover the surface of cells serve some purpose – often completely unrelated to transfusion. </p>
<p>One of the 36 blood group systems mentioned above is the Colton blood group. This is interesting because the molecules recognised by the immune system as Colton blood group antigens are actually located on an <a href="https://www.nobelprize.org/nobel_prizes/chemistry/laureates/2003/agre-diploma.html">aquaporin (AQP1) molecule</a> - one of a family of molecules responsible for water passage into and out of cells, and abundant in the red cell membrane. Professor Peter Agre and colleagues described this in 1992 and he received a <a href="https://www.nobelprize.org/nobel_prizes/chemistry/laureates/2003/agre-lecture.pdf">Nobel Prize</a> for this work.</p>
<p>Another interesting example is the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1378024/pdf/10762551.pdf">Duffy protein</a>, named after a haemophiliac patient <a href="http://www.ncbi.nlm.nih.gov/books/NBK2271/">Mr Duffy</a>. In 1950, he developed an antibody to what we know today as the Duffy “a” antigen, to which he had been exposed by receiving a blood transfusion.</p>
<p>One of the known functions of the Duffy antigens is binding one type of malaria parasite, <em>Plasmodium vivax</em>, which grants it entry into the red cell, where it can multiply and then cause the cell to burst. </p>
<p>The red cells of people who lack Duffy antigens are more resistant to infection by this parasite. More than two-thirds of people of African origin lack the Duffy antigens, whereas it is rare for people originating from Europe or Asia to do so. </p>
<p>Many thousands of years ago, in Africa where the <em>Plasmodium vivax</em>-bearing mosquitoes flourished, people who lacked Duffy antigens were resistant to this potentially fatal form of malaria and survived to parent future generations, passing on this particular resilience to their offspring.</p>
<p>Fascinatingly, the normal function of ABO and Rh, the two most important blood group systems, is still essentially unknown. <a href="http://www.ncbi.nlm.nih.gov/books/NBK2267/">The frequency of ABO antigens</a> varies greatly between different populations, and so it is thought that perhaps particular ABO blood types confers survival advantage in different settings. </p>
<p>Different ABO blood types occur more frequently in some medical conditions. Stomach ulcers, for example, are <a href="http://aje.oxfordjournals.org/content/172/11/1280.full.pdf+html">more common</a> in those with group O blood but stomach cancer is more common in those with group A blood. We don’t really know exactly why this occurs, or its consequences.</p><img src="https://counter.theconversation.com/content/62179/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Our bodies contain trillions of red blood cells. Each is covered in an array of proteins and sugars, inherited from our parents, which determine our blood group.Erica Wood, Associate Professor; Head, Transfusion Research Unit, Monash UniversityLucy Fox, Clinical Research Fellow in Haematology, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/281532014-07-08T20:12:37Z2014-07-08T20:12:37ZExplainer: one day science may cure sickle cell anaemia<p>Genetic mutations that affect our blood cells’ <a href="http://dictionary.reference.com/browse/haemoglobin">haemoglobin</a> are the most common of all mutations. <a href="http://www.who.int/mediacentre/factsheets/fs308/en/">It has been estimated</a> that around 5% of the world’s population carry a defective <a href="http://dictionary.reference.com/browse/globin">globin</a> gene.</p>
<p>Haemoglobin is the molecule in red blood cells that picks up oxygen from the lungs and transports it throughout your body to other tissues.</p>
<p>We can tolerate a single mutation in a globin gene but when individuals inherit two mutant copies – one from their mother and one from their father – they may suffer from genetic disorders, such as <a href="http://www.nlm.nih.gov/medlineplus/ency/article/000527.htm">sickle cell anaemia</a> or <a href="http://www.nlm.nih.gov/medlineplus/ency/article/000587.htm">thalassaemia</a>.</p>
<p>Many affected individuals live in developing countries so the challenge of treating these diseases is very great.</p>
<p>But why are globin mutations so common and what types of treatments might be possible?</p>
<h2>Depends where do you come from</h2>
<p>The mystery surrounding the prevalence of the mutations was solved by considering geography. Comparing areas affected by <a href="http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001646/">malaria</a> with regions where blood disorders are common showed that the two zones overlap.</p>
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<img alt="" src="https://images.theconversation.com/files/53233/original/z4hnn298-1404782480.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53233/original/z4hnn298-1404782480.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=341&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53233/original/z4hnn298-1404782480.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=341&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53233/original/z4hnn298-1404782480.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=341&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53233/original/z4hnn298-1404782480.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=429&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53233/original/z4hnn298-1404782480.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=429&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53233/original/z4hnn298-1404782480.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=429&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Mutations in the blood depend on where you come from.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/ianhumes/3263620112/in/photostream/">Flickr/Ian Humes</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<p>So we find blood mutations are prevalent across Africa, the Middle East, South East Asia and Central America.</p>
<p>They are also common in the Mediterranean, a region which is not subject to malaria today, but which harboured mosquitoes and the parasite they transmit until relatively recently.</p>
<p>In North America sickle cell anaemia and thalassaemia are common in African Americans.</p>
<h2>Mutations and malaria</h2>
<p>The link between malaria and the mutations might lead us to propose that the defects protect against malaria.</p>
<p>Unfortunately, individuals with two mutant globin genes are not protected and may be especially vulnerable to malaria. But those with one good copy and one mutant copy, do indeed to enjoy some resistance.</p>
<p>The mechanism may vary depending on the particular mutation but in general it seems that having one mutant globin makes blood cells slightly more fragile and fewer parasites can survive within the blood, thus the symptoms and mortality are reduced.</p>
<p>Over evolutionary time it has been beneficial to have one mutant globin gene in your genome - so the mutations have been passed on through generations.</p>
<p>But it is not good to have two mutant copies. If you have two defective copies then the red blood cells will tend to be very fragile and anaemia may result.</p>
<p>Worse still the iron released from damaged blood cells may accumulate to toxic levels and cell fragments may block tiny blood vessels called capillaries.</p>
<h2>Sickle cell anaemia</h2>
<p>The most common mutation affecting globin genes is known as the sickle cell mutation. This was also the first ever human mutation to be understood.</p>
<p>In 1957 <a href="http://www.pnas.org/content/101/40/14323.full">Vernon Ingram</a> and colleagues showed that the substitution of a glutamate in the sixth position in the globin chain for another residue valine was responsible for sickle cell anaemia.</p>
<p>This simple change produced a mutant globin molecule that stuck to other globin chains to form a solid aggregate that made red blood cells fragile.</p>
<p>In low oxygen the red blood cells lost their doughnut shape and appeared as elongated sickles, hence the name of the disease.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/51516/original/dd6xdc3f-1403073147.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/51516/original/dd6xdc3f-1403073147.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/51516/original/dd6xdc3f-1403073147.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=368&fit=crop&dpr=1 600w, https://images.theconversation.com/files/51516/original/dd6xdc3f-1403073147.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=368&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/51516/original/dd6xdc3f-1403073147.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=368&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/51516/original/dd6xdc3f-1403073147.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=462&fit=crop&dpr=1 754w, https://images.theconversation.com/files/51516/original/dd6xdc3f-1403073147.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=462&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/51516/original/dd6xdc3f-1403073147.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=462&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="attribution"><span class="source">joshya</span></span>
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<p>Other common mutations involve entire deletions of globin genes.</p>
<p>Globin gene biology is complicated. The haemoglobin molecule is actually made up of two alpha chains and two beta chains. Having a deletion in either the alpha or the beta genes can lead to chain imbalance and a special form of anaemia called thalassaemia.</p>
<p>In beta-thalassaemia it is thought to be the excess of alpha chains that damages the red blood cells, rather than the overall shortage of haemoglobin molecules.</p>
<h2>Treatments available</h2>
<p>There are a number of treatments for sickle cell anaemia and thalassaemia. One treatment involves blood transfusions - adding new blood to replace the fragile and damaged blood.</p>
<p>This treatment is important but obviously it does not remove the cell fragments and toxic levels of iron that can cause significant symptoms. So researchers are seeking ways to actually repair the defective red blood cells.</p>
<p>One approach has been gene therapy. The idea is to introduce a new globin gene into red blood cells, or since they have no nuclei and are short-lived, into their progenitor cells, blood stem cells.</p>
<p>This approach has <a href="http://www.ncbi.nlm.nih.gov/pubmed/20844535">worked in at least one instance</a>, but it has proved very difficult to obtain the level of globin production required and the generation of high quantities of gene therapy viruses is extremely expensive.</p>
<h2>Other solutions investigated</h2>
<p>One of the most exciting new approaches comes from studying naturally occurring globin mutations.</p>
<p>It was found that a few families with severe globin mutations exhibited only mild symptoms. They turned out to carry additional compensating mutations in another gene, a super globin called foetal globin.</p>
<p>Foetal globin binds oxygen very tightly and allows babies to snatch oxygen from their mother’s blood. The foetal globin gene is expressed in-utero but is turned off naturally shortly after we are born.</p>
<p>In a few families with mutations in its control regions the foetal globin stays on throughout life.</p>
<p>Normally this is not noticeable – surprisingly it does not even appear to interfere with normal pregnancy – but if one happens to have a defective adult globin gene this super globin can take over. It can make up for deficiencies in globin and it is even good at binding up excesses of toxic alpha globin.</p>
<h2>Super globin to the rescue</h2>
<p>About 30 years ago researchers began asking whether we could turn on the super globin genes in patients suffering from sickle cell anaemia and thalassaemia.</p>
<p>Remarkably there are several chemical agents that do stimulate blood cells to produce this super globin – <a href="http://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0010627/?report=details">hydroxyurea</a> is perhaps the most widely used.</p>
<p>The mechanism by which it and other agents operate remains controversial. It is possible that it directly turns on the foetal globin gene, or it may damage blood cells and trigger an emergency response involving super globin production.</p>
<p>The search for new agents that target the foetal globin gene itself, turning it on and only it on, continues.</p>
<p>The most recent advances have come from looking at variations in foetal globin in the normal population via Genome Wide Association Studies (<a href="http://www.genome.gov/20019523">GWAS</a>).</p>
<p>It was discovered that individuals with particularly high foetal globin had variations in a regulatory gene, called <a href="http://www.nlm.nih.gov/cgi/mesh/2011/MB_cgi?mode=&index=198907&view=expanded">BCL11A</a>. This gene encodes a DNA-binding protein that specifically represses foetal globin expression.</p>
<p>Efforts have now begun to knockdown BCL11A activity in red blood cell progenitors, either by RNA silencing, by genome editing or by chemical agents.</p>
<p>If this can be done it would, at least in theory, provide a treatment for these common genetic disorders that would hopefully be available to everyone and for ever.</p>
<p>Most importantly, a chemical treatment might provide help in developing countries where lifelong transfusions are difficult to deliver.</p><img src="https://counter.theconversation.com/content/28153/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Merlin Crossley receives funding from the University of New South Wales, the National Health and Medical Research Council and the Australian Research Council.</span></em></p>Genetic mutations that affect our blood cells’ haemoglobin are the most common of all mutations. It has been estimated that around 5% of the world’s population carry a defective globin gene. Haemoglobin…Merlin Crossley, Dean of Science and Professor of Molecular Biology, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/158562013-07-05T13:39:27Z2013-07-05T13:39:27ZNew twist in age-old war against malaria parasite<figure><img src="https://images.theconversation.com/files/26980/original/4pyvcw9z-1373021037.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C2746%2C1683&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Falciparum malaria parasite carried by mosquitoes might be cerebral but has it been outsmarted?</span> <span class="attribution"><span class="source">PA/Danny Lawson</span></span></figcaption></figure><p>Cerebral malaria, or malaria of the brain, means being deeply unconscious with perpetual cycles of seizures and spasms. It can cause death, or often disability. <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11425178">About 600,000 people suffer this terrible affliction each year</a> and most of them are children. </p>
<p>Children who get cerebral malaria have <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14745442">a one-in-five chance of dying</a>. If they survive, they have <a href="http://www.ncbi.nlm.nih.gov/pubmed/21056005">a high chance of being disabled</a> - with hearing or vision loss, epilepsy or learning difficulties. But with little understanding of how to stop the brain becoming damaged, we’ve so far we’ve been fighting the battle blindfolded.</p>
<h2>A tale of two halves - and six species</h2>
<p>Malaria is caused by the Plasmodium parasite, which lives half its life in humans and the other half in the guts of female mosquitoes, who infect the next human victim when they feed on blood to make their eggs. </p>
<p>The deadliest of the Plasmodium parasites is found in Africa and accounts for <a href="http://www.who.int/features/factfiles/malaria/en/">90% of all malaria deaths</a>. It kills mostly children under five.</p>
<p>But only one of the six types of malaria parasites that is found in humans - <em>Falciparum malaria</em> - causes cerebral malaria. <em>Falciparum malaria</em> also occurs most commonly in Africa and also in Asia and South America.</p>
<h2>An evasive parasite</h2>
<p>For malaria to survive in our bodies <a href="http://www.ncbi.nlm.nih.gov/pubmed/21623767">it must trick our immune system</a>. It’s a battle that has been waged between our immune systems and the malaria parasite for as long as recorded human history (malaria proteins have been found in ancient mummies).</p>
<p>Despite our defences, malaria has some tricks up its sleeve. Because the immune system is highly adapted to recognise anything foreign in the blood, the counter move is to hide and multiply inside our own red blood cells.</p>
<p>The body can also filter out abnormal red blood cells through the spleen but <em>Falciparum malaria</em> is especially tricky because it escapes the spleen by sticking to the walls of blood vessels - particularly the tiny blood vessels in the fat under your skin, the lungs, heart, gut and brain. </p>
<p>This ability to stick to the blood vessels in vital organs - called sequestration - is what makes the falciparum parasite more deadly than the other types of malaria. But given that sequestration occurs in many different places in our body, why is it so particularly damaging to the brain?</p>
<h2>Sticking around, causing trouble</h2>
<p><a href="http://bloodjournal.hematologylibrary.org/content/early/2013/06/05/blood-2013-03-490219.full.pdf">To study this vital question</a> we examined the brains of children who had died of cerebral malaria. We found thousands of tiny clots that weren’t found in other organs in the blood vessels of their brains. We noticed that these clots occurred in parts of the vessels where the parasites were stuck. We therefore wondered what was different about the lining of blood vessels in the brain than other organs and what the parasite was doing to cause clotting.</p>
<p>The lining of blood vessels - called the endothelium - is a highly specialised non-stick surface. Yet it must be able to rapidly adapt. When the body faces a bacterial or viral infection, the blood vessel lining traps the immune system’s white blood cells by becoming more sticky - catching them and passing them through into the tissue where the infection is to kill it. In the case of damage from injury it must rapidly cause the blood to clot so we don’t bleed to death. </p>
<p>The endothelium detects changes in the blood using receptors that jut out from its surface and it then feeds back messages to the blood cell. A particular set of receptors - the protein C receptors - act like a form of biological Teflon, keeping the blood cells from sticking and clotting. </p>
<p>However, we found that when the <em>Falciparum malaria</em> parasite sticks to the lining of the blood cells it removes these protein C receptors, allowing the parasite to hijack the endothelium’s signalling system. So the blood vessel becomes stickier, helping other parasites to stick and, at the same time, causing the blood to clot. This happens particularly easily in the brain because there are fewer protein C receptors in the brain than in other organs.</p>
<h2>Sometimes a ‘cure’ isn’t good enough</h2>
<p>There are medicines that are very good at killing the malaria parasite by clearing the infection from the blood. But if the process of developing cerebral malaria has already taken hold, the disease can carry on getting worse and even cause death before the drugs kill enough parasites to turn the situation around. </p>
<p>Because our understanding of how the cerebral malaria parasite caused damage in the brain was incomplete there have so far been no effective therapies for treating it. </p>
<p>Our research, which was published in <a href="http://bloodjournal.hematologylibrary.org/content/early/2013/06/05/blood-2013-03-490219.full.pdf">Blood</a>, the journal of <a href="http://www.hematology.org/">The American Society of Hematology</a>, suggests that treatments that stop clotting or that restore a normal signal to the endothelium might help prevent the terrible damage caused by cerebral malaria to the brain - and help prevent people who get it from dying or from becoming disabled before the anti-malarial drugs have a chance to kill all the parasites.</p>
<p>If so, it would give the immune system another weapon to fight the battle with <em>Falciparum malaria</em> and takes us one step closer to one day win the war.</p><img src="https://counter.theconversation.com/content/15856/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Moxon received funding from The Wellcome Trust through a Clinical PhD Fellowship to conduct this work.</span></em></p>Cerebral malaria, or malaria of the brain, means being deeply unconscious with perpetual cycles of seizures and spasms. It can cause death, or often disability. About 600,000 people suffer this terrible…Chris Moxon, Clinical Research Fellow, Liverpool School of Tropical MedicineLicensed as Creative Commons – attribution, no derivatives.