Category: Blood

What Is MCH? Mean corpuscular hemoglobin (MCH) is indeed a measurement that provides information about the average amount of hemoglobin in each red blood cell. Hemoglobin is a vital protein responsible for carrying oxygen to the body’s tissues and removing carbon dioxide. When your MCH level is lower or higher than the normal range, it can suggest certain underlying conditions. What Does Low MCH Mean? An MCH level below the normal range can indeed be indicative of hypochromic anemia, which occurs when there is an insufficient amount of hemoglobin in the blood. The most common cause of hypochromic anemia in the United States is iron deficiency. Iron is essential for the production of hemoglobin, and without enough iron, hemoglobin levels decrease. This condition is commonly referred to as iron-deficiency anemia. Iron-deficiency anemia can develop due to various factors, including: Blood loss: Heavy menstrual periods, gastrointestinal bleeding (caused by conditions like inflammatory bowel disease), surgery, or traumatic injuries can result in significant blood loss, leading to a depletion of iron stores and subsequent iron deficiency. Problems absorbing iron: Certain genetic conditions, engaging in endurance sports, gastrointestinal and digestive disorders, and surgeries affecting the stomach or intestines can interfere with the absorption of iron from the diet. This impaired absorption hinders the body’s ability to acquire sufficient iron, contributing to iron deficiency. Kidney disease: In some cases of kidney disease, the kidneys may produce lower levels of erythropoietin, a hormone necessary for the production of red blood cells. Insufficient erythropoietin production can hinder the development of new red blood cells, leading to decreased hemoglobin levels and iron-deficiency anemia. Chronic inflammatory conditions: Certain chronic conditions characterized by persistent inflammation, such as autoimmune disorders or chronic infections, can disrupt iron utilization within the body. Chronic inflammation can impair the body’s ability to effectively absorb, transport, and utilize iron, resulting in iron-deficiency anemia. Inadequate dietary iron intake: While less common in the United States, insufficient iron intake can occur, particularly in specific age groups such as children between 9 months and 1 year of age who may have limited access to iron-rich foods. Inadequate dietary intake of iron can lead to depleted iron stores and subsequently contribute to iron-deficiency anemia. Pregnancy and breastfeeding: During pregnancy, the body requires increased amounts of iron to support the growing fetus and placenta. If the dietary iron intake is insufficient or the body’s iron stores are depleted, iron-deficiency anemia can occur. Breastfeeding also places additional demands on iron stores, increasing the risk of anemia if the mother’s iron intake is inadequate. Rapid growth periods: Infants, children, and adolescents undergo rapid periods of growth, which require an increased supply of iron to support the production of new red blood cells. Inadequate dietary iron intake during these critical growth phases can result in iron-deficiency anemia. Vegetarian or vegan diets: Individuals who follow strict vegetarian or vegan diets may have a higher risk of iron deficiency due to the absence or limited availability of heme iron, which is predominantly found in animal-based foods. Plant-based sources of iron, such as legumes, fortified grains, and leafy greens, are non-heme iron, which is less readily absorbed by the body. Proper planning and inclusion of iron-rich plant-based foods or supplementation are essential to prevent iron-deficiency anemia in these dietary choices. Chronic gastrointestinal conditions: Conditions that affect the gastrointestinal tract, such as celiac disease, Crohn’s disease, or gastric bypass surgery, can impair the absorption of nutrients, including iron. Malabsorption of iron in these conditions can lead to iron-deficiency anemia if not properly managed. Menstruation: Women of reproductive age experience monthly menstrual bleeding, which can result in regular iron loss. Heavy or prolonged menstrual periods, in particular, can increase the risk of iron deficiency over time, especially if dietary iron intake is insufficient to compensate for the loss. Medications and medical treatments: Certain medications, such as proton pump inhibitors (used to treat acid reflux) or anticoagulants (blood thinners), can interfere with iron absorption or increase the risk of gastrointestinal bleeding, contributing to iron-deficiency anemia. Additionally, individuals undergoing frequent blood transfusions or those receiving chemotherapy or radiation therapy for cancer may experience decreased red blood cell production, leading to anemia. Genetic disorders: Inherited conditions, such as thalassemia or hereditary spherocytosis, can affect the normal production or function of red blood cells, increasing the risk of developing iron-deficiency anemia. Symptoms of Low MCH In cases of iron deficiency anemia associated with a low MCH level, some individuals may not experience noticeable symptoms. However, if symptoms are present, they can include: Tiredness or fatigue: Feeling excessively tired or lacking energy, even with adequate rest. Shortness of breath: Difficulty breathing or a sensation of breathlessness, especially during physical activity or exertion. Chest pain: Discomfort or pain in the chest, which may be a result of reduced oxygen supply to the heart muscles. Dizziness or lightheadedness: Feeling dizzy or lightheaded, often upon standing up or during sudden movements. Cold hands and feet: Decreased blood flow to the extremities can cause a sensation of coldness in the hands and feet. Pale skin: A paler complexion than usual, often noticeable in the face, lips, and nail beds. What Does High MCH Mean? An MCH level above normal levels may indicate the presence of anemia due to low folate or vitamin B12 levels. Folate-deficiency anemia can develop when there is an insufficient intake of folate in the diet, long-term heavy alcohol use, or the use of certain medications. On the other hand, vitamin B12 deficiency anemia can occur when the body is unable to properly absorb vitamin B12 due to factors such as a lack of intrinsic factor, heavy alcohol use, certain medications, certain medical conditions, or inadequate dietary intake of vitamin B12. Chemotherapy can also cause high MCH levels as a side effect. Additionally, falsely high MCH levels may be observed in individuals with high cholesterol. If you have anemia due to low folate or B12 levels, you may experience symptoms such as fatigue, weakness, pale skin, shortness of breath, and lightheadedness. Symptoms of

What Is Anemia? Anemia is a condition characterized by a reduced number of red blood cells or a low hemoglobin level in the blood, resulting in decreased oxygen-carrying capacity. This can lead to various symptoms and health complications. While anemia can affect people of all ages and backgrounds, certain factors increase the risk of developing the condition. There are several types of anemia, including iron-deficiency anemia, vitamin deficiency anemia (such as folate or vitamin B12 deficiency), hemolytic anemia (where red blood cells are destroyed prematurely), and others. The specific treatment approach for anemia depends on the underlying cause and severity of the condition. In cases of mild to moderate anemia, treatment often involves addressing the underlying deficiency through dietary changes and supplementation. For instance, iron-deficiency anemia may be treated with iron supplements or by increasing dietary intake of iron-rich foods. Vitamin deficiency anemia may require supplements of the deficient vitamin, such as folic acid or vitamin B12. Types Anemia encompasses various types, and while some are more common and treatable, all types can lead to complications if not addressed. Iron Deficiency Anemia Iron deficiency anemia occurs when there is insufficient iron in the body, leading to a decrease in the production of red blood cells. This type of anemia is common, particularly among women and children, and can be caused by inadequate dietary intake of iron, blood loss, or conditions that affect iron absorption. While iron deficiency anemia rarely results in death, it can have significant consequences. Symptoms may include fatigue, headaches, restless legs syndrome, and heart problems. Additionally, pregnant individuals with iron deficiency anemia may experience complications such as preterm labor and low birth weight. It is important to address iron deficiency anemia as it can exacerbate other medical conditions and hinder the effectiveness of treatments. Pernicious Anemia Pernicious anemia is an autoimmune disorder characterized by the body’s immune system mistakenly attacking healthy cells. Although relatively rare, it affects a small percentage of individuals over the age of 60 globally. In pernicious anemia, there are low levels of vitamin B12 in the body, which is necessary for the production of healthy red blood cells and proper functioning of the nervous system. This condition leads to the production of larger-than-normal red blood cells that have difficulty dividing and moving out of the bone marrow, resulting in impaired oxygen transport throughout the body. If left untreated, pernicious anemia can give rise to serious complications, including bleeding, infections, and irreversible damage to the brain or nerves. Infants born to individuals with vitamin B12 deficiency are at a higher risk of developmental delays and birth defects, particularly affecting the brain and spinal cord. Aplastic Anemia Aplastic anemia is a rare but severe blood disorder characterized by the inability of the bone marrow to produce an adequate number of new blood cells, including red blood cells, white blood cells, and platelets. This condition affects approximately two out of every one million people in the United States and is often caused by damage to the stem cells within the bone marrow. In aplastic anemia, the immune system mistakenly attacks and destroys these crucial stem cells, leading to a significant decrease in blood cell production. If left untreated, aplastic anemia can result in serious complications such as an irregular heartbeat, heart failure, increased susceptibility to bleeding disorders, and a higher risk of developing leukemia or other blood-related cancers. The condition carries a high mortality rate, with about 70% of individuals dying within one year if left untreated. However, with appropriate treatment and medical care, the five-year survival rate for individuals under the age of 20 is approximately 80%. It is crucial to seek prompt medical attention and proper treatment to improve outcomes and increase the chances of survival in aplastic anemia. Hemolytic Anemia Hemolytic anemia is a condition characterized by the accelerated destruction of red blood cells, surpassing the rate at which they can be replaced. There are various types of hemolytic anemia, which can be acquired or inherited, and the underlying cause is not always known. This condition is relatively rare, affecting approximately 1-3 individuals per 100,000 people each year, and can occur at any age. While some individuals with mild hemolytic anemia may not require treatment, those with more severe cases are at risk of experiencing serious complications if the condition is left untreated. These complications may include an irregular heartbeat, an enlarged heart, and heart failure. Prompt diagnosis and appropriate management of hemolytic anemia are crucial to prevent and minimize the risk of complications and ensure optimal health outcomes. It is important for individuals with suspected or diagnosed hemolytic anemia to work closely with their healthcare provider to determine the most suitable treatment approach for their specific condition. Anemia Symptoms Symptoms of anemia can vary depending on the severity of the condition and its underlying cause. In mild cases, individuals may not experience noticeable symptoms, while symptoms tend to worsen as anemia progresses. Common initial symptoms of anemia include abnormally pale skin and a feeling of weakness or fatigue. As the condition advances, additional symptoms may manifest, such as dizziness, increased thirst, sweating, rapid pulse, fast breathing, mouth symptoms like tongue swelling, dry mouth, and ulcers, as well as brittle, spoon-shaped nails (koilonychia) and hair loss. More severe anemia can lead to lower leg cramps, shortness of breath, and even brain damage. It is not uncommon to experience heart-related symptoms with anemia, as the heart has to work harder to compensate for the reduced oxygen-carrying capacity of the blood. These symptoms can range from abnormal heart rhythms (arrhythmias) and heart murmurs to an enlarged heart and heart failure. What Causes Anemia? Anemia can arise from three primary causes: Inadequate red blood cell production: This can occur due to nutritional deficiencies, such as insufficient intake of iron, vitamin B12, or folate, which are essential for red blood cell synthesis. Certain medical conditions, like bone marrow disorders or kidney disease, can also hinder the production of red blood cells. Accelerated destruction of red blood

What Is Iron Deficiency Anemia? Iron deficiency anemia occurs when there is an inadequate amount of iron in the body to produce sufficient hemoglobin, the protein responsible for carrying oxygen in red blood cells. Insufficient iron levels can result in anemia, leading to symptoms such as headaches, pale skin, fatigue, and others. The causes of iron deficiency anemia can include insufficient dietary intake of iron, blood loss (such as from menstruation or gastrointestinal bleeding), and certain medical conditions that affect iron absorption or utilization. Treatment approaches vary depending on the underlying cause but often involve dietary modifications to increase iron consumption or the use of iron supplements. Iron deficiency anemia is a prevalent condition, affecting approximately 30% of the global population. While it can occur in individuals of any age or gender, it is more commonly observed in women and children. Early detection and appropriate management are key to addressing iron deficiency anemia and restoring optimal health. Iron Deficiency Anemia Symptoms Iron deficiency anemia is often characterized by a gradual onset of symptoms, which worsen as the condition progresses and the body experiences reduced oxygen supply. While some individuals with mild iron deficiency anemia may not experience noticeable symptoms, common manifestations of the condition can include: Fatigue or a persistent lack of energy Shortness of breath or chest pain, particularly during physical activity Dizziness or lightheadedness Headaches Pale or yellowish skin Cold hands and feet Rapid heartbeat or palpitations Unexplained weakness Pica, which involves cravings for non-food items like clay or ice Swollen or sore tongue Hair loss Brittle nails What Causes Iron Deficiency Anemia? Iron deficiency anemia develops when there is an insufficient amount of iron available in the body to produce an adequate amount of hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen to tissues throughout the body. Low iron levels can occur due to various factors. Inadequate Iron Intake Your body relies on dietary sources of iron to maintain healthy iron levels. Consuming iron-rich foods is crucial to prevent iron deficiency and maintain optimal iron status. The recommended dietary allowance (RDA) for iron varies depending on age, sex, and life stage. Here are the RDAs for different population groups: Infants 0-6 months: 0.27 mg Infants 7-12 months: 11 mg Children 1-3 years: 7 mg Children 4-8 years: 10 mg Children 9-13 years: 8 mg Adolescents 14-18 years: 11 mg for males, 15 mg for females Adults 19-50 years: 8 mg for males, 18 mg for females Adults 51+ years: 8 mg Pregnancy: 27 mg Breastfeeding: 9-10 mg Problems Absorbing Iron Several medical conditions and medications can interfere with iron absorption, leading to iron deficiency anemia. These include: Gastrointestinal conditions: Conditions like Crohn’s disease, celiac disease, ulcerative colitis, or an H. pylori infection can affect the absorption of iron in the gastrointestinal tract. Digestive system surgery: Certain surgeries, such as bariatric (weight loss) surgery, can alter the normal functioning of the digestive system and impact iron absorption. Genetic conditions: Genetic disorders like cystic fibrosis can impair the body’s ability to absorb iron properly. Medications: Certain medications used to treat heartburn, ulcers, and other acid-related conditions, such as proton-pump inhibitors (PPIs), calcium carbonate, and histamine-2 receptor antagonists, can interfere with iron absorption when taken long-term. Blood Loss Blood loss can lead to iron deficiency anemia as the body loses iron during bleeding. The causes of blood loss associated with iron deficiency anemia include: Heavy menstruation: Women with heavy or prolonged menstrual periods may experience significant blood loss, leading to iron deficiency anemia over time. Internal bleeding in the gastrointestinal tract: Conditions such as inflammatory bowel disease (e.g., Crohn’s disease, ulcerative colitis), colon cancer, or other gastrointestinal disorders can cause internal bleeding, resulting in iron loss. Bleeding during childbirth: Women who experience excessive bleeding during childbirth can develop iron deficiency anemia. Regular use of over-the-counter pain relievers: Long-term or excessive use of nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen can lead to gastrointestinal bleeding, contributing to iron deficiency anemia. Traumatic injury or surgery: Severe injuries or surgical procedures that involve significant blood loss can deplete iron stores and lead to anemia. Urinary tract bleeding: Bleeding in the urinary tract, such as from a urinary tract infection (UTI), can also result in iron loss and contribute to iron deficiency anemia. Risk Factors Iron deficiency anemia is indeed common and can affect individuals of all ages. Certain risk factors can increase the likelihood of developing this condition. These include: Following a vegetarian or vegan diet: Vegetarian and vegan diets may be lower in iron, especially heme iron found in animal-based sources. This can increase the risk of iron deficiency anemia, but it can be managed by ensuring adequate intake of iron-rich plant-based foods or through iron supplementation. Pregnancy, recent childbirth, and breastfeeding: During pregnancy, the demand for iron increases to support the growing fetus and placenta. Blood loss during childbirth can also deplete iron stores. Additionally, breastfeeding can lead to further iron depletion if the mother’s diet does not provide sufficient iron. Children who consume excessive cow’s milk: Consuming more than 16-24 ounces of cow’s milk per day in young children can interfere with iron absorption and contribute to iron deficiency anemia. It is important to limit cow’s milk intake and ensure children have a well-balanced diet that includes iron-rich foods. Having a chronic inflammatory disease: Chronic inflammatory conditions, such as heart failure or obesity, can disrupt iron metabolism and increase the risk of iron deficiency anemia. Inflammation can affect iron absorption, utilization, and storage in the body. Having myelodysplastic syndrome (MDS): Myelodysplastic syndrome is a group of disorders characterized by abnormal production of blood cells in the bone marrow. In MDS, the bone marrow may produce too few healthy red blood cells, leading to anemia, including iron deficiency anemia. Diagnosis To diagnose iron deficiency anemia, healthcare providers typically start with a thorough evaluation, including a physical exam and review of symptoms, medical history, and risk factors. They may then order specific blood tests to confirm

Only have a minute? Listen instead Volunteers donate blood at Vitalant Blood Center on Nov. 19, 2018, in McAllen. (Joel Martinez | [email protected]) The nonprofit blood services provider Vitalant says it has an emergency blood shortage and is urging Rio Grande Valley residents to schedule a donation, a move the organization says could prevent treatment delays for patients in need of lifesaving transfusions. According to a news release, the Fourth of July holiday exacerbated the situation and the available blood supply is down 25% since May, resulting in less than a three-day supply for most types. The release called maintaining that supply critical to victims of accidents and emergencies, along with people being treated for cancer and other chronic diseases. “If enough blood is not available at any given moment, delays in patient care can have life-threatening consequences,” Vitalant Chief Medical and Scientific Officer Dr. Ralph Vassallo wrote in the release. “By making an appointment today and donating tomorrow, next week, even a couple weeks from now, you become a lifeline for patients.” The release says that donations and drives become more scarce over the summer as demand increases due to an increase in outdoor activities that can lead to accidents and injuries. “All blood types are needed, but especially type O, the most transfused blood type,” the release reads. “O-negative can be used to help any patient in an emergency and O-positive can support anyone with a positive blood type. Platelet donations play a vital role for cancer patients and those undergoing open-heart surgeries and transplants. Platelets are constantly needed and must be used within a week of donation to ensure the best possible patient outcomes.” To donate, residents can check out vitalant.org, use the Vitalant app or call (877) 258-4825.

#inform-video-player-1 .inform-embed { margin-top: 10px; margin-bottom: 20px; } #inform-video-player-2 .inform-embed { margin-top: 10px; margin-bottom: 20px; } Fairbanks residents donated enough blood Wednesday at Fairbanks Memorial Hospital to save 100 lives. The Blood Bank of Alaska’s LIFEmobile was parked at the hospital between 10 a.m. and 5 p.m. Wednesday, soliciting donors. Jody Starkey, FMH Blood Bank supervisor, said her department treats patients who need transfusions and they cannot operate without blood donors, adding that the most needed blood types are O+ and O-. #inform-video-player-3 .inform-embed { margin-top: 10px; margin-bottom: 20px; }

FARGO, N.D. (Valley News Live) – Blood service providers are issuing an urgent warning about the blood supply in the region after a deadly shooting sent several people to the hospital. Vitalant is issuing an emergency blood shortage, saying blood supply is down 25 percent since May. Combined with holiday injuries the past few weeks and now a major shooting in Fargo, the blood supply is a less than three-day supply for most blood types, according to Vitalant. “Immediately following Fridays deadly shooting, blood was ordered stat to ensure the victims had the lifesaving blood products they needed,” explains Jennifer Bredahl, Regional Director of Vitalant Blood Donation Center. “We are grateful that we had the blood that was needed in this tragic situation, but we need to make sure we replenish that supply here locally as soon as possible.” Vitalant says it will accommodate as many walk-ins as possible, but they encourage people to set up an appointment here. All blood types are needed, especially Type O, the blood type most people can use when given a transfusion. “This community stands strong and will pull through together. We owe it to each other and rely on each other to do our part, this is one thing you can do to make a difference” Bredahl said. Copyright 2023 KVLY. All rights reserved.

HARLINGEN, Texas (ValleyCentral) — Vitalant, a non-profit blood service provider, announced an emergency blood shortage. The organization encourages eligible donors to donate blood in July to help those in need. “By making an appointment today and donating tomorrow, next week, even a couple weeks from now, you become a lifeline for patients,” Vitalant Chief Medical and Scientific Officer Dr. Ralph Vassallo said. Disc golf group gathers to save park from proposed business development According to a news release from Vitalant, blood donations have dropped 25% since May. Vitalant said, during the summer fewer donors have been available and fewer organizations have hosted blood drives causing the blood shortage. “All blood types are needed, but especially type O,” Vitalant said. Those interested in donating, can make an appointment at vitalant.org. Donors can also download the Vitalant app or call 877-25-VITAL (877-258-4825).

Credit: Pixabay/CC0 Public Domain Researchers have cracked how a particular type of immune cell develops in the body and protects against infection and disease. And the discovery could help in the development of more preventive treatments, according to a new study. The research, led by Murdoch Children’s Research Institute and Federation University Australia, has uncovered how these specialized white blood cells operate and can produce an immune response. Associate Professor Dan Pellicci said by understanding the function of these cells, they could be harnessed to help prevent cancer and highly infectious diseases such as COVID-19, Strep A and tuberculosis. Published in Science Immunology, the study involved samples donated to the Melbourne Children’s Heart Tissue Bank from heart surgery patients up to 16 years old. From these samples, the researchers looked at the role of “gamma delta T cells” within the thymus gland, a small organ located within the chest, close to the heart. Associate Professor Pellicci said the study showed for the first time how this organ produced these infection-fighting immune cells. “We have large numbers of these specialized cells in our blood and tissues, which accumulate as we become adults. Until our study, it was unclear how these cells develop in the body,” he said. “We have shown how these cells are trained over three stages, similar to receiving a primary, secondary and tertiary education, and fully formulate within the thymus. Following this education, the cells are ready to enter the rest of the body and are completely capable of fighting infections.” Associate Professor Pellicci said previous studies suggested that these immune cells were mainly derived in the liver during a baby’s development in the womb, but this research debunked that theory. “Many experts assumed that after birth, the thymus played little role in the development of these cells as we age, but we now know this little unsung organ helps the body prepare for a lifetime of good health,” he said. “The more we know about these cells the greater the likelihood of unlocking new ways to treat infectious diseases and cancer.” Researchers from the University of Melbourne, The Fiona Elsey Cancer Research Institute, Federation University, Peter Doherty Institute for Infection and Immunity, Melbourne Center for Cardiovascular Genomics and Regenerative Medicine, The Royal Children’s Hospital and the Walter and Eliza Hall Institute of Medical Research also contributed to the findings. More information: Louis Perriman et al, A three-stage developmental pathway for human Vγ9Vδ2 T cells within the postnatal thymus, Science Immunology (2023). DOI: 10.1126/sciimmunol.abo4365 Provided by Murdoch Children’s Research Institute Citation: New study discovers how specialized white blood cells operate, could lead to preventive treatments (2023, July 17) retrieved 18 July 2023 from https://medicalxpress.com/news/2023-07-specialized-white-blood-cells-treatments.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Published: 7/25/2023 WISCONSIN RAPIDS – Looking for a way to help others, but maybe don’t have much time or money to spare? Blood donation costs nothing, takes less than an hour, and saves lives. Blood cannot be manufactured; so donation is the only hope for someone whose life depends on the generosity of others. The Blood Center of Northcentral Wisconsin will hold blood drives in Wisconsin Rapids on Tuesday, August 15, from 10 am to 3 pm and on Monday, August 28, from 2 pm to 7 pm. The drives will take place in the former East Junior High School music room at 311 Lincoln Street. (Use Lincoln Street entrance.) The Blood Center of Northcentral Wisconsin is the primary supplier of blood to Aspirus Riverview Hospital in Wisconsin Rapids. Appointments are encouraged to promote social distancing; but walk-ins are also welcome. To schedule an appointment or for more information, please call the Blood Center of Northcentral Wisconsin’s toll-free number at 866-566-5900. People with medical conditions or who are taking any medications are asked to call the toll-free number before attending a blood drive to find out if they are eligible to donate. <!– Back –>

With the advent of disease-modifying Alzheimer’s drugs, everyone in the world of Alzheimer’s diagnostics is bracing for the crush. Based on their ability to slow cognitive decline, the Eisai/Biogen drug Leqembi won full approval from the FDA this month, and donanemab by Eli Lilly could be approved by year end. Clinicians now have to decide which patients are most suitable for treatment, which means better Alzheimer’s tests need to be developed. advertisement “There’s going to be capacity issues because there’s just not enough neurologists in the world to treat this pool of patients with Alzheimer’s disease at the moment,” said Mark Stearman, a senior international product manager at Roche focusing on Alzheimer’s diagnostics. Currently, diagnosing Alzheimer’s is slow. The standard confirmation test is an amyloid-PET scan, but by the time the disease is evident on the PET scan, the disease has already progressed, said Valerie Daggett, a bioengineering professor at the University of Washington. “A lot has to happen before you get there and you see those deposits,” she said. Enter: blood tests. A glut of these tests — some used in clinical trials for Leqembi and donanemab — have received FDA breakthrough device designation, though none have been authorized yet. Newer tests and biomarkers are even trying to diagnose patients before they develop Alzheimer’s symptoms. advertisement But as the market for these diagnostics opens up and researchers and clinicians increasingly lean upon these biomarkers to diagnose disease, it’s also causing researchers and neurologists to question what exactly Alzheimer’s is. Last week, the National Institute on Aging and the Alzheimer’s Association presented new guidelines redefining Alzheimer’s, partially because of the advent of blood biomarkers. “This is, I think, not the 1 million [dollar], but the 10 million [dollar] question for Alzheimer’s disease: What is Alzheimer’s?” said Tamas Fülöp, a professor of medicine and geriatrics at the University of Sherbrooke in Canada. “Is this only clinical, is this only pathological? Is this both?” Joseph Quinn, a professor of neurology at Oregon Health & Science University, agreed. “The field and the world still has to come to grips with the idea that the pathology in the brain exists even before there are symptoms and exactly how we’re going to describe people who have biomarker evidence of Alzheimer pathology but no symptoms at all.” How it works These blood tests are based on the idea that Alzheimer’s is caused by a protein fragment called beta-amyloid, which eventually clusters into clumps called plaques. Thus, the amount of amyloid people have floating freely in their cerebrospinal fluid (CSF) or blood should decrease if they have Alzheimer’s and the beta-amyloid is clumping into plaques. Neurofibrillary tangles are also thought to have a role in Alzheimer’s and other neurodegenerative diseases. These filaments form around neurons when tau proteins become altered by a process called phosphorylation and end up aggregating together. Thus, finding elevated amounts of phosphorylated tau, or ptau, in blood or CSF is also a way to measure Alzheimer’s. Each person has a bit more than a tenth of a liter of cerebrospinal fluid, cushioning and hydrating their brain and spinal cord at any given moment. As one of its functions, the fluid helps carry waste out of the brain — including the bits of proteins used as biomarkers for neurodegenerative diseases like Alzheimer’s. Practitioners can sample a patient’s CSF through a lumbar puncture, which isn’t the ideal or easiest procedure for routine testing. However, the biomarkers in the CSF are clear and strong enough that this procedure can be used to confirm an Alzheimer’s diagnosis. CSF releases its waste cargo into the bloodstream for further breakdown and elimination, which means those same biomarkers can be detected in blood. But they get diluted in the bloodstream, since a person has about five liters of blood, about 40 times as much volume as a person’s CSF. One reason these blood tests can’t be run at individual doctor’s offices and are currently evaluated at either a company’s centralized facility — in the case of St. Louis-based C2N Diagnostics, for example — or centralized labs with trained staff on the company’s instruments, as in the case of Roche or biomarker analysis company Quanterix, is that these dilute bits of amyloid and ptau are hard to detect. “Whereas in the CSF, it’s a nice clean fluid that you can measure, in the blood it’s a bit of a minestrone soup and we are measuring these compounds at very low concentrations with lots and lots of background noise because there’s so many other proteins in the blood,” said Stearman at Roche. “So it is challenging to take these samples into the blood.” The need Because Leqembi and the Lilly antibody donanemab both aim to get rid of amyloid, patients need to confirm that they have amyloid buildup before they’re eligible for the treatment. That means they will need both a scan to get diagnosed, and to monitor if the treatment is working, which is more than the current number of scans the Centers for Medicare and Medicaid Services covers: one. But just last week, CMS proposed eliminating one hurdle to PET access — loosening its previous policy to allow patients to get multiple scans, and get them outside of the context of a clinical trial. The trouble is there are only about 2,000 PET centers in the United States, and they’re heavily booked, said Masoud Toloue, CEO of Quanterix, which makes an Alzheimer’s blood test. Using simpler screenings to decrease the barriers to getting an Alzheimer’s diagnosis could make it easier to get people treatment earlier in the course of the disease, said Maria Glymour, chair of the epidemiology department at Boston University, in an email to STAT. She warned this would pay off only if healthy people are not incorrectly diagnosed with the disease, and if there are Alzheimer’s treatments with substantial, long-term benefits. “As of today, we have treatments with clear evidence of a small, short-term benefit. We don’t have good evidence on whether the short-term benefit stays