Blood donation can do a lot more to help than you probably think. Happy World Blood Donor Day, enjoy the cookies and juice!
Is blood more than the sum of its parts? It’s not likely and that’s a great thing! In the past blood was collected, stored, and used for transfusions when needed. Now blood is being separated into its basic components such as red cells, stem cells, plasma, and platelets. So why is this a good thing? Separating blood allows the treatment of patients with only the specific parts of blood that they really need. This means a single blood donation can help several patients and no single component is wasted.
What are the components and how are they used?
Red blood cells make up approximately 40% of human blood. These are doughnut-shaped cells that are responsible for supplying oxygen to your body’s organs and tissues. Transfusion of red blood cells can be used to treat conditions such as trauma where there is severe blood loss. This type of transfusion can also be used to treat chronic anemia – lower than normal red blood cells or hemoglobin. Chronic anemia is a symptom in many different types of conditions ranging from autoimmune diseases to cancer. Red blood cells are separated from whole blood through a process of filtration. This means that donors can donate blood as they normally would without any extra hassle.
Plasma is a protein-rich liquid that makes up the other half of human blood. Plasma is mostly made up of water but contains other nutrients such as proteins, fats, sugars, and vitamins. Plasma is important for transporting all the components of blood around the body. It is responsible for helping white cells (immune cells) and antibodies circulate throughout the entire body so they can fight infections. The proteins in plasma have many functions, each of which is vitally important. Albumin is the most abundant protein in plasma and is made in the liver. Albumin helps maintain what is called osmotic pressure meaning it helps keep water inside the blood vessels and maintain fluidic pressure. Clotting factors, as the name suggests, help the blood to clot in the case of injury. Plasma is mainly used to treat trauma or server burns. It can also be used to treat patients with bleeding disorders, liver disease, and some cancers. Plasma can be harvested from donors in two ways, the first is through a collection of whole blood and subsequent filtration processes. The second and more efficient process is through what is called apheresis. This is where the separation takes place during the donation process and components of the blood such as red and white blood cells as well as platelets are put back into the donor immediately. Apheresis is more efficient than whole blood donation because a larger volume of plasma can be collected using this method.
Blood products are proteins within the plasma. These are sometimes harvested and used to make medications. Octaplex® is a good example, this is a drug that is made up of a number of clotting factors (II, VII, IX, X) found in plasma. Octaplex® is often used to treat patients who are using warfarin (blood thinner) during surgery or if these patients experience excessive bleeding. Antibodies that are found in plasma are also isolated to make blood products. The antibodies are also called immune globulins and they are often given intravenously to patients with low immunity – patients that don’t produce enough of their own antibodies. This is known as intravenous immune globulin (IVIG) and is the most widely used plasma blood product.
Platelets are plate-shaped cell fragments that are responsible for forming blood clots. They stick together and for a plug that blocks holes that may appear in blood vessels. If the hole in a blood vessel occurs on the skin the platelets are responsible for forming scabs. Platelets are used to treat patients with excessive bleeding, often seen in trauma and surgery. Interestingly, platelets are also used to treat a variety of genetic disorders that affect regular platelet function and bone marrow dysfunction. Platelet transfusions are also used to help cancer patients undergoing chemotherapy. Chemotherapy affects the functioning of the bone marrow, which prevents the platelets from being made.
Blood stem cells are a special kind of cell found in the bone marrow. These cells have the ability to mature into any kind of blood cell – white cell, red cell, or platelets. These stem cells are critical for helping the body replenish its supply of blood. Especially when you consider that we make 200 billion new red blood cells every day and that is only one cell type. There are numerous genetic disorders and autoimmune diseases that affect the correct function of bone marrow and the treatment for these diseases is to replace the damaged tissue with stem cells from a donor. Cancers of the blood and bone marrow such as leukemia, lymphoma, or myeloma can also be treated with stem cell transplants. Stem cells can be collected from donors in three separated procedures, blood donation, bone marrow donation, and umbilical cord blood donation.
Whole blood is still a valuable resource when it comes to donating blood, particularly if you have a rare blood type. Blood types are determined by the proteins that sit on the surface of red blood cells, these are known as antigens. Blood types are usually categorized using A, B, and O antigens. There are however over 600 different kinds of antigens. Your blood may be rare depending on the types of antigens your red blood cells have. Donation of rare blood types is important as they are an extremely limited resource.
It is clear that a single donation of blood can go a long way to helping patients with a variety of different diseases. World blood donor day is a great way to recognize and celebrate all the blood donors out there saving lives. Well done and enjoy the juice!
Written by Tarryn Bourhill Msc, PhD Candidate
References
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