Blood Transfusions

Blood Component Transfusions

Blood component transfusions are one of the most commonly performed medical procedures. Tens of millions of transfusions take place during the span of a year within the United States. Transfusions can be required for many situations such as acute blood loss anemia due to trauma or surgery, blood cancers like leukemia, chemotherapy involved in treating leukemias, iron deficiency causing anemia, infections, etc. The vast majority of blood component transfusions are acquired through the selflessness and generosity of the general public donating their time and literally part of themselves to help save another life. In rare cases, a patient may elect to do an "autologous" donation in which they donate their own blood which can then be used for an upcoming surgery if the patient for any reason refuses an allogeneic (meaning not from one's self, but from someone else) transfusion. 

Donors must be screened ahead of time prior to donation to ensure they are healthy enough to donate and meet the requirements of a donor. Different donation types will typically have slightly different requirements. The vast majority of donations performed in the United States involves donating "Whole Blood" which will drain via gravity into a (usually) 500 milliliter(mL) donation bag. Whole Blood simply means that it contains the entirety of the circulating blood which is made up of Red Blood Cells (roughly 40-45% of the blood's composition), plasma (the straw yellow liquid portion of the blood comprising 50%+ of the total blood volume), and platelets/white blood cells. 

The old catchphrase "You can save up to 3 lives with just one donation!" comes from the fact that the donated blood will then be sent to the Blood Center's manufacturing department. The blood will then be centrifuged (spun in a machine that goes several thousand rotations per minute) which causes the parts of the blood to separate. The blood center can then create individual products out of the layers. Packed Red Blood cells, Plasma (which is then frozen until use, and Platelets. Three separate products that can then be given to three separate lives in need. The white blood cells are almost universally always filtered out. The reason for this will follow on a separate page. There are only very specific instances in which White Blood Cells are wanted and used in transfusion.

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All donations in the US must be screened for infectious diseases before it can be released to a transfusion center for use. The Blood Donation center will also perform a Blood Type on the donor unit. Every donation will be screened via laboratory testing for HIV (Human Immunodeficiency Virus) Types 1 and 2, Hepatitis B, Hepatitis C, HTLV (Human T-Lymphotropic virus) I and II, Treponema pallidum (the causative agent of Syphilis), West Nile Virus, and Zika virus. All first time donors will be tested for Trypanosoma cruzi the causative agent of Chagas disease. All platelets will be screened for bacterial infection via culture every donation as well. Other infections that may be screened for include Babesia and Cytomegalovirus.

Donor Blood draining through a leukoreduction filter
Blood donations for the purpose of transfusion in a medical setting are almost ALWAYS on a volunteer donor basis. Paid blood donation is extremely rare, especially in the United States. In fact, per FDA guidelines volunteer and paid blood donations MUST be labeled as such. Most transfusion centers would not accept paid donations in their inventory due to safety concerns. The reasoning behind this is simple. Volunteer donations exist because good people exist and they want to do their part to help society and their community, and this is one fantastic way of giving. Volunteer donors need not be paid, their paid in the satisfaction of knowing they helped save a life. Keeping this in mind, there would be no reason to lie during their pre-donation medical screening and questionnaire. A paid system, however, opens up a liability where people may want to donate for less altruistic reasonings. A paid system gives more incentive for a person to lie about their medical history, which puts themselves and the potential recipient of the product in an unsafe situation. It could lead to the donor becoming unwarrantedly ill with a bloodborne infection, or other issues that could have been avoided with a purely volunteer system.  

Directed donation is another form of donation in which a close family member or friend donates blood products for the patient in need. This is more common than a Paid Donor situation, but also happens very infrequently, at least in the United States. Similar problems can occur involving friends or family members lying about their medical history potentially jeopardizing the health of the recipient. Donations from close relatives can also pose other risks such as transfusion related Graft vs Host disease in which the white blood cells remaining after leukoreduction can start to activate and attack the cells of the recipient. More about this in the transfusion reaction section. 

Once infectious disease testing is completed, the components have been fully manufactured, the units have been labeled appropriately, and the blood is determined to be safe for transfusion the Blood Center can officially send it out to transfusion centers. The most common recipient of blood products are hospital Blood Banks. Blood Banks are overseen medically usually by a Pathologist specializing in Transfusion Medicine. Pathologists are medical doctors. The employees of a hospital Blood Bank consist mostly of Medical Laboratory Technicians and Medical Laboratory Scientists (a 2 and 4 year degree, respectively). Some may have their masters, and some may have a Blood Bank specialist certification. These specialist employees may be in managerial/supervisory roles, or work in a Lead Technologist role on their shift. Other Blood Bank members such as lab assistants, generally only need a High School or High School equivalent. 

Transfusions are a very safe procedure with heavy regulation and guidelines backing it to ensure the process goes smoothly from donation to transfusion. 

Bombay Phenotype

Bombay phenotype is a rare blood type that affects a very small percentage of the global population. It is named such, as it was first discovered in Bombay (Mumbai), India. This blood type can present significant challenges for those who require blood transfusions, as people with Bombay phenotype cannot receive blood from most other blood types. In this article, we will explore Bombay phenotype in more detail, including how it affects transfusions and what steps can be taken to ensure the safety of those with this rare blood type.

What is Bombay phenotype?

The Bombay phenotype is a rare blood type that occurs when an individual has inherited two copies of a recessive gene that affects the production of certain antigens on the surface of red blood cells. Specifically, individuals with Bombay phenotype do not produce the H antigen, which is the precursor to the A and B antigens that determine the ABO blood type system. As a result, people with Bombay phenotype have blood that appears to be type O, even though they may have genes for type A or B blood.

How does Bombay phenotype affect transfusions?

Because people with Bombay phenotype lack the H antigen, their blood can be incompatible with blood from other ABO blood types. This means that people with Bombay phenotype cannot receive blood from most other blood types, including type A, B, AB, and O. In fact, people with Bombay phenotype can only receive blood from other individuals with the same rare blood type.

For this reason, it is essential that individuals with Bombay phenotype are identified and properly tested before any blood transfusions. If someone with Bombay phenotype receives blood from an incompatible blood type, it can lead to a severe and potentially life-threatening reaction known as a transfusion reaction.

What steps can be taken to ensure safe transfusions for people with Bombay phenotype?

To ensure the safety of people with Bombay phenotype who require blood transfusions, it is crucial to identify individuals with this rare blood type early on. This can be done through blood typing tests, which can determine whether or not someone has the H antigen.

Once someone with Bombay phenotype has been identified, steps can be taken to ensure that they receive compatible blood during transfusions. This typically involves identifying other individuals with the same rare blood type and maintaining a supply of their blood for use in transfusions. Blood banks and hospitals often work together to create networks of donors with rare blood types, including Bombay phenotype, to ensure that there is always a supply of compatible blood available.

In addition to proper identification and blood banking, it is also important to monitor people with Bombay phenotype closely during and after blood transfusions. This can help to identify any potential complications or adverse reactions early on and ensure that prompt treatment is provided if necessary.

Frozen Blood

Blood for people with Bombay phenotype can be frozen and stored for future use, and one of the most common methods of blood preservation is glycerolization.

Glycerolization is a process in which red blood cells are mixed with a solution of glycerol and other chemicals before freezing. This solution helps to protect the cells from damage during the freezing and thawing process and allows the blood to be stored for longer periods of time.

During glycerolization, the red blood cells are mixed with a solution containing glycerol, a sugar called trehalose, and other chemicals that help to stabilize the cells. The cells are then slowly cooled to a temperature below freezing, typically around -80°C. Once the cells are frozen, they can be stored for several years, if necessary, without significant loss of quality.

When the blood is needed for transfusion, the frozen blood is thawed slowly and carefully, and the glycerol and other chemicals are removed. The red blood cells can then be transfused into the patient as needed.

Glycerolization is a common method of blood preservation for people with rare blood types like Bombay phenotype because it allows compatible blood to be stored for longer periods of time, which can be especially important in emergency situations or when a suitable donor is not immediately available. 

Autologous Donation

People with Bombay phenotype can donate their own blood for autologous transfusions. In fact, autologous blood donation can be a valuable strategy for people with rare blood types like Bombay phenotype to ensure that they have access to compatible blood when needed.

Autologous blood donation involves collecting and storing a person's own blood for future transfusion. The process usually involves donating blood several weeks or months before it is needed, and the blood is tested and processed to ensure that it is safe and compatible with the person's own blood type.

Because people with Bombay phenotype have a rare blood type that is not compatible with most other blood types, autologous blood donation can be a useful strategy for ensuring that they have access to compatible blood when needed. It can be particularly important in situations where there may be limited access to compatible blood, such as in remote or resource-limited settings.

It's important to note that the process of autologous blood donation and transfusion requires careful planning and coordination to ensure that the blood is collected, processed, and stored properly, and that it is used before it reaches its expiration date.