Research Units

When the body attacks its own cells, the results can be devastating. Immune thrombocytopenia (ITP) is an autoimmune disease in which the body produces antibodies against blood platelets. These antibodies bind to platelets and tag them, causing them to be recognized as "foreign" by the immune system and destroyed. Platelets work by sticking together and forming a plug that seals broken blood vessels, so the loss of too many platelets can lead to serious bleeding.

Proteins are responsible for most of the work in cells. Based on their functions, locations, and interactions with each other, proteins keep cells, tissues, organs and bodies healthy and working well. Within cells, proteins are built up and broken down as needed. Each protein is made of individual building blocks called amino acids. To build proteins, amino acids bond with each other to make short chains, called peptides, and longer chains, called proteins. Conversely,proteolysis is the process of cutting proteins into peptides or individual amino acids. During proteolysis, bonds between amino acids are cut by proteins called proteases.

Research from Canadian Blood Services has transformed understanding of a severe bleeding disorder in fetuses and newborns. Fetal and Neonatal Alloimmune Thrombocytopenia, also called FNAIT, affects about 1 in 1000 live births. FNAIT can be lifethreatening. Intracranial (within the skull) bleeds are a major risk and occur in about 10 to 20 per cent of FNAIT cases. These can lead to brain damage, death, and loss of the fetus.

Canadian Blood Services’ researchers have been exploring new ways to fool the immune system. Why? The hope is to provide blood to patients for whom a match cannot be found

Despite many safety improvements, blood transfusion still has some risks. These include the risk of illness if blood is contaminated with microorganisms called ‘pathogens’ such as viruses and bacteria that cause disease. Many approaches are used to reduce or prevent pathogen contamination in the blood supply. For example, donors are screened and blood donations are tested. However, testing only works for known pathogens. Unknown pathogens that cannot be tested for, called ‘emerging’ pathogens, are a risk to the blood system. This and other issues including the sensitivity limits of pathogen testing means there is a need for alternative ways to improve blood safety.

When a blood vessel is injured, a clot forms at the vessel wall to plug the injury. This is necessary to stop bleeding. However, clots may also form within vessels, for example when an atherosclerotic deposit (plaque) ruptures. These clots can become life-threatening, causing a heart attack or stroke. Maintaining a balance between preventing blood loss (called hemostasis) and preventing unnecessary clotting (called thrombosis) is critical. While much is known about how hemostasis/thrombosis is controlled in the body, the process is not fully understood.

Occasionally, blood components become contaminated with bacteria. The source of contamination is often found to be bacteria that normally live on the skin. Human skin is home to millions of microorganisms. Skin ‘microflora’ includes many different types of bacteria, which may enter the blood unit during the donation process. If bacteria enter a unit, some may survive and even thrive during storage. The risk is greatest with platelet components. Stored at room temperature, platelets provide a particularly good environment for bacteria to grow. Although harmless on the skin of healthy people, if enough bacteria enter the blood stream of a recipient they can cause severe and even fatal infections, especially in patients who are already ill.

Ever wonder why we prick potential donors’ fingers before whole blood donation? It’s to check levels of hemoglobin, the protein in blood that transports oxygen from the lungs to the cells in the body. If a potential donor’s hemoglobin is below a certain level, they cannot give blood. Hemoglobin contains iron, and low hemoglobin levels (called anemia) is often linked with low iron levels (called iron deficiency). So, why is iron important? Iron is an essential mineral; it is necessary for our body to function well, but we must get the iron we need from our diet.

TRALI stands for Transfusion-Related Acute Lung Injury. As its name suggests, TRALI is lung damage that occurs in reaction to a blood transfusion. It is uncommon, but potentially fatal, and symptoms range from mild to life-threatening breathing difficulties. TRALI occurs when antibodies in the donor’s blood react with incompatible proteins in the recipient. This reaction may cause immune cells (called neutrophils) in the recipient’s lung to produce substances that damage the lung. However, why a patient develops TRALI is often not clear, and much remains to be understood about how this reaction happens. If a patient shows symptoms of TRALI, the transfusion is stopped and supportive care (e.g. oxygen to help breathing) is given. Unfortunately, there is no effective treatment for this potentially fatal reaction.

Premature infants often require red blood cell (RBC) transfusions to manage anemia of prematurity. However, there is some evidence that RBC transfusions may be associated with necrotizing enterocolitis, a devastating and potentially deadly disease affecting the intestines. Feeds are often stopped before, during and after transfusion to try to reduce the chance of this disease occurring. Unfortunately, this practice comes with other risks. Most importantly, stopping feeds around the time of a transfusion places the infant in danger of developing low blood sugar levels. To avoid this high-risk situation, the infant may also need intravenous infusions of dextrose (sugar) solution.