CAN A BLOOD TRANSFUSION COME IN THE WAY OF GETTING A TRANSPLANT?

The answer is yes.

The body’s immune system forms certain proteins called antibodies that protects us from bacteria and viruses. These antibodies can also be formed after a previous blood transfusion, pregnancy or an organ transplant. The antibodies are formed because the immune system recognizes the new cells after a blood transfusion as “foreign” and tries to protect us from these “invaders”. It is a well known fact that kidney failure patients sometimes require multiple blood transfusions during their dialysis treatments to treat low blood counts or anemia. Every pint of blood that they receive contains different cells or “antigens” to which the immune system will form the antibodies. These antibodies are also called “donor-specific antibodies” and are responsible for an increased chance of a rejection, should the patient receive a kidney from a donor that happens to have these antigens.

Prior to any transplant procedure, physicians check the blood of the recipient for antibodies to the donor kidney. A small sample of blood is mixed with white blood cells from the donor. This is the crossmatch procedure. A positive crosmatch means that the number of antibodies to that particular donor is high and there is a high likelihood of severe rejection of that donor’s kidney if it is used for transplantation. A negative crossmatch means that the number of circulating antibodies to the donor is low and will therefore not result in rejection right after the procedure. Keep in mind that multiple anti-rejection drugs are needed after the transplant and these drugs are required to be taken for life in order to prevent rejection of the transplanted organ.

Some dialysis patients have a very high level of multiple different antibodies. A blood sample can be used to calculate the PRA or panel reactive antibody. A high PRA means that the number of antibodies to potential donors is high, which makes it more difficult to find an appropriate donor. Typically, patients with high PRA have a longer waiting period and are given priority for transplantation. The good news is that most patients have a lower level of PRA and can therefore not have to wait too long for a transplant. The average waiting time today is 3 to 5 years for a kidney transplant in the US.

Pregnancy and previous organ transplants are also known to trigger the formation of antibodies that can cause the PRA to be high and hence a longer wait time. Different strategies to overcome the presence of these antibodies have been used. Some of these strategies include medications such as rituximab, intravenous immunoglobulin (IVIg) and plasma exchange, all of which work to lower the antibody levels so that a timely transplant without the fear of early rejection can be performed.