Transfusion-related immunomodulation refers to the transient depression of the immune system

Immune system

An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...

 following transfusion

Blood transfusion

Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...

 of blood products. This effect has been recognized in groups of individuals who have undergone kidney transplantation

Kidney transplantation

Kidney transplantation or renal transplantation is the organ transplant of a kidney into a patient with end-stage renal disease. Kidney transplantation is typically classified as deceased-donor or living-donor transplantation depending on the source of the donor organ...

 or have had multiple miscarriage

Miscarriage

Miscarriage or spontaneous abortion is the spontaneous end of a pregnancy at a stage where the embryo or fetus is incapable of surviving independently, generally defined in humans at prior to 20 weeks of gestation...

s. Some research studies have shown that, because of this immune depression, blood transfusions increase the risk of infections and cancer

Cancer

Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

 recurrence. However, other studies have not shown these differences and the degree of impact transfusion has on infection and tumor recurrence is not well understood. The Blood Products Advisory Committee of the Food and Drug Administration

Food and Drug Administration

The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

 recommends that all transfused blood products undergo leukocyte reduction

Leukoreduction

Leukoreduction is the removal of white blood cells from the blood or blood components supplied for blood transfusion. After the removal of the leukocytes, the blood product is said to be leukoreduced.- Benefits and costs :...

in order to offset the contribution of donor white blood cells to immune suppression.