What is Antibody-Mediated Rejection?

Antibody-mediated rejection (AMR) is a condition that may occur after receiving a transplanted kidney or another organ. During a rejection episode, the immune system recognizes the transplanted organ as foreign, developing white blood cells and proteins, called antibodies, to attack it. Antibodies that cause AMR can severely damage or even destroy the new organ. Anti-rejection medications may help to prevent or control some parts of the rejection response, but once AMR occurs, it can be difficult to treat and may slowly damage the new organ over a long period.

AMR in kidney transplantation is often discovered through routine blood work. After the transplant, doctors will monitor for symptoms such as increased serum creatinine level, or increased protein in the urine (also called proteinuria). AMR is diagnosed through a biopsy, a procedure that removes a very small piece of the kidney for analysis in a laboratory under a microscope.