Test Details: Human leukocyte antigens (HLA) are a system of glycoproteins that have a functional role in the presentation of peptides to the immune system. However, as a highly polymorphic system, HLA molecules can become the targets of antibody responses in people during pregnancy, transfusion of blood products, or organ transplant rejection. Generally, alloimmunization leads to the production of HLA antibodies in approximately 33% of exposed individuals. The presence or absence of these HLA-specific antibodies has negative effect on survival of transplant allografts. The complement-dependent cytotoxicity crossmatch is a technique that uses T and B lymphocytes to detect donor-specific antibodies and has been widely used for the detection of alloantibodies in transplant patients. The crossmatch compatibility is usually performed more than once - when the donor is initially identified and again just before 48hrs of actual transplant procedure to check Anti-HLA antibody level.