Human Leukocyte Antigens (HLA), also known as histocompatibility antigens, are molecules found on all nucleated cells in the body. Histocompatibility antigens help the immune system to recognize whether or not a cell is foreign to the body. These antigens are inherited from one’s parents. Human leukocyte antigens are used to determine the compatibility of kidneys and pancreata for transplantation from one individual to another. The major groups of HLA antigens are HLA-A, HLA-B, and HLA-DR. The values shown in this report are based on the six HLA antigens (two each for the A, B, and DR loci) reported for both donors and recipients. Tables reporting the level of HLA mismatch indicate the number of HLA antigens found in the donor that are not shared by the recipients. Generally speaking, the smaller the number of HLA mismatches the better the compatibility between donor organ and recipient.