Consensus and Controversies on HLA Matching and Crossmatching in Transplantation

Transplantation of organs is becoming increasingly successful. What was once an experimental and life-saving emergency procedure has now been transformed into a life-enhancing and technologically advanced form of therapy. Histocompatibility testing between the donor and recipient consist of identification of HLA antigens known as tissue typing, and testing for pre-formed antibodies in the recipient against the donor HLA antigens, known as crossmatching. The importance of matching of HLA antigens has been debated ever since the first successful renal transplant was performed in 1954. Powerful and newer immunosuppressive drugs have not been able to establish an operational state of long-term organ tolerance. In this article, an attempt is made to show the clear and obvious effect of HLA antigen matching on the long-term graft survival. Also, the merits and demerits of different crossmatching methods and their proper interpretation and application to improve the overall graft survival are discussed.