Strategies for human leukocyte antigen antibody detection

This review discusses the current state-of-the-art in human leukocyte antigen (HLA) antibody detection. Evolving from cell-based methods to solid-phase single antigen detection systems (SPADS), HLA antibody testing now provides an unprecedented and comprehensive assessment of a patient's antibody repertoire. Not surprisingly, improved antibody detection has brought new challenges to the HLA community. The challenge is how best to utilize this new information in a way that facilitates, not hinders, appropriate transplantation.

Although very sensitive, recent studies have shown that not all donor-specific HLA antibodies (DSA) identified by SPADS predict a positive crossmatch or correlate with poor outcome. The lack of an absolute correlation between DSA, crossmatching and outcome presents a serious dilemma for the transplant community. The dilemma is compounded by variable testing procedures and nonstandardized test kits that contribute to inconsistencies among laboratories. In addition, new functional assays are beginning to be applied and may identify potentially deleterious antibodies. Finally, advances in immunosuppressive therapies have made it possible to transplant across a positive crossmatch further confounding data integration.

Strategies for HLA antibody detection are now predicated on solid-phase testing methods. These methods are sensitive, specific and provide the clinician with a comprehensive assessment of a patient's HLA antibody profile. This review will discuss the evolution of antibody testing and point out the pitfalls, problems and challenges these new technologies have engendered.