HLA antibody detection with solid phase assays: great expectations or expectations too great?

Area of Science:

• Immunology and Transplantation
• Histocompatibility Testing

Background:

• Alloantibodies targeting human leukocyte antigen (HLA) present a major obstacle to long-term solid organ allograft survival.
• The presence of preformed, donor-directed HLA alloantibodies can range from an acceptable risk to a complete contraindication for transplantation, significantly impacting patient access to donor organs.

Purpose of the Study:

• To review the evolution of methodologies used for identifying HLA antigens and antibodies.
• To discuss the strengths and weaknesses of various HLA antibody detection assays, including traditional and modern approaches.

Main Methods:

• Historical overview of serological methods for HLA antigen and antibody identification.
• Introduction of DNA-based HLA antigen testing utilizing polymerase chain reaction (PCR) in the early 1990s.
• Development of microparticle-based technology with flow cytometry for detecting both class I and II HLA antibodies by the mid-1990s.

Main Results:

• Early serological methods had limitations in accurately identifying HLA antigens and antibodies.
• The advent of PCR enabled DNA-based HLA typing, enhancing specificity.
• Microparticle-based flow cytometry assays revolutionized histocompatibility testing by enabling robust detection of HLA class I and II antibodies.

Conclusions:

• Technological advancements have significantly improved the ability to detect HLA antibodies, crucial for solid organ transplantation.
• Modern assays, such as those employing flow cytometry, represent a substantial improvement over older serological techniques.
• Understanding the capabilities and limitations of different HLA antibody detection methods is vital for optimizing clinical histocompatibility testing.