Technical Aspects of Crossmatching in Transplantation

The presence of antibodies directed against HLA molecules expressed on the donor's cells is one the most important risk factor for serious clinical complications after transplantation. The lymphocyte crossmatch is one of the most important tests available to the laboratory as this assay detects the presence of donor-specific anti-HLA antibodies in potential allograft recipients. Early crossmatch methods used a complement-dependent cytotoxicity test, which was useful for detecting anti-HLA antibodies responsible for hyperacute graft rejection but lacked adequate sensitivity and specificity. Consequently, more sensitive and specific crossmatch methods were developed ultimately leading to the flow cytometry crossmatch as the preferred methodology.