PROGRESS REPORT ON THE ASHI/CAP PROFICIENCY SURVEY PROGRAM IN HISTOCOMPATIBILITY TESTING .2. HLA-DR,DQ SEROLOGIC TYPING, ANTIBODY IDENTIFICATION, AND B-CELL CROSS-MATCHING

This report summarizes the 8-year experience of the DR survey program designed to evaluate the performance of histocompatibility laboratories in the serologic typing of cell specimens for HLA-DR and HLA-DQ polymorphisms and the HLA class II antibody identification and B-cell crossmatching of serum specimens. The number of participants increased from 45 in 1985 to 214 in 1992. Although the performance criteria are based on laboratory consensus, the availability of DNA typing since 1990 has enabled a critical assessment of the reliability of serologic HLA-DR,DQ typing. The survey results shows that unsplit HLA class II antigens DR1-DR8, DR52/53, and DQ1-3 are generally correctly identified in over 90% of the participating laboratories. DR9 and DR10 have not yet been tested and testing for DQ4 has not yet achieved this level on consensus. In contrast, the assignments of serologic subtypes of HLA-DR and HLA-DQ are less consistent and frequently unreliable. Although the B-cell crossmatches show generally high laboratory consensus rates, the serum screening results show frequently inconsistent results regarding HLA class-II-specific antibody identification