HLA typing with monoclonal antibodies: evaluation of 356 HLA monoclonal antibodies including 181 studied during the 10th International Histocompatibility Workshop

During the 10th International Histocompatibility Workshop (10th WS), 181 HLA MoAbs were studied using lymphocytotoxicity micro-technique (LCT) and/or enzyme immuno-assay (EIA), and their capacity to serve as typing reagents was evaluated. 129 MoAbs were tested by both techniques. Results obtained with 92 class I and 86 class II polymorphic MoAbs (10th WS) were compared to published data concerning 180 class I and 176 class II polymorphic MoAbs, listed in an HLA-MoAbs Register maintained in our laboratory. The following conclusions can be proposed: 1/ HLA-A, B typing by LCT with MoAbs is possible for about 14 specificities. Some specificities are clearly recognized (HLA-A3, B8, B13, Bw4, Bw6), others are recognized as cross-reacting groups (B7+27+w22+40), others are not currently recognized by any MoAb with restricted specifity (B5, B15). Several MoAbs confirmed the existence of shared epitopes between products from a single locus (A2-A28, A25-A32), or from A and B loci (A2-B17, Bw4-A9-A32). A single HLA-Cw MoAb has been described. 2/ HLA class II typing by LCT with MoAbs is more difficult than class I typing. DR2, DR3, DR4, DR5 and DR7 as well as DRw52 and DRw53 are well defined; other DR specificities are poorly or not at all defined. Particular associations (DR1+DR4, DR3+DRw6, all DR except DR7) are recognized by several MoAbs. All DQw specificities are well recognized, including new specificities defined only by MoAbs: WA (DQw4), TA10 (DQw7), 2B3 (DQw6+w8+w9). Only two HLA-DP MoAbs have been described. 3/ Satisfactory results, similar to those of LCT, were obtained with EIA using lymphoid cell lines as targets. 4/ Human MoAbs (12 in the Register) are satisfactory typing reagents. They could represent in the future a significant contribution to HLA typing with MoAbs.