SEROLOGICAL IDENTIFICATION OF A NEW HLA-B7 VARIANT ANTIGEN - HLA-B7QUI

A new HLA-B antigen, HLA-B7Qui that appears to be a variant of HLA-B7 has been identified. This antigen, which is HLA-Bw6 associated, reacts with approximately two-thirds of cytotoxic antisera stimulated by HLA -B7 or B27 that lack a B27 or B7 component, respectively. All anti-B727 antisera (stimulated by either B7 or B27) react with B7Qui as do mo st B22-stimulated sera possessing a B7 component. However, sera stimul ated by B60, with or without a B7 component, fail to react with B7Qui. Family studies show the B7Qui allele to be unique to the haplotype - HLA-A32 CW6 B7Qui Bf()S C4A(*)6 C4B(*)1 DR11 DQ7 (GLO2). Six Caucasoi d subjects on the panel of 6861 HLA-typed potential bone marrow donors have this antigen (phenotype frequency, 0.08745%; gene frequency, 0.0 4473%). Work undertaken during the 11th International Histocompatibili ty Workshop (Reekers et al., 1992) showed that B7Qui has the same isoe lectric point as HLA-B702 and HLA-B703 (Bpot) and that B7Qui is distin ct from the HLA-B7 variants B703, B7SL, BDT, B7x40, BRI, and B41v.