Antigen Report: HLA-DR5 and Its Subtypes HLA-DRw11 and HLA-DRw12

The existence of splits of HLA-DR5 were not accepted during the Eighth Histocompatibility Workshop, although some laboratories had claimed the existence of subsets [1]. At the present Workshop, difficulties in the distinction of DR5 from DRw6 and DRw8-related specificities led us to analyze several groups of sera differentiating these specificities. The segregation pattern of the sera mentioned in Table 1 were studied in informative families. Further details are given in the Joint Report on DRw6 (Schreuder et al., this volume). In brief, families were selected in which serum reactions appeared sufficiently strong and clearly segregated from parents to offspring. Such segregation patterns were termed haplotypes. Examples of such haplotypes are shown in Table 2. Several DR5-related patterns were observed in which all DRw52, DR5+w13 (6.6) and DR5+w8+w13 sera were positive. DR5 sera were invariably found positive in all haplotypes of patterns a, b, and c in Table 2.