HLA‐D clusters associated with DR2 and the definition of HLA‐D“AZH”: a new DR2 related HLA‐D specificity in Israel

Abstract

In order to investigate the HLA-D clusters associated with DR2 in Israeli Jews, 40 DR2 positive unrelated individuals were studied with a panel of DR2 associated homozygous typing cells (HTC) which detect the lymphocyte defined specificities HLA-Dw2, Dw12, Dw9 and D-WJR. The results confirmed the existence of 2 distinct HLA-D clusters associated with the same serologically defined DR2. Of 40 individuals, 22.5% (9/40) were Dw2 and 50% (20/40) were Dw12 carriers. No HLA-D specificity could be assigned to the remaining 11 DR2 positive individuals. A unique DR2-associated Dw specificity, HLA-D"AZH" was defined. The donor of the HTC was of Moroccan origin and an offspring of a 1st cousin marriage. This cell was not typeable with the known DR2-associated homozygous typing cells nor with other HTC which define the well established HLA-Dw1 to Dw11 specificities. It was shown to segregate with DR2 positive HLA haplotypes in family analysis and in a population study, typed out 7 of 11 unrelated DR2 positive, DW blank individuals, thus identifying a unique and new HLA-D cluster provisionally designated D"AZH".