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's) which detect the lymphocyte defined specificities HLA‐Dw2, Dw12, Dw9 and D‐WJR. The results confirmed the existence of two 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. Yet, no HLA‐D specificity could be assigned to the remaining 11 DR2 positive individuals. In the present study we have defined a unique DR2‐associated Dw specificity, HLA‐D“AZH”. The donor of the HTC was of Moroccan origin and an offspring of a first cousin marriage. This cell was not typeable with the known DR2‐associated homozygous typing cells nor with other HTC's 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”.