DR2: Antigen Report of the Cellular Studies of the Tenth International Histocompatibility Workshop

Abstract

Among the serologically defined DR2 (DRw15) cluster, two distinct haplotypes, Dw2 and Dw12, have been recognized since the Eighth International Workshop. These two haplotypes differ by at least three amino acids in one of their DRβ molecules and by at least one amino acid in the second DRβ chain. Although Dw2 and Dw12 are both associated with the DQw6 subtype of DQw1, they nevertheless exhibit multiple amino acid differences in their DQβ chains (1) and have distinct DQα chains (2). A third DR2-associated specificity, which is distinct from Dw2 and Dw12, has been designated LD-2s since cells with this specificity have been associated with the “DR2 short” serologic specificity, now designated DRwl6. This specificity has been designated MN2, FJO, AZH, and WT24 in various reports (3) and is now designated Dw21. LD-5a is a related specificity which is also associated with the DR2 short-DRw16 specific ity (4) and is now designated Dw22. Sequence analysis has demonstrated that one DRβ chain is identical in cells typing as Dw21 and Dw22 (but differs by at least five amino acids from each of the DRw15 haplotypes) (1,5).