Cross idiotypic specificity among cold agglutinins in relation to combining activity for blood group-related antigens.

Abstract

The previous observations of cross idiotypic specificity of IgM cold agglutinins were further investigated in quantitative precipitin assays and attempts were made to relate shared idiotypic specificity to combining specificity for I, i and Pr antigens of red cells. Shared idiotypic determinants were observed among anti-I and anti-i antibodies which are now known to have combining specificity for determinants present on precursors of the ABH and Lewis blood group substances. There was evidence that one cold agglutinin, Ma, which had previously been shown to have an unusual kind of I specificity was deficient in the idiotypic determinants associated with the other anti-I proteins.