COMPLEMENT FIXATION ANTIBODIES TO GLYCOSPHINGOLIPIDS IN SERA OF RARE BLOOD GROUP p AND Pk PHENOTYPES

Abstract

Blood group P antigen and P^k antigen were recently identified as glycosphingolipid globoside, GalNAc(β, 1→3)Gal(α, 1→4)Gas(β, 1→4)Glc(β, 1→1)ceramide, and trihexosylceramide, Gal(α, 1→4)Gal(β, 1→4)Gld(β, 1→1)ceramide, respectively (Naiki & Marcus, 1974). The presence of antibodies to both antigens in the sera from rare p donors and antibodies to P antigen in the serum from a rare P^k donor were first demonstrated by the complement fixation test with the optimal antigen preparations containing each purified glycolipid, lecithin and cholesterol. In the serum from a p donor, most of antibody population of anti-P was IgM and was cross-reacted to Forssman glycolipid, GalNAc(α, 1→3)GalNAc(β, 1→3)Gal(α, 1→4)Gal(β, 1→4)Glc(β, 1→1) ceramide, but the rest of the anti-P antibodies and most of anti-P^k antibodies were IgG and had marked specificities for globoside and trihexosylceramide, respectively.