Abnormal Glycolipid Composition of Erythrocytes with a Weak P Antigen

Abstract

The erythrocytes of a normal man were agglutinated more weakly than normal cells by several anti-P₁PP^k sera, and exhibited a decreased capacity to absorb these antibodies. Analysis of his erythrocyte glycosphingolipids revealed that the globoside (P antigen) content was less than 25% of normal, and trihexosyl ceramide (the P^k antigen) was 30–40% of normal. The ganglioside content of his erythrocytes was approximately four times normal and sialosyl-paragloboside was increased about sixfold. It appears that his erythrocytes are unable to synthesize normal quantities of trihexosyl ceramide, and that these serological and chemical features constitute a new phenotype in the P blood group system.