Report on a patient with paroxysmal cold hemoglobinuria

Antibodies against the human blood group P antigen (anti-P alloantibodies) agglutinate phenotype P₁ and P₂ erythrocytes treated with papain at 4°C but not phenotype P(K) and p erythrocytes. This condition is referred to as an autoimmune disease of paroxysmal cold hemoglobinuria (PCH), and the anti-P specificity is found in the cold hemagglutinins. Serum from a patient suspected to be suffering from PCH by the cold auto-agglutination properties was tested for anti-P specificity, using papain-treated O blood group erythrocytes. The serum-mediated hemagglutination and the serum and complement-mediated immunohemolysis were inhibited by globoside (P antigen GalNAcβ1-3Galα1-4Galβ1-4Glc-ceramide) and Forssman glycosphingolipid (GalNAcα1-3GalNAcβ1-3Galα1-4Galβ1-4Glc-ceramide). Therefore, we concluded that she had PCH. She was completely cured 6 months later.