Relationship Between I and H Antigens

Abstract

The H and I antigens were studied in the plasma and saliva of 52 group O [human] subjects, by hemagglutination inhibition at continuous flow. H plasma substance was detected with 1 anti-H antibody from a Bh donor. Secretors have more H plasma substance than do non-secretors, but there was no relationship between the amounts of I and H substances in the plasma. The amounts of I substance in the saliva detected by anti-I (Sti) is a function of secretor status. Nonsecretors had a much greater amount of I in saliva than did secretors. I antigen (detected by anti-I (Sti)) is a part of the substrate of H antigen.