Relationship Between I and II Antigens. II. Study of the II and I Deficient Phenotypes

H and I substances are present in the plasma and the saliva. In the plasma there is no quantitative relationship between H and I substances, whereas in the saliva only non-secretors produce I substance [shown by anti-IS serum, (Sti.)]. The study of I and H substances in the plasma and the saliva of H and I deficient subjects gives a better understanding and enables the completion of the classification of these rare phenotypes. The results also allow the proposal of a synthetic scheme of IS and H substances in the saliva.