MEASURING H-TYPE-1 AND H-TYPE-2 ANTIGENS IN HUMAN SALIVA BY IMMUNOASSAY USING ARTIFICIAL ANTIGENS AS STANDARD SUBSTANCES

A time-resolved fluorometric immunoassay for water-soluble H antigens of ABH blood group substances has been developed. Introducing artifici al antigens (trisaccharide-albumin complexes for H type 1 and H type 2 ) as reference substances, H blood group substances in human saliva we re measured. The monoclonal antibody, anti-H 1E3, reacted with both H type 1 and type 2 chains, and the commercially available anti-H reacte d with H type 2 chain. Using these two antibodies we found 10-20-fold higher concentration of H type 1 compared with that of H type 2 in hum an saliva. The H type 2 was not found in the saliva samples from nonse cretors, irrespective of ABO phenotypes. The results suggest that simi lar to 90% of A and B blood group substances in human saliva are built on type 1 chains.