HUMAN BLOOD-GROUP A-SPECIFIED AND H-SPECIFIED GLYCOSYLTRANSFERASE LEVELS IN SERA OF NEWBORN-INFANTS AND THEIR MOTHERS

Abstract. The level of blood‐group A1‐specified α, 3′‐N‐acetyl‐D‐gaIactosaminyl‐transferase in the serum of recently‐delivered women was found to be appreciably lower than the level of this enzyme in the serum of non‐pregnant adults and of newborn infants; a similar but less striking decrease was observed in the levels of the A2‐specified α, 3′‐N‐acetyl‐D‐galactosaminyl‐transferase and the H‐specified α, 2′‐L‐fucosyltransferase. Although the red cells of newborn infants are known to have relatively few A and H antigen sites, the serum of neonates was found to have a level of A1‐ and A2‐dependent N‐acetylgalactosaminyltransferases and H‐dependent fucosyltransferase as high as, if not higher than, the serum of non‐pregnant adults. This finding is compatible with the fact that the haemopoietic tissue contributes only about 20% of the serum transferase level. © 1978 Blackwell Publishing Ltd