Perinatal expression of the Lewis and secretor blood group systems

摘要

Studies on expression at birth and on maturation of the secretor and Lewis blood group systems, as manifest on red cells and in saliva, have been carried out on a series of infants using three Lewis reagents: anti-Lea,-Leb and -Lex.Among adults, 20% are Lewis red cell type Le(a+b+?x+) and 70% are Le(a?b+x+); both types are essentially absent at birth. A third type Le(a?b?x?) is found in both 10% of adults and in 10% of infants: 90% of newborn infants, however, have the unique type Le(a?b?x?+). Infants of the latter type undergo a rapid maturation during the first week of life of the adult Le(a+b?x+) type. Then, if they are salivary non secretors of ABH, they remain that type throughout life. Whereas those who are secretors evolve during the ensuing four months to Le(a+b+x+) which is also a type practically unique to infancy; finally, by two years of age, they evolve to the most common adult type, Le(a?b+x+).Salivary phenotypic expression of the genes involved in the above red cell types is found in soluble form but the state of development at birth is more advanced than on the red cell and the subsequent maturation is more rapid. Prematures show a relatively delayed maturation in the expression of these genes. Thus, unlike other blood group systems, the Lewis system is unique in infancy; it shows differential tissue expressivity and, with growth and development, undergoes a systematic pattern of distinct qualitative changes.The biological significance of the phenotypic expression of this blood group system during fetal life and of its well organized maturation process during early infancy remains obscure.