Significance of the Presence of Lewis Substances in Serum during Infancy

Abstract

IT has been found that infants who develop into adults with the following phenotype: red cells Le (a − b +), ABH secretor, Les (a + b +)^*, go through a phase in which the red-cell phenotype is Le (a + b +), and the secretions, as in the adult, contain ABH, Le^a and Le^b. We have been able to establish that during the phase in which Le^a substance is detectable on the red cells of these infants, it is also detectable in their serum. In the adult with Le (a − b +) red cells, although Le^b substance is present in serum, Le^a substance is not detectable although it is found in the water-soluble secretions. Our observations are summarized in Table 1.