Group-specific component in neonatal breast secretion: relationship to the cellular content

Group-specific component (Gc) and total albumin concentrations in the breast secretions from 20 full-term infants were measured. The Gc concentrations as well as the albumin concentrations correlated significantly (p less than 0.02) with the total cell count and the absolute concentration of each white blood cell type in the breast fluid. The ratio of albumin in neonatal breast secretion to that in neonatal serum was similar to the comparable ratio for Gc. Since albumin and Gc are of similar molecular size, these observations suggest leakage of these two proteins from serum to breast secretion and a possible chemotactic relationship between these proteins and the mononuclear cells in neonatal milk.