Beta2-microglobulin in human colostrum and milk: effect of breast feeding and physico-chemical characterization.

A statistically significant increase in beta2-microglobulin concentration in babies' sera after birth was accompanied by a decrease in beta2-microglobulin concentration in sera of nursing and non-nursing mothers; the amount by which babies' sera concentrations increased was not correlated with the decrease in serum or milk concentrations in their mothers. These results suggest that breast feeding does not affect the concentration of beta2-microglobulin in babies' sera. Furthermore, there was no relationship between serum beta2-microglobulin concentration of mothers and their babies at either point of observation. In all instances, however, the beta2-microglobulin concentration was significantly higher in infants' sera than in mothers' sera.