Decreased production of specific antibodies to cow's milk proteins in premature infants during the first six months of life.

Concentrations of IgG and IgM antibodies to casein, beta-lactoglobulin, lactalbumin and bovine serum albumin (BSA) in sera of premature infants of less than 36 weeks gestation, at 5 weeks of age, were less than in age-matched term infants. At 6 months of age IgG antibodies to BSA in preterms were still significantly lower than in term infants.