Normal values of immunoglobulins in premature and in full-term infants, calculated as percentiles.

Immunoglobulin values were determined in carefully selected healthy, normal children of different gestational and chronological ages. Criteria for "normality" were eutrophy (length, weight, head circumference) and absence of obvious malformation, infection or other disease. Immunoglobulin concentrations were measured in radial immunodiffusion, calibrated by a standard serum according to WHO recommendations.