SERUM IMMUNOGLOBULINS: I. LEVELS IN NORMAL CHILDREN AND IN UNCOMPLICATED CHILDHOOD ALLERGY

In 201 normal individuals from infancy to adulthood, serum concentrations of immunoglobulins G, A, and M are presented as geometric mean values (mg/l00 ml) and as percents of adult mean values for each of these proteins. A statistical analysis revealed a significant relationship between age and both IgG and IgA concentrations up to ages 6 and 7 years. No correlation was present between age and immunoglobulin concentrations beyond that time, suggesting that the adult concentrations of IgG and IgA are normally reached and maintained after ages 6 and 7 years. In contrast, analysis of the IgM data suggested that the adult value is reached by age 1 year. No truly significant differences were found in immunoglobulin concentrations which could be attributed to sex. Significantly higher concentrations of IgG were found in normal Negro than in normal Caucasian subjects after age 6 years, but no significant differences were found below this age for IgG or at any age for IgA and IgM. Similarly determined serum immunoglobulins in 85 allergic children, selected because they had no complicating illnesses, were compared with the normal group according to the age of the child. No significant differences were found in concentrations of either IgG or IgA. Some differences were found in IgM, but these were small and were primarily associated with the relationship of IgM to age in the allergic group.