The IgG and IgA concentrations in children show a gradual rise with increasing age. The IgA level is generally about the same in both sexes. Girls typically have higher IgM and IgG levels than boys.
The confidence interval bounded by two standard deviations about the mean excludes 5% of apparently healthy controls.
Elevated IgM, low IgA, low IgG, low IgM, and elevated IgA are the commonest changes observed in apparently healthy humans.
Humoral immunodeficiency is commonly defined as IgG, IgM or IgA level that is two standard deviations (2 SD) below the mean level for IgG, IgM or IgA, respectively, for the particular age group and gender.
Serum levels of IgM, IgG and IgA. Source: Pediatrics, 1966 and Immunologic disorders in infants and children, by E. Richard Stiehm, Hans D. Ochs, Jerry A. Winkelstein.
Typical pattern of immunoglobulin levels (IgG, IgA, IgM) in humoral immunodeficiency. Click here to enlarge the table.
Serum immunoglobulin levels in healthy children and adults. J. W. Stoop, B. J. M. Zegers, P. C. Sander, and R. E. Ballieux. Clin Exp Immunol. 1969 January; 4(1): 101–112.
The relationship of race, sex, and age to concentrations of serum immunoglobulins expressed in international units in healthy adults in the USA. S. E. Maddison, C. C. Stewart, C. E. Farshy, and C. B. Reimer. Bull World Health Organ. 1975; 52(2): 179–185.
Serum immunoglobulin concentrations in preschool children measured by laser nephelometry: reference ranges for IgG, IgA, IgM. D Isaacs, D G Altman, C E Tidmarsh, H B Valman, and A D Webster. J Clin Pathol. 1983 October; 36(10): 1193–1196.
D Isaacs, A D Webster, and H B Valman. Clin Exp Immunol. 1984 November; 58(2): 335–340.
Serum Immunoglobulin Levels Throughout the Life-Span of Healthy Man. Ann of Int Med, November 1, 1971, Vol. 75 no. 5 673-682.