Infants with low immunoglobulin levels: Isolated low IgA level vs other immunoglobulin abnormalities

Background The International Union of Immunological Societies defined transient hypogammaglobulinemia of infancy as decreased IgG and IgA levels. Some others, however, include decreased IgA level alone. We compared infants with decreased levels of IgG and IgA, all isotypes, and IgA alone. Objective To determine whether infants presenting with diminished IgA only differ clinically and in time of immunoglobulin recovery, from those with decreased levels of IgG and IgA, or of all major isotypes. Methods Eighty-seven term infants found to have immunoglobulin isotype(s) 2 or more SDs below mean, normal antibody response, intact cellular immunity, and absence of other immunodeficiency syndrome features were evaluated between January 1, 1977 and December 31, 2008. Infants had decreased IgA level (group 1, n = 43), decreased IgA and IgG levels (group 2, n = 39), or low IgA, IgG, and IgM levels (group 3, n = 5). Results Groups had similar histories. Immunoglobulins normalized in a similar percentage of all groups during infancy but earlier for group 1 (P = .005). Conclusion Little reason exists to separate infants with isolated decreased IgA levels from those with decreased levels of IgA and IgG or all isotypes.