Transient hypogammaglobulinemia of infancy: clinical and immunologic features of 40 new cases.

Background: Transient hypogammaglobulinemia of infancy (THI) results from a delay in the maturation of immunoglobulin production.
Methods: The clinical and immunologic data of 40 patients with THI are presented. Clinically, the majority of patients presented with recurrent respiratory infections and otitis media, bronchitis and/or bronchial asthma and recurrent gastroenteritis.
Results: Ten of 40 children had isolated low IgG; isolated low IgA and isolated low IgM were detected in one and three patients, respectively. At initial evaluation, levels of all three immunoglobluins were low in nine patients. Ten patients had diminished IgG and IgA levels, six had diminished IgA and IgM levels and one had low IgG and IgM levels. Two patients were given intravenous immunoglobulin replacement therapy for 1 year. None of the patients has experienced serious infections during their follow-up period.
Conclusions: Prospective evaluation of patients (age range 5-60 months) revealed that immunoglobulin levels in 33 patients recovered before 36 months of age. Seven patients still had low immunoglobluin levels at 40-57 months of age. Three of these patients had low levels of both IgG and IgA, while two patients had low IgM levels and a further two patients had low IgA levels.