Transient hypogammaglobulinemia of infancy is a temporary decrease in serum IgG and sometimes IgA and other immunoglobulin (Ig) isotypes to levels below age-appropriate normal values.
(See also Overview of Immunodeficiency Disorders and Approach to the Patient With an Immunodeficiency Disorder.)
Transient hypogammaglobulinemia of infancy is a primary immunodeficiency disorder that involves humoral immunity deficiencies. In this disorder, IgG levels continue to be low after the physiologic fall in maternal IgG at about age 3 to 6 months. The cause and inheritance patterns are unknown.
The condition rarely leads to significant infections and is not thought to be a true immunodeficiency. The condition is usually asymptomatic. However, a few patients develop sinopulmonary or gastrointestinal infections, candidiasis, and/or meningitis.
Diagnosis of transient hypogammaglobulinemia is based on low serum Ig levels (at least 2 standard deviations below the mean for age) and tests showing that antibody production in response to vaccine antigens (eg, tetanus, diphtheria) is normal. Thus, this condition can be distinguished from permanent forms of hypogammaglobulinemia, in which specific antibodies to vaccine antigens are not produced.
Patients with recurrent infections can be temporarily treated with prophylactic antibiotics. Immune globulin is usually unnecessary.
Transient hypogammaglobulinemia of infancy may persist for months to a few years but usually resolves.
