Evolution of IgA deficiency to IgG subclass deficiency and common variable immunodeficiency.

FIRST REPORT: male child with repeated pulmonary infections from the age of 4 months. He was diagnosed as IgA deficiency (undetectable IgA levels) at the age of 3 years, when he presented repeated bouts of pneumonia and tonsillitis. Several immunologic evaluations were made between the ages of 4 months and 8 years. At 8 years and 9 months, the diagnosis of IgA deficiency was confirmed, and associated IgG2 and IgG4 deficiency (29.0 mg/dl y 0.01 mg/dl) with normal total IgG serum level was found. With the administration of intravenous gammaglobulin, the lung infections remitted and the subsequent clinical course has been uneventful up to now. SECOND REPORT: a boy with repeated infections since the age of 2 months. IgA deficiency was diagnosed at 1 year 7 months (undetectable serum IgA levels). At age 51/2 years, his clinical course worsened and more serious infections appeared. A new immunologic study revealed IgA deficiency associated with CD4 cell deficiency (432 cells/mm3) and normal CD3, CD19, and CD8 levels. Despite intensive antibiotic treatment and care, the child died. The findings suggest an association of IgA deficiency and common variable immunodeficiency.