Anti-IgA antibody associated reactions to intravenous gammaglobulin in a patient who tolerated intramuscular gammaglobulin.

A patient with common variable immunodeficiency syndrome tolerated intramuscular IgG (which contains IgA) and an initial infusion with intravenous (IV) IgG, but developed reactions to subsequent IV IgG. High-titre, class-specific anti-IgA antibodies were detected suggesting immunization by the IgA-contaminated IV immunoglobulin. Subsequent IgG replacement was achieved with IgA-deficient plasma infusions. Patients who tolerate intramuscular IgG may not tolerate the IV preparations.