Gammaglobulin treatment and anti-IgA antibodies in IgA-deficient patients.

Antibodies to IgA may cause severe anaphylactic reactions during blood transfusions. Tests for anti-IgA antibodies were carried out on six patients with IgA deficiency (five of whom also had hypogammaglobulinaemia) who had received continuous gammaglobullin treatment for chronic or recurrent infections for three to eight years. Three patients had minute amounts of IgA, and three had none (less than 0.01 microgram/ml). Only one patient had anti-IgA. Her antibody titre did not change during treatment. No patient had any untoward effects of treatment, which relieved the symptoms of infection in every case. IgA determinations should be performed by more accurate methods than radial immunodiffusion when evaluating the risks of giving gammaglobulin to patients with hypogammaglobulinaemia and IgA deficiency. Probably the stimulus provided by intramuscular gammaglobulin in such patients is insufficient for the formation of anti-IgA antibody.