Anti-IgA antibodies in two brothers with selective serum IgA deficiency

A selective serum IgA deficiency with anti-IgA antibodies at high titer were found in a patient who suffered severe transfusion reactions. The same abnormalities were detected in his brother, a 72-year-old-man in good general condition. Anti-IgA antibodies were found in the IgG fraction and were directed against alpha-chains. A deficiency of isoagglutinins and an absence of heteroagglutinins in the propositus' serum could be shown.