Serologic Specificity of Human Anti-IgA and its Significance in Transfusion

Abstract

Abstract Anti-IgA antibodies detected by a passive hemagglutination assay are either specific for the IgA class or they are of limited specificity. Persons lacking IgA can produce class-specific anti-IgA as a result of parenteral exposure to incompatible IgA globulin in blood and its components. In contrast, persons with normal levels of IgA may produce anti-IgA of limited specificity. Either type of anti-IgA antibodies was present in 86 per cent of anaphylactoid and urticarial transfusion reactions. A majority of these antibodies are of the IgG class.