IgA in commercial gamma-globulin preparations.

The presence of anti-IgA has been related to adverse reactions to injection or infusion of IgA-containing material. In this study IgA was demonstrated in all of the investigated commercial gamma-globulin preparations. In the material from a few producers it was, however, very low. By immuno-gel filtration it could be shown that the IgA consisted of aggregates as well as a 7S component and fragments. By immunoelectrophoresis-immunofluorescence IgG-IgA complexes could also be detected. The IgA aggregates could be almost completely degraded by reduction-alkylation. It is implied that such changed IgA in gamma-globulin preparations for injection may increase the risk of immunization against IgA.