STUDIES ON IGA CLASS CIRCULATORY RED-CELL ANTIBODIES .1. PREPARATION AND IDENTIFICATION OF IGA CLASS ANTI-A, ANTI-B

To elucidate the role of IgA class alloantibodies in transfusion pract ice, anti-A, anti-B was prepared using pooled serum from healthy group O donors. IgG was removed by protein A and protein G, whilst IgM was extracted by concanavalin A and anti-human mu chain. The final prepara tion contained both IgA1 and IgA2; it had an IgA concentration similar to the original serum pool and an environment as near to normal as po ssible; the absence of IgG and IgM was confirmed by sensitive enzyme-l inked antiglobulin tests, and extensive haemagglutination studies show ed that anti-A, anti-B was the only red cell anti-body present.