DIRECT IDENTIFICATION OF UNEXPECTED SERUM ANTIBODIES AGAINST RED-CELLANTIGENS

A new method to detect the identity of unexpected antibodies ill the s era of prospective transfusion recipients is presented. The method is based on a macroscopic hemagglutination inhibition assay. In this assa y, incubation of phenotypically defined test red blood cells with pati ent sera containing non-agglutinating antibodies to one or more specif ic antigen systems block monoclonal IgM induction of red cell agglutin ation. Since the specificities of the IgM antibodies are known, the id entity of the patient's antibody(ies) can be directly determined. This method, which uses only reagents that are commercially available, is specific and eliminates the use of the indirect antiglobulin test (IAT ) and the use of elimination panels.