Determination of Leukoagglutinin Specificity by In Vivo and In Vitro Studies

Results of testing sera from normal individuals and pathological patients, using a bromelin technique for the detection of leukoagglutinins, are reported. These results, supported further by an in vivo experiment, suggested that the phenomenon of leukoagglutination is immunologic in nature and that leukoagglutinins may be the cause of some febrile transfusion reactions. These are specifically directed against leukocytes, and do not involve the red cell series. Furthermore, the antigen (or antigens) is probably present in both the granulocytes and the mononuclear leukocytes. Anti-platelet antibodies could be presumed to be the cause of thrombocytopenia