This study was undertaken to document the incidence of immediate, nonhemolytic
transfusion reactions and to identify a technique or set of techniques that would best
identify the different causes of these reactions. A variety of tests were employed to detect
lymphocyte, granulocyte, platelet and anti-IgA antibodies. During this study 26,318 units of
blood components were transfused on 5,030 occasions. 191 immediate, nonhemolytic reactions
were experienced giving an incidence per unit of 0.73%. Blood specimens from 101 of
these patients were investigated along with serum from 57 patients who showed no reaction
to transfusion as controls. We show that standard B cell lymphocytotoxicity testing is the
technique with which most antibodies can be detected (64% of reactors positive vs. 30% of
controls, p< 0.001). Additional tests did not significantly increase the level of antibody
detection.