Transfusion of frozen erythrocytes from a donor with sickle trait.

We describe a nonanaphylactic hemoglobinuric reaction caused by transfusion of frozen red cells, deglycerolyzed by standard technique, obtained from a donor with undiagnosed sickle trait. Although significant hemoglobinemia and hemoglobinuria were noted, the recipient experienced no adverse clinical reactions. The benign clinical course supports the hypothesis that red cell antigen-antibody complexes, rather than free hemoglobin or red cell stroma, are responsible for the life-threatening complications of acute hemolytic transfusion reactions. This report also emphasizes the importance of screening donors of red cells for cryopreservation for sickle trait and the necessity of modifying deglycerolization technique should it be necessary to freeze red cells with AS hemoglobin.