Transfusion reactions in patients with cancer.

In general, the true incidence of transfusion reactions is difficult to determine with certainty. In patients with cancer, it becomes even more complex to define. During a four-year study period in which 100,177 units of red blood cell transfusions were given to 25,744 cancer patients, 245 episodes of transfusion reactions were reported. The incidence of overall reaction was 0.3% of all transfused units, which is significantly lower than other studies. Febrile nonhemolytic reactions and allergic urticarial reactions were the most frequently noted, constituting 51.3% and 36.7%, respectively, of total reactions. There were only 17 hemolytic reactions (four immediate and 13 delayed-type). The incidence of delayed hemolytic reactions in cancer patients is significantly lower than that reported for patients in non-oncology hospital settings. This could result from the inability of cancer patients to produce alloantibodies against blood group antigens as frequently and efficiently as can those with non-neoplastic conditions.