WBC-reduced blood transfusions and clinical outcome in children with acute lymphoid leukemia

BACKGROUND: WBC reduction offers a variety of benefits to patients requiring multiple transfusions during induction therapy for childhood acute lymphoid leukemia (ALL), including reductions in febrile transfusion reactions, HLA alloimmunization, and CMV transmission. One potential benefit is a reduction in the deleterious effects of transfusion immunomodulation. In the surgical setting, transfusion immunomodulation has been linked to increases in postoperative infections and decreases in host cellular immunity that are mitigated by WBC reduction of transfused blood. STUDY DESIGN AND METHODS: A retrospective review was conducted of the medical records of 68 consecutive children undergoing induction therapy for newly diagnosed ALL from 1988 through 1995, a period whose midpoint is 1991, the year WBC reduction was introduced in this hospital. RESULTS: WBC reduction of platelet and RBC transfusions was associated with fewer days with fever (mean, 5.7 days [no WBC reduction] and 2.1 days [WBC reduction]; p = 0.012) and days with positive microbial cultures (mean, 1.5 [no WBC reduction] and 0.71 [WBC reduction]; p = 0.0055). There were more high-risk ALL patients in the group receiving WBC-reduced transfusions. CONCLUSION: Allogeneic WBCs in transfused blood may cause impairment of host defenses against microbial infection during induction therapy for childhood ALL.