Is the Number of Blood Products Transfused Associated With Lower Survival in Children With Acute Lymphoblastic Leukemia?

Background. Blood transfusion during acute lymphoblastic leukemia (ALL) of childhood is scarcely documented. Children with ALL are immunosuppressed by both the disease and its therapy. Transfusion may contribute to the course of ALL through its transfusion-related immunomodulation (TRIM) effect. Procedure. Blood transfusion history and response to therapy for 108 children <16 years of age at the time of ALL diagnosis was documented. Clinical files, electronic records, and blood bank registries were scrutinized. Overall survival (OS) and event-free survival (EFS) in relation to blood product type and number of transfusions was determined. Hazard ratios (HR) for death and relapse were estimated through uni- and multivariate Cox regression analysis. Results. One hundred eight ALL patients were included. Median age was 6 years (range: 0-15 years). Ninety-seven patients (89.8%) were transfused. Median number of transfused products was seven (range: 0-345). After multivariate analysis, transfusion of >5 packed red blood cells (PRBC) remained a significant predictor for death (P = 0.003) and relapse (P = 0.011). For platelets, maximal significance was observed when >30 platelet concentrates (PC) were transfused (P < 0.001). When both, PRBC and PC were considered, maximal significance for predicting death was observed with transfusion of >30 blood products (P < 0.001). Conclusions. The number of blood products transfused to children with ALL appears to be significantly associated with lower survival rates. This may reflect both the severity of the disease and the TRIM effect, which may decrease immune surveillance capacity and the probability of leukemic clone eradication. Pediatr Blood Cancer 2011; 57: 217-223. (C) 2011 Wiley-Liss, Inc.