Prognostic effect of blood transfusion in children with acute lymphoblastic leukemia.

backgroundMost children with acute lymphoblastic leukemia (ALL) receive blood transfusions. Transfusions may affect ALL outcomes through transfusion-related immunomodulation (TRIM).

methodsWe analyzed overall survival (OS) and event-free survival (EFS) in relation to leukocyte reduced and irradiated (LR/IRR) blood products transfused during the induction phase in 136 children with ALL. Hazard ratios (HRs) for death and relapse were estimated through Cox regression analysis.

resultsOne hundred and twenty patients (89%) were transfused with packed red blood cells (PRBCs) and 79 (58%) with single donor platelets (SDPs). The median number of transfusions was 2 (interquartile range [IQR]=1-3 events) and 1 (IQR=0-3 events) for PRBCs and SDPs, respectively. Patients who had white blood cell (WBC) count >50,000×10(9)/L, were classified as high risk according to the high National Cancer Institute criteria, displayed a T cell phenotype, or were minimal residual disease-positive at end of induction were more likely to receive >3 transfusions during induction (P=0.001, 0.002, 0.03, and 0.01, respectively). In univariate analysis, PRBC, SDP, and fresh frozen plasma transfusions did not have any significant association with relapse or death. For PRBC transfusions, the HRs for EFS and OS were 1.02 (95% CI, 0.85-1.24; P=0. 76) and 1.03 (95% CI, 0.83-1.27; P=0.76), respectively. For SDP transfusions, HRs were 1.03 (95% CI, 0.90-1.18; P=0.64) and 0.98 (95% CI, 0.80-1.20; P=0.87) for EFS and OS, respectively.

conclusionLR/IRR blood products may not confer a TRIM effect in childhood ALL and are unlikely to affect outcome.