Growth factor-associated graft-versus-host disease and mortality 10 years after allogeneic bone marrow...

This study analysed the effects of growth factor on outcome after haematopoietic stem-cell transplantation (HSCT) with >9 years follow-up. Of 1887 adult patients with acute leukaemia who received bone marrow from human leucocyte antigen (HLA)-identical siblings and were treated with myeloablative conditioning, 459 (24%) were treated with growth factor. Growth factor hastened engraftment of neutrophils (P < 0·0001), but reduced platelet counts (P = 0·0002). Graft-versus-host disease (GVHD)-free survival (no acute GVHD grade II-IV or chronic GVHD) at 10 years was 12 ± 2% (±SE) in the growth factor group, as opposed to 17 ± 2% in the controls [hazard ratio (HR) 0·81, P = 0·001]. Similar differences in GVHD-free survival were seen in patients with or without conditioning with total body irradiation (TBI). Non-relapse mortality (NRM) was higher in the growth factor group irrespective of whether or not TBI conditioning was included [HR = 1·48; 95% confidence interval (CI): 1·15-1·9; P = 0·002; HR = 1·59; 95% CI: 1·07-2·37; P = 0·02, respectively]. Both groups had similar probabilities of leukaemic relapse (HR = 0·96; 95% CI: 0·78-1·18; P = 0·71). Leukaemia-free survival (LFS) at 10 years was 35 ± 2% in those receiving growth factor prophylaxis, as opposed to 44 ± 1% in the controls (HR = 0·70; 95% CI: 0·60-0·82; P = 0·00001). Prophylaxis with growth factor increases the risk of GVHD, does not affect relapse, increases NRM and reduces LFS > 10 years after HSCT, regardless of conditioning with TBI.