Post-transplant ferritin level predicts outcomes after allogeneic hematopoietic stem cell transplant, independent from pre-transplant ferritin level

Allogeneic hematopoietic stem cell transplantation (HCT) is associated with significant morbidity and mortality. Elevated pre-transplant ferritin level (ferritin^Pre-HCT) is reported to be associated with increased mortality following HCT. The present study attempted to determine whether post-transplant ferritin level (ferritin^Post-HCT) is associated with outcomes post-HCT, especially in the subgroups which developed acute or chronic graft-versus-host disease (GVHD). Out of 229 patients with serum ferritin level measured post-HCT, median ferritin^Post-HCT was 2178 ng/mL. Patients were stratified into low- or high-risk groups using recursive partitioning, based on ferritin^Post-HCT (≤ 3169 vs > 3169 ng/mL) and ferritin^Pre-HCT (≤ 669 vs > 669 ng/mL). Compared to the low ferritin^Post-HCT group, the high ferritin^Post-HCT group had lower 3-year overall survival (OS) (40.0% vs 66.7%, p < 0.001) and higher non-relapse mortality (NRM) (48.6% vs 17.8%, p < 0.001), but no difference in relapse (10.5% vs 19.7%, p = 0.079). Multivariate analysis confirmed ferritin^Post-HCT as an independent prognostic factor for OS (p = 0.001, HR = 2.323) and NRM (p < 0.001, HR = 3.905). However, ferritin^Pre-HCT did not stratify well for OS or NRM. Ferritin^Post-HCT was also found to be an independent prognostic marker for OS and NRM in the subgroups which developed GVHD. In our cohort, high ferritin^Post-HCT levels were significantly associated with decreased OS and increased NRM independent of ferritin^Pre-HCT or GVHD. Additional studies including larger sample sizes and prospective investigation are warranted to clarify the prognostic significance and pathophysiology of pre- and post-transplant hyperferritinemia.