Association between the pre-transplantation serum ferritin level and outcomes of hematopoietic stem cell transplantation: A systematic review and meta-analysis.

Background: Iron overload, as indicated by evaluated serum ferritin (SF) level, occurs commonly in patients with hematological diseases. To evaluate the association between pre-transplant SF level and outcomes of hematopoietic stem cell transplantation (HSCT), we performed this systematic review and meta-analysis.

Methods: PubMed, Embase, Web of Science and the Cochrane Library electronic database were searched from inception to August 2023, and 56 studies with 14149 patients were found to be eligible.

Results: An elevated pre-transplantation SF level was associated with inferior overall survival (hazard ratio [HR],1.77; 95 % confidence interval [CI],1.61-1.96) and disease-free survival (HR, 1.86; 95 % CI, 1.58-2.19), and increased risk of non-relapse mortality (HR, 1.73; 95 % CI, 1.49-2.02), and relapse (HR, 1.46; 95 % CI, 1.29-1.65). However, no meaningful association was observed between SF levels and acute graft-versus-host disease (GVHD) (risk ratio [RR], 1.09; 95 % CI, 0.96-1.24), or chronic GVHD (RR, 0.95; 95 % CI, 0.79-1.16). Furthermore, an elevated pre-transplantation SF level was associated with a higher risk of fungal infection (RR, 1.56; 95 % CI, 1.16-2.10), but not with bacterial infection (RR, 1.09; 95 % CI, 0.80-1.50). Moreover, an elevated pre-transplantation SF level was related to a higher risk of death due to relapse/disease progression (RR, 1.72; 95 % CI, 1.33-2.23) and infection (RR, 2.21; 95 % CI, 1.55-3.15), but not death due to GVHD (RR, 1.18; 95 % CI, 0.79-1.77).

Conclusions: A higher pre-transplantation SF level was significantly associated with a higher risk of relapse/disease progression and infections, which contributed to worse survival in patients undergoing HSCT. In particular, a higher SF level was related to a higher risk of fungal infection, indicating that patients with a higher pre-transplantation SF level require more attention regarding the risk of fungal infection after HSCT.