Early Post-Transplantation Serum Ferritin Level Predicts Survival in Recipients of Haploidentical Stem Cell Transplantation Using Post-Transplantation Cyclophosphamide as Graft-versus-Host Disease Prophylaxis

Abstract

The negative impact of high serum ferritin level (SFL) before and after allogeneic hematopoietic cell transplantation (allo-HSCT) on outcomes is well recognized. However, it is poorly documented in adults undergoing haploidentical HSCT (haplo-HSCT) with post-transplantation cyclophosphamide (PTCY) for hematologic malignancies. The main objective was to assess the impact of pretransplantation and post-transplantation SFL on overall survival (OS), disease-free survival (DFS), and nonrelapse mortality (NRM) in patients undergoing haplo-HSCT with PTCY. The secondary objective was to identify factors associated with outcomes after transplantation by comparing SFL with other parameters related to the status of patients or donors. This multicentric retrospective study included 223 consecutive patients who underwent haplo-HSCT with PTCY in 4 French centers (Nantes, Angers, Besançon, and Brest) between October 2013 and January 2020. The impact of SFL on OS, DFS, and NRM at different time points was assessed based on receiver operating characteristic curves. With a median follow-up of 37.6 months (interquartile range, 23.5 to 51.0 months), 3-year OS, DFS, and NRM were 48.1 ± 4%, 46.3 ± 4%, and 30.0 ± 3%, respectively. Pretransplantation SFL had no impact on outcomes irrespective of the cutoff tested. Considering patients alive at 3 months post-transplantation, an SFL ≥3500 µg/L at 3 months was statistically significantly associated with worse 3-year OS (32.7 ± 8.7% versus 53.4 ± 7.2%; P = .01) and DFS (30.1 ± 8.2% versus 53.1 ± 7.1%; P = .008), with a trend toward higher NRM (33.2 ± 8.6% versus 17.6 ± 5.4%; P = .10). Similarly, high SFL (≥2700 µg/L) at 6 months post-transplantation was associated with worse 3-year OS (56.1 ± 9.1% versus 79.2 ± 6.0%; P = .02) and DFS (53.6 ± 8.7% versus 74.9 ± 6.2%; P = .01), with a trend toward higher NRM (21.4 ± 7.4% versus 8.2 ± 4.0%; P = .10). In multivariate analysis, high 3-month and 6-month FL remained associated with lower OS and DFS, with a trend toward higher NRM. Pretransplantation SFL appears to have no impact on outcomes in haplo-HSCT with PTCY, in contrast to what is documented in the matched allo-HSCT setting. In contrast, in the haplo-HSCT setting, high SFL early post-transplantation is associated with lower survival and a trend toward higher NRM.

Keywords: Age; Allogeneic hematopoietic stem cell transplantation; Disease Risk Index; Ferritin; Haploidentical; Post-transplantation cyclophosphamide.