Possible prognostic impact of WT1 mRNA expression at day+30 after haploidentical peripheral blood stem cell transplantation with posttransplant cyclophosphamide for patients with myeloid neoplasm: a multicenter study from the Okayama Hematological Study Group

Background Previous studies have revealed that relapse of myeloid neoplasms after allogeneic hematopoietic stem cell transplantation (allo-HSCT) could be predicted by monitoring Wilms' tumor 1 (WT1) mRNA expression. However, only a few studies have investigated patients who received human leukocyte antigen-haploidentical stem cell transplantation with posttransplant cyclophosphamide (PTCY-haplo). In this study, we investigated the relationship between WT1 mRNA levels and clinical outcomes in the PTCY-haplo group, and compared them with those in the conventional graft-versus-host disease prophylaxis group (conventional group). Methods We retrospectively analyzed 130 patients who received their first allo-HSCT between April 2017 and December 2020, including 26 who received PTCY-haplo. Results The WT1 mRNA expression level at day + 30 after allo-HSCT associated with increased risk of 1-year cumulative incidence of relapse (CIR) was >= 78 copies/mu g RNA in the conventional group (p < 0.01) and >= 50 copies/mu g RNA in the PTCY-haplo group (p = 0.03). Conclusions The appropriate cutoff level of WT1 mRNA at day + 30 after allo-HSCT for predicting prognosis in patients treated with PTCY-haplo may be < 50 copies/mu g RNA.

Automated summary

This study investigated the relationship between WT1 mRNA levels and clinical outcomes in patients treated with PTCY-haplo, and found that the WT1 mRNA level at day +30 after allo-HSCT is associated with increased risk of relapse. The appropriate cutoff level for predicting prognosis in PTCY-haplo patients may be <50 copies/μg RNA.