Relapse remains the leading cause of treatment failure after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute myeloid leukemia (AML). Early identification of patients at increased post-transplant relapse risk is essential to enable intensified surveillance and pre-emptive therapeutic strategies. Wilms’ tumor 1 (WT1) is overexpressed in most AML cases and represents a broadly applicable molecular marker; however, its utility as a peripheral blood (PB) measurable residual disease (MRD) marker after allo-HSCT remains incompletely defined. In this prospective multicenter cohort study, 43 adults with AML in complete remission underwent allo-HSCT between 2021 and 2023. WT1 expression in PB was quantified using standardized real-time quantitative PCR before transplantation (WT1ₚre) and at day +30 (WT1₃0). Receiver operating characteristic analysis identified an optimal threshold for relapse prediction. A WT1 cutoff of ≥3 copies/104 ABL discriminated relapse risk. WT1₃0 demonstrated strong prognostic performance (AUC 0. 79; p = 0. 005), whereas WT1ₚre showed more modest predictive value (AUC 0. 69; p = 0. 037). Patients with WT1₃0 ≥ 3 had inferior 12-month progression-free survival compared with those with WT1₃0 < 3 (52. 9% vs. 90. 9%, p = 0. 0059) and a higher 12-month cumulative incidence of relapse (31% vs. 9%, p = 0. 054). WT1ₚre ≥ 3 was also associated with inferior progression-free and overall survival (both p = 0. 0008). Relapsed patients had significantly higher WT1₃0 levels than non-relapsed patients (median 5. 0 vs. 2. 0 copies/104 ABL; p = 0. 018). Peripheral blood WT1 expression, particularly at day +30, is associated with an increased relapse risk after allo-HSCT in AML and may support early post-transplant risk stratification. The identified cutoff should be considered exploratory and requires validation in larger independent cohorts.
Blaslov et al. (Thu,) studied this question.