Abstract
KMT2A partial tandem duplication (KMT2A-PTD) is a recurrent genetic alteration in acute myeloid leukemia (AML), but its role as a measurable residual disease (MRD) marker before allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains unclear. We retrospectively analyzed 180 KMT2A-PTD AML patients undergoing allo-HSCT at Peking University People’s Hospital between 2015 and 2025. Pre-transplant KMT2A-PTD MRD was quantified by real-time quantitative PCR, with positivity defined as ≥1500 copies/10⁵ ABL1. Among 158 patients transplanted in complete remission (CR), 144 had pre-transplant MRD assessment, and 34 (24%) were MRDpositive. Compared with MRD-negative patients, MRD-positive patients had significantly inferior 3- year overall survival (OS, 49% vs. 80%; p