Association of EASIX Score with Non-relapse Mortality and Overall Survival in Pediatric Acute Leukemia Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation.

Allogeneic hematopoietic stem cell transplantation (HSCT) for pediatric acute leukemia is limited by non-relapse mortality (NRM) and relapse. This study evaluated whether the endothelial activation and stress index (EASIX) score-calculated with the formula [lactate dehydrogenase (LDH; U/L) × serum creatinine (mg/dL)]/platelets (10/L)]-could be associated with NRM and overall survival (OS). We analyzed 195 patients (< 25 years) with acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML) who underwent first-time peripheral blood HSCT at a single center between 2014 and 2022. The EASIX score was assessed pre-transplant (EASIX.PRE) and on day + 7 post-transplant (EASIX.POST). Cutoff values for EASIX.PRE (0.836) and EASIX.POST (1.632) were established using receiver operating characteristic (ROC) curves. Patients with EASIX.PRE scores below the cutoff exhibited significantly improved 12-month OS (84.67% vs. 66.12%, P = 0.028). Multivariable analysis confirmed that an EASIX.PRE score above the cutoff was an independent prognostic factor for inferior OS (HR = 1.83, P = 0.039). Similarly, patients with an EASIX.POST score below the cutoff showed a higher 12-month OS rate (87.78% vs. 72.65%, P = 0.046). However, in multivariable analysis, an EASIX.POST score above the cutoff did not demonstrate a significant relationship with reduced OS. Neither EASIX.PRE nor EASIX.POST score was independently associated with NRM, relapse, graft-versus-host disease (GvHD), leukemia-free survival (LFS), or GvHD-free, relapse-free survival (GRFS). This study highlights the prognostic utility of EASIX.PRE for OS in pediatric HSCT recipients but underscores its limited role in predicting NRM or GvHD. Further studies with larger cohorts and dynamic EASIX assessments are required to confirm these findings and refine risk stratification in pediatric HSCT.