Utility of Pediatric European Society for Blood and Marrow Transplantation Criteria as a Sensitive Tool for Identifying Pediatric Sinusoidal Obstruction Syndrome Associated With Nonrelapse Mortality: A Retrospective Single-Center Study

Sinusoidal obstruction syndrome (SOS) is a potentially fatal complication of hematopoietic stem cell transplantation (HSCT). Although SOS has traditionally been diagnosed using the Baltimore or modified Seattle criteria (conventional criteria), the European Society for Blood and Marrow Transplantation recently proposed diagnostic criteria for children (pEBMT). This study assessed how conventional and pEBMT criteria affect SOS incidence, severity, and outcomes. We retrospectively analyzed pediatric HSCT procedures conducted from 2007 to 2023. Out of 186 HSCT procedures, 36 met at least 1 SOS criterion. Of these, 30 met the pEBMT criteria, 16 met the conventional criteria, and 10 met both. Patients meeting either criterion had a significantly worse prognosis than those without SOS. All SOS cases with nonrelapse mortality (NRM) fulfilled the pEBMT criteria, and the cumulative incidence of NRM was higher in the pEBMT group than in the conventional group. Furthermore, even in all HSCT cases, the pEBMT criteria were associated with NRM and served as a risk factor. The finding that pEBMT may serve as a sensitive tool for predicting NRM is new and provides a noteworthy aspect of this study. Following the pEBMT criteria closely and initiating early treatment for SOS may help reduce NRM in affected patients.