Impact of Oral Eicosapentaenoic Acid on Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome Onset Prevention: Single-Center Retrospective Analysis.

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a serious complication associated with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although ursodeoxycholic acid and defibrotide can reduce the risk of VOD/SOS, preventive efforts remain insufficient. In 2009, we began prescribing oral eicosapentaenoic acid (EPA) to mitigate post-transplant complications. Notably, no patients receiving EPA developed VOD/SOS. In this retrospective study, we analyzed 138 transplants from 123 patients who underwent allo-HSCT at Ehime University Hospital between April 2008 and June 2024. Ninety-one patients received EPA after allo-HSCT (EPA group), while 47 patients did not (no-EPA group). EPA was administered at a dose of 1800 mg/d, divided into 2 or 3 doses. All patients were taking ursodeoxycholic acid. VOD/SOS occurred in 3 patients in the no-EPA group (6.5%) and in none of the EPA group (P = 0.014). Early post-transplant mortality within 100 d did not differ significantly between groups. Although causal inference is limited by the retrospective design of the study, our findings suggest that EPA use may be associated with a lower incidence of VOD/SOS. These findings warrant prospective, multicenter trials to determine whether EPA can improve transplant outcomes by reducing the incidence of VOD/SOS.