Hematopoietic cell transplantation in pediatric EB virus-associated hemophagocytic lymphohistiocytosis.

Background: Few reports exist on the transplant outcomes of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). This nationwide survey evaluated the clinical outcomes of pediatric patients with EBV-HLH who underwent allogeneic HCT.

Methods: Data from 32 pediatric patients with EBV-HLH who underwent their first allogeneic HCT between 2000 and 2020 were reviewed retrospectively.

Results: Of the 32 patients, 12 had a performance status of 3-4 and 8 had multiple organ dysfunction. The cumulative incidence of engraftment on day 30 was 53.1% (95% confidence interval [CI] 34.1-68.9). The 1-year overall survival (OS) rate of the entire cohort was 56.2% (37.6-71.3). Univariate analysis revealed that poor ECOG-PS at HCT and a reduced-intensity conditioning regimen were significant risk factors for OS. Furthermore, multivariate analysis revealed that only ECOG-PS was a significant risk factor for OS. Sixteen of the 32 (50.0%) patients died after HCT, and the main causes of death were HLH progression (n = 12) and infection (n = 2). Most notably, 12 of the 13 patients with primary graft failure died of HLH.

Conclusion: Good general condition prior to HCT, which is typically achieved through optimal disease control, is essential for stable engraftment and long-term survival following allogeneic HCT.