Early eosinophilia after hematopoietic stem cell transplantation is associated with chronic graft-versus-host disease

This study aimed to evaluate whether an early elevation of absolute eosinophil count after allogeneic hematopoietic stem cell transplantation (allo-HSCT) was associated with the development of chronic graft-versus-host disease (cGVHD) in children and adolescents.

A total of 165 consecutive patients who received allo-HSCT were included in the study. Patients who had previously received allo-HSCT, relapsed or died before Day 100, and did not achieve engraftment, were excluded. Eosinophilia was defined as an eosinophil count exceeding 500/μL in peripheral blood within 60 days of stem cell infusion.

Eosinophilia was observed in 67 patients (40.6%). There were no significant differences in disease type, graft source, donor type, conditioning regimen, and GVHD prophylaxis and treatment between the patients with or without eosinophilia. The 3-year cumulative incidence rate of cGVHD in the entire cohort was 39.3% (95% confidence interval (CI): 32.2-47.4). Patients with eosinophilia had a higher 3-year cumulative incidence rate of cGVHD compared to those without eosinophilia (49.1% vs. 32.7%, p = 0.007). Cox proportional hazards model analysis revealed that eosinophilia was associated with an increased risk of cGVHD (adjusted hazard ratio: 2.12; 95% CI: 1.16-3.85, p = 0.014).

Early eosinophilia after allo-HSCT may serve as a predictor for the development of cGVHD in children and adolescents.