Prognostic impacts of peripheral blood erythroblasts after single-unit cord blood transplantation.

INTRODUCTION The appearance of erythroblasts (EBLs) in peripheral blood occurs in a variety of serious conditions and has been associated with mortality in critically ill patients. However, the incidence, risk factor, and outcomes of EBLs after cord blood transplantation (CBT) remain unclear. METHODS We have investigated the impact of EBLs on transplant outcomes on 225 adult patients who underwent single-unit CBT at our single institute. RESULTS The cumulative incidences of EBL ≥200 × 106 /L and EBL ≥1000 × 106 /L at 60 days after CBT were 17% and 4%, respectively, detected after a median of 35 days and 36.5 days. Multivariate analysis using erythroblastosis as time-dependent covariates demonstrated the significant association of EBL ≥1000 × 106 /L, but not EBL ≥200 × 106 /L, with the development of grade III-IV acute graft-versus-host disease (GVHD, hazard ratio [HR]: 18.56; P < .001), higher nonrelapse mortality (HR: 13.38; P < .001), and overall mortality (HR: 4.97; P = .001). CONCLUSION These data suggested that higher levels of EBLs were recognized as a significant risk factor for severe acute GVHD and mortality after single-unit CBT. Higher levels of EBLs may serve as a surrogate marker for poor single CBT outcomes.