Splenomegaly negatively impacts neutrophil engraftment in cord blood transplantation: A single institute analysis of 502 recipients.

Abstract Delayed neutrophil engraftment (NE) has been reported in cord blood transplantation (CBT) as compared with other stem cell transplantation methods. The number of total nucleated cells (TNCs), CD34+ cells (generally ≥ 1 × 105/kg), and colony-forming units of granulocyte/macrophage (CFU-GM) significantly impact NE. Splenomegaly exerts negative effects on NE, but the appropriate cell dose for the patients with splenomegaly has not been determined yet, especially in CBT. We retrospectively investigated the effect of splenomegaly and number of CD34+ cells infused on NE through the analysis of outcomes in 502 consecutive patients who underwent single CBT for the first time at Toranomon Hospital between 2011 and 2018. Spleen index Lmax × Hvert (SI Lmax × Hvert) was defined as maximal length at any transverse section (Lmax) × vertical height (Hvert), and splenemegaly was defined as SI Lmax x Hvert ≥ 115 cm2. Our results showed that splenomegaly (harzard ratio (HR), 0.60; p