CMV infection is a risk factor for hemorrhagic cystitis after hematopoietic stem cell transplantation

Hemorrhagic cystitis (HC) is a common complication after transplantation. The purpose of this study was to examine the incidence and risk factors for HC after hematopoietic stem cell transplantation (HSCT). The records of patients who underwent allogenic HSCT from January 2012 to December 2018 at our institution were retrospectively reviewed. Cox proportional regression and Kaplan-Meier analyses were performed to determine independent risk factors for HC. The statistical analysis was performed in May 2020. A total of 173 patients underwent HSCT, and 53 (30.6%) developed grade 2 or 3 HC cystitis at a median of 37 days (range - 5 to 98 days) after transplantation. Thirty-two patients developed moderate (grade 2) cystitis and 21 severe (grade 3) cystitis. Of the 173 patients, 61 developed acute graft-versus-host disease (GVHD) (median onset day 24) and 79 experienced cytomegalovirus (CMV) reactivation (median onset day 35). The relative risk (RR) of developing a CMV infection for patients with acute GVHD was 2.77 times that of patients without acute GVHD (P < 0.001). CMV infection was the only independent variable significantly associated with HC in both univariate and multivariate analyses. The estimated hazard ratio (HR) of CMV infection for the development of HC was 5.57 (95% confidence interval [CI]: 2.52 to 12.33, P < 0.001). CMV infection is an independent risk factor for the development of HC after HSCT, and acute GVHD is a risk factor for CMV reactivation. Decreasing the frequency of GVHD after HSCT may result in a lower frequency of HC.