Clinical profile and outcome of urotheliotropic viral haemorrhagic cystitis following haematopoietic stem cell transplantation: a 7-year tertiary centre analysis.

Viral haemorrhagic cystitis (HC) is a significant complication after haematopoietic stem cell transplantation (HSCT), with a potential for major morbidity. The aim of this 7-year analysis of 1160 HSCT patients was to evaluate risk factors for the incidence, severity, toxicity of therapy, clinical course, and outcome of this condition. The overall incidence of HC was 5·8%, with most cases occurring after allogeneic HSCT. Unrelated donors (P = 0·001), non-peripheral blood stem cell source (P = 0·005), myeloablative conditioning (P<0·001), use of alemtuzumab in conditioning (P = 0·001), and severe acute graft versus host disease (P<0·001) were independent risk factors for an increased incidence of HC post-allogeneic transplant on multivariate analysis. Severe forms of HC were associated with grades II-IV acute graft versus host disease and a longer duration of haematuria. Contrary to previous studies which were carried out on smaller patient populations, busulphan, cyclophosphamide, anti-thymocyte globulin, and total body irradiation were not found to independently increase the risk of viral HC, unless used in a myeloablative combination. Neither duration of viriuria nor peak viral load in urine influenced the severity of HC on multivariate analysis. Severe HC contributed to the deaths of two patients. Overall survival was not statistically different between patient subgroups with non-severe and severe HC.