Incidence, clinical outcome, and management of virus-induced hemorrhagic cystitis in children and adolescents after allogeneic hematopoietic cell transplantation.

We analyzed the incidence, etiology, risk factors, and clinical management of hemorrhagic cystitis (HC) in 102 children who underwent allogeneic stem cell transplantation: 28 from matched siblings, 57 from unrelated donors, and 17 from mismatched relatives. Conditioning regimens consisted of high-dose chemotherapy (n=83) or total body irradiation (n=19). In all children, urine and plasma were prospectively screened for human polyomavirus (HPV; BK virus [BKV] and JC virus [JCV]) or adenovirus (AdV) DNA with a polymerase chain reaction-based assay. Viral DNA was detected in the urine of 56 children (54.9%): BKV in 48 (47%), JCV in 4 (3.9%), and AdV in 4 (3.9%). HC occurred in 26 children (25.5%), and viruria was detected in all of them: BKV in 21 (80.8%), AdV in 4 (14.4%), and JCV in 1 (3.8%). All patients with AdV viruria developed HC. The cumulative incidence of HC in patients with HPV viruria was 0.43. The only significant risk factor for HC in patients with HPV-positive urine was conditioning with high-dose chemotherapy. Twenty-two children were treated with cidofovir, with no significant toxicity. In all treated patients but 1, the clinical symptoms were moderate, and no HC-related death was observed. We conclude that virus-induced HC is a frequent complication after allogeneic hematopoietic cell transplantation. Treatment with cidofovir is feasible, and further studies are warranted to evaluate its activity in HC mediated by BKV or JCV.