Risk factors and predictors of severity score and complications of pediatric hemorrhagic cystitis.

PURPOSE: We retrospectively analyzed our institutional incidence of hemorrhagic cystitis, identified risk factors, and examined associations of risk factors with disease severity and genitourinary complication rates.

MATERIALS AND METHODS: We reviewed charts of all consecutive pediatric patients treated from 1986 to 2010. We analyzed demographics, underlying diagnosis and treatment data to assess risk factors for hemorrhagic cystitis. We also correlated disease severity scores with clinical predisposing factors, and performed univariate and multivariate analyses to examine associations between risk factors and outcomes.

RESULTS: Hemorrhagic cystitis was observed in 97 of 6,119 children (1.6%), most of whom (75%) had severity scores of II or III. Mean ± SD age was 12.2 ± 6.3 years for patients with hemorrhagic cystitis and 10.5 ± 7 years for patients without hemorrhagic cystitis (p = 0.017). On univariate analysis increased risk of hemorrhagic cystitis was significantly associated with age greater than 5 years, male gender, cyclophosphamide or busulfan chemotherapy, bone marrow or peripheral blood stem cell transplantation, pelvic radiotherapy and underlying diagnoses of rhabdomyosarcoma, acute leukemia and aplastic anemia. On multivariate analysis age greater than 5 years, allogeneic bone marrow or peripheral blood stem cell transplantation and pelvic radiotherapy were significantly associated with increased risk of hemorrhagic cystitis. Older age, late onset hemorrhagic cystitis, positive urine culture for BK virus and bone marrow or peripheral blood stem cell transplantation were associated with greater disease severity. Patients with higher severity scores more frequently experienced bladder perforation, hydronephrosis, overall hemorrhagic cystitis complications, and increased creatinine and blood urea nitrogen levels during followup.

CONCLUSIONS: Older age, previous bone marrow or peripheral blood stem cell transplantation and BK virus in the urine are risk factors for hemorrhagic cystitis and are associated with a higher severity score. Higher severity scores are associated with increased rates of genitourinary complications and renal impairment.