A Prospective Study on the Predictive Value of Plasma BK Virus-DNA Load for Hemorrhagic Cystitis in Pediatric Patients After Stem Cell Transplantation

Background. In hematopoietic stem cell transplantation (HSCT), late hemorrhagic cystitis (HC) has been associated with BK virus (BKV) infection. We assessed the value of plasma BKV load in predicting HC. Methods. Plasma and urine BKV-DNA load were assessed prospectively in 107 pediatric patients. Results. Twenty patients developed grade II and III HC, with 100-day cumulative incidence of 18.8%. At diagnosis of HC, the median load of BKV DNA was 2.3 × 10 3 copies/mL. A plasma BKV-DNA load of 10 3 copies/mL had a sensitivity of 100% and a specificity of 86% with a negative predictive value (NPV) of 100% and a positive predictive value (PPV) of 39% for HC. A urine BKV-DNA load of >10 7 copies/mL had a sensitivity of 86% and a specificity of 60% with a NPV of 98% and a PPV of 14% for HC. A BKV load of 10 3 copies/mL on plasma was significantly associated with HC in multivariate analysis (hazard ratio [HR], 6.1; P= .0006). Patients with HC had a significantly higher risk of mortality than patients who did not have HC (HR, 2.6; P= .018). Conclusions. The above values were used to monitor plasma BKV-DNA load, and they provided a better prediction of patients at risk of HC than urine BKV-DNA load.