Treatment of BK virus-associated hemorrhagic cystitis in pediatric hematopoietic stem cell transplant recipients with cidofovir: a single-center experience

BackgroundBK virus (BKV)-associated hemorrhagic cystitis (BKV-HC) is a severe complication after hematopoietic stem cell transplantation (HSCT). Cidofovir (CDV) has emerged as an effective agent for the treatment of BKV nephropathy, but its use for BKV-HC in pediatric HSCT recipients has not yet been established as a standard therapy. Patient and methodsWe retrospectively investigated the efficacy and safety of CDV therapy for patients with BKV-HC at a single institution and analyzed the clinical management outcomes. ResultsFrom April 2009 to July 2011, 12 patients developed BKV-HC at a median of 37days after transplant (range 15-59days). The cumulative incidence was 9% and the median peak of the urine BKV load was 2.5x10(10) copies/mL (range 1.4x10(9)-1.2x10(11) copies/mL). Eleven patients received intravenous CDV (5mg/kg/dose, with probenecid), whereas 1 patient received CDV (5mg/kg/dose, without probenecid) intravesically. The median duration of therapy was 25days (range 9-73days), and a median of 2 doses was given (range 1-4). A reduction of 1 log in the BKV load was found in 11 patients, while 1 patient did not have any significant change in BKV load. Clinical improvement was observed in all cases, and no HC-related death was observed. CDV-related toxicity occurred in 1 patient (8%) and spontaneously resolved. ConclusionsCDV appears to be an effective and safe treatment for BKV-HC in pediatric HSCT recipients, but prospective trials are warranted to support its use.