title: BK polyomavirus-associated hemorrhagic cystitis among pediatric allogeneic bone marrow transplant recipients: treatment response and evidence for nosocomial transmission.
abstract: BACKGROUND
  BK polyomavirus-associated hemorrhagic cystitis (BK-PyVHC) is a significant complication of allogenic hematopoietic stem cell transplantation (HSCT), but risk factors and treatment are currently unresolved. BK-PyVHC typically presents with clinical cystitis, macrohematuria, and increasing urine and blood BKV loads.
  
  
  OBJECTIVE
  Characterization of children undergoing allogeneic HSCT with BK-PyVHC and their clinical and antibody response to cidofovir treatment.
  
  
  METHODS
  By prospective screening of urine and plasma in 50 pediatric allogenic HSCT performed between 2008 and 2010, we identified 6 (12%) children with BK-PyVHC. Cidofovir was administered intravenously to 5 patients and intravesically to 4 patients (3 double treatments).
  
  
  RESULTS
  Decreasing BKV viremia of>2log(10)copies/mL and clinical resolution was seen in 4 patients over 5-12 weeks. Responses occurred only in patients mounting BKV-specific IgM and IgG responses. Epidemic curve plots, BKV genotyping and contact tracing provided evidence of transmission between 2 BKV-seronegative patients, but ruled out transmission among the remaining four patients
  
  
  CONCLUSIONS
  The data suggest that BK-PyVHC may be the result of nosocomial transmission in children with low/undetectable BKV antibodies and raises urgent questions about appropriate infection control measures and the role of cidofovir.
authors.affiliation: Division of Hematology-Oncology and Stem Cell Transplantation, Childrens' Hospital and Helsinki University Central Hospital, Helsinki, Finland. minna.koskenvuo@utu.fi
authors.forename: Minna
authors.initials: M
authors.lastname: Koskenvuo
authors.forename: Alexis
authors.initials: A
authors.lastname: Dumoulin
authors.forename: Irmeli
authors.initials: I
authors.lastname: Lautenschlager
authors.forename: Eeva
authors.initials: E
authors.lastname: Auvinen
authors.forename: Laura
authors.initials: L
authors.lastname: Mannonen
authors.forename: Veli-Jukka
authors.initials: VJ
authors.lastname: Anttila
authors.forename: Kirsi
authors.initials: K
authors.lastname: Jahnukainen
authors.forename: Ulla M
authors.initials: UM
authors.lastname: Saarinen-Pihkala
authors.forename: Hans H
authors.initials: HH
authors.lastname: Hirsch
mesh_terms: D061605:Administration, Intravenous; D000283:Administration, Intravesical; D000998:Antiviral Agents / Q000008:administration & dosage; D001739:BK Virus / Q000302:isolation & purification*; D016026:Bone Marrow Transplantation / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D000077404:Cidofovir; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission*; D003556:Cystitis / Q000188:drug therapy / Q000453:epidemiology* / Q000473:pathology / Q000821:virology*; D003596:Cytosine / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D006470:Hemorrhage / Q000453:epidemiology / Q000473:pathology / Q000821:virology; D006801:Humans; D008297:Male; D063065:Organophosphonates / Q000008:administration & dosage; D010949:Plasma / Q000821:virology; D027601:Polyomavirus Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission*; D014180:Transplantation; D016896:Treatment Outcome; D014556:Urine / Q000821:virology; D019562:Viral Load
chemical_list: D000998:Antiviral Agents; D063065:Organophosphonates; D003596:Cytosine; D000077404:Cidofovir