title: Viremic co-infections in children with allogeneic haematopoietic stem cell transplantation are predominated by human polyomaviruses.
abstract: BACKGROUND
  Viral infections remain the cause of key complications following haematopoietic stem cell transplantation (HSCT). The impact of multiple, concurrent viral reactivations/infections remains to be delineated.
  
  
  METHODS
  The clinical correlates of single or multiple viremic infections following HSCT and especially the occurrence of respiratory viruses in the bloodstream were investigated. We retrospectively searched for 23 viruses in a total of 184 sera from 53 paediatric patients. The time-points of interest were pre-HSCT, one, two and three months post-HSCT, and at discharge or death. The viruses were analyzed by quantitative or qualitative PCR.
  
  
  RESULTS
  Of the 53 patients, 13 (25%) had viraemias by multiple viruses and 27 (51%) by a single virus. Thirteen patients (25%) had no viruses detected by PCR during the study period. In the children with viremic co-infections, polyomaviruses predominated over herpes viruses. Nearly half the patients, 24/53 (45%) had a polyomavirus in their serum at one or more time-points. At 12/15 time-points and in 11/13 patients with co-infections polyomaviruses were involved, compared with 6/15 time-points and 6/13 patients for cytomegalovirus. Acute graft-versus-host disease (GvHD) and steroid use were significant risk factors for the viraemias caused by more than one virus.
  
  
  CONCLUSIONS
  Viral co-detection is a common finding in children undergoing HSCT. With large-scale viral screening also viruses other than CMV could be found as potential pathogens. In this study, BKPyV predominated over CMV as a contributor in viraemias caused by multiple viruses in children receiving HSCT.
authors.affiliation: a Division of Hematology-Oncology and Stem Cell Transplantation , Children's Hospital, Helsinki University Central Hospital, University of Helsinki , Finland.|b Department of Pediatrics , University of Turku , Turku , Finland.
authors.forename: Minna
authors.initials: M
authors.lastname: Koskenvuo
authors.affiliation: a Division of Hematology-Oncology and Stem Cell Transplantation , Children's Hospital, Helsinki University Central Hospital, University of Helsinki , Finland.|c Department of Pediatrics , Porvoo Hospital , Porvoo , Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Rahiala
authors.affiliation: d Department of Virology , University of Helsinki , Helsinki , Finland.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Sadeghi
authors.affiliation: e Department of Clinical Virology , Turku University Hospital , Turku , Finland.|f Department of Virology , University of Turku , Turku , Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Waris
authors.affiliation: e Department of Clinical Virology , Turku University Hospital , Turku , Finland.|f Department of Virology , University of Turku , Turku , Finland.
authors.forename: Tytti
authors.initials: T
authors.lastname: Vuorinen
authors.affiliation: g Department of Virology and Immunology , Helsinki University Central Hospital Laboratory Services (HUSLAB) , Helsinki , Finland.
authors.forename: Maija
authors.initials: M
authors.lastname: Lappalainen
authors.affiliation: d Department of Virology , University of Helsinki , Helsinki , Finland.
authors.forename: Päivi
authors.initials: P
authors.lastname: Norja
authors.affiliation: d Department of Virology , University of Helsinki , Helsinki , Finland.
authors.forename: Mari
authors.initials: M
authors.lastname: Toppinen
authors.affiliation: a Division of Hematology-Oncology and Stem Cell Transplantation , Children's Hospital, Helsinki University Central Hospital, University of Helsinki , Finland.
authors.forename: Ulla
authors.initials: U
authors.lastname: Saarinen-Pihkala
authors.affiliation: h Department of Clinical Microbiology , Karolinska University Hospital , Stockholm , Sweden.
authors.forename: Tobias
authors.initials: T
authors.lastname: Allander
authors.affiliation: d Department of Virology , University of Helsinki , Helsinki , Finland.
authors.forename: Maria
authors.initials: M
authors.lastname: Söderlund-Venermo
authors.affiliation: d Department of Virology , University of Helsinki , Helsinki , Finland.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hedman
authors.affiliation: b Department of Pediatrics , University of Turku , Turku , Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Ruuskanen
authors.affiliation: a Division of Hematology-Oncology and Stem Cell Transplantation , Children's Hospital, Helsinki University Central Hospital, University of Helsinki , Finland.
authors.forename: Kim
authors.initials: K
authors.lastname: Vettenranta
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000453:epidemiology / Q000821:virology*; D003587:Cytomegalovirus / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000097:blood / Q000453:epidemiology; D004279:DNA, Viral / Q000097:blood; D005260:Female; D005387:Finland / Q000453:epidemiology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects* / Q000401:mortality; D006801:Humans; D007223:Infant; D008297:Male; D016133:Polymerase Chain Reaction; D011120:Polyomavirus / Q000235:genetics / Q000302:isolation & purification*; D027601:Polyomavirus Infections / Q000453:epidemiology / Q000821:virology*; D012189:Retrospective Studies; D014412:Tumor Virus Infections / Q000097:blood / Q000453:epidemiology / Q000821:virology; D014766:Viremia / Q000453:epidemiology / Q000821:virology*; D014780:Viruses / Q000145:classification / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D004279:DNA, Viral
keywords: BKV; CMV; HSCT; Viraemia; children; co-infection