title: Lack of detection of enteroviral RNA or bacterial DNA in magnetic resonance imaging-directed muscle biopsies from twenty children with active untreated juvenile dermatomyositis.
abstract: OBJECTIVE
  To investigate for the presence of increased titers of circulating antibody to putative infectious agents and for detectable viral RNA or bacterial DNA in children with active recent-onset juvenile dermatomyositis (DM).
  
  
  METHODS
  Magnetic resonance imaging-directed muscle biopsies were performed in 20 children with active, untreated, recent-onset juvenile DM and in age-matched children with neurologic disease. Sera were tested for complement-fixing antibody to Coxsackievirus B (CVB), influenza A and B, parainfluenza 1 and 3, Mycoplasma pneumoniae, mumps, respiratory syncytial virus, and Reovirus; and by immunofluorescence for IgG antibody to Toxoplasma gondii cytomegalovirus and IgM antibody to Epstein-Barr virus. Muscle from juvenile DM patients and control children, CD-1 Swiss mice with and without CVB1 infection, and viral stock positive for CVB1-6 were tested using reverse-transcriptase polymerase chain reaction with 5 primer sets, 4 probes (1 Coxsackievirus, 3 Enterovirus), and universal primers for DNA.
  
  
  RESULTS
  No increased antibody, viral RNA, or bacterial DNA was present in the juvenile DM patients or the control children.
  
  
  CONCLUSIONS
  Juvenile DM may be triggered by unidentified agent(s) in the genetically susceptible host.
authors.affiliation: Northwestern University Medical School, Chicago, Illinois, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Pachman
authors.forename: D L
authors.initials: DL
authors.lastname: Litt
authors.forename: A H
authors.initials: AH
authors.lastname: Rowley
authors.forename: J R
authors.initials: JR
authors.lastname: Hayford
authors.forename: J
authors.initials: J
authors.lastname: Caliendo
authors.forename: S
authors.initials: S
authors.lastname: Heller
authors.forename: B S
authors.initials: BS
authors.lastname: Ticho
authors.forename: M
authors.initials: M
authors.lastname: Christensen
authors.forename: B
authors.initials: B
authors.lastname: Patterson
authors.forename: S R
authors.initials: SR
authors.lastname: Ytterberg
mesh_terms: D000293:Adolescent; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001483:Base Sequence; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000302:isolation & purification*; D003882:Dermatomyositis / Q000382:microbiology* / Q000473:pathology / Q000821:virology; D004770:Enterovirus / Q000276:immunology / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009132:Muscles / Q000382:microbiology* / Q000473:pathology / Q000821:virology; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000302:isolation & purification*
chemical_list: D000914:Antibodies, Viral; D004269:DNA, Bacterial; D012367:RNA, Viral