title: Identification of HPV DNA in patients with juvenile-onset recurrent respiratory papillomatosis using SYBR Green real-time PCR.
abstract: OBJECTIVE
  Recurrent respiratory papillomatosis (RRP) is the most common benign neoplasm affecting the larynx and upper respiratory tract in children. Human papillomavirus (HPV) has been implicated as the cause of RRP, most commonly types 6 and 11. The present study was undertaken to evaluate the occurrence of HPV types in a group of patients with juvenile-onset RRP (JORRP).
  
  
  METHODS
  The study group consists of 23 patients with JORRP. The clinical records of the patients were reviewed, and JORRP was classified as non-aggressive or aggressive. The laryngeal biopsies were taken and investigated for HPV DNA presence using real-time polymerase chain reaction (PCR) with a set of consensus primers (MY09/11). Viral typing was subsequently performed by real-time PCR with type-specific primers for HPV types 6, 11, 16, 18, 31, and 33.
  
  
  RESULTS
  HPV presence was detected in all samples with amplifiable DNA. HPV-11 was revealed in 61.9% of the patients and HPV-6 in 23.8%. Double positivity for HPV types 6 and 11 was identified in 14.3%. Our findings suggest that RRP runs a more aggressive clinical course when HPV-11 infection is present (p=0.0265).
  
  
  CONCLUSIONS
  Our results suggest a high frequency of HPV infection in the upper respiratory tract of the studied patients. We believe that the routine application of molecular techniques such as PCR for detection and analysis of HPVs in patients with RRP has diagnostic and prognostic significance.
authors.affiliation: Laboratory of Molecular Virology, Department of Virology, National Center of Infectious and Parasitic Diseases, 44-A Stoletov Blvd., 1233 Sofia, Bulgaria.
authors.forename: Pavel
authors.initials: P
authors.lastname: Draganov
authors.forename: Spiridon
authors.initials: S
authors.lastname: Todorov
authors.forename: Ivan
authors.initials: I
authors.lastname: Todorov
authors.forename: Todor
authors.initials: T
authors.lastname: Karchev
authors.forename: Zlatko
authors.initials: Z
authors.lastname: Kalvatchev
mesh_terms: D017668:Age of Onset; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007822:Laryngeal Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000821:virology*; D008297:Male; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D010212:Papilloma / Q000453:epidemiology / Q000473:pathology* / Q000821:virology*; D027383:Papillomaviridae / Q000235:genetics* / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012720:Severity of Illness Index