title: Viral load and mRNA expression of HPV type 6 among cases with recurrent respiratory papillomatosis.
abstract: OBJECTIVE
  To determine viral load of human papillomavirus type 6 (HPV6), physical state of HPV6-DNA, and transcription level of HPV6 E7-mRNA in laryngeal papilloma and in adjacent healthy mucosa.
  
  
  METHODS
  Case series.
  
  
  METHODS
  A papilloma biopsy was collected from each of 25 adult patients with respiratory recurrent papillomatosis. From 14 of the 25 patients, we first collected a biopsy from healthy mucosa of the false vocal fold and another from the papilloma. Quantity of HPV6 and E7-mRNA was measured by polymerase chain reaction.
  
  
  RESULTS
  For the papilloma, the median load of HPV6 was 41 copies/cell, and the lowest amount was 5.4 copies/cell. Human papillomavirus type 6 was detected in 50% (7/14) of the healthy mucosa, with a median of 1.1 copies/cell, and the highest amount was 6.6 copies/cell. Overall, viral load was higher in papilloma than in healthy mucosa (P < 0.05). The average HPV6 E2/E7-DNA ratio was 1.3, indicating an episomal state. Human papillomavirus type 6-mRNA was detected in all HPV6-DNA-positive samples. The transcription median ratio of HPV6-mRNA/HPV6-DNA was 1.5 in papilloma and 3.8 in healthy mucosa.
  
  
  CONCLUSIONS
  The amount of HPV6-DNA was consistently higher in the papilloma than in healthy mucosa. The transcription level of HPV6 E7 mRNA was similar in the papilloma and in normal mucosa. We suggest that interfering with replication of HPV6 and suppression of HPV6 to fewer than five copies/cell may be curative.
authors.affiliation: Department of Laboratory Medicine, Medical Microbiology, Lund University, Malmö
authors.forename: Ola
authors.initials: O
authors.lastname: Forslund
authors.affiliation: Department of Laboratory Medicine, Lund University, Lund.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwartz
authors.affiliation: Department of Clinical Sciences, Division of Otorhinolaryngology, Umeå University, Umeå
authors.forename: Katarina
authors.initials: K
authors.lastname: Olofsson
authors.affiliation: Department of Clinical Sciences, Division of Otorhinolaryngology, Head and Neck Surgery, Scania University Hospital, Lund University, Scania, Sweden.
authors.forename: Roland
authors.initials: R
authors.lastname: Rydell
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D005260:Female; D052163:Human papillomavirus 6; D006801:Humans; D008297:Male; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000821:virology*; D012333:RNA, Messenger / Q000032:analysis*; D060888:Real-Time Polymerase Chain Reaction; D012141:Respiratory Tract Infections / Q000821:virology*; D019562:Viral Load
chemical_list: D012333:RNA, Messenger
keywords: Papillomavirus; healthy laryngeal tissue; recurrent respiratory papillomatosis