title: Detection of epidermodysplasia verruciformis-associated human papillomavirus DNA in nongenital seborrhoeic keratosis.
abstract: BACKGROUND
  DNA of epidermodysplasia verruciformis (EV)-associated human papillomaviruses (HPVs) has been widely detected in lesions of malignant skin tumours, benign tumours and other proliferative diseases of epithelial origin.
  
  
  OBJECTIVE
  To investigate the presence of EV-associated HPV DNA in nongenital seborrhoeic keratosis (SK) and to elucidate the prevalence of distinct HPV genotypes.
  
  
  METHODS
  We investigated HPV DNA in 55 nongenital SK biopsies, which were compared with 48 normal skin biopsies (healthy controls) using a nested polymerase chain reaction (PCR) using consensus primers CP65/CP70 and CP66/CP69. The positive PCR products were retracted and used to prepare recombination clones with T-vector. Distinct clones were analysed with endonucleases, and HPV genotypes were identified by direct sequencing.
  
  
  RESULTS
  EV-associated HPV DNA was detected in 42 of 55 (76%) nongenital SK biopsies vs. only 13 of 48 (27%) healthy controls (chi2 = 22.087; P < 0.005). The prevalence was higher in patients with more than five lesions than in those with only one lesion (P < 0.05). Ten distinct HPV genotypes were detected in the nongenital SK biopsies: HPV 20, 23, 5, renal transplant recipient (RTR) X7, HPV 17, 37, 17b, RTRX4, RTRX4b and strain SK3. HPV 20 was found in 26 of 42 (62%) positive specimens, followed by HPV 23 (11 of 42, 26%) and HPV 5 (six of 42, 14%). Existence of multiple HPV genotypes was observed in 12 of 42 (29%) positive specimens. In healthy controls, five genotypes of EV-associated HPV (HPV 20, 23, 5, 17 and RTRX4) were detected, with the same predominant genotype of HPV 20 (five of 13, 38%). Several distinct HPV genotypes were found to coexist in four of 13 (31%) positive specimens.
  
  
  CONCLUSIONS
  This study provides some evidence that EV-associated HPVs might play a part in the pathogenesis of nongenital SK.
authors.affiliation: Department of Dermatology, No. 1 Hospital of China Medical University, Shenyang 110001, China.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Li
authors.forename: G
authors.initials: G
authors.lastname: Chen
authors.forename: X-P
authors.initials: XP
authors.lastname: Dong
authors.forename: H-D
authors.initials: HD
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D004279:DNA, Viral / Q000032:analysis*; D004819:Epidermodysplasia Verruciformis / Q000821:virology*; D005260:Female; D005838:Genotype; D006801:Humans; D017492:Keratosis, Seborrheic / Q000473:pathology / Q000821:virology*; D008297:Male; D008875:Middle Aged; D027383:Papillomaviridae / Q000145:classification / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000150:complications* / Q000821:virology; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D004279:DNA, Viral