Presence of human papillomavirus type-6-related sequences in inverted nasal papillomas

Twenty DNA samples obtained from seven cases of inverted papillomas, eight cases of nasal polyps and five cases of chronic sinusitis were investigated by Southern blot hybridization for the possible presence of sequences homologous to human papillomavirus (HPV) types 6, 11, 16 and 18. HPV type-6-related DNA was identified in one of the seven inverted papillomas. The restriction endonuclease cleavage patterns showed that this latter DNA is a new subtype of HPV type 6 DNA. In the other six papillomas and in all cases of nasal polyps and chronic sinusitis, no HPV sequence could be demonstrated, even under low stringent conditions (Tm-40 degrees C). These results indicate that HPV infection might be one of the possible causative factors in the pathogenesis of inverted papillomas but is not essential for the induction of the tumor.