Human papillomavirus prevalence in mouthwashes of patients undergoing tonsillectomy shows dominance of HPV69, without the corresponding finding in the tonsils

Background: The role of human papillomavirus (HPV) in tonsillar squamous cell carcinomas (TSCC) is of interest, since a considerable proportion of TSCC in Sweden and other Western countries is HPV positive. Nevertheless, the natural history of HPV in normal tonsils, and the progression from localized infection to pre-malignant lesion to cancer are poorly understood. The aim of this study was to investigate whether HPV types found in mouthwash samples correlated to those in tonsillar tissue from the same individuals undergoing tonsillectomy. Methods: Mouthwash samples from 232 patients, aged 3-56 years, undergoing tonsillectomy, the majority with chronic tonsillitis, were collected at the time of surgery and analysed for the presence of 27 HPV types by a bead based multiplex assay. Results: An HPV prevalence of 10.3% (24/232) was observed in mouthwash samples, with HPV 69 being the dominant type (10/24). Ten patients were positive for high risk HPV (HPV 16, 33, 35, 45, 56, 59). None of the tonsils resected from patients with HPV-positive mouthwash samples were positive for HPV. Conclusions: Despite an oral HPV prevalence of 10.3% in mouthwash samples from tonsillectomized patients, with dominance of HPV 69, none of the corresponding tonsillar samples exhibited the presence of HPV.