HPV is found in an increasing number of tonsillar carcinomas. Thus, knowledge about the prevalence of viral infection in the oral cavity in the general population is of importance. Hypertrophic palatine tonsils are removed in all age groups and are suitable for epidemiologic studies. We examined the prevalence of HPV in benign tonsillar tissues removed in the period 1996 – 2014 at two Norwegian county hospitals, Akershus University Hospital (Ahus) and Vestfold Hospital (SiV).
Formalin-fixed and paraffin-embedded tonsils from patients ≤ 50 years were identified in the diagnostic archives from pathology departments at Ahus and SiV. DNA was isolated from all paraffin blocks, and from both palatines if present. 4 x 10 µm sections were cut from each paraffin block using standard procedures for preventing contamination. DNA was extracted according to standard procedures (Qiagen). The presence of HPV was investigated by using a modified GP5+/6+ PCR protocol, followed by hybridization of type-specific oligonucleotide probes coupled to fluorescence labeled polystyrene beads (Luminex suspension array technology), detecting and genotyping 37 HPV types (WHO validated protocol). Sample adequacy was evaluated through a beta-globin PCR.
487 benign tonsillar samples were included. In the first 143 cases, HPV was identified in three samples (2,1%), two HPV16 and one HPV6. These samples were from patients aged 19 to 40 years and with a male/female ratio 2/1.
Preliminary data indicate a low HPV prevalence in cancer free tonsillar tissue. Data from all cases will be presented.