Physical state and copy numbers of HPV16 in oral asymptomatic infections that persisted or cleared during the 6-year follow-up

Persistent human papillomavirus (HPV) infection is a key event in HPV-induced carcinogenesis. As part of the prospective Finnish Family HPV Study, we analysed the physical state and viral copy numbers of HPV16 in asymptomatic oral infections that either persisted or cleared during the 6-year follow-up. The persister group comprised 14 women and 7 men with 51 and 21 HPV16-positive brush samples. The clearance group included 41 women and 13 men, with 64 and 24 samples, respectively. Physical state and viral DNA load were assessed by using quantitative PCR for HPV16 E2 and E6 genes. E2/E6 ratio was calculated and HPV16 was classified as episomal, mixed or integrated with values of 0.93-1.08
The Finnish Family HPV Study has been supported by the Academy of Finland (no. 116438/2006, no. 130204/2008), Finnish Cancer Foundation, Solberg Foundation, Finnish Dental Society Apollonia and the Government Special Foundation (EVO) to Turku University Hospital. The funders had no role in the study design and data analysis, decision to publish or preparation of the manuscript