Persistent oral human papillomavirus infection is associated with smoking and elevated salivary immunoglobulin G concentration

Abstract

BackgroundPrevalence and risk factors for human papillomavirus (HPV) persistence in oral mucosa are largely unknown. Furthermore, the antiviral effects of saliva in the outcome of oral HPV infections are unexplored. ObjectivesTo compare the levels of selected salivary defence proteins in women with a persistent oral HPV infection and in those without any signs of oral HPV. Lifestyle factors including the use of oral contraceptives, oral sex, smoking and alcohol drinking habits were also assessed. Study designThis nested case–control study of the Finnish Family HPV Study included 60 women with a persistent oral HPV infection and 117 women who remained HPV DNA negative throughout a 6-year follow-up. Whole saliva samples and oral scrapings for HPV testing were collected at the same visit. The oral HPV status was related to salivary concentrations of lactoferrin, lysozyme, IgA, IgG, total protein and sodium as well as to the use of oral contraceptives, oral sex, smoking and alcohol drinking habits. ResultsWomen with a persistent oral HPV infection had higher salivary levels of IgG (p=0.007) and lysozyme (p=0.002, when adjusted to the total protein concentration), than those without an HPV infection. Lactoferrin and IgA concentrations were not related to the HPV-status. Smoking increased the risk of a persistent oral HPV infection (p=0.020), but the oral HPV status was not related to other life-style factors studied. ConclusionsSmoking is a risk factor for a persistent oral HPV infection. Oral HPV infection may be associated with increased concentrations of salivary IgG and lysozyme.