Assessing Gammapapillomavirus infections of mucosal epithelia with two broad-spectrum PCR protocols

Human papillomaviruses (HPVs) have been divided into mucosal and cutaneous types according to their primary epithelial tissue tropism. However, recent studies showed the presence of several cutaneous types in mucosal lesions and healthy mucosa from different anatomical sites.

Here, the HPV prevalence and type-specific distribution were assessed in a variety of mucosal samples from 435 individuals using a combination of two established broad-spectrum primer systems: Gamma-PV PCR and CUT PCR.

Overall HPV prevalence in anal canal swabs, cervical cancer biopsies, genital warts and oral swabs was 85, 47, 62 and 4%, respectively. In anal canal swabs, Alpha-PVs were most frequently found (59%), followed by Gamma- (37%) and Beta-PVs (4%). The prevalence and persistence of HPV infection in the anal canal of 226 individuals were further explored. Overall HPV, Gamma-PVs and multiple HPV infections were significantly higher in men vs. women (p = 0.034, p = 0.027 and p = 0.003, respectively); multiple HPV infections were more common in individuals ≤40 years (p = 0.05), and significantly higher prevalence of Gamma-PVs and multiple HPV infections was observed in HIV-1-positive vs. HIV-1-negative individuals (p = 0.003 and p = 0.04, respectively). Out of 21 patients with follow-up anal swabs, only one persistent infection with the same type (HPV58) was detected.

Our findings suggest that Gamma-PVs (except species Gamma-6) are ubiquitous viruses with dual muco-cutaneous tissue tropism. Anal canal Gamma-PV infections may be associated with sexual behavior and the host immune status. This study expands the knowledge on Gamma-PVs' tissue tropism, providing valuable data on the characteristics of HPV infection in the anal canal.