Epidemiology and biology of cutaneous human papillomavirus

Cutaneous human papillomaviruses (HPVs) include β- and γ-HPVs, in addition to a small fraction of α-HPVs. β-HPVs were first isolated from patients with the rare genetic disorder Epidermodysplasia verruciformis, and they are associated with the development of nonmelanoma skin cancer at sun-exposed skin sites in these individuals. Organ transplant recipients also have greater susceptibility to β-HPV infection of the skin and an increased risk of developing nonmelanoma skin cancer. In both immunosuppressed and immunocompromised individuals, cutaneous HPVs are ubiquitously disseminated throughout healthy skin and may be an intrinsic part of the commensal flora. Functional analysis of E6 and E7 proteins of specific cutaneous HPVs has provided a mechanistic comprehension of how these viruses may induce carcinogenesis. Nevertheless, additional research is crucial to better understand the pathological implications of the broad distribution of these HPVs.

Uncommon non-oncogenic HPV genotypes, TP53 and MDM2 genes polymorphisms in HIV-infected women in Southern Brazil

Background: It is believed that Human Papillomavirus (HPV) and Human Immunodeficiency Virus coinfection contributes to increase the risk for cervical intraepithelial injuries. Several factors may contribute to cervical cancer (CC) development, including genetic variants such as TP53 and MDM2 gene polymorphisms. Materials and methods: A hundred HIV-infected women were examined for HPV detection and its genotypes, as well as the frequencies of the SNPs Arg72Pro and SNP309 and their associations with CC risk factors. Nested Polymerase Chain Reaction (nPCR) was used for HPV detection and PCR-RFLP for TP53 and MDM2 SNP309 genotyping. Results: HPV DNA was detected in 68% of samples. A higher frequency of low-risk HPV genotypes (66.7%) was observed when compared to high-risk genotypes (33.3%). Nine different HPV genotypes were identified, with the highest prevalence of HPV-6, followed by HPV-16 and 31. p53 Arg72Arg and SNP309 TG genotype were the most prevalent. HPV genotyping was performed by sequencing. Conclusion: The data obtained suggest that HIV-infected women are more susceptible to be infected by low-risk HPV (LR-HPV) genotypes than by high-risk (HR-HPV), and Pro72Pro of TP53 gene and TG of MDM2 SNP309 genotypes apparently seem to be protective factors among HIV-infected women for HPV acquisition and HR-HPV infection, respectively, in a sample of Southern Brazilian woman. Future investigations in larger populations are necessary to better understand the potential roles of these SNPs and the behavior of non-oncogenic HPV genotypes in HIV-mediated immunosuppression cases. .

High incidence of oncogenic HPV genotypes found in women from Southern Brazil

Oncogenic HPV genotypes are strongly associated with premalignant and malignant cervical lesion. The purpose was to determine human papillomavirus (HPV) prevalence and genotypes, and to estimate cervical cancer risk factor associations. Cervical samples were obtained from 251 women seeking gynecological care at the Pelotas School of Medicine Clinic. This is a cross-sectional study. HPV-DNA was amplified by nested-PCR using MY09/11 and GP5/6 primers, and the sequencing was used for genotyping. Sociodemographic and behavioral risk factors were obtained by closed questionnaire, and its relationship to HPV infection prevalence were analyzed. Statistical analyses were performed using SPSS 16.0 software, and differences were considered significant at p < 0.05. As results, the prevalence of HPV infection was 29.9%. The most frequent genotype was HPV-16 (41.3%), followed by HPV-18 (17.3%), and HPV-33 (9.3%). Others nine HPV genotypes were also found. On this population, prevalence of oncogenic HPV genotypes was high, but does not seem to confer relationship with the risk factors investigated. Future investigations in larger populations are necessary, for the proposition of more appropriated monitoring strategies and treatment according to the Brazilian health service reality, as well as patients.

Comparison between two methods for molecular characterization of human papillomavirus

A sensitive method of detection for Human Papillomavirus (HPV) is important to facilitate the early treatment of cervical cancer precursors.Objective: to analyze the spectrum of HPV infection and compare the sensibility of DNA HPV detection using polymerase chain reaction (PCR) and nestedPCR (nPCR) methods in a group of 251 women of Pelotas-RS. Methods: genomic DNA was extracted from the collected samples and was submitted toPCR methods with the primers MY09/11 and nPCR with the pair of primers MY09/MY11 and GP5+/6+. The results were applied to the softwares Epi-Info v.3.5.1* and STATA v.11 * for analyzes. Results: the prevalence of HPV infection was 6.8% with the use of primers MY09/11. When associated withprimers GP5/6, this result increased to 29.9% (p < 0.001). Conclusion: the increase founded in HPV DNA detection from 6.8 to 29.9% suggests that thetechnique of nPCR MY09/11 followed by GP5/6 is the most sensitive method to detect HPV DNA from cervical specimens.