Prevalence of Human Papillomavirus Infection in the Head and Neck Area of Patients After Kidney Transplantation Treated With Immunosuppressive Therapy

Risk factors associated with oral Human Papillomavirus (HPV) prevalence within a young adult population

BACKGROUND

The prevalence of, and risk factors for, genital Human Papillomavirus (HPV) infections within the young adult population are well-established; the same is not known for oral HPV. This observational study aimed to determine oral HPV prevalence and abundance within a UK young adult population, and examine if sexual practices and established risk factors of oropharyngeal squamous cell carcinomas (OPSCCs) (such as smoking and alcohol consumption) influenced HPV prevalence.

METHODS

Convenience sampling was used to recruit a small sample of 452 UK-based young adults studying at a higher education (HE) institution to the study; the study was not powered. A highly sensitive real-time PCR HPV screening method was developed for the detection of multiple HPV subtypes from oral swabs. HPV-positive samples were subsequently screened by qPCR for viral subtypes HPV-6, HPV-11, HPV-16, HPV-18. Results were analysed by univariate and multivariate methods and stratified for gender, with lifestyle behaviour data collected via questionnaire. Socio-economic status was not captured within the questionnaire.

RESULTS

We found a high oral HPV prevalence of 22.79%, with a dominance of high-risk viral type HPV-16 (prevalence 19.12%; abundance average 1.08 × 105 copies/million cells) detected within healthy young adults. Frequent smoking (p = .05), masturbation (p = .029), and engagement in multiple sexual activities (p = .057), were found to be associated with oral HPV prevalence, and HPV-16 prevalence, whilst behaviours traditionally associated with genital HPV were not.

CONCLUSIONS

Our results strengthen the link between sexual practices and oral HPV transmission. We suggest that young adults should be considered high-risk for the contraction of oral HPV, although acknowledge that this sample of HE students may not be representative of the wider population. We show that high-risk HPV-16 is prevalent in the healthy population, as well as dominating within OPSCC; this study is one of the first to determine the dominance of oral HPV-16 prevalence and abundance within this population, presenting a clear need for greater awareness of oral HPV infections, and the risk factors for HPV-positive OPSCC within young adults.

Human papillomavirus in the setting of immunodeficiency: Pathogenesis and the emergence of next-generation therapies to reduce the high associated cancer risk

Human papillomavirus (HPV), a common sexually transmitted virus infecting mucosal or cutaneous stratified epithelia, is implicated in the rising of associated cancers worldwide. While HPV infection can be cleared by an adequate immune response, immunocompromised individuals can develop persistent, treatment-refractory, and progressive disease. Primary immunodeficiencies (PIDs) associated with HPV-related disease include inborn errors of GATA, EVER1/2, and CXCR4 mutations, resulting in defective cellular function. People living with secondary immunodeficiency (e.g. solid-organ transplants recipients of immunosuppression) and acquired immunodeficiency (e.g. concurrent human immunodeficiency virus (HIV) infection) are also at significant risk of HPV-related disease. Immunocompromised people are highly susceptible to the development of cutaneous and mucosal warts, and cervical, anogenital and oropharyngeal carcinomas. The specific mechanisms underlying high-risk HPV-driven cancer development in immunocompromised hosts are not well understood. Current treatments for HPV-related cancers include surgery with adjuvant chemotherapy and/or radiotherapy, with clinical trials underway to investigate the use of anti-PD-1 therapy. In the setting of HIV co-infection, persistent high-grade anal intraepithelial neoplasia can occur despite suppressive antiretroviral therapy, resulting in an ongoing risk for transformation to overt malignancy. Although therapeutic vaccines against HPV are under development, the efficacy of these in the setting of PID, secondary- or acquired- immunodeficiencies remains unclear. RNA-based therapeutic targeting of the HPV genome or mRNA transcript has become a promising next-generation therapeutic avenue. In this review, we summarise the current understanding of HPV pathogenesis, immune evasion, and malignant transformation, with a focus on key PIDs, secondary immunodeficiencies, and HIV infection. Current management and vaccine regimes are outlined in relation to HPV-driven cancer, and specifically, the need for more effective therapeutic strategies for immunocompromised hosts. The recent advances in RNA-based gene targeting including CRISPR and short interfering RNA (siRNA), and the potential application to HPV infection are of great interest. An increased understanding of both the dysregulated immune responses in immunocompromised hosts and of viral persistence is essential for the design of next-generation therapies to eliminate HPV persistence and cancer development in the most at-risk populations.

The Key Differences between Human Papillomavirus-Positive and -Negative Head and Neck Cancers: Biological and Clinical Implications

Head and neck squamous cell carcinoma (HNSCC) is a unique malignancy associated with two distinct risk factors: exposure to typical carcinogens and infection of human papillomavirus (HPV). HPV encodes the potent oncoproteins E6 and E7, which bypass many important oncogenic processes and result in cancer development. In contrast, HPV-negative HNSCC is developed through multiple mutations in diverse oncogenic driver genes. While the risk factors associated with HPV-positive and HPV-negative HNSCCs are discrete, HNSCC patients still show highly complex molecular signatures, immune infiltrations, and treatment responses even within the same anatomical subtypes. Here, we summarize the current understanding of biological mechanisms, treatment approaches, and clinical outcomes in comparison between HPV-positive and -negative HNSCCs.