Anal Human Papillomavirus Infection in Kidney Transplant Recipients Compared With Immunocompetent Controls

HPV-related diseases in male patients: an underestimated conundrum

PURPOSE

Human papillomavirus (HPV) infection is the most common sexually transmitted disease, in males and females worldwide. While the role of HPV in female diseases is well known and largely studied, males have negligibly been included in these programs, also because the proportion of women suffering and dying from HPV-related diseases is much larger than men. The aim of this review is to focus on HPV-related diseases in male patients.

METHODS

We performed a literature analysis on the electronic database PubMed. We considered randomized trials, observational and retrospective studies, original articles having as topic the relationship between HPV male infection and the following items: oral, anal penile cancers, warts, condylomas, male infertility, altered sperm parameters, anti-sperm antibodies (ASA). We also included experimental in vitro studies focused on the effects of HPV infection on oocyte fertilization, blastocyst development, and trophoblastic cell invasiveness. In addition, studies describing the adjuvant administration of the HPV vaccination as a possible strategy to promote HPV clearance from semen in infected males were included.

RESULTS

Regarding head and neck HPV-related diseases, the most important non-neoplastic disease is recurrent respiratory papillomatosis (RRP). Regarding neoplastic diseases, the proportion of head and neck cancers attributable to HPV has increased dramatically worldwide. In addition, nowadays, it is thought that half of head and neck squamous cell carcinomas (HNSCCs) cases in the United States are caused by infection with high-risk HPV. HPV is noteworthy in andrological practice too. It was described as having a high HPV prevalence, ranging between 50 and 70%, in male penile shaft, glans penis/coronal sulcus, semen as well as in scrotal, perianal, and anal regions. Moreover, in male patients, HPV infection has been associated, among other diseases, with penile cancers. HPV semen infection has been reported in about 10% in men from the general population and about 16% in men with unexplained infertility, although these data seem widely underestimated according to clinical experience. In particular, HPV semen infection seems to be most related to asthenozoospermia and to anti-sperm antibodies (ASAs).

CONCLUSIONS

HPV infection represents a health problem with a detrimental social and public impact. Despite this evidence, little has been done to date to widely promote vaccination among young males.

Human papillomavirus infection-related cancer risk for kidney transplant recipients during adult life can be reduced by vaccination during childhood and adolescence

Malignancies are found between the first three reasons of mortality in pediatric and adult kidney transplant recipients, who overall have disproportionately higher rates of cancer compared to the general population, including human papillomavirus (HPV)-related genital, anal and oropharynx region cancers. Therefore, preventing HPV in this patient population is extremely important. HPV-vaccine was demonstrated to prevent HPV infection in individuals with intact immune systems. In addition, recent data reported less precancerous HPV lesions and cervical cancers with use of HPV vaccine. Since HPV is a sexually transmitted virus that is typically acquired shortly after the onset of sexual activity, it is best to administer the HPV vaccine immunization prior to the onset of sexual activity. This article reviews the epidemiology and pathophysiology of the HPV infection, as well as its role in the development of HPV-related pre-cancerous lesions and cancers in both general population and kidney transplant recipients. The focus is on the most effective primary prophylactic strategy, which is the HPV vaccination. The particularities of HPV vaccination strategies in kidney transplant recipients are compared to the general population. In addition, the article analyzes the various causes of suboptimal HPV immunization rates in kidney transplant candidates and recipients and discusses vaccination optimization strategies that can be applied during childhood and adolescence to reduce the burden of HPV-related disease states and cancer among adult kidney transplant recipients.