Background
Kidney transplant recipients (KTRs) have increased risk of human papillomavirus (HPV)-related cancers, including cervical and anal cancer. In this cross-sectional clinical study, we investigated the prevalence of cervical high-risk HPV (hrHPV) and low-risk (lrHPV), risk factors for cervical hrHPV infection, and the prevalence of cervical and anal hrHPV co-infection in KTRs and immunocompetent controls.

Methods
During 2016–2017, we recruited 125 female KTRs and 125 female immunocompetent controls from one dermatology department (KTRs and controls) and five nephrology departments (KTRs) in Denmark. Liquid-based cervical and anal cytology samples were tested for HPV DNA using the INNO-LiPA test and participants answered a questionnaire on lifestyle. Odds ratios (ORs) were estimated using logistic regression, adjusting for age, lifetime sexual partners, smoking, and (in models concerning anal HPV) receptive anal sex.

Results
KTRs had higher prevalence of cervical hrHPV than controls (35.5% vs. 18.2; ORadjusted = 2.9, 95% CI, 1.5–5.5). In contrast, the prevalence of lrHPV was similar in KTRs and controls (25.6% vs. 23.1; ORadjusted = 1.2, 95% CI, 0.7‒2.3). KTRs were more likely than controls to have cervical and anal hrHPV co-infection (27.3% vs. 6.6%, ORadjusted = 6.3, 95% CI, 2.7–15.0).

Conclusions
Female KTRs had high prevalence of cervical hrHPV, and co-infection with anal and cervical hrHPV was common. Our results underline that KTRs are an important target group for preventive efforts against HPV-related diseases.