Risk of Anal High-grade Squamous Intraepithelial Lesions Among Renal Transplant Recipients Compared With Immunocompetent Controls

Background: Renal transplant recipients (RTRs) have increased risk of human papillomavirus (HPV)-related cancers, including anal cancer. We investigated the prevalence of anal high-grade intraepithelial lesions (HSILs) in RTRs compared with immunocompetent controls and risk factors for anal HSIL in RTRs.

Methods: We included 247 RTRs and 248 controls in this cross-sectional study. We obtained anal samples for HPV testing with INNO-LiPA and performed high-resolution anoscopy on all participants. The participants completed a questionnaire on lifestyle and sexual habits. We used logistic regression to estimate odds ratios (ORs) of histologically confirmed anal HSIL in RTRs vs controls and risk factors for anal HSIL in RTRs, stratified by sex and anal high-risk (hr) HPV status, adjusting for age, smoking, lifetime sexual partners, and receptive anal sex.

Results: RTRs had higher anal HSIL prevalence than controls, both among men (6.5% vs 0.8%; adjusted OR [aOR], 11.21 [95% confidence interval {CI}, 1.46-291.17]) and women (15.4% vs 4.0%; aOR, 6.41 [95% CI, 2.14-24.10]). Among those with anal hrHPV, RTRs had higher anal HSIL prevalence than controls (33.8% vs 9.5%; aOR, 6.06 [95% CI, 2.16-20.27]). Having had receptive anal sex (aOR, 6.23 [95% CI, 2.23-19.08]) or genital warts (aOR, 4.21 [95% CI, 1.53-11.48]) were risk factors for anal HSIL in RTRs. All HSIL cases occurred in individuals with anal hrHPV.

Conclusions: RTRs had increased risk of anal HSIL compared with immunocompetent controls, with particularly high prevalence in female RTRs. Receptive anal sex, previous genital warts, and anal hrHPV infection were risk factors for anal HSIL in RTRs. Screening for anal HSIL in RTRs should be considered.

Clinical trials registration: NCT03018927.