Risk of Anogenital Warts in Renal Transplant Recipients Compared with Immunocompetent Controls: A Cross-sectional Clinical Study.

Renal transplant recipients have increased risk of human papilloma virus-related anogenital (pre)cancers. Less is known about their risk of anogenital warts. The aim of this study was to estimate the prevalence and odds of anogenital warts in renal transplant recipients compared with immunocompetent controls, and to assess risk factors for intra- and perianal warts in renal transplant recipients. The study examined 248 renal transplant recipients and 250 controls for cutaneous and mucosal anogenital warts. Participants completed a questionnaire on lifestyle and sexual habits. For external anogenital warts (including penile, vulvar and perianal warts), renal transplant recipients had higher prevalence and odds than controls, both in men (8.1% vs 1.6%, adjusted odds ratio (ORadjusted)=5.09, 95% confidence interval (95% CI), 1.03-25.04) and women (11.3% vs 1.6%, ORadjusted=8.09, 95% CI 1.69-38.82). For intra-anal warts, there was no clear pattern of higher odds in renal transplant recipients than controls. Current smoking and having had receptive anal sex increased the risk of intra-/perianal warts in renal transplant recipients. In conclusion, renal transplant recipients in this study had higher odds of external anogenital warts than controls.