Until the introduction of the quadrivalent HPV vaccine in the Danish childhood vaccinationprogram in 2009, the incidence of ano-genital warts increased parallel to many other sexual transmitted diseases (STDs) like chlamydia, gonorrhea and syphilis, but has now declined among young vaccinated women, whereas the incidence of the other STDs continues to increase. Also among young men, the incidence has declined as they are indirectly protected by “herd protection”. The incidence has remained unchanged among the non-vaccinated populations. In the Clinic of Sexual transmitted diseases at Bispebjerg Hospital we have also noted a significant decline in the number of treatments for ano-genital warts in this period of time, but still we treat many patients who have experienced a high number of recurrences or unsuccesfull treatments for ano-genital warts. It is known that men, who have sex with men (MSM), and especially hiv-infected MSM are at an increased risk of precancer lesions in the anal canal caused by oncogenic HPV types.
Few studies have been published among the risk of ano-genital warts or precancer lesions among organ transplant recipients.
In coorperation with The Danish Cancer Society we are studying the risk of HPV, ano-genital warts and precancer lesions among renal transplant recipients compared to healthy controls, conducted as register-based studies, and in a clinical study. The clinical study includes 250 renal transplant recipients and 250 healthy controls. We will try to identify factors associated with the development of ano-genital warts and anal or cervical precancer lesions.
All participants are tested for ano-genital and oral HPV, anal and cervical cytology. All participants are examined for the presence of ano-genital warts and with a colposcopic examination of the anal canal called high-resolution anoscopy for the presence of anal precancer lesions, which still is only used for research purpose in Denmark.
High resolution anoscopy might have a potential as a future screening tool for anal precancer lesions in Denmark for high-risk populations.