Anal dysplasia in kidney transplant recipients

Although the risk of anal cancer in immunosuppressed individuals is significantly higher than in the general population, methods for detecting precancerous anal dysplasia have not been well studied in solid-organ transplant recipients. We sought to identify the incidence of anal dysplasia in kidney transplant recipients and associated factors that increase the likelihood of dysplasia.

We prospectively analyzed kidney transplant recipients who had been immunosuppressed for at least 6 months with a functioning allograft. We interviewed willing participants and performed anal cytology sampling and high-resolution anoscopy; if we found microscopic abnormalities, we performed biopsies. We used univariate analysis to measure the association between variables and anal dysplasia.

Of the 40 participants, 15 were women and 25 were men; their mean age was 61 years. Their median duration of immunosuppression was 5.6 years; 23 (59%) had fewer than 5 lifetime sexual partners, and 2 (5%) reported ever practicing anal intercourse. Of all cytology specimens, 35 (88%) had sufficient cells for interpretation and 2 (6%) demonstrated dysplasia. We performed biopsies in 11 patients; 6 had dysplasia (4 low-grade, 2 high-grade). Of these patients, five had normal anal cytology. The sensitivity of cytology to predict histologic evidence of dysplasia was 17%. Overall, seven (18%) had dysplasia according to either cytology or histology specimens; two (5%) had high-grade dysplasia. We found no significant associations between the tested variables and the presence of dysplasia.

A significant proportion of kidney transplant recipients harbor anal dysplasia. One time anal cytology sampling was not predictive of histologic findings. Although these findings confirm their high risk for dysplasia, a larger sample is required to more accurately quantify risk factors for dysplasia and progression to cancer.