Dysplastic epidermal change in immunosuppressed patients with renal transplants.

The prevalence of non-melanoma skin cancer has been studied in a group of 85 patients who have undergone renal transplantation. We also investigated the relationship between the development of neoplastic lesions and the duration of immunosuppression, previous sun exposure and infection with human papilloma virus. The overall prevalence of neoplastic and pre-neoplastic epidermal lesions in the group was 25 per cent, higher than that previously reported in studies from the United Kingdom. In patients who had survived for more than 80 months after transplantation the prevalence of these lesions was 38 per cent. There was no apparent relationship between sun exposure or skin type and the development of cutaneous neoplasia, despite the fact that the majority of lesions were found on sun-exposed sites. Exposure to ultraviolet radiation (UVR) is probably important as an initiator or co-factor rather than as a precipitant. In both sexes, high sun exposure was associated with the presence of viral warts. In females, there was a strong association between the presence of viral warts and the occurrence of neoplastic lesions elsewhere, giving support to the hypothesis that ultraviolet radiation may be acting as a co-factor in virally-mediated oncogenesis. Epidermal cell kinetic studies in 39 patients using in-vitro exposure to 3H thymidine and autoradiographic techniques showed no difference between the patients with neoplastic lesions and unaffected patients, and is not therefore a useful method of identifying an 'at risk' group.