T cell defect in patients with epidermodysplasia verruciformis due to human papillomavirus type 3 and 5.

Most of the patients with epidermodysplasia verruciformis (EV) were anergic to sensitization to dinitrochlorobenzene (DNCB) and were shown to have a decreased number of T lymphocytes and reduced lymphocyte PHA responsiveness. Preserved cell-mediated immunity (CMI) was found only in the abortive cases of EV infected with human papillomavirus type 3 (HPV-3). CMI was impaired to the same extent in patients with EV induced by HPV-3 and HPV-5, and in EV cases with combined infection with both viruses. In contrast to this, malignant transformation, i.e. of Bowen's carcinoma type, was observed only in the 7 patients infected with HPV-5. This could indicate that malignancy in EV is related rather to the oncogenic potential of HPV-5 type than to the extent of T cell defect that was similar in both EV varieties due to HPV-3 and HPV-5.