Immunological studies in epidermodysplasia verruciformis.

Immunofluorescence and cell mediated immunity studies have been performed in 14 cases of epidermodysplasia verruciformis (EV), 3 of those abortive or regressing in members of the families of the patients with EV. Two different types of human papillomavirus (HPV)--HPV3 and HPV4--have been found in cases of EV. HPV3 was detected also in flat warts without features of EV. There was no cross-reactivity between these two viruses, neither with HPV1 responsible for plantar warts nor with HPV2 inducing common warts. There was a relationship between the type of HPV and the clinical picture of EV as well as the malignant transformation, namely HPV4 has been found to be more oncogenic. Cell mediated immunity (CMI) seems to be an important factor because it was depressed in a vast majority of active cases and preserved in regressing and abortive cases (in the members of the families of EV patients). However, low CMI has been found in EV cases infected with HPV3 and in persistent flat warts also due to HPV3, which did not undergo malignant transformation. In contrast, in a case of EV due to HPV4 a malignant transformation occured in spite of still preserved, although lowered CMI. Various human papillomaviruses seem to differ in their oncogenic potential. HPV1 responsible for plantar warts, and HPV2 for common warts have no evident oncogenic potential, HPV3 inducing both EV and flat warts has a low oncogenicity, whereas HPV4 inducing some cases of EV seems more oncogenic.