Do epidermodysplasia verruciformis human papillomaviruses contribute to malignant and benign epidermal proliferations?

The aim of this review is to present new data on epidermodysplasia verruciformis (EV) and EV human papillomaviruses (HPVs), regarded previously as specific to the disease. Recently introduced highly sensitive molecular methods for virologic studies allow detection of EV HPVs in non-EV populations. In this article, we present the most recent findings on EV and EV HPVs, which shed new light on a possible contribution of EV viruses to malignant and benign epidermal proliferation. We discuss the significance of EV HPV DNA detection in premalignant cutaneous lesions and nonmelanoma skin cancers; however, direct evidence for the causative role of EV HPV is still not available. In psoriasis, a high frequency of EV HPV-5 and other EV HPVs in the skin and the presence of specific HPV-5 antibodies strongly suggest expression of EV HPV proteins in this extensive epidermal proliferation. Epidermodysplasia verruciformis HPV-5 may also be transiently expressed in epidermal repair processes, whereas in psoriasis there is a continuous epidermal proliferation that could result in persistent viral expression. A potential contribution of EV HPVs to the pathogenesis of psoriasis is also supported by the recently disclosed co-localization of susceptibility loci for psoriasis and EV in the same region of chromosome arm 17qter; however, specific genes for both conditions are still not identified.