Angiogenesis and vasodilation in skin warts. Association with HPV infection

Angiogenesis is required for tumour growth. Since human papillomavirus (HPV) infection is associated with the development of neoplastic lesions, the aim of this study was to determine the possible association between HPV infection and angiogenesis in benign tumours.

Specimens of skin warts which were either negative for HPV types 1, 2, 3 and 4 (HPV-ve; n = 15), or positive for HPV2 (HPV+ve; n = 19) were compared with normal skin (NS, n = 10). Vascularity and inflammation were assessed in consecutive sections. vWF-positive blood vessels were classified as small or large using a cut-off value of 50 microns diameter.

Vascularity values for small vessels increased significantly from NS to HPV-ve warts and from HPV-ve to HPV+ve warts. Large vessels were found only in warts and their abundance was not related to HPV status. No significant association was found between vascularity and inflammation or between vascularity values for small and large vessels.

The development of skin warts is accompanied by angiogenesis and vasodilation and these two processes may be independently regulated. Further increased angiogenesis, but not vasodilation, is associated with the presence of HPV type 2 DNA.