Ex vivo analyses of ano-genital wart lymphocytes to study the human papillomavirus immune response.

Sir, Human papillomavirus (HPV) is the causative agent of certain benign and malignant tumours. HPV subtypes 6 and 11 cause approximately 90% of cases of genital warts (the most common sexually transmitted disease) (1, 2) and virtually all cases of recurrent respiratory papillomatosis (3, 4). They are classified as low-risk for carcinogenesis, whilst the high-risk subtypes, such as 16 and 18, cause approximately 70% of cases of cervical cancer worldwide (5, 6). There has been intense public interest recently in the HPV prophylactic vaccines for the prevention of cervical cancer (7, 8). Since HPV infection is primarily a peripheral infection (and not a systemic one), the study of the immune response at the site of infection is a necessity in understanding and designing better therapies. We have examined the feasibility of studying the lymphocytes infiltrating ano-genital warts as a model for studying HPV infection and associated immune responses in the periphery.