The subtypes, distribution and location of human papillomavirus DNA in genital warts and genital Bowen's disease--a study using in situ DNA.DNA hybridization.

The aim of this study is to investigate the difference in subtypes and distribution of human papillomavirus (HPV) between the benign pathological condition- Genital wart (condyloma acuminatum, verruca- like lesion and papular lesion) and genital Bowen's disease (Bowenoid papulosis, Mollucum contagiosum with Bowenoid papulosis and Condyloma acuminatum with verruca- like lesion and pathological bowenoid change) of genitalia by in situ DNA.DNA hybridization. In situ DNA.DNA hybridization was performed by hybridizing the RNAse treated and denatured frozen skin section with 3H-labeled HPV 6, 11, 16 and 18-DNAs probes and then developed autoradiogram on a glass slide. The results reveal that: (1) The benign cases are strongly associated with HPV 6/11, while the bowenoid cases are associated with HPV 16/18, indicating 16 positive in 24 cases and 3 positive in 5 cases respectively; (2) Four of sixteen benign cases were doubly infected with HPV 6/11 and 16/18; and 2 of 2 bowenoid cases were infected with HPV 16/18 only (3) In benign cases, HPV distributes through the upper third of epidermis and in bowenoid cases, HPV scatters throughout the whole epidermis including parabasal layers. These findings may indicate that the subtypes of HPV, the interaction of weak oncogenic virus (HPV 6/11) and strong oncogenic virus (HPV 16/18) and the presence of HPV on proliferating cells (parabasal layers) all play a part in oncogenicity. The detectability of HPV 6/11 DNA in both the nucleus and cytoplasm indicate that: 1). In situ DNA.DNA hybridization is a more sensitive method than the immunological detection of capsid antigen. 2). In addition to the nucleus, the cytoplasm is a site through which HPV 6/11 virus should pass during their life cycle. Using PEG hybridization mixture, it was revealed that 6 of the 6 HPV 6/11 positive condyloma acuminata harbored HPV 6. This result indicates that the subtype of HPV determine the gross morphology of skin lesion.