Human papillomavirus in paired normal and abnormal cervical biopsies--implications for treatment.

A total of 143 consecutive patients with abnormal cervical cytology was examined at a large colposcopy clinic in Glasgow. Each patient had paired biopsies from normal and abnormal cervical epithelium examined both histologically and by immunoperoxidase staining for human papillomavirus (HPV) infection. More than 71% of the abnormal biopsies and 39% of the normal paired biopsies had histological evidence of HPV infection. Cytological evidence of HPV infection was seen in 38.5% of cervical smears. Immunocytochemistry revealed HPV antigen in 22% of the abnormal biopsies and in 4.2% of the 'normal' biopsies. The presence of HPV infection in colposcopically normal cervical tissue both inside and outside the transformation zone may help to explain why current methods for treatment of cervical HPV infection are often unsuccessful.