Chlamydial cervicitis and cervical intraepithelial neoplasia: an immunohistochemical analysis.

Studies using serological and culture techniques indicate that chlamydial infection is frequently associated with cervical intraepithelial neoplasia (CIN). This relationship was investigated by examining a series of biopsies containing normal epithelium, non-neoplastic condylomatous epithelium, and neoplastic epithelium (CIN). In each case the degree of inflammation and the presence of reparative atypia were recorded from an examination of the hematoxylin and eosin stained sections and serial sections were stained for chlamydial antigens using a polyclonal antichlamydial antibody and the immunoperoxidase technique. Overall, staining for chlamydia was positive in 0, 2, and 16% of biopsies with mild, moderate, and severe inflammation, respectively. In cases of severe inflammation positive staining was present in 20, 25, and 8% of biopsies containing non-neoplastic, condylomatous, and neoplastic epithelium, respectively. In all positive cases the staining was most prevalent in areas of the most intense inflammation. A spectrum of squamous epithelial changes was found in the infected biopsies and their distinction from CIN is discussed. This study suggests that tissue staining for chlamydia is related more to the extent of the coexisting inflammation than the presence or absence of CIN. Chlamydial infection, however, was frequently associated with inflammation-related squamous atypia in the transformation zone, which may be confused histologically with CIN.