The expression of HLA-DR antigen in cervical neoplasia

The purpose of this study was to evaluate the relationship between cervical neoplasia and HLA-DR antigen (class II antigen) expression. Seventy-seven formaldehyde-fixed uterine specimens comprising morphologically normal cervix (12), chronic cervicitis (10), cervical intraepithelial neoplasia (CIN) of various grades (42), and invasive squamous cell carcinoma (13) were studied for the degree and type of inflammation, and immunohistochemically for the HLA-DR antigen expression in the epithelium. The nonneoplastic ectocervical squamous epithelium was consistently negative for HLA-DR antigen, even in sections showing significant lymphoplasmacytic infiltration. We found HLA-DR antigen positivity in endocervical glandular epithelium, immature metaplastic squamous epithelium, CIN, and invasive carcinoma. In cases of CIN, the aberrant expression of the antigen generally corresponded to the level of dysplasia. Specific cells exhibiting koilocytic change were negative. All the cases of squamous cell carcinoma expressed the antigen, albeit variable in intensity and distribution. These findings suggest that aberrant HLA-DR antigen expression in the uterine ectocervix may be a consequence of dysplastic changes of the squamous epithelium that is maintained even after malignant transformation. On the other hand, HLA-DR positivity in immature metaplastic epithelium is probably a mere reflection of the fact that normal endocervical glandular epithelium can express the antigen.