THE EXPRESSION OF HLA-DR ANTIGEN IN CERVICAL NEOPLASIA

The purpose of this study was to evaluate the relationship between cer vical neoplasia and HLA-DR antigen (class 11 antigen) expression. Seve nty-seven formaldehyde-fixed uterine specimens comprising morphologica lly normal cervix (12), chronic cervicitis (10), cervical intraepithel ial 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 epi thelium. The nonneoplastic ectocervical squamous epithelium was consis tently negative for HLA-DR antigen, even in sections showing significa nt lymphoplasmacytic infiltration. We found HLA-DR antigen positivity in endocervical glandular epithelium, immature metaplastic squamous ep ithelium, CIN, and invasive carcinoma. In cases of CIN, the aberrant e xpression of the antigen generally corresponded to the level of dyspla sia. Specific cells exhibiting koilocytic change were negative. All th e cases of squamous cell carcinoma expressed the antigen, albeit varia ble in intensity and distribution. These findings suggest that aberran t HLA-DR antigen expression in the uterine ectocervix may be a consequ ence of dysplastic changes of the squamous epithelium that is maintain ed even after malignant transformation. On the other hand, HLA-DR posi tivity in immature metaplastic epithelium is probably a mere reflectio n of the fact that normal endocervical glandular epithelium can expres s the antigen.