Alterations in the expression of selected MHC antigens in premalignant lesions and squamous carcinomas of the uterine cervix

Abstract

Background: The objective of the study was to determine whether there is a correlation between expression of selected major histocompatibility complex (MHC) antigens and the presence of carcinoma and premalignant lesions of the cervix. We also attempted to determine whether there is a correlation between expression of the selected MHC antigens in each grade of cervical intraepithelial neoplasia (CIN) and invasive carcinoma of the cervix.

Methods: Quantitative comparative analysis of MHC class I and class II expression between specimens of the uterine cervix was carried out. For detecting human leukocyte antigen (HLA) class I molecules, two primary antibodies were used, recognizing either epitopes of all free heavy chain class I molecules or epitopes of the HLA-Bw4 antigen. HLA class II antigens were detected by antibodies reacting with the alpha-chain of the HLA-DR molecule. An indirect immunoperoxidase technique was carried out using paraffin-embedded sections. The following groups of sections were formed: squamous metaplasia, CIN of different grades, and invasive carcinoma. The specimens were taken from women in whom routine histopathologic diagnosis of cervical lesions had been performed.

Results: A significant decrease in the mean number of stained cells showing expression of MHC class I antigens (HC 10 and Bw4) was found in the invasive cancer group of specimens. A decrease in Bw4 expression was also found in the CIN III group. The highest expression of the HLA-DR antigens was detected in the metaplastic epithelium compared to the other groups. In the dysplastic epithelium the expression of the HLA-DR antigens was increased in the highest grade of dysplasia (CIN III). Upregulation of HLA-DR expression was detected in invasive cancer specimens.

Conclusions: Alterations in MHC expression are found in premalignant lesions and squamous carcinomas of the uterine cervix. Quantitative assessment with the use of an image analysis system is valuable in helping to discriminate staining patterns of HLA expression. Further studies are indicated to evaluate the prognostic value of the expression of selected MHC antigens.