Products of the Major Histocompatibility Complex and CD4/CD8 Cell Infiltration in Cervical Intraepithelial Neoplasia and in Cervical Carcinoma.

OBJECTIVE

Major histocompatibility complex (MHC) products and the CD4/CD8 cell ratio in the lymphocyte infiltrate in cervical preneoplastic and neoplastic lesions are investigated to determine the correlation between the infiltration of lymphocytes in subepithelial stromal tissue and the expression of MHC class I and MHC class II antigens on epithelial cells.

METHODS

The expression of MHC products and the lymphocyte infiltration were studied by an indirect immunohistochemical staining (alkaline phosphataseanti-alkaline phosphatase) in 6 biopsies of normal cervical squamous epithelium, in 22 biopsies of cervical intraepithelial neoplasia (CIN), and in 9 biopsies of cervical carcinoma. Immunohistochemically positive lymphocytes were counted in highpower fields. The density of MHC expression in CIN and cervical carcinoma was described semiquantitatively in the histological slides.

RESULTS

We have seen a number of differences in the expression of MHC products between normal cervical squamous epithelium and CIN or cervical carcinoma. Our results also show that the CD4/CD8 cell ratio in normal, in dysplastic, and in malignant cervical tissues differs from peripheral blood. We found statistically significant differences (Mann Whitney U test, p < .05) between the CD4/CD8 ratio of the normal epithelium when compared to the preneoplastic and neoplastic cervical lesions. In the histological sections tested, CD8 cells exceeded the number of CD4 cells in CIN and cervical carcinoma. Expression of MHC products is independent of the infiltration of CD4 and CD8 cells in the tissue of low-grade and high-grade cervical squamous intraepithelial lesions (SILs) and in cervical carcinoma.

CONCLUSIONS

We found a significant decrease of the CD4/CD8 cell ratio in low-grade SILs, high-grade SILs, and squamous cell carcinoma compared to normal cervical epithelium. The loss of MHC class I antigen expression in poorly differentiated tumor cells does not correlate with the amount of lymphocyte infiltration.