Immunohistochemical study of HLA-DR antigen in endometrial tissue of patients with endometriosis.

In order to evaluate the expression of HLA-DR antigen in glandular cells in eutopic and ectopic endometrium in patients with endometriosis, 19 infertile patients with endometriosis were analyzed immunohistochemically by labelled streptavidin biotin (LSAB) method. Nineteen infertile patients without endometriosis were studied as controls. The results showed that the expression of HLA-DR antigen in the glandular cells in both eutopic and ectopic endometrium was increased significantly as compared with that in the controls (P < 0.01). It is likely that aberrant expression of HLA-DR antigen in endometriotic tissue is involved in abnormal immunogenesis of endometriosis.