Expression of major histocompatibility complex class II antigen in endometriotic tissue in patients with endometriosis and adenomyosis

OBJECTIVE: To evaluate the expression of major histocompatibility complex class II antigen (human leukocyte antigen, HLA-DR) in glandular cells in eutopic and ectopic endometria in patients with endometriosis and adenomyosis. PATIENTS: Subjects consisted of 50 patients with adenomyosis and 18 patients with endometriosis. Controls consisted of 17 patients with adenomyoma and 42 infertile women without habitual abortion and autoimmune diseases. DESIGN: Glandular cells in eutopic and ectopic endometria were analyzed immunohistochemically to localize the expression of HLA-DR antigen. The sections were scored from 0 to 5 according to the evaluation nomogram. RESULTS: Immunohistochemical analysis revealed significantly increased expression of HLA-DR antigen in the glandular cells in eutopic and ectopic endometria, compared with materials from patients with adenomyoma and infertile patients. CONCLUSIONS: It is likely that aberrant expression of HLA-DR antigen in glandular cells of eutopic and ectopic endometria in endometriosis and adenomyosis is deeply involved in various immunological abnormalities.