The depolarized expression of the alpha-6 integrin subunit in the endometria of women with endometriosis.

OBJECTIVE: The current study sought to compare the endometrial localization of the integrin subunit alpha-6 in women with endometriosis and women without the disease. Alpha-6 integrins have an important function, not only in the attachment of cells to the extracellular matrix and laminin, but they also serve as inductors of cell migration and invasion, depending on their pattern of expression in the cell membrane. METHODS: The endometriosis group consisted of 32 women with a confirmed diagnosis of endometriosis by laparoscopy or laparotomy. The control group consisted of 20 women not having endometriosis or any other gynecologic disease at laparoscopy. Endometria were obtained by biopsy. Immunohistochemical techniques were used to assess alpha-6 localization. In each section, the percentage of positive cells and the localization of expression were evaluated. RESULTS: All glandular cells expressed alpha-6 in all of the samples but presented two different patterns, either only in the basal side of the cells (polarized) or also in other sides of the cells (depolarized). The percentage of samples showing depolarized expression was significantly higher in the endometriosis group (66.6% vs 15.8%, chi2 =12.09, P = .001). CONCLUSIONS: The endometria of women with endometriosis more frequently show a depolarized expression of integrin subunit alpha-6, a characteristic usually found in highly proliferating cells with migrating and invasive abilities.

The endometria of patients with endometriosis show higher expression of class I human leukocyte antigen than the endometria of healthy women.

OBJECTIVE: To compare the expression of class I human leukocyte antigen (HLA I) in endometrial samples from patients with and without endometriosis. DESIGN: Cross-sectional study. SETTING: Acute-care teaching hospital in Barcelona, Spain. PATIENT(S): The endometriosis group included 32 patients for whom the only diagnosis during an operation was endometriosis. The control group included 20 women who underwent a laparoscopy and in whom no evidence of endometriosis or any other genital disease was seen. INTERVENTION(S): Samples of endometrium were obtained by curettage and immediately frozen. A pan-HLA I mouse antihuman IgG2a monoclonal antibody was used for immunohistochemical study. MAIN OUTCOME MEASURE(S): Frequency of positive glandular and stromal cells was evaluated in each section. RESULT(S): A significantly higher expression of HLA I in the endometriosis group than in controls, both in the glandular cells (median 100% vs. 80%) and in the stromal cells (median 60% vs. 20%), was observed. CONCLUSION(S): Patients with endometriosis had a significantly higher expression of HLA I molecules in endometrial cells than did the controls. This could be a possible explanation for their higher resistance to natural killer cytolysis.