HLA I expression raised in endometriosis

February 2006

Researchers in Barcelona suggest that expression of class I human leukocyte antigen (HLA I) is significantly higher in endometrial samples from patients with endometriosis than in those from other people.

In a cross sectional study, 32 patients who underwent an operation were diagnosed as having only endometriosis were enrolled, alongside a control group of 20 women who underwent laparoscopy and were found to have no evidence of endometriosis or any other genital disease. Samples of endometrium were obtained by curettage and immediately frozen. A pan-HLA I mouse antihuman IgG2a monoclonal antibody was used for immunohistochemical study.

María Del Mar Vernet-Tomás, who lead the team of researchres, found that there was significantly higher expression of HLA I in endometriosis patients than in controls, at 100%and 80%respectively. In stromal cells, the same pattern was observed, at a median of 60%and 20%, respectively.

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.


Vernet-Tomas del M, Perez-Ares CT, Verdu N, Molinero JL, Fernandez-Figueras MT, Carreras R. The endometria of patients with endometriosis show higher expression of class I human leukocyte antigen than the endometria of healthy women. Fertility and Sterility 2006; 85: 78-83.

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