Antinuclear antibodies in patients with endometriosis: A cross-sectional study in 94 patients

Markers of autoimmunity, such as autoantibodies, have been found in patients with endometriosis. These include the antinuclear antibodies (ANA). We aimed to evaluate the prevalence of ANA in a sample of patients with endometriosis and its possible clinical associations. Ninety-four patients with endometriosis and 91 controls were studied for ANA and extractable nuclear antigen (ENA; anti-Ro, anti-La, anti-Sm, and anti-RNP) profiles and anti-dsDNA. Epidemiological, clinical, and staging data in endometriosis were obtained. Patients with autoimmune disorders were excluded. Patients with endometriosis had a 21.2% prevalence of positive ANA vs. 5.4% in controls (P = 0.001). The ENA profile and anti-dsDNA were negative. Patients with positive ANA were more asymptomatic (P = 0.03) and had less dysmenorrhea. No associations with disease duration, patient age, or endometriosis stage were found. We found a high prevalence of positive ANA in patients with endometriosis. The presence of this autoantibody may be linked to a milder clinical expression of the disease.