Co-occurrence of immune-mediated conditions and endometriosis among adolescents and adult women

Problem: Associations between immune dysfunction conditions (eg, systemic lupus erythematous, rheumatoid arthritis) and endometriosis have been observed in adult women, but not assessed among a younger population. We investigated the association between immune-mediated conditions and endometriosis among young women. Method of Study: This cross-sectional analysis in the Women's Health Study: From Adolescence to Adulthood included 551 participants with surgically diagnosed endometriosis (median age=19) and 652 controls without endometriosis (median age=24). Participants completed an expanded Endometriosis Phenome and Biobanking Harmonization Project questionnaire. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to investigate the associations between autoimmune/inflammatory, atopic, chronic pain/fatigue, and endocrine disorders with endometriosis, adjusting for confounders. Results: Participants with any autoimmune and/or inflammatory condition had an increased odds of co-occurring endometriosis (OR: 1.87; CI: 0.92–3.80), as did participants with allergies (OR: 1.76; CI: 1.32–2.36), asthma (OR: 1.35; CI: 0.97–1.88), chronic fatigue syndrome and/or fibromyalgia (OR: 5.81; CI: 1.89–17.9), or previous mononucleosis (OR: 1.75; CI: 1.14–2.68). Odds of endometriosis were lower among participants with eczema (OR: 0.68; CI: 0.44–1.04). We observed a positive trend between the number of immune-mediated conditions and the odds of endometriosis (p-trend=0.0002). Endocrine disorders were not associated with endometriosis. Conclusions: Among this population of adolescents and adult women, endometriosis was more likely among participants with autoimmune and/or inflammatory diseases, allergies, asthma, previous mononucleosis infection, and chronic fatigue and/or fibromyalgia. We observed that an increasing number of immune-mediated conditions were positively associated with endometriosis risk. It is important for clinicians who care for adolescents and women with these conditions to consider endometriosis as a comorbidity.