Incidence of Autoimmune Diseases in Celiac Disease: Protective Effect of the Gluten-Free Diet

Background & Aims: Celiac disease may be associated with autoimmune diseases. The aims of the present study were to determine in celiac patients which factors modulate the risk of autoimmune disease and to evaluate the effect of the gluten-free diet. Methods: The occurrence of autoimmune disease and compliance to gluten-free diet were specified retrospectively in 924 celiac patients recruited from 27 French pediatric and adult gastroenterology centers. Results: One or several autoimmune diseases had developed in 178 patients. The cumulative risk of autoimmune disease was 8.1% ± 1% at age 15, and 15.7% ± 1.5% at age 30. Factors associated with an increased risk were family history of autoimmunity (hazard ratio, 2.36; 95% confidence interval, 1.71-3.31) and diagnosis of celiac disease before 36 years of age (hazard ratio, 2.65; 95% confidence interval, 1.79-3.85). After diagnosis of celiac disease, 55 of 788 patients developed an autoimmune disease. The cumulative risk of subsequent autoimmune disease was lower in patients compliant to a gluten-free diet versus noncompliant patients (at 10 years, 6% ± 2% vs 15.6% ± 5.9%, respectively; P = .02). The incidence of autoimmune diseases was 5.4 per 1000 patient-years during adherence to a gluten-free diet versus 11.3 per 1000 patient-years during nonadherence to the diet (P = .002). Results were similar in both the pediatric and the adult populations. Conclusions: Celiac patients most at risk for autoimmune disease are those diagnosed early in life and having a family history of autoimmunity. The gluten-free diet has a protective effect.