Chagas disease and systemic autoimmune diseases among Bolivian patients in Switzerland

Yves Jackson, Drenusha Vieira de Mello Pula, Axel Finckh, Carlo Chizzolini, François Chappuis

Chronic cardiomyopathy occurs in 20-40% of the patients with Chagas disease. Autoimmune mechanisms may contribute to its pathogenesis. We diagnosed several cases of systemic autoimmune diseases among Bolivian migrants in Geneva with a high prevalence of Chagas disease. We tested the hypothesis of a clinical association between systemic autoimmune diseases and Chagas disease, particularly with the development of cardiomyopathy. We retrospectively searched the medical records of all Bolivian patients visiting Geneva University Hospitals between 2012 and 2015 for diagnosis of Chagas disease or systemic autoimmune diseases. Of the 2,189 eligible patients, 28 [1.3%; 95% confidence interval (CI) = 0.9-1.9%] presented with systemic autoimmune disease. The Chagas status was known in 903 (41.3%) patient, of whom 244 (27.0%; 95% CI = 24.2-30.0%) were positive. Eight (28.6%; 95% CI = 15.3-47.1%) of the 28 cases of systemic autoimmune disease had Chagas disease. We found no association between both entities (p = 1.000) or with Chagasic cardiomyopathy (p = 0.729). Moreover, there was no evidence of a temporal relationship between antiparasitic chemotherapy and the development of systemic autoimmune diseases. Our results do not support a clinical association between chronic Chagas disease and systemic autoimmune diseases. However, prospective studies in areas endemic for Chagas disease should better assess the prevalence of systemic autoimmune diseases and thus a possible relationship with this infection.