Coexistence of immune-mediated diseases in sarcoidosis. Frequency and clinical significance in 1737 patients.

OBJECTIVE: To analyze whether immune-mediated diseases (IMDs) occurs in sarcoidosis more commonly than expected in the general population, and how concomitant IMDs influence the clinical presentation of the disease.

METHODS: We searched for coexisting IMDs in patients included in the SARCOGEAS-cohort, a multicenter nationwide database of consecutive patients diagnosed according to the ATS/ESC/WASOG criteria. Comparisons were made considering the presence or absence of IMD clustering, and odds ratios (OR) and their 95% confidence intervals (CI) were calculated as the ratio of observed cases of every IMD in the sarcoidosis cohort to the observed cases in the general population.

RESULTS: Among 1737 patients with sarcoidosis, 283 (16%) patients presented at least one associated IMD. These patients were more commonly female (OR: 1.98, 95% CI: 1.49-2.62) and were diagnosed with sarcoidosis at an older age (49.6 vs. 47.5years, P<0.05). The frequency of IMDs in patients with sarcoidosis was nearly 2-fold higher than the frequency observed in the general population (OR: 1.64, 95% CI: 1.44-1.86). Significant associations were identified in 17 individual IMDs. In comparison with the general population, the IMDs with the strongest strength of association with sarcoidosis (OR>5) were common variable immunodeficiency (CVID) (OR: 431.8), familial Mediterranean fever (OR 33.9), primary biliary cholangitis (OR: 16.57), haemolytic anemia (OR: 12.17), autoimmune hepatitis (OR: 9.01), antiphospholipid syndrome (OR: 8.70), immune thrombocytopenia (OR: 8.43), Sjögren syndrome (OR: 6.98), systemic sclerosis (OR: 5.71), ankylosing spondylitis (OR: 5.49), IgA deficiency (OR: 5.07) and psoriatic arthritis (OR: 5.06). Sex-adjusted ORs were considerably higher than crude ORs for eosinophilic digestive disease in women, and for immune thrombocytopenia, systemic sclerosis and autoimmune hepatitis in men.

CONCLUSION: We found coexisting IMDs in 1 out of 6 patients with sarcoidosis. The strongest associations were found for immunodeficiencies and some systemic, rheumatic, hepatic and hematological autoimmune diseases.