Autoimmune thyroid disorders (AITD) are the most common autoimmune human disorders as the thyroid gland is a main target for autoimmunity. The association between rheumatologic and thyroid disorders has long been known, the most common being the association with rheumatoid arthritis. Our study was conducted to screen for the presence of symptoms, signs, and immune markers suggesting the presence of Sjogren's syndrome among patients with autoimmune thyroid disorders. Eighty AITD patients (46 patients with Hashimoto's thyroiditis and 34 patients with Graves' disease) were included in the study and 40 healthy subjects matched age and sex as a control group. The two groups were compared according to 2002 the American-European Consensus Group (AECG) criteria for diagnosis of primary Sjogren's syndrome. 12.5% of AITD patients (n = 10 patients) were diagnosed with Sjogren's syndrome (AITD-SS). Eight out of ten of AITD-SS had Hashimoto's disease while only two had Grave's disease. Anti-Ro was detected in serum of seven patients of the AITD patients with Sjogren syndrome while anti-La was detected in serum of eight patients. The most independent predictors of Sjogren's syndrome in AITD patients are anti-La, ESR, and salivary gland sonographic change. Sjogren's syndrome has been found in patients with AITD, and also patients with AITD have symptoms that mimic sicca disease despite not fulfilling the criteria for diagnosis.
Keywords: Endocrinology; autoantibodies; autoimmune diseases; endocrine system diseases; thyroid diseases.