Rheumatic manifestations of euthyroid, anti-thyroid antibody-positive patients

The aim of this study is to define the rheumatic manifestations of euthyroid patients with chronic lymphocytic thyroiditis (CLT) but without a well-defined connective tissue disease. Forty-six consecutive patients with anti-thyroid peroxidase (αTPO) and/or anti-thyroglobulin antibodies (αTG), and normal thyroid function in the absence of a well-defined connective tissue disease were included in a case–cohort study. Arthralgias were a presenting complaint in 98 % of patients. Fibromyalgia syndrome was found in 59 % of patients. Raynaud’s phenomenon occurred in 28 % and sicca symptoms in 26 % of patients. Two patients had seronegative arthritis resembling rheumatoid arthritis. Arthritis was radiographically present in 88 %, affecting the spine in 45 % of patients. Thyroid-stimulating hormone (TSH) levels positively correlated with levels of αTPO, but not with erythrocyte sedimentation rate (ESR) or αTG levels. A positive ANA was found in 24 % of patients. One patient developed subclinical hypothyroidism during the study. Rheumatic manifestations frequently occur in patients with CLT in the absence of overt thyroid dysfunction and mimic the presentation of the well-defined connective tissue diseases.