The diagnostic associations of patients with antinuclear antibodies referred to a community rheumatologist.

The referral of patients with positive antinuclear antibodies (ANA) to a rheumatologist for evaluation occurs commonly in clinical practice. We report our experience in a large community setting. Two hundred seventy-six patients (8.8% of total referrals) had ANA titers greater than or equal to 1:40 without a diagnosis. A specific diagnosis was made in 239 patients (86.6%) and no diagnosis in 37 (13.4%). Of those diagnosed, 142 (51.4%) had connective tissue diseases, 44 (15.9%) had organ-specific autoimmune diseases, 23 (8.3%) had infectious diseases, 8 (2.9%) had neoplasia and 30 (10.9%) had miscellaneous other diseases. The commonest were systemic lupus erythematosus (SLE) in 52 (18.8%) and autoimmune thyroid disease in 29 (10.5%). Undiagnosed autoimmune thyroid disease and SLE are common diagnostic associations of positive ANA in patients referred to a community rheumatologist and positive ANA are frequently associated with clinical disease.