Subclinical articular involvement in primary Sjögren's syndrome assessed by ultrasonography and its negative association with anti-centromere antibody.

OBJECTIVES: To evaluate the subclinical articular involvement in patients with primary Sjögren's syndrome (pSS) using musculoskeletal ultrasound (MSUS), and to correlate the findings with laboratory results and clinical manifestations.

METHODS: Forty-eight consecutive patients with pSS were enrolled. The bilateral metacarpophalangeal, proximal interphalangeal, and interphalangeal joints were examined using MSUS, and the synovial hypertrophy and power Doppler signal were recorded for each joint using semi-quantitative scores (0 = normal, 1 = mild change compared with undamaged joint, 2 = moderate change, and 3 = severe change).

RESULTS: Mild or moderate synovial hypertrophy was found in 151 (15.7%) and 2 (0.2%) out of 960 hand joints, respectively, and power Doppler signals were present in 19 (2.0%) of the 960 joints. While anti-centromere antibody (ACA) was found in 10 patients (20.8%), none of the patients with MSUS-confirmed synovitis was positive for ACA. No other autoantibodies, laboratory tests, or clinical manifestations correlated with MSUS-confirmed synovitis.

CONCLUSION: MSUS is useful for detecting subclinical synovitis in pSS patients. MSUS showed that ACA-positive pSS patients had a low prevalence of synovitis.