Subclinical Synovitis in Systemic Lupus Erythematosus: Ultrasound Insights.

Background: Systemic Lupus Erythematosus (SLE) is a chronic inflammatory autoimmune disorder associated with a wide range of symptoms and physical findings. Joint involvement is one of the most common features of SLE. In routine clinical practice, joint involvement is usually assessed with physical examination and radiographical studies. Objectives: the purpose of this study was to assess the prevalence of the subclinical synovitis in small joints of hand and wrist joints of the SLE patients using ultrasonography (US), compare the findings with healthy controls, and correlate them with disease activity and various disease parameters. Results: SLE patients (mean age 31.3 ± 8.9 years, 80.7% females) showed a significantly higher prevalence of grey-scale synovitis (22.8% vs. 4%, p = 0.005) and tenosynovitis (15.8% vs. 0%, p = 0.003) compared to controls. Patients with MSUS-detected synovitis had significantly longer disease duration (p = 0.021), higher ESR (p = 0.012), increased 24-hour urinary protein (p = 0.045), and higher SLEDAI scores (p = 0.036). Alopecia and anti-dsDNA positivity were also significantly related. Logistic regression identified elevated ESR, positive anti-dsDNA and alopecia as independent predictors of subclinical synovitis. Conclusion: Subclinical synovitis and tenosynovitis are common in SLE and can be effectively detected by MSUS, even in the absence of clinical arthritis, highlighting the value of MSUS in routine SLE evaluation for early detection and monitoring of musculoskeletal involvement. Higher ESR, positive anti-dsDNA, and alopecia may serve as useful predictors of subclinical synovitis in SLE.