The role of ultrasound in assessing musculoskeletal symptoms of systemic lupus erythematosus: a systematic literature review.

Objectives: Musculoskeletal symptoms are common in SLE and are associated with significant morbidity. However, assessing their nature can be challenging, with implications for treatment decisions and measuring response. US has been shown to be valid and reliable for the assessment of other inflammatory arthritides, but data in SLE are more limited. The objectives of this systematic literature review were to determine the characteristics of musculoskeletal US abnormalities in SLE and to evaluate the metric properties of US in the detection and quantification of musculoskeletal symptoms.

Methods: We systematically searched the literature using the PubMed, Embase and Cochrane Library databases for studies using musculoskeletal US for assessing SLE. Studies were assessed for quality using the Quality Assessment of Diagnostic Accuracy Studies tool and for their metric qualities, including reliability and validity.

Results: Nine studies were identified. Most studies investigated construct validity. Rates of abnormality were highly variable: synovitis and tenosynovitis were reported in 25-94% and 28-65% of patients, respectively; power Doppler and erosions were reported in 10-82% and 2-41% of patients, respectively. There was poor to moderate association between US abnormalities and disease activity indices and immunological findings. There was moderate to high risk of bias and there were concerns about applicability in most studies.

Conclusion: US has potential value in the assessment of musculoskeletal symptoms in SLE. However, there is methodological variation between studies that may account for lack of consensus on US abnormalities. Studies that address these problems are required before US can used as an outcome measure in SLE.