Ultrasound to identify lupus patients with inflammatory joint symptoms with a better response to therapy: The USEFUL longitudinal multicentre study

ObjectiveTo determine whether SLE patients with inflammatory joint symptoms and ultrasound-synovitis achieve better clinical responses to glucocorticoid compared to patients with normal scans. Secondary objectives included identification of clinical features predicting ultrasound-synovitis. MethodsA longitudinal muticentre study of SLE patients with physician-diagnosed inflammatory joint pain was undertaken. Clinical assessments, patient-reported outcomes, and bilateral hands and wrist ultrasound were collected at 0-, 2- and 6-weeks after intramuscular methylprednisolone 120mg. The primary outcome (determined via internal pilot analysis) was EMS-VAS at 2-weeks, adjusted for the baseline value, comparing patients with positive (GS[≥]2 and/or PD[≥]1) and negative ultrasound. Post-hoc analyses adjusting for fibromyalgia were performed. ResultsOf 133 patients recruited, 78/133 had positive ultrasound, but only 68% of these had [≥]1 swollen joint. Of 66/133 patients with [≥]1 swollen joint, 20% had negative ultrasound. Positive ultrasound was associated with joint swelling, symmetrical small joint distribution and serology. In full analysis set (n=133) there was no difference in baseline-adjusted EMS-VAS at week 2 (-7.7mm 95% CI - 19.0mm, 3.5mm, p=0.178). After excluding 32 fibromyalgia patients, response was significantly better in patients with positive ultrasound at baseline (baseline-adjusted EMS-VAS at 2-weeks - 12.1 mm, 95% CI -22.2mm, -0.1mm, p=0.049). This difference was greater when adjusted for treatment (-12.8mm (95% CI -22mm, -3mm), p=0.007). BILAG and SLEDAI responses were higher in ultrasound-positive patients. ConclusionsIn SLE patients without fibromyalgia, those with positive ultrasound had a better clinical response to therapy. Imaging-detected synovitis should be used to select SLE patients for therapy and enrich clinical trials.