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

Abstract

Objective To determine whether SLE patients with inflammatory joint symptoms and ultrasound-detected synovitis achieve better clinical responses to glucocorticoid compared to patients with normal ultrasound scans. Secondary objectives included identification of clinical features predicting ultrasound-synovitis. Methods A longitudinal muticentre study of SLE patients with physician-diagnosed inflammatory joint pain requiring treatment (intramuscular methylprednisolone 120mg) was undertaken. Clinical assessments, patient-reported outcome measures, and bilateral hands and wrist ultrasound data were collected at 0, 2 and 6 weeks post-glucocorticoid. The primary outcome (determined via internal pilot analysis) was EMS-VAS at 2 weeks, adjusted for the baseline value, comparing patients with positive (GS and/or PD) and negative ultrasound. Post-hoc analyses adjusting for fibromyalgia were performed. Results Of 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 active 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). Conclusions In 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.