Sonographic estimation of monosodium urate burden predicts the fulfillment of the 2016 remission criteria for gout: a 12-month study

Objective: To investigate whether baseline monosodium urate (MSU) burden estimated by ultrasound (US) predicts the achievement of the 2016 remission criteria for gout after 12 months. Methods: In this 12-month prospective, observational and single-center study, patients with gout fulfilling all the domains of the 2016 preliminary remission criteria for gout at baseline and on urate-lowering therapy (ULT) for at least the preceding 6 months were consecutively enrolled. The US findings indicative of MSU deposits [aggregates, double contour (DC) sign, and/or tophi] were identified according to the Outcome Measure in Rheumatology US Working Group definitions. The US MSU burden was estimated by evaluating elbows, wrists, 2nd metacarpophalangeal joints, knees, ankles, and 1st metatarsophalangeal joints. Results: Remission criteria were fulfilled in 21 (42.0%) out of 50 patients at 12 months. The baseline US MSU burden was significantly lower in patients who achieved remission than in those who did not fulfill the remission criteria at 12 months (1.9±1.8 vs 5.1±3.1, p<0.01). US scores and ongoing flare prophylaxis were the only significant predictors of remission with an odds ratio of 10.83 [(95%CI=1.14-102.59), p=0.04] for the absence of MSU deposits, 5.53 [(95%CI=1.34-22.76), p<0.01] for the absence of aggregates, 7.33 [(95%CI=1.71-31.44), p<0.01] for the absence of DC sign, 3.88 [(95%CI=1.08-13.92), p=0.04] for the absence of tophi, and 0.23 [(95%CI=0.07-0.75), p=0.02] for ongoing flare prophylaxis. Conclusion: In gout, baseline US estimation of MSU burden is an independent predictor of the achievement of the remission criteria at 12 months.