An observational study of ultrasound semiquantitative scoring for predicting the risk of gout flare.

Objective: An observational study was conducted to determine whether semiquantitative scoring of ultrasound signs of gout predicted flare over 12 months.

Methods: Gout patients were enrolled consecutively in this 12-month prospective observational single-center study. Ultrasound evaluation and clinical assessment were performed at baseline. All patients were examined bilaterally evaluating 14 joints (knee, ankle, metatarsophalangeal joints 1-5) and 10 tendons (posterior tibial, quadriceps, peroneus longus and brevis scored as one, patellar, and Achilles tendons). The following ultrasound features were examined and semiquantitative scoring was performed: DC sign, aggregates, tophi, bone erosion, synovial hypertrophy, PD activity, and tenosynovitis. Patients were divided into two groups, one with flares during the follow-up period and the other without flares.

Results: A total of 119 participants completed the study; 61 (51.3%) participants experienced at least one flare over 12 months, with a median of 2.0 flares. The ultrasound findings indicative of DC sign, aggregate, tophi, bone erosion, and PD activity at baseline were significantly correlated with the development of gout flares over 12 months. Logistic regression analysis suggested that DC sign score (OR: 2.41, 95% CI: 0.92-4.37; P = 0.02), tophi score (OR: 1.87, 95% CI: 0.65-2.28; P = 0.04), and PD activity score (OR: 1.93, 95% CI: 0.58-3.26; P = 0.03) were independent predictors of flare. ROC curve analysis to assess ultrasound semiquantitative scoring has good sensitivity and specificity for the prediction of gout flares.

Conclusion: Ultrasound semiquantitative scoring can predict the risk of flare, and ultrasound findings indicative of DC sign, tophi, and PD activity are independent predictors of gout flares over 12 months.