Imaging of crystalline arthropathy in 2020

Ultrasonography in the prediction of gout flares: a 12-month prospective observational study

OBJECTIVES

To evaluate whether US findings indicating MSU deposits and US-detected inflammation (i.e. power Doppler signal) predict gout flares over 12 months.

METHODS

Gout patients on urate-lowering therapy for at least the preceding 6 months were enrolled consecutively in this 12-month prospective, observational, single-centre study. A nested case-control analysis was performed. Cases were participants with at least one flare in the follow-up period, while controls did not self-report any gout flare. The US assessment included elbows, wrists, second MCP joints, knees, ankles, and first MTP joints. The US findings indicating MSU deposits [i.e. aggregates, double contour (DC) sign and tophi] were identified as present/absent according to the Outcome Measure in Rheumatology definitions. Power Doppler signal was scored semiquantitatively. Summated scores were calculated for each US finding.

RESULTS

Eighty-one gout participants were enrolled, and 71 completed the study. Thirty (42.3%) of 71 participants experienced at least one flare over 12 months, with a median of 2.0 flares. Cases had a greater US burden of MSU deposits (6.7 ± 4.7 vs 2.9 ± 2.6, P = 0.01) and power Doppler signal (3.73 ± 3.53 vs 0.82 ± 1.44, P < 0.01) than controls, at baseline. The baseline US scores indicating MSU deposits and US-detected inflammation were significantly associated with the occurrence (total MSU score, adjusted odds ratio:1.75, 95% CI: 1.26, 2.43; power Doppler score, adjusted odds ratio: 1.63, 95% CI: 1.12, 2.40) and the number (total MSU score, adjusted incidence risk ratio: 1.17, 95% CI: 1.08, 1.26; power Doppler score, adjusted incidence risk ratio: 1.29, 95% CI: 1.19, 1.40) of flares over 12 months in multivariate analyses.

CONCLUSIONS

Baseline US findings indicating MSU deposits and US-detected inflammation are independent predictors of gout flares over 12 months.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02568-x.