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

Abstract

Objectives To evaluate whether ultrasound (US) findings indicating monosodium urate (MSU) deposits and US-detected inflammation [i.e. power Doppler (PD) signal] predict gout flares over 12 months. Methods Gout patients on urate-lowering therapy for at least the preceding six 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, 2nd metacarpophalangeal joints, knees, ankles, and 1st metatarsophalangeal 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. PD 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 PD 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 (aOR):1.75, 95%CI : 1.26–2.43; PD score, aOR : 1.63, 95%CI : 1.12–2.40] and the number (total MSU score, aIRR : 1.17, 95%CI : 1.08–1.26; PD score, aIRR : 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.

An ultrasonographic study of gouty arthritis: Synovitis and its relationship to clinical symptoms: A retrospective analysis

“…Katz et al suggested that MSU crystals may be deposited on the synovium of medium vessels, particularly in the active phase 25 . Cipolletta et al observed that MSU burden and inflammation detected by US were independent predictors of gout lasting longer than 12 months 26 . In addition, flares should be carefully prevented in patients with a high MSU deposition burden, especially DCS and tophi and inflammation detected by US.…”

Dynamic assessment of the double contour sign by ultrasonography helps to distinguish between gout and calcium pyrophosphate deposition disease

“…A cross-sectional analysis of data from consecutive patients acquired during two prospective cohort studies8 9 and a cross-sectional case–control study10 between September 2019 and June 2022 was carried out at the Polytechnic University of Marche (Ancona, Italy). Data collection and study’s hypothesis were planned before the index test and reference standard were performed.…”

“…US assessments were carried out according to the 2017 EULAR standardised procedures for US imaging in rheumatology11 by a rheumatologist blinded to patients’ diagnosis 8–10…”

“…Patients with gout meeting the 2015 ACR/EULAR classification criteria and patients with a crystal-proven diagnosis of CPPD were consecutively recruited from among those participating in three US imaging studies. [8][9][10] These criteria were selected as the current and internationally recognised criteria for classifying patients as having gout or CPPD disease. Patients with mixed crystal arthritis were excluded from all studies.…”

“…US assessments were carried out according to the 2017 EULAR standardised procedures for US imaging in rheumatology 11 by a rheumatologist blinded to patients' diagnosis. [8][9][10] The hyaline cartilage of the scanned joints was explored to detect US findings indicative of crystal deposits (ie, DC sign and CPP deposits within the cartilage layer), 1 12 paying particular attention to differentiate the DC sign from the cartilage interface sign, which is visible only when the outer margin of the hyaline cartilage is perpendicularly insonated by the US beam and usually is thinner than the DC sign and the bony cortex (figure 1). Furthermore, once a DC sign was identified, its dynamic behaviour during joint movement was evaluated while holding the probe steady (ie, movement of the DC sign together with the hyaline cartilage and the subchondral bone, indicating crystals attached on the cartilage surface or in the opposite direction, indicating crystals in the joint capsule Crystal arthropathies Crystal arthropathies Crystal arthropathies or ligaments) (online supplemental video S1 and online supplemental video S2).…”