Are patients with gout with negative dual-energy computed tomography for monosodium urate crystal deposition easy-to-treat?

Victor Laurent; Charlotte Jauffret; Vincent Ducoulombier; Aurore Pacaud; Julie Legrand; Stéphane Verdun; Laurène Norberciak; Jean-François Budzik; Tristan Pascart

doi:10.1093/rheumatology/keae061

Are patients with gout with negative dual-energy computed tomography for monosodium urate crystal deposition easy-to-treat?

Rheumatology (Oxford). 2024 Feb 9:keae061. doi: 10.1093/rheumatology/keae061. Online ahead of print.

Authors

Victor Laurent¹, Charlotte Jauffret¹, Vincent Ducoulombier¹, Aurore Pacaud¹, Julie Legrand², Stéphane Verdun³, Laurène Norberciak³, Jean-François Budzik², Tristan Pascart¹

Affiliations

¹ Department of Rheumatology, Hôpital Saint-Philibert, Université Catholique de Lille, Lomme, France.
² Department of Radiology, Hôpital Saint-Philibert, Université Catholique de Lille, Lomme, France.
³ Research Department-Biostatistics and Methodology, Hôpital Saint-Philibert, Université Catholique de Lille, Lomme, France.

PMID: 38336883
DOI: 10.1093/rheumatology/keae061

Abstract

Objectives: To determine the clinical associations and predictive value of two thresholds of negative dual-energy CT (DECT) for MSU crystal deposition in gout patients initiating urate lowering therapy (ULT), and identify which threshold is more clinically relevant.

Methods: Patients from the CRYSTALILLE cohort with a diagnosis of gout naive to ULT with baseline DECT scans of knees and feet were selected. Two thresholds of positivity for DECT detection of MSU crystal deposition were considered (<0.01 cm3 and <0.1 cm3). Baseline characteristics and the prediction of key outcomes after ULT initiation including reaching serum urate (SU) levels <6.0 and 5.0 mg/dl and occurrence of flares at 6, 12 and 24 months, associated with both thresholds of negative DECTs were compared with those of.

Patient: s having positive DECT scans.

Results: 211 patients aged 66.2 years [57; 75.8] with a symptom duration of 3 years [0; 7.8] were included. 38/211 (18%) and 90/211 (43%) had negative DECT scans for the 0.01 and 0.1 cm3 thresholds, respectively. Factors associated with negative DECT scans were younger age, shorter symptom duration, and absence of cardiovascular disease for both volume thresholds. 9/39 (23.1%), 3/26 (11.5%), and 1/18 (5.6%) of patients with <0.1 cm3 MSU crystals had flares at 6, 12 and 24 months, respectively, compared with 18/45 (40.0%), 9/36 (25.0%) and 2/18 (11.1%) patients with ≥0.1 cm3 (p> 0.05).Overall, 95 patients (68.3%) reached SU levels <6.0 mg/dl and 68 (48.9%) <5.0 mg/dl, without any difference between positive and negative DECTs, with ULT dosages which tended to be lower in patients with negative DECT.

Conclusion: The 0.1 cm3 threshold was better correlated to clinical presentation and evolution than 0.01 cm3. Patients with gout with negative DECTs exhibit milder disease and a lower comorbidity burden. They do not exhibit particularly easy-to-treat hyperuricemia, but may have a lower risk of flares.

Keywords: dual-energy computed tomography; gout; monosodium urate; serum urate.