New urate depositions on dual-energy computed tomography in gouty arthritis during urate-lowering therapy

Reduction of urate depositions in the joints, on dual-energy computed tomography (DECT), in patients with gout during urate-lowering therapy (ULT) was demonstrated in previous studies. The aim of this study was to further investigate the changes in distribution of urate deposits during ULT. This randomized controlled trial enrolled 46 patients diagnosed with gout from Zhongshan Hospital, China, between October 2013 and June 2014. Epidemiological data, serum uric acid level, and arthritis attacks were recorded at monthly follow-up visits. DECT of bilateral feet and ankles was performed at baseline and after 6 months of ULT. Overall, 163 areas of urate deposition were found in the 46 patients; of these, 133/163 (81.6%) areas were associated with former arthritis attacks. On DECT at 6 months, the number of urate deposits decreased to 126, with 68 areas disappearing and 31 new deposits areas. The mean volume of urate deposits at baseline was 1.3 ± 3.8 cm3, decreasing to 0.6 ± 2.1 cm3 at the end of 6 months (P = 0.01), with 3/46 (6.5%) patients showing complete disappearance of urate deposits. New urate depositions were found in 21/46 (45.7%) patients, while urate depositions in some joints disappeared in some joints in 31/46 (67.4%) patients. High-sensitivity C-reactive protein was significantly lower in patients with new deposits (4.6 ± 9.3 vs. 7.1 ± 7.6 mg/dL; P = 0.01). There is dynamic redistribution of urate depositions in gout patients receiving ULT.