Urate Lowering Therapy Reduces Ultrasound-Detected Crystal Load in Gout

gout of the knee
gout of the knee
Patients with gout receiving urate lowering therapy by a treat-to-target approach demonstrate a reduced burden of monosodium urate crystals detected on ultrasound.

A treat-to-target therapy approach with urate lowering treatment (ULT) in patients with gout is associated with a significant reduction of ultrasound-detected crystal depositions after 12 months, according to study results published in Annals of the Rheumatic Diseases.

Monosodium urate crystals can be identified using ultrasound or dual-energy computed tomography; both tests are included in the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for gout.

The objectives of the current observational study were to identify the most frequent locations for urate crystal depositions in patients with gout during ULT with a treat-to-target approach and to explore the extent of erosions in the metatarsophalangeal (MTP) 1 joints and the resolution of crystal depositions.

The prospective, observational study included patients with a recent flare of gout, receiving ULT by a treat-to-target approach. Clinical assessment, blood tests, and ultrasound examinations were completed at baseline and after 3, 6, and 12 months. Ultrasound examinations were performed by a rheumatologist. Monosodium urate depositions were assessed according to 3 specific types of depositions, including double contour, tophi, and aggregates. A new scoring system was used to quantify the amount of depositions during follow-up, based on the specific types of deposition.

A total of 209 patients with gout (mean age, 56.4±13.8 years; 95.2% men) were assessed by ultrasound, and 184 completed the 12-month follow-up. At baseline, mean serum urate was 500±77 µmol/L, which decreased to 312±49 µmol/L after 12 months (P <.001).

Data suggest that the MTP1 joint was the most common location for all elementary lesions, including double contour, tophi, and aggregates. Furthermore, compared with MTP1 joints with no erosions, the researchers frequently found erosions of the metatarsal head, which were associated with significantly higher scores of all elementary lesions (mean scores, 0.53 vs 1.54 for double contour; 0.57 vs 1.91 for tophi; and 0.71 vs 1.81 for aggregates; P <.001 for all).

The mean sum scores of all 3 elementary lesions during the 12-month follow-up decreased from 20.0 at baseline to 11.7 at 12 months (P < .001), including a decrease from 4.3 to 1.3 for double contour, from 6.5 to 3.8 for tophi, and from 9.3 to 6.7 for aggregates. Of the elementary lesions, double contour was the most sensitive to change during treatment.  

“The present study gives important results by showing that patients in clinical practice who are followed by a treat-to-target approach regarding ULT reduced their burden of [monosodium urate] crystals as measured by ultrasound,” concluded the researchers.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Hammer HB, Karoliussen L, Terslev L, Haavardsholm EA, Kvien TK, Uhlig T. Ultrasound shows rapid reduction of crystal depositions during a treat-to-target approach in gout patients: 12-month results from the NOR-Gout study. Ann Rheum Dis. Published online July 15, 2020. doi:10.1136/annrheumdis-2020-217392