AB0818 Ultrasonography Signs of MSU Urate Deposition in Patients with Hyperuricemia and Early Diagnosis of Gout

Prevalence and discrimination of OMERACT-defined elementary ultrasound lesions of gout in people with asymptomatic hyperuricaemia: A systematic review and meta-analysis

OBJECTIVES

Ultrasound lesions of gout have been described in people with asymptomatic hyperuricemia. However, the anatomical sites and ultrasound lesions most frequently involved in asymptomatic hyperuricemia have not yet been established. This systematic review and meta-analysis aimed to determine the prevalence of the Outcome Measures in Rheumatology (OMERACT) elementary ultrasound lesions of gout (double contour, aggregates, tophus, erosion) at various sites in people with asymptomatic hyperuricemia and to determine which sites and lesions discriminate from people with normouricemia.

METHODS

A systematic search of electronic databases, conference abstracts and reference lists was undertaken. Studies were included if they used ultrasound to image people with asymptomatic hyperuricemia and reported ≥1 OMERACT-defined lesion of gout. Meta-analyses were undertaken for the pooled prevalence of site-specific lesions in people with asymptomatic hyperuricemia, and the pooled odds ratios of these lesions compared to people with normouricemia.

RESULTS

Twenty studies were included. The most common site scanned was the first metatarsophalangeal joint (1MTP) (n = 17 studies) and the most common lesion reported, the double contour (n = 18). Meta-analyses of pooled prevalence showed 1MTP double contour was the most frequent finding in people with asymptomatic hyperuricemia (0.31, 95% confidence interval (CI) 0.20-0.42), followed by femoral condyle double contour (0.16, 95%CI 0.08-0.24) and 1MTP tophus (0.16, 95%CI 0.03-0.29). The highest pooled odds ratios for asymptomatic hyperuricemia vs. normouricemia were 6.98 (95%CI 3.14-15.57) for 1MTP double contour, 13.67 (95%CI 5.42-34.49) for femoral condyle double contour and 6.10 (95%CI 1.55-24.04) for 1MTP tophus.

CONCLUSION

In people with asymptomatic hyperuricemia, scanning of the 1MTP and femoral condyle for double contour, plus the 1MTP for tophus, has the highest prevalence and discrimination compared to those with normouricemia.

Ultrasound Features of the First Metatarsophalangeal Joint in Gout and Asymptomatic Hyperuricemia: Comparison With Normouricemic Individuals

OBJECTIVE

The first metatarsophalangeal (MTP1) joint is frequently affected in gout. The aim of this study was to identify ultrasound features of the MTP1 joint in people with gout and people with asymptomatic hyperuricemia compared with normouricemic controls.

METHODS

Participants with gout (n = 23) and asymptomatic hyperuricemia (n = 29), and age- and sex-matched normouricemic control participants (n = 34), underwent a gray-scale and power Doppler ultrasound assessment of bilateral MTP1 joints by a single musculoskeletal radiologist. No participants had clinical evidence of joint inflammation at the time of scanning. The static images were later read by 2 musculoskeletal radiologists for the presence of the double contour sign, tophus, erosion, effusion, synovial hypertrophy, synovitis, and cartilage thickness.

RESULTS

Compared to normouricemic control participants, participants with gout and participants with asymptomatic hyperuricemia had more frequent double contour sign (odds ratio [OR] 3.91, P = 0.011 and OR 3.81, P = 0.009, respectively). Participants with gout also had more erosion (OR 10.13, P = 0.001) and synovitis (OR 9.00, P < 0.001) and had greater tophus and erosion diameters (P = 0.035 and P < 0.001, respectively). More severe erosion and synovitis grades and a less severe effusion grade were independently associated with gout compared with asymptomatic hyperuricemia (R²  = 0.65, P < 0.001).

CONCLUSION

Urate deposition, synovitis, and bone erosion are common at the MTP1 joint in people with gout, even in the absence of flare. Although individuals with asymptomatic hyperuricemia lack ultrasound features of inflammation or structural joint changes, they demonstrate a similar frequency of urate deposition.