More information about text formats
In an article published in Annals of the Rheumatic Diseases, Chowalloor et al. suggested, based on a literature review, that ultrasonography (US) is a promising tool which could be used in the diagnosis and management of gout . In this letter, we wish to add further data to the Chowalloor et al. conclusion. We have performed a meta-analysis (up to July 2012) to investigate the frequency of ultrasonograph...
In an article published in Annals of the Rheumatic Diseases, Chowalloor et al. suggested, based on a literature review, that ultrasonography (US) is a promising tool which could be used in the diagnosis and management of gout . In this letter, we wish to add further data to the Chowalloor et al. conclusion. We have performed a meta-analysis (up to July 2012) to investigate the frequency of ultrasonographic signs, i.e. joint effusion, synovitis, bone erosion, tophi and double contour (DC), in gout and asymptomatic hyperuricaemia compared with controls.
We searched MEDLINE to identify all reports of interest published prior to July 2012 using the following search terms: (“echography” OR “sonography” OR “ultrasonography” OR “US”AND (“gout” OR “urate” OR “uric acid”. We retrieved a total of 195 articles. In addition, we searched for congress abstracts from the annual scientific meetings held by the French Society for Rheumatology, European League Against Rheumatism and American College of Rheumatology between 2008 and 2012 using the terms “echography” AND “gout”. Comprehensive Meta-analysis (version 2, BioStat Corporation) was used to conduct the meta-analytical statistical analysis . Heterogeneity in the study results was evaluated by examining forest plots, confidence intervals and formal tests for homogeneity based on the I² statistics. Random effects meta-analyses were conducted when data could be pooled.
After reading the title, abstract and full text of all articles, we retained eight, along with four abstracts, involving a total of 446 patients with gout, 102 with asymptomatic hyperuricaemia and 249 controls. The prevalence of ultrasonographic signs in patients with gout is summarized in Table 1. In patients with asymptomatic hyperuricaemia and controls, data were only available and analyzed for a DC sign that was reported in one healthy control. Pineda found this sign in 42 joints (42/200, 21%) in asymptomatic hyperuricaemia and Howard in just 8.8% of joints (6/68) [3,4].
Our study results provide information that reinforces the conclusion of Chowalloor et al., who suggested that ultrasonography is useful in the diagnosis of gout. However, not all sonographic signs have the same importance in this diagnosis. Joint effusion and synovitis are not very specific whereas a DC sign or tophus, especially in the first metatarsal joint, points more towards gout. Naredo et al. recently confirmed the importance of looking for DC signs in the first metatarsal .
The diagnosis of gout is confirmed by the microscopic demonstration of monosodium urate crystals in synovial fluid analysis. In the absence of joint effusion, or to support the diagnosis, joint and cartilage ultrasonography, especially in the first metatarsal joint, is indeed very useful.
1 Chowalloor PV, Keen HI. A systematic review of ultrasonography in gout
and asymptomatic hyperuricaemia. Ann Rheum Dis 2013; 72(5):638-45.
2 Borenstein M, Hedges L, Higgins J, et al. Comprehensive Meta-Analysis
Version 2. Engelwood NJ. BioStat; 2005.
3 Pineda C, Amezcua-Guerra LM, Solano C, et al. Joint and tendon
subclinical involvement suggestive of gouty arthritis in asymptomatic
hyperuricemia: an ultrasound controlled study. Arthritis Res Ther 2011;13(1):R4.
4 Howard RG, Pillinger MH, Gyftopoulos S, et al. Reproducibility of
musculoskeletal ultrasound for determining monosodium urate deposition:
concordance between readers. Arthritis Care Res (Hoboken) 2011;63(10):1456-62.
5 Naredo E, Uson J, Jim?nez-Palop M, et al. Ultrasound-detected
musculoskeletal urate crystal deposition: which joints and what findings
should be assessed for diagnosing gout?
This letter contains a table and a figure that can be found at the ePage on the ARD website, accompanying an issue.