Update of the current role of ultrasound in asymptomatic hyperuricemia. A systematic literature review.

Ultrasound (US) is a recognized imaging modality for the assessment of gout. Recently it is being explored for its potential role in the evaluation of subjects with asymptomatic hyperuricemia (AH). Preliminary reports demonstrated the presence of monosodium urate (MSU)-crystal deposits including aggregates, double contour sign and/or tophi in both intra-articular and periarticular tissues of AH individuals. Although these results are exciting, the value and potential application of US in AH remain to be clearly delineated. In this systematic literature review, we aim to summarise the recent publications regarding the role of US in the assessment of AH. We analyzed possible application of US in the daily clinical practice and its future clinical and research potential in the evaluation of AH individuals.

Levels of Cytokines and MicroRNAs in Individuals With Asymptomatic Hyperuricemia and Ultrasonographic Findings of Gout: A Bench-to-Bedside Approach.

OBJECTIVE: To assess potential associations among serum cytokines and microRNA (miR) levels with ultrasound (US) findings suggestive of urate deposits in chronic asymptomatic hyperuricemia and gout. METHODS: All participants underwent musculoskeletal US and measurements of serum interleukin-1ß (IL-1ß), IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, interferon-γ, tumor necrosis factor, monocyte chemoattractant protein 1, and epithelial neutrophil-activating peptide 78, as well as miR-146a, miR-155, and miR-223 levels. RESULTS: Thirty individuals with asymptomatic hyperuricemia, 31 normouricemic controls, and 30 patients with gout were included. The frequency of synovitis and double contour sign using US was similar between asymptomatic hyperuricemia (67% and 27%, respectively) and patients with gout (77% and 27%, respectively), and each had a higher frequency than controls (45% and 0%, respectively). Serum IL-6 and IL-8 levels were similar between patients with asymptomatic hyperuricemia (mean ± SD 69.7 ± 73.4 and 18.5 ± 25.6 pg/ml, respectively) and gout (mean ± SD 75.8 ± 47.6 and 24.4 ± 31.7 pg/ml, respectively), and higher than controls (mean ± SD 28.2 ± 17.6 and 7.4 ± 6.0 pg/ml, respectively). A similar distribution was observed for miR-155 levels in asymptomatic hyperuricemia, patients with gout, and controls (mean ± SD 0.22 ± 0.18, 0.20 ± 0.14, and 0.08 ± 0.04, respectively). Associations between morphostructural abnormalities suggestive of urate deposits (regardless of clinical diagnosis) and serum markers were assessed. Subjects with urate deposits had higher IL-6 (257.2 versus 47.0 pg/ml; P = 0.005), IL-8 (73.2 versus 12.0 pg/ml; P = 0.026), and miR-155 (0.21 versus 0.16; P = 0.015) levels than those without deposition findings. CONCLUSION: In individuals with chronic asymptomatic hyperuricemia, the presence of synovitis and double contour sign by US may represent a subclinical manifestation of monosodium urate crystal nucleation, capable of triggering inflammatory pathways (IL-6 and IL-8) and mechanisms of intercellular communication (miR-155), similar to what is observed in patients with gout.

A pilot study on dual-energy computed tomography for detection of urate deposits in renal transplant patients with asymptomatic hyperuricemia.

BACKGROUND: An increasing role of dual-energy computed tomography (DECT) scan in tophaceous gout assessment is recognized, whereas its role in asymptomatic hyperuricemia is unknown. OBJECTIVE: The objective of this study was to assess the prevalence of joint and renal monosodium urate deposits by DECT in asymptomatic hyperuricemia. METHODS: Among a renal transplant population with at least 1 year of follow-up, we included 27 patients with sustained hyperuricemia and 11 with normal serum uric acid (SUA) levels. We excluded patients with gout or history of monoarthritis or oligoarthritis. We registered demographic data, drugs, hyperuricemia onset, comorbidities, renal function, and SUA. We used a 128-slice dual-source CT system, and the acquisition protocol included the pelvis and imaging of elbows, wrists, hands, knees, ankles, and feet. The reading process was performed by 2 radiologists. RESULTS: The mean age was 43.7 ± 12 years, 57.8% were males, and median follow-up was 7 years. Hyperuricemia presented after a median time of 0.61 years after transplantation and had persisted for a median of 3.2 years (0.5-16.8 years). For the hyperuricemic group, the median SUA at the DECT scan and the maximum SUA levels were 7.9 and 8.9 mg/dL, respectively. Groups were similar in most of the clinical variables. We did not find any articular or renal deposit; conversely, we demonstrated a quadriceps tendon deposition in 1 patient with hyperuricemia (prevalence of 0.03%; 95% confidence interval, 0.006%-0.17%). CONCLUSIONS: In these patients with asymptomatic hyperuricemia, the prevalence of monosodium urate deposition assessed by DECT was low; however, larger studies need to be performed for further validation.

Relationship between serum uric acid and internal carotid resistive index in hypertensive women: a cross-sectional study.

BACKGROUND: The impact of serum uric acid (SUA) on arteries of hypertensive subjects remains to be fully established. This study investigated the relationship between SUA and carotid structural and hemodynamic parameters in hypertensive men and women. METHODS: Three hundred and thirty eight patients (207 women and 131 men) were cross-sectionally evaluated by clinical, laboratory, hemodynamic and carotid ultrasound analysis. Common carotid diameters, circumferential wall tensions, Young's Elastic Modulus, Stiffness Index, Arterial Compliance and intima-media thickness (IMT) were determined. Internal carotid artery resistive index (ICRI), a hemodynamic measure that reflects local vascular impedance and microangiopathy, was also assessed. RESULTS: Univariate analysis showed no significant correlation of SUA with carotid diameters, elasticity/stiffness indexes, IMT and circumferential wall tensions in both genders. Conversely, SUA correlated with ICRI (r=0.34; p<0.001) in women, but not in men, and hyperuricemic women presented higher ICRI than normouricemic ones (0.684 ± 0.007 vs. 0.649 ± 0.004; p<0.001). Stepwise and logistic regression analyses adjusted for potential confounding factors showed that ICRI was independently associated with SUA and hyperuricemia in women. CONCLUSIONS: This study demonstrated that SUA was associated with ICRI in hypertensive women, suggesting that there might gender-related differences in the relationship between SUA and vascular damage in subjects with systemic hypertension.

Joint and tendon subclinical involvement suggestive of gouty arthritis in asymptomatic hyperuricemia: an ultrasound controlled study.

INTRODUCTION: In this study, we aimed to investigate ultrasonographic (US) changes suggestive of gouty arthritis in the hyaline cartilage, joints and tendons from asymptomatic individuals with hyperuricemia. METHODS: We conducted a cross-sectional, controlled study including US examinations of the knees and first metatarsal-phalangeal joints (first MTPJs), as well as of the tendons and enthesis of the lower limbs. Differences were estimated by χ² or unpaired t-tests as appropriate. Associations were calculated using the Spearman's correlation coefficient rank test. RESULTS: Fifty asymptomatic individuals with hyperuricemia and 52 normouricemic subjects were included. Hyperechoic enhancement of the superficial margin of the hyaline cartilage (double contour sign) was found in 25% of the first MTPJs from hyperuricemic individuals, in contrast to none in the control group (P < 0.0001). Similar results were found on the femoral cartilage (17% versus 0; P < 0.0001). Patellar enthesopathy (12% versus 2.9%; P = 0.01) and tophi (6% versus 0; P = 0.01) as well as Achilles enthesopathy (15% versus 1.9%; P = 0.0007) were more frequent in hyperuricemic than in normouricemic individuals. Intra-articular tophi were found in eight hyperuricemic individuals but in none of the normouricemic subjects (P = 0.003). CONCLUSIONS: These data demonstrate that morphostructural changes suggestive of gouty arthritis induced by chronic hyperuricemia frequently occur in both intra- and extra-articular structures of clinically asymptomatic individuals.