2015 Gout Classification Criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative

Reducing Immunogenicity of Pegloticase With Concomitant Use of Mycophenolate Mofetil in Patients With Refractory Gout: A Phase II, Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVE

Pegloticase is used for the treatment of severe gout, but its use is limited by immunogenicity. This study was undertaken to evaluate whether mycophenolate mofetil (MMF) prolongs the efficacy of pegloticase.

METHODS

Participants were randomized 3:1 to receive 1,000 mg MMF twice daily or placebo for 14 weeks, starting 2 weeks before receiving pegloticase and continuing while receiving intravenous pegloticase 8 mg biweekly for 12 weeks. Participants then received pegloticase alone from week 12 to week 24. The primary end points were the proportion of patients who sustained a serum urate level of ≤6 mg/dl at 12 weeks and the rate of adverse events (AEs). Secondary end points included 24-week durability of serum urate level ≤6 mg/dl. Fisher's exact test and Wilcoxon's 2-sample test were used for analyses, along with Kaplan-Meier estimates and log rank tests.

RESULTS

A total of 32 participants received ≥1 dose of pegloticase. Participants were predominantly men (88%), with a mean age of 55.2 years, mean gout duration of 13.4 years, and mean baseline serum urate level of 9.2 mg/dl. At 12 weeks, a serum urate level of ≤6 mg/dl was achieved in 19 (86%) of 22 participants in the MMF arm compared to 4 (40%) of 10 in the placebo arm (P = 0.01). At week 24, the serum urate level was ≤6 mg/dl in 68% of MMF-treated patients versus 30% of placebo-treated patients (P = 0.06), and rates of AEs were similar between groups, with more infusion reactions occurring in the placebo arm (30% versus 0%).

CONCLUSION

Our findings indicate that MMF therapy with pegloticase is well tolerated and shows a clinically meaningful improvement in targeted serum urate level of ≤6 mg/dl at 12 and 24 weeks. This study suggests an innovative approach to pegloticase therapy in gout.

Differentiation of Crystals Associated With Arthropathies by Spectral Photon-Counting Radiography: A Proof-of-Concept Study

OBJECTIVES

The aims of this study were to test whether spectral photon-counting radiography (SPCR) is able to identify and distinguish different crystals associated with arthropathies in vitro and to validate findings in a gouty human third toe ex vivo.

MATERIALS AND METHODS

Industry-standard calibration rods of calcium pyrophosphate, calcium hydroxyapatite (HA), and monosodium urate (MSU) were scanned with SPCR in an experimental setup. Each material was available at 3 different concentrations, and a dedicated photon-counting detector was used for SPCR, whereas validation scans were obtained on a clinical dual-energy computed tomography (DECT) scanner. Regions of interest were placed on SPCR images and consecutive DECT images to measure x-ray attenuation characteristics, including effective atomic numbers (Zeff). Statistical tests were performed for differentiation of Zeff between concentrations, materials, and imaging modalities. In addition, a third toe from a patient with chronic gouty arthritis was scanned with SPCR and DECT for differentiation of MSU from HA.

RESULTS

In both SPCR and DECT, significant differences in attenuation and Zeff values were found for different concentrations among (P < 0.001) and between different materials (P < 0.001). Overall, quantitative measurements of Zeff did not differ significantly between SPCR- and DECT-derived measurements (P = 0.054-0.412). In the human cadaver toe, gouty bone erosions were visible on standard grayscale radiographic images; however, spectral image decomposition revealed the nature and extent of MSU deposits and was able to separate it from bone HA by Zeff.

CONCLUSIONS

Identification and differentiation of different crystals related to arthropathies are possible with SPCR at comparable diagnostic accuracy to DECT. Further research is needed to assess diagnostic accuracy and clinical usability in vivo.

Risk of osteoporotic thoracic vertebral fractures in patients with gout

OBJECTIVES

Osteoporosis causes significant morbidity and mortality by the development of fragility fractures, including vertebral fractures. Patients with gout may show an increased risk of osteoporotic fractures, as accelerated bone resorption is likely linked to urate crystal-led inflammatory state. This study aims to evaluate the risk of osteoporotic dorsal vertebral fractures associated with gout.

METHODS

Cross-sectional study carried out in patients admitted for cardiovascular events. Patients with available lateral view of chest radiography (on admission or in the previous six months) were selected. Two observers blinded to clinical data reviewed the radiographies simultaneously. Vertebral fracture was defined as a vertebral height loss ≥20%, and presence, number, and severity (by Genant semi-quantitative scale) were registered. To analyse the relationship between gout and the presence of vertebral fractures, the odds ratio (OR) with 95% confidence interval (95%CI) was calculated by multiple logistic regression.

RESULTS

126 patients were analysed, 21 of them (16.67%) suffered from gout. Eighteen cases with fractures were detected, with a prevalence of 14.3%. A significant association was found between gout and vertebral fracture (28.6% gout, 11.4% controls; OR 3.10, 95%CI 1.01-9.52). There were no differences in the number of fractures, while the severity was found to be higher in the controls. The association between gout and vertebral fracture persisted after multivariate adjustment (OR 5.21, 95% CI 1.32-20.61).

CONCLUSION

An independent association between gout and radiological thoracic vertebral fractures was revealed in patients with a cardiovascular event.

A Randomized, Phase II Study Evaluating the Efficacy and Safety of Anakinra in the Treatment of Gout Flares

OBJECTIVE

To evaluate the efficacy and safety of anakinra compared to triamcinolone in the treatment of gout flares.

METHODS

Patients for whom nonsteroidal antiinflammatory drugs and colchicine were not suitable treatments were enrolled in this multicenter, randomized, double-blind study with follow-up for up to 2 years. The study was designed to assess superiority of anakinra (100 or 200 mg/day for 5 days) over triamcinolone (40 mg in a single injection) for the primary end point of changed patient-assessed pain intensity in the most affected joint (scored on a visual analog scale of 0-100) from baseline to 24-72 hours. Secondary outcome measures included: safety, immunogenicity, and patient- and physician-assessed global response.

RESULTS

One hundred sixty-five patients were randomized to receive anakinra (n = 110) or triamcinolone (n = 55). The median age was 55 years (range 25-83), 87% were men, the mean disease duration was 8.7 years, and the mean number of self-reported flares during the prior year was 4.5. A total of 301 flares were treated (214 with anakinra; 87 with triamcinolone). Anakinra in both doses and triamcinolone provided clinically meaningful reduction in patient-assessed pain intensity in the first and subsequent flares. For the first flare, the mean decline in pain intensity from baseline to 24-72 hours for total anakinra and triamcinolone was -41.2 and -39.4, respectively (P = 0.688). Anakinra performed better than triamcinolone for most secondary end points. There were no unexpected safety findings. The presence of antidrug antibodies was not associated with adverse events or altered pain reduction.

CONCLUSION

Anakinra was not superior to triamcinolone for the primary end point, but had comparable efficacy in pain reduction and was favored for most secondary end points. Anakinra is an effective option for gout flares when conventional therapy is unsuitable.

Recognizing and Minimizing Artifacts at Dual-Energy CT

Dual-energy CT (DECT) is an exciting innovation in CT technology with profound capabilities to improve diagnosis and add value to patient care. Significant advances in this technology over the past decade have improved our ability to successfully adopt DECT into the clinical routine. To enable effective use of DECT, one must be aware of the pitfalls and artifacts related to this technology. Understanding the underlying technical basis of artifacts and the strategies to mitigate them requires optimization of scan protocols and parameters. The ability of radiologists and technologists to anticipate their occurrence and provide recommendations for proper selection of patients, intravenous and oral contrast media, and scan acquisition parameters is key to obtaining good-quality DECT images. In addition, choosing appropriate reconstruction algorithms such as image kernel, postprocessing parameters, and appropriate display settings is critical for preventing quantitative and qualitative interpretive errors. Therefore, knowledge of the appearances of these artifacts is essential to prevent errors and allows maximization of the potential of DECT. In this review article, the authors aim to provide a comprehensive and practical overview of possible artifacts that may be encountered at DECT across all currently available commercial clinical platforms. They also provide a pictorial overview of the diagnostic pitfalls and outline strategies for mitigating or preventing the occurrence of artifacts, when possible. The broadening scope of DECT applications necessitates up-to-date familiarity with these technologies to realize their full diagnostic potential.

Tophaceous gout of the atlantoaxial joint: a case report

Background

To report the occurrence of tophaceous gout in the cervical spine and to review the literature on spinal gout.

Case presentation

This report details the occurrence of a large and clinically significant finding of tophaceous gout in the atlantoaxial joint of the cervical spine in an 82-year-old Caucasian man with a 40-year history of crystal-proven gout and a 3-month history of new-onset progressive myelopathy. The patient's American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria score was 15.0.

Conclusion

Spinal gout is more common than previously thought, and it should be considered in patients who present with symptoms of myelopathy. Diagnosis can be made without a tissue sample of the affected joint(s) with tools like the ACR/EULAR criteria and the use of the “diagnostic clinical rule” for determining the likelihood of gout. Early conservative management with neck immobilization and medical management can avoid the need for surgical intervention.

Altered distribution and enhanced osteoclastogenesis of mucosal-associated invariant T cells in gouty arthritis

OBJECTIVE

This study was designed to investigate the role of mucosal-associated invariant T (MAIT) cells in gouty arthritis (GA) and their effects on osteoclastogenesis.

METHODS

Patients with GA (n = 61), subjects with hyperuricaemia (n = 11) and healthy controls (n = 30) were enrolled in this study. MAIT cells, cytokines, CD69, programmed death-1 (PD-1) and lymphocyte-activation gene 3 (LAG-3) levels were measured by flow cytometry. In vitro osteoclastogenesis experiments were performed using peripheral blood mononuclear cells in the presence of M-CSF and RANK ligand.

RESULTS

Circulating MAIT cell levels were significantly reduced in GA patients. However, their capacities for IFN-γ, IL-17 and TNF-α production were preserved. Expression levels of CD69, PD-1 and LAG-3 in MAIT cells were found to be elevated in GA patients. In particular, CD69 expression in circulating MAIT cells was increased by stimulation with MSU crystals, suggesting that deposition of MSU crystals might contribute to MAIT cell activation. Interestingly, MAIT cells were found to be accumulated in synovial fluid and infiltrated into gouty tophus tissues within joints. Furthermore, activated MAIT cells secreted pro-resorptive cytokines (i.e. IL-6, IL-17 and TNF-α) and facilitated osteoclastogenesis.

CONCLUSION

This study demonstrates that circulating MAIT cells are activated and numerically deficient in GA patients. In addition, MAIT cells have the potential to migrate to inflamed tissues and induce osteoclastogenesis. These findings provide an important role of MAIT cells in the pathogenesis of inflammation and bone destruction in GA patients.

Serum levels and gene polymorphisms of angiopoietin 2 in systemic lupus erythematosus patients

This study aimed to discuss association between serum Angiopoietin2 (Ang2) levels, Ang2 gene polymorphisms and systemic lupus erythematosus (SLE) susceptibility. It was carried out by 235 SLE, 342 other inflammatory autoimmune diseases patients and 380 healthy individuals. Serum Ang2 levels was examinated by ELISA, and Ang2 rs12674822, rs1823375, rs1868554, rs2442598, rs3739390 and rs734701 polymorphisms were genotyped using KASP. Increased Ang2 concentrations in SLE patients were observed compared with healthy controls and patients with other inflammatory autoimmune diseases. For allelic contrast, except for rs1823375 (P = 0.058) and rs2442598 (P = 0.523), frequencies of alleles for other polymorphisms were significantly different between SLE patients and controls. Genotypes for rs12674822 (TT), rs1868554 (TT, TA and TT+TA), rs734701 (TT) were negatively correlated with SLE susceptibility (OR = 0.564 for rs12674822; OR = 0.572, OR = 0.625, OR = 0.607 for rs1868554; OR = 0.580 for rs734701). Patients carrying rs1868554 T allele and rs3739390 G allele were more likely to develop hematuria (P = 0.039; P = 0.003). The G allele frequencies of rs12674822 and rs2442598 were higher in SLE patients with proteinuria (P = 0.043; P = 0.043). GC genotype frequency of rs3739390 was higher in patients with ds-DNA (+) (P = 0.024). In summary, SLE had increased serum Ang2, which may be a potential biomarker, and the polymorphisms correlated with SLE.

Dual-Energy CT Images: Pearls and Pitfalls

Dual-energy CT (DECT) is a tremendous innovation in CT technology that allows creation of numerous imaging datasets by enabling discrete acquisitions at more than one energy level. The wide range of images generated from a single DECT acquisition provides several benefits such as improved lesion detection and characterization, superior determination of material composition, reduction in the dose of iodine, and more robust quantification. Technological advances and the proliferation of various processing methods have led to the availability of diverse vendor-based DECT approaches, each with a different acquisition and image reconstruction process. The images generated from various DECT scanners differ from those from conventional single-energy CT because of differences in their acquisition techniques, material decomposition methods, image reconstruction algorithms, and postprocessing methods. DECT images such as virtual monochromatic images, material density images, and virtual unenhanced images have different imaging appearances, texture features, and quantitative capabilities. This heterogeneity creates challenges in their routine interpretation and has certain associated pitfalls. Some artifacts such as residual iodine on virtual unenhanced images and an appearance of pseudopneumatosis in a gas-distended bowel loop on material-density iodine images are specific to DECT, while others such as pseudoenhancement seen on virtual monochromatic images are also observed at single-energy CT. Recognizing the potential pitfalls associated with DECT is necessary for appropriate and accurate interpretation of the results of this increasingly important imaging tool. Online supplemental material is available for this article. ©RSNA, 2021.

Computed tomography in rheumatology - From DECT to high-resolution peripheral quantitative CT

In this chapter, we discuss current updates and applications of Dual Energy Computed Tomography (DECT), iodine-DECT mapping, and high-resolution peripheral quantitative CT (HR-pQCT) in rheumatology. DECT provides a noninvasive diagnosis of gout and can help to differentiate gout from CPPD. Accuracy of DECT varies in various stages of gout. DECT needs specialized hardware, software, and skilled post-processing and interpretation. Sensitivity reduces significantly with deeper tissues such as hip and shoulder. Iodine map enables to delineate inflammatory lesions such as capsulitis and tenosynovitis by improving iodine contrast. Iodine quantification with an iodine map is a promising objective method to evaluate therapeutic effect of inflammatory arthritis. HR-pQCT allows for highly sensitive and specific measures of bone erosions and osteophytes in inflammatory joint diseases, documenting change over time, e.g. in cohorts undergoing immunosuppressive treatments. However, assessing the images requires trained readers, and (semi)-automated scripts to detect bone damage are still undergoing validation and further development.

Can Dual-Energy Computed Tomography Be Used to Identify Early Calcium Crystal Deposition in the Knees of Patients With Calcium Pyrophosphate Deposition?

OBJECTIVE

To assess the ability of dual-energy computed tomography (DECT) in identifying early calcium crystal deposition in menisci and articular cartilage of the knee, depending on the presence/absence of chondrocalcinosis seen on conventional CT.

METHODS

One hundred thirty-two knee DECT scans from patients with suspected crystal-associated arthropathy were reviewed and assigned to a calcium pyrophosphate deposition (CPPD) group (n = 50) or a control group (n = 82). Five DECT attenuation parameters were measured in preset regions of interest (ROIs) in menisci and articular cartilage and compared between groups using linear mixed models with adjustment for confounders. Subgroup analysis, excluding ROIs with chondrocalcinosis seen on conventional CT, was performed.

RESULTS

In both menisci and articular cartilage, and for all 5 DECT attenuation parameters, calcified ROIs in CPPD patients showed significantly higher values than ROIs in controls (P ≤ 0.036). Conversely, noncalcified ROIs in CPPD patients were comparable with those in controls (P ≥ 0.09). While specific DECT parameters yielded good accuracy (area under the curve [AUC] 0.87-0.88) in differentiating calcified ROIs in CPPD patients from ROIs in controls, DECT failed to distinguish between noncalcified ROIs in CPPD patients and controls (AUC 0.58-0.59).

CONCLUSION

While DECT has the potential to characterize knee intraarticular mineralization, this technique cannot yet accurately identify early calcium crystal deposition that is not visible as chondrocalcinosis on conventional CT.

Management of Hyperuricemia in Patients with Chronic Kidney Disease: a Focus on Renal Protection

PURPOSE OF REVIEW

In chronic kidney disease (CKD), plasma uric acid levels are increased because of the decrease in glomerular filtration rate. However, in addition to CKD, hyperuricemia is frequently associated with a number of other conditions such as hypertension, type 2 diabetes, obesity, and heart failure, overweight, and cardiovascular disease.

RECENT FINDINGS

It is now becoming increasingly clear that, in many clinical conditions, elevated levels of uric acid have a much greater role beyond just causing gout. The present review will summarize current knowledge on the relation between hyperuricemia, CKD, and existing comorbidities, as well as the mechanisms of uric acid-related renal damage. In addition, the role and evidence for urate-lowering therapy in prevention and cardiovascular protection in CKD patients is discussed with a focus on allopurinol and febuxostat. To date, several clinical studies have provided evidence that urate-lowering therapy may help to prevent and delay the decline of renal function in patients with CKD. Use of a xanthine oxidase inhibitor should be considered in patients who are at high renal risk and/or with declining renal function in the presence of hyperuricemia with and without deposition, although additional studies are warranted to define treatment targets. Notwithstanding, the possibility to delay deterioration of renal function in patients with CKD merits consideration.

Ultrasound Proven Monosodium Urate Crystal Deposits in the Joints are Associated with Smaller Kidney Size, Decreased Intrarenal Blood Flow and Arteriosclerotic Type Vascular Changes

Objective: To establish the association between ultrasound (US) burden with articular MSU crystals and renal morphology, blood supply, function and arteriosclerotic carotid arteries alterations in gout patients, individuals with asymptomatic hyperuricemia and no sign of inflammatory arthritis and psoriatic arthritis subjects with asymptomatic hyperuricemia.

Methods: 121 consecutive patients were included: 85 patients with gout, 27 subjects with asymptomatic hyperuricemia and 9 psoriatic arthritis patients. Subjects underwent US of both kidneys, common carotid arteries and bilateral US of the joints of the hands, elbows, knees, ankles and feet. For intrarenal blood flow we judged by measuring the renal resistive index (RRI). By US of the carotid arteries were determined intima-media thickness (IMT), common carotid artery resistive index (CCARI) and the presence of atherosclerotic plaques was registered.

Results: Individuals with articular US MSU deposits compared to those without had higher RRI (p = 0.035) and smaller kidney size (p = 0.014), but renal parenchymal thickness (p = 0.893), echogenicity (p = 0.291), IMT (p = 0.165), CCARI (p = 0.097), the frequency of nephrolithiasis (p = 0.438) and atherosclerotic plaques (p = 0.830) were similar. Subjects with US evidence of MSU crystals in two or more joint regions had the highest RRI (p = 0.002) and CCARI (p = 0.019). Compared to gout patients the risk of MSU crystal accumulation in the joints of asymptomatic hyperuricemia group was lower by 82.7%, OR = 0.173 (95% CI; 0.060 – 0.498, p = 0.001), while in psoriatic arthritis patients the risk was lower by 82%, OR = 0.180 (95% CI; 0.038-0.861, p = 0.032).

Conclusions: This study points out that subjects with larger extent of articular MSU burden have greater vascular stiffness. The accumulation of MSU crystals in the joints may be associated with the accumulation of crystals mainly in the renal interstitium.

Association of urate deposition shown by ultrasound and frequent gout attacks

BACKGROUND

There are few data demonstrating the association between urate burden assessed by ultrasound (US) and gout flares. The aim of this study was to determine the association of urate deposition shown by US and frequent gout attacks.

MATERIALS AND METHODS

Patients with gout were divided into two groups according to the frequency of gout attacks in the previous 12 months: frequent (>2 attacks) and infrequent (0-2 attacks). Urate deposition in the hands, knees, and feet was assessed by US.

RESULTS

Overall, 106 patients were enrolled in this study, of whom 32 (30.1%) had had frequent gout attacks (>2 attacks) in the previous 12 months (the average number of gout attacks was 4.7, range 3-12). Those with frequent gout attacks had significantly longer gout duration, a higher serum urate level, and more urate deposition shown by US than those with infrequent gout attacks (P < 0.05). In both univariate and logistic regression analyses, frequent gout attacks were correlated with gout duration, serum urate level, and urate deposition as shown by US (P < 0.05).

CONCLUSION

These findings indicate that urate deposition shown by US is independently associated with frequent gout attacks. Special attention should be given to the prevention of flares in patients with an initially high urate burden as assessed by US.

Gout flare severity from the patient perspective: a qualitative interview study

OBJECTIVE

The patient experience of a gout flare is multi-dimensional. To establish the most appropriate methods of flare measurement, there is a need to understand the complete experience of a flare. This qualitative study aimed to examine what factors contribute to the severity of a flare from the patient perspective.

METHODS

Face-to-face interviews were conducted with people with gout. Participants were asked to share their experience with their worst gout flare and contrast it to their experience of a less severe or mild flare. Interviews were audio-recorded and transcribed verbatim. Data was analysed using a reflexive thematic approach.

RESULTS

Twenty-two participants with gout (17 males, mean age 66.5 years) were interviewed at an academic centre in Auckland, New Zealand. Four key themes were identified as contributing to the severity of a flare: flare characteristics (pain intensity, joint swelling, redness and warmth, duration, and location), impact on function (including walking, activities of daily living, wearing footwear, and sleep), impact on family and social life (dependency on others, social connection, and work) and psychological impact (depression, anxiety, irritability, and sense of control).

CONCLUSION

A wide range of interconnecting factors contribute to the severity of a gout flare from the patient perspective. Capturing these domains in long-term gout studies would provide more meaningful and accurate representation of cumulative flare burden.

Imaging of crystalline arthropathy in 2020

Crystal-related arthropathies are the result of crystal deposition in joint and periarticular soft tissues. Identification of urate crystals is mandatory to distinguish gout from other crystalline arthropathies, including calcium pyrophosphate dihydrate and basic calcium phosphate crystal deposition diseases. ACR/EULAR classification criteria for gout included dual-energy computed tomography and ultrasound with equal impact to the final score. Different diagnostic strengths of these imaging modalities depend on disease duration and scanned anatomic site. While ultrasound has been indicated as the first-choice imaging technique, especially in the early stages of the disease, dual-energy computed tomography has shown to be highly specific, allowing the detection of crystal deposits in anatomic sites not accessible by ultrasound, such as the spine. At the spinal level, MRI findings are usually nonspecific. Finally, there is preliminary evidence that at the knee, dual-energy computed tomography may discriminate calcium pyrophosphate dihydrate from basic calcium phosphate crystal deposits.

Gout Is Prevalent but Under-Registered Among Patients With Cardiovascular Events: A Field Study

Objectives: Gout is an independent cardiovascular (CV) risk factor with significant morbidity and mortality. We aimed to estimate the prevalence of gout, characteristics and management in a hospitalized population for CV disease, a topic that remains to be defined. Methods: An observational, descriptive, cross-sectional study was carried out in patients admitted for CV events in the Cardiology, Neurology, and Vascular Surgery units of a tertiary center. Patients were selected following a non-consecutive, systematic sampling. Data about CV disease and gout were obtained from face-to-face interviews and patients' records. Gout diagnosis was established using the 2015 ACR/EULAR clinical classification criteria. The registration rate of gout was assessed by auditing patients' records and hospital discharge reports of CV events from the units of interest in the previous 2 years. To predict the presence of gout, multivariate logistic regression models were built to study the possible explanatory variables. Results: Two hundred and sixty six participants were recruited, predominantly males (69.9%) and Caucasians (96.6%) with a mean age of 68 years. Gout was identified in 40 individuals; thus, the prevalence was 15.0% (95% CI 10.9-19.2%). In 35% of cases, the diagnosis was absent from patients' records. Gout was found in 1.4-2.6% of hospital discharge reports of CV events, also indicating under-registration. The disease was long-standing, but with low reported rates of flares, involved joints, and tophi. At admission, only half of the gout patients were on urate-lowering therapy, being 38.5% of them on serum urate <6 mg/dl. The only independent predictor of gout was the existence of previous hyperuricemia (median serum urate in previous 5 years ≥7 mg/dl), with an odds ratio of 2.9 (95% CI 1.2-7.1); if hyperuricemia is not included in the model, the only independent predictor was chronic kidney disease (odds ratio 3.0; 95% CI 1.4-6.6). Conclusion: Gout is highly prevalent among patients admitted for CV events, with significant lack of awareness and suboptimal management, despite being a well-established independent CV risk factor.

Urate in fingernail represents the deposition of urate burden in gout patients

Urate in the fingernails of gout patients and healthy volunteers was successfully detected by high-performance liquid chromatography (HPLC) with ultraviolet (UV) in our previous research. This study aimed to further investigate whether nail urate could be a proxy for the burden of monosodium urate (MSU) crystals deposits in gout. To this end, we conducted a study in two parts. Firstly, we successfully detected urate in the nail by HPLC-UV and evaluated nail urate concentrations in control subjects and patients with gout. As expected, we found that levels of nail urate were significantly higher in patients with gout than in healthy controls, and the nail urate level was significantly correlated with the volume of MSU crystals deposits measured by dual-energy CT (DECT). Secondly, we found that nail urate can reflect changes in urate levels in the body during urate lowering therapy through a 3-month follow-up study. Our results provide the possibility of quantification of urate in human fingernails as a non-invasive alternative for assessing MSU crystals deposits in gout.

UltraSound evaluation in follow-up of urate-lowering therapy in gout phase 2 (USEFUL-2): Duration of flare prophylaxis

OBJECTIVES

To determine whether changes in ultrasonography (US) features of monosodium urate crystal deposition is associated with the number of gouty flares after stopping gout flare prophylaxis.

METHODS

We performed a 1-year multicentre prospective study including patients with proven gout and US features of gout. The first phase of the study was a 6-month US follow-up after starting urate-lowering therapy (ULT) with gout flare prophylaxis. After 6 months of ULT, gout flare prophylaxis was stopped, followed by a clinical follow-up (M6 to 12) and ULT was maintained. Outcomes were the proportion of relapsing patients between M6 and M12 according to changes of US features of gout and determining a threshold decrease in tophus size according to the probability of relapse.

RESULTS

We included 79 gouty patients [mean (±SD) age 61.8±14 years, 91% males, median disease duration 4 (IQR 1.5;10) years]. Among the 49 completers at M12, 23 (47%) experienced relapse. Decrease in tophus size ≥50% at M6 was more frequent without than with relapse (54% vs. 26%, P=0.049). On ROC curve analysis, a threshold decrease of 50.8% in tophus size had the best sensitivity/specificity ratio to predict relapse [AUC 0.649 (95% confidence interval 0.488; 0.809)]. Probability of relapse was increased for patients with a decrease in tophus size <50% between M0 and M6 [OR 3.35 (95% confidence interval 0.98; 11.44)].

CONCLUSION

A high reduction in US tophus size is associated with lower probability of relapse after stopping gout prophylaxis. US follow-up may be useful for managing ULT and gout flare prophylaxis.

A Detailed Analysis of the Association between Urate Deposition and Erosions and Osteophytes in Gout

OBJECTIVE

To characterize in detail the structural bone changes associated with the deposition of monosodium urate crystals in the first metatarsophalangeal (MTP1) joint in patients with tophaceous gout.

METHODS

Twenty patients with tophaceous gout and involvement of the MTP1 joint received both dual-energy computed tomography (DECT) of the feet for the detection of tophi and high-resolution peripheral quantitative computed tomography (HR-pQCT) of the feet for the detection of bone erosions and osteophytes. Demographic and clinical data were collected. Tophi in DECT and erosions and osteophytes in HR-pQCT were overlayed to define their anatomical relation. In addition, the feet of 20 sex- and age-matched healthy controls were scanned to define the normal architecture of the MTP1 joint.

RESULTS

Patients with gout had an increased number and extent of bone erosions and osteophytes compared with their healthy counterparts (erosions: 5 [0-17] vs 1 [1-2], 45.32 mm³ [7.26-550.32] vs 0.82 mm³ [0.15-21.8]; osteophytes: 10.5 [0-26] vs 1 [0-10], 4.93 mm [0.77-7.19 mm] vs 0.93 mm [0.05-7.61 mm]; all P < 0.001). The median tophi volume detected by DECT (0.12 mm³ [0.01-2.53]) was highly associated with the total volume of erosions (r = 0.597, P = 0.005).

CONCLUSION

Gout patients show increased changes in their bone microarchitecture. The extent of uric acid deposition is positively correlated with the extent of bone loss at the MTP1 joint, highlighting the strong cohesion of inflammation and erosive changes.

Evaluation of the Influence of Genetic Variants of SLC2A9 (GLUT9) and SLC22A12 (URAT1) on the Development of Hyperuricemia and Gout

Urate transporters, which are located in the kidneys, significantly affect the level of uric acid in the body. We looked at genetic variants of genes encoding the major reabsorption proteins GLUT9 (SLC2A9) and URAT1 (SLC22A12) and their association with hyperuricemia and gout. In a cohort of 250 individuals with primary hyperuricemia and gout, we used direct sequencing to examine the SLC22A12 and SLC2A9 genes. Identified variants were evaluated in relation to clinical data, biochemical parameters, metabolic syndrome criteria, and our previous analysis of the major secretory urate transporter ABCG2. We detected seven nonsynonymous variants of SLC2A9. There were no nonsynonymous variants of SLC22A12. Eleven variants of SLC2A9 and two variants of SLC22A12 were significantly more common in our cohort than in the European population (p = 0), while variants p.V282I and c.1002+78A>G had a low frequency in our cohort (p = 0). Since the association between variants and the level of uric acid was not demonstrated, the influence of variants on the development of hyperuricemia and gout should be evaluated with caution. However, consistent with the findings of other studies, our data suggest that p.V282I and c.1002+78A>G (SLC2A9) reduce the risk of gout, while p.N82N (SLC22A12) increases the risk.

Associations of serum uric acid level and gout with cardiac structure, function and sex differences from large scale asymptomatic Asians

Hyperuricemia (HU) is a marker for heart failure. There are relatively few data in the Asian population regarding the effects of hyperuricemia and gouty disorders on cardiac remodeling and diastolic dysfunction (DD), an intermediate stage in the development of heart failure. We consecutively recruited asymptomatic Asian individuals to undergo cardiovascular surveys. We categorized them into Non-HU, HU, and Gout groups. We measured cardiac structure and indices for diastolic function, including tissue Doppler (TDI)-derived LV e’ and E/e’. Among 5525 participants, 1568 had HU and 347 had gout. The presence of gout and higher uric acid levels (SUA) (<4, 4–6, 6–8, 8–10, > = 10 mg/dL) were associated with greater LV wall thickness, greater LV mass/volumes, larger LA volume, lower LV e’ and higher E/e’. Higher SUA was associated with greater LV mass index (adjusted coefficient: 0.37), greater mass/volume ratio (adjusted coefficient: 0.01) and larger LA volume index (adjusted coefficient: 0.39, all p<0.05). Both HU and Gout groups were associated with lower LV e’ (coefficient: -0.086, -0.05), higher E/e’ (coefficient: 0.075, 0.35, all p <0.05), larger LA volume, and higher DD risk (adjusted ORs: 1.21 and 1.91 using Non-HU as reference, respectively, both p <0.05). SUA set at 7.0 mg/dL provided the optimal cut-off for identifying DD, with markedly lower e’ (HU: 8.94 vs 8.07, Gout: 7.94 vs 7.26 cm/sec) and higher LV E/e’ in HU/Gout women than in men (HU: 7.84 vs 9.79 cm/sec for men and women, respectively, all p <0.05). Hyperuricemia, even at a relatively low clinical cut-off, was associated with unfavorable remodeling and was tightly linked to diastolic dysfunction. The presence of gout likely aggravated these conditions. Women with hyperuricemia or gout had worse diastolic indices than men despite similar degrees of LV remodeling.

PD-1 mRNA expression in peripheral blood mononuclear cells as a biomarker for different stages of primary gouty arthritis

There is currently a lack of biomarkers to assist the diagnosis and prediction of primary gouty arthritis (PG). Therefore, we evaluated the clinical value of programmed cell death protein 1 (PD-1) mRNA expression in peripheral blood mononuclear cells (PBMCs) of patients with PG. This study included 36 patients with acute phase PG (APPG), 48 with non-acute phase PG (NAPPG), 42 with asymptomatic hyperuricemia (AH) and 79 normal controls (NCs). PD-1 mRNA expression levels were detected by qRT-PCR. PD-1 mRNA expression was statistically analysed by ANOVA or t tests, while correlations between PD-1 mRNA and clinical variables were assessed using Pearson correlation tests. Receiver operator characteristic (ROC) curve analysis was used to evaluate the diagnostic value of PD-1 in different PG stages. PD-1 mRNA expression was significantly lower in patients with APPG than that in NAPPG, AH and NCs (P < 0.01). Correlation analysis revealed that PD-1 mRNA levels correlated negatively with T-score (r = -0.209, P < 0.01). ROC curve analysis showed that serum uric acid (SUA), PD-1 mRNA and both combined displayed higher diagnostic value in patients with PG, NAPPG and APPG compared to that in NCs and patients with non-PG arthritis (NPG). Moreover, ROC curve analysis showed that SUA and PD-1 mRNA had good diagnostic value in APPG, with the greatest diagnostic power when combined. PD-1 mRNA could be a clinical auxiliary diagnostic biomarker for APPG, and the combined use of PD-1 mRNA and SUA is better than that of SUA alone.

Dual-Energy Computed Tomography Detection of Cardiovascular Monosodium Urate Deposits in Patients With Gout

Importance

The prevalence of gout has increased in recent decades. Several clinical studies have demonstrated an association between gout and coronary heart disease, but direct cardiovascular imaging of monosodium urate (MSU) deposits by using dual-energy computed tomography (DECT) has not been reported to date.

Objective

To compare coronary calcium score and cardiovascular MSU deposits detected by DECT in patients with gout and controls.

Design, Setting, and Participants

This prospective Health Insurance Portability and Accountability Act-compliant study included patients with gout and controls who presented to a rheumatologic clinic from January 1, 2017, to November 1, 2018. All consecutive patients underwent DECT to assess coronary calcium score and MSU deposits in aorta and coronary arteries. In addition, cadavers were assessed by DECT for cardiovascular MSU deposits and verified by polarizing microscope. Analysis began in January 2017.

Main Outcomes and Measures

Detection rate of cardiovascular MSU deposits using DECT in patients with gout and control group patients without a previous history of gout or inflammatory rheumatic diseases.

Results

A total of 59 patients with gout (mean [SD] age, 59 [5.7] years; range, 47-89 years), 47 controls (mean [SD] age, 70 [10.4] years; range, 44-86 years), and 6 cadavers (mean [SD] age at death, 76 [17] years; range, 56-95 years) were analyzed. The frequency of cardiovascular MSU deposits was higher among patients with gout (51 [86.4%]) compared with controls (7 [14.9%]) (χ2 = 17.68, P < .001), as well as coronary MSU deposits among patients with gout (19 [32.2%]) vs controls (2 [4.3%]) (χ2 = 8.97, P = .003). Coronary calcium score was significantly higher among patients with gout (900 Agatston units [AU]; 95% CI, 589-1211) compared with controls (263 AU; 95% CI, 76-451; P = .001) and also significantly higher among 58 individuals with cardiovascular MSU deposits (950 AU; 95% CI, 639-1261) compared with 48 individuals without MSU deposits (217 AU; 95% CI, 37-397; P < .001). Among 6 cadavers, 3 showed cardiovascular MSU deposits, which were verified by polarizing light microscope.

Conclusion and Relevance

Dual-energy computed tomography demonstrates cardiovascular MSU deposits, as confirmed by polarized light microscopy. Cardiovascular MSU deposits were detected by DECT significantly more often in patients with gout compared with controls and were associated with higher coronary calcium score. This new modality may be of importance in gout population being at risk from cardiovascular disease.

The Role of Musculoskeletal Ultrasound in the Rheumatoid Arthritis Continuum

PURPOSE OF REVIEW

Rheumatoid arthritis (RA) is no longer considered a fixed phenotype but rather a disease continuum. This review outlines the current and potential value of applying ultrasound (US) along this continuum: from the prediction of progression to RA in at-risk individuals, to confirmation of the early diagnosis of RA, as well as the consideration of differential diagnoses, and the use in disease monitoring and defining remission.

RECENT FINDINGS

In individuals at-risk of RA (i.e., positive autoantibodies with symptoms but without synovitis), US has shown a promising predictive value for the development of clinical arthritis, providing the opportunity to improve risk stratification (and disease prevention) of these individuals. The detection of inflammation on US in patients with early undifferentiated arthritis, in which a definite diagnosis cannot be reached, could predict evolution to persistent arthritis, mostly RA. This, in addition to the US potential ability to identify disease specific patterns for different rheumatic conditions, might facilitate early diagnosis and, therefore, improve the management of patients with RA, or other types of inflammatory arthritides. US has also demonstrated the capability to predict radiographic progression, and relapse risk after treatment discontinuation, in RA patients in remission according to the clinical instruments, raising implications in the management, including therapy discontinuation, of these patients. US has an undeniable value in the management of patients at different stages along the RA continuum. Further research is needed to identify which groups of patients benefit the most from US imaging.

Musculoskeletal ultrasound imaging training, use, and knowledge among rheumatologists in China

INTRODUCTION/OBJECTIVES

Musculoskeletal ultrasound (MSUS) has been extensively studied by rheumatologists in Europe and the Americas, but less is known about MSUS use in Asia. Our hypothesis is that MSUS use is less prevalent in China as compared with its Western counterparts. This study reports the most up-to-date recommendations for MSUS use in rheumatology globally and is also the first study to characterize the current practices, training, and perceptions regarding MSUS of rheumatologists in China.

METHOD

A 43-question survey was designed and distributed via mobile application to members of the Chinese Rheumatology Association, primarily to investigate the current prevalence and utilization of MSUS in China. Statistical analyses included the use of chi-square tests and independent-samples t tests, with p values less than 0.05 considered statistically significant.

RESULTS

The results showed low rates of MSUS training (129/528, 24%) and current MSUS use (89/524, 17%) in China. However, there was a high level of interest in learning MSUS, especially among younger respondents. Lack of access to training programs and user variability in skill were seen as significant barriers to the uptake of MSUS.

CONCLUSIONS

Despite low rates of MSUS training and utilization, the vast majority of respondents believe that MSUS should become a standard clinical tool in rheumatology, and there was great interest in undergoing training. Importantly, lack of access to MSUS training programs and user variability in skill were seen as significant obstacles to the more widespread use of MSUS, which suggests a need for more standardized, high-quality MSUS training in China. Key Points • A low percentage of Chinese rheumatologists (17%) currently use MSUS. • Chinese rheumatologists expressed a high level of interest in obtaining MSUS training. • The greatest perceived obstacle to more widespread MSUS use is the lack of training programs.

Comparison of persistence rates between allopurinol and febuxostat as first-line urate-lowering therapy in patients with gout: an 8-year retrospective cohort study

INTRODUCTION/OBJECTIVES

Lifelong urate-lowering therapy (ULT) with xanthine oxidase inhibitors (XOIs), such as allopurinol and febuxostat, is the cornerstone of gout treatment. This study aimed to compare drug persistence between allopurinol and febuxostat as first-line ULT in patients with gout in real practice.

METHOD

In this retrospective cohort study, we evaluated 602 patients with gout in whom allopurinol or febuxostat was newly initiated from December 2011 to November 2018 at a tertiary rheumatology centre. Persistence was defined as the duration from the first description date to the end of treatment with XOIs or the end of the study period (November 2019).

RESULTS

Among the 602 gout patients, the mean age was 60.2 years and 234 (38.9%) patients had tophi. Allopurinol and febuxostat were started in 237 (39.3%) and 365 (60.6%) patients, respectively. During the study period, 282 (46.8%) patients stopped taking XOIs, and the most common reason for XOI withdrawal was poor health literacy (61.3%). The 1- and 5-year persistence rates of XOIs were 67.2% and 40.9%, respectively. In the Kaplan-Meier analysis, persistence rates of allopurinol were significantly lower than those of febuxostat (p < 0.001). In the multivariable Cox regression model, allopurinol use was a significant risk factor for discontinuation of XOIs (HR = 2.01, p < 0.001). In addition, the presence of tophi and symptom duration < 24 months was independently associated with a higher risk of XOI withdrawal.

CONCLUSIONS

Long-term persistence of XOIs was suboptimal, and allopurinol had worse persistence rates than febuxostat among patients with gout. Key Points • Long-term persistence of xanthine oxidase inhibitors (XOIs) as first-line urate-lowering therapy (ULT) among patients with gout was suboptimal, and the major reason for XOI discontinuation was poor health literacy in our study. • We demonstrated that allopurinol had worse persistence rates than febuxostat among patients with gout, suggesting that febuxostat is a better option for long-term ULT in light of medication adherence in a real-world setting. • Patients with gout with tophi and shorter symptom duration were found to be at high risk for poor persistence of XOIs.

Using genetics to prioritize diagnoses for rheumatology outpatients with inflammatory arthritis

It is challenging to quickly diagnose slowly progressing diseases. To prioritize multiple related diagnoses, we developed G-PROB (Genetic Probability tool) to calculate the probability of different diseases for a patient using genetic risk scores. We tested G-PROB for inflammatory arthritis-causing diseases (rheumatoid arthritis, systemic lupus erythematosus, spondyloarthropathy, psoriatic arthritis, and gout). After validating on simulated data, we tested G-PROB in three cohorts: 1211 patients identified by International Classification of Diseases (ICD) codes within the eMERGE database, 245 patients identified through ICD codes and medical record review within the Partners Biobank, and 243 patients first presenting with unexplained inflammatory arthritis and with final diagnoses by record review within the Partners Biobank. Calibration of G-probabilities with disease status was high, with regression coefficients from 0.90 to 1.08 (1.00 is ideal). G-probabilities discriminated true diagnoses across the three cohorts with pooled areas under the curve (95% CI) of 0.69 (0.67 to 0.71), 0.81 (0.76 to 0.84), and 0.84 (0.81 to 0.86), respectively. For all patients, at least one disease could be ruled out, and in 45% of patients, a likely diagnosis was identified with a 64% positive predictive value. In 35% of cases, the clinician's initial diagnosis was incorrect. Initial clinical diagnosis explained 39% of the variance in final disease, which improved to 51% (P < 0.0001) after adding G-probabilities. Converting genotype information before a clinical visit into an interpretable probability value for five different inflammatory arthritides could potentially be used to improve the diagnostic efficiency of rheumatic diseases in clinical practice.

Musculoskeletal Ultrasound Instruction in Adult Rheumatology Fellowship Programs

OBJECTIVE

Musculoskeletal ultrasound (MSUS) in rheumatology in the US has advanced by way of promotion of certifications and standards of use and inclusion of core fellowship curriculum. In order to inform endeavors for curricular integration, the objectives of the present study were to assess current program needs for curricular incorporation and the teaching methods that are being employed.

METHODS

A needs-assessment survey (S1) was sent to 113 rheumatology fellowship program directors. For programs that taught MSUS, a curriculum survey (S2) was sent to lead faculty. Programs were stratified according to program size and use of a formal written curriculum.

RESULTS

S1 (108 of 113 respondents; response rate 96%) revealed that 94% of programs taught MSUS, with 41% having a curriculum. Curricular implementation was unaffected by program size. Formal curricular adoption of MSUS was favored by 103 directors (95.3%), with 65.7% preferring such adoption to be optional. S2 (74 of 101 respondents; response rate 73%) showed that 41% of programs utilized a formal curriculum. Multiple teaching strategies were used, with content that was generally similar. Use of external courses, including the Ultrasound School of North American Rheumatologists course, was prevalent. Fewer barriers were noted compared to past surveys, but inadequate time, funding, and number of trained faculty still remained. Lack of divisional interest (P = 0.046) and interest of fellows (P = 0.012) were noted among programs without a formal curriculum.

CONCLUSION

MSUS is taught by a significantly larger number of rheumatology fellowship programs today. Multiple teaching strategies are used with common content, and barriers still remain for some programs. Most program directors favor inclusion of a standardized MSUS curriculum, with many favoring inclusion to be optional.

Bone microstructure and volumetric bone mineral density in patients with hyperuricemia with and without psoriasis

We analyzed volumetric bone mineral density (vBMD) and bone microstructure using HR-pQCT in subjects with normouricemia (NU) and subjects with hyperuricemia (HU) with and without psoriasis (PSO). HU was associated with higher cortical vBMD and thickness. Differences in average and trabecular vBMD were found between patients with PSO + HU and NU.

INTRODUCTION

Hyperuricemia (HU) and gout are co-conditions of psoriasis and psoriatic arthritis. Current data suggest a positive association between HU and areal bone mineral density (BMD) and a negative influence of psoriasis on local bone, even in the absence of arthritis. However, the influence of the combination of HU and psoriasis on bone is still unclear. The aim of this study was to assess the impact of HU with and without psoriasis on bone microstructure and volumetric BMD (vBMD).

METHODS

Healthy individuals with uric acid levels within the normal range (NU), with hyperuricemia (HU), patients with hyperuricemia and psoriasis (PSO + HU), and patients with uric acid within the normal range and psoriasis (PSO + NU) were included in our study. Psoriasis patients had no current or past symptoms of arthritis. Average, trabecular, and cortical vBMD (mgHA/cm³); trabecular number (Tb.N, 1/mm) and thickness (Tb.Th, mm); inhomogeneity of the network (1/N.SD, mm); and cortical thickness (Ct.Th., mm) were carried out at the ultradistal radius using high-resolution peripheral quantitative computed tomography. In addition, bone turnover markers such as DKK-1, sclerostin, and P1NP were analyzed.

RESULTS

In total, 130 individuals were included (44 NU participants (34% female), 50 HU (24%), 16 PSO + HU (6%), 20 PSO + NU (60%)). Subjects were aged: NU 54.5 (42.8, 62.1), HU 57.5 (18.6, 65.1), PSO + HU 52.0 (42.3, 57.8), and PSO + NU 42.5 (34.8, 56.8), respectively. After adjusting for age, sex, BMI, and diabetes, patients in the HU group revealed significantly higher values of cortical vBMD (p < 0.001) as well as cortical thickness (p = 0.04) compared to the NU group. PSO + NU showed no differences to NU, but PSO + HU demonstrated both lower average (p = 0.03) and trabecular vBMD (p = 0.02). P1NP was associated with average, cortical, and trabecular vBMD as well as cortical thickness while sclerostin levels were related to trabecular vBMD.

CONCLUSION

Hyperuricemia in otherwise healthy subjects was associated with a better cortical vBMD and higher cortical thickness. However, patients with both psoriasis and hyperuricemia revealed a lower vBMD.

Activation Status of NLRP3 Inflammasome in Peripheral Blood Mononuclear Cells From Patients With Gout Flare

BACKGROUND/OBJECTIVE

Although gout flares are featured by systemic signs of inflammation, cellular sources of inflammatory mediators are not yet properly characterized. Our objective was to evaluate serum levels and gene expression in peripheral blood mononuclear cells (PBMCs) of several molecules associated with the activation of NLRP3 inflammasome.

METHODS

Fifteen patients with gout flare and 15 individuals with asymptomatic hyperuricemia were cross-sectionally studied. Serum levels of interleukin 1β (IL-1β), IL-18, monocyte chemoattractant protein 1/chemokine (C-C motif) ligand 2 (CCL2), and vascular cell adhesion molecule 1 were measured as a reflection of systemic inflammation, whereas the expression of NLRP3, CASP1, IL18, and CCL2 genes was measured to assess the inflammatory characteristics of PBMCs.

RESULTS

Serum levels of IL-1β (1.27 [0.07-1.99] pg/mL vs. 0 [0-0.82] pg/mL, p = 0.032) and vascular cell adhesion molecule 1 (606 [435-748] pg/mL vs. 349 [305-422] pg/mL, p = 0.014) were significantly higher in patients with gout flare than in individuals with asymptomatic hyperuricemia, whereas differences in IL-18 and monocyte chemoattractant protein 1/CCL2 were not found. Notably, no differences were observed in the expression of NLRP3, CASP1, IL18, or CCL2 in PBMCs from individuals of one or another group.

CONCLUSIONS

Systemic inflammation during gout flares does not appear to be associated with NLRP3 inflammasome activation in PBMCs, suggesting that it may represent the systemic spread of local (synovial) inflammation to monosodium urate crystals, which provides a rationale for redirecting anti-inflammatory therapy from a systemic approach to one centered on the inflamed joint.

Changes in Urinary Microalbumin Levels after Correction of Hyperuricemia in Patients with Gout: An Observational Cohort Study

Background

Gout is commonly associated with metabolic syndrome. Strong association between the serum uric acid level and microalbuminuria has also been observed in various studies.

Aim

To observe the change in urinary microalbumin after urate-lowering treatment in patients with gout and microalbuminuria. Methodology. A prospective, observational study was conducted at a tertiary-level rheumatic center (NCRD) in Kathmandu, Nepal. Adults diagnosed with gout using the 2015 ACR/EULAR criteria and microalbuminuria were enrolled in the study after obtaining informed consent. Sociodemographic profile and clinical history were recorded at baseline. Serum uric acid levels, spot urinary microalbumin (MAU) excretion, blood sugar, lipid profile, and blood pressure were measured at baseline, 3-month follow-up, and 6-month follow-up. A paired t-test was used to compare the change in mean MAU after treatment.

Results

A total of 778 patients diagnosed with gout were screened for microalbuminuria. Among them, 114 (14.6%) had urinary microalbumin levels of >30.0 mg/L during presentation. Mean MAU level among those with microalbuminuria was 132.4 ± 124.6 mg/L. Thirty-five patients had concomitant HTN and were put on ARBs (20 mg of telmisartan). All received 40 mg of febuxostat. In patients with ARBs, MAU reduced significantly after 3 months of treatment with ARBs. Reduction in MAU in those without ARBs was seen after the 6-month follow-up, and the change was statistically significant.

Conclusions

There is significant reduction in MAU after the use of urate-lowering drugs in patients with gout.

Prevalence and Factors Associated With Bone Erosion in Patients With Gout

OBJECTIVE

To determine the prevalence, distribution, and factors associated with bone erosion detectable by ultrasound in patients with gout.

METHODS

Ultrasound scans were performed in 980 patients with gout, and bone erosion was detected. The prevalence and distribution of bone erosion in gout patients were calculated. Both clinical variables and ultrasound signs were entered into a multivariate logistic regression analysis to clarify the factors associated with bone erosion in patients with gout.

RESULTS

Bone erosion was found in 431 (44.0%) of the 980 patients with gout, and in 338 (78.4%) of these patients, the bone erosion was found in the first metatarsophalangeal (MTP) joint. A multivariable logistic regression analysis showed that age, duration of gout, the existence of tophi, ultrasound-detected synovial hypertrophy, and joint effusion were independently associated with bone erosion. A tophus was the most powerful factor associated with bone erosion, with an odds ratio (OR) of 4.218 (95% confidence interval 3.092-5.731). The risk for bone erosion also increased as the number of tophi increased (P < 0.001). However, after stratifying the size of tophi, the ORs did not increase significantly (P = 0.206).

CONCLUSION

A high percentage of gout patients had bone erosions; the first MTP joint was the most frequently involved site. Age, duration of gout, tophi, and synovial hypertrophy were factors associated with bone erosion in gout patients. The number of tophi, but not their size, was strongly associated with bone erosion in patients with gout.

The Utility of the Random Urine Uric Acid-to-Creatinine Ratio for Patients with Gout Who Need Uricosuric Agents: Retrospective Cross-Sectional Study

BACKGROUND

The 24-hour uric acid excretion measurement is important in assessing disease status and helping to select the appropriate uric acid-lowering agent for patients with gout, however, it is inconvenient. The authors investigated the efficacy of the random urine uric acid-to-creatinine (UA/CR) ratio to screen the patients who under-secreted 24-hour urine uric acid.

METHODS

This was a retrospective cross-sectional study. Ninety patients with gout, without undergoing uric acid-lowering treatment were enrolled. Twenty-four-hour urine and random urine samples were obtained on the same day. Six hundred mg of uric acid in the 24-hour urine sample was used as a standard for distinguishing between over and under-excretion groups.

RESULTS

The random urinary UA/CR ratio showed positive correlation with 24-hour urine uric acid excretion (γ = 0.398, P < 0.001). All the patients with the random UA/CR less than 0.2 excreted less than 600 mg uric acid in 24-hour urine collection. When the random urine UA/CR ratio < 0.2 was regarded as a positive result, the positive predictive value, negative predictive value, sensitivity, and specificity in the uric acid under-excretion were 100% (8 of 8), 64.6% (53 of 82), 21.6% (8 of 37), and 100% (53 of 53), respectively.

CONCLUSION

There is a moderate positive correlation between the random urinary UA/CR ratio and 24-hour urine uric acid excretion, so that UA/CR ratio may not be a good predictor of 24-hour urine uric acid excretion. However, the random urine UA/CR ratio 0.2 can be a useful predictor to screen the gouty patients who need to be treated with uricosuric drugs.

Differential DNA Methylation of Networked Signaling, Transcriptional, Innate and Adaptive Immunity, and Osteoclastogenesis Genes and Pathways in Gout

OBJECTIVE

In gout, autoinflammatory responses to urate crystals promote acute arthritis flares, but the pathogeneses of tophi, chronic synovitis, and erosion are less well understood. Defining the pathways of epigenomic immunity training can reveal novel pathogenetic factors and biomarkers. The present study was undertaken to seminally probe differential DNA methylation patterns utilizing epigenome-wide analyses in patients with gout.

METHODS

Peripheral blood mononuclear cells (PBMCs) were obtained from a San Diego cohort of patients with gout (n = 16) and individually matched healthy controls (n = 14). PBMC methylome data were processed with ChAMP package in R. ENCODE data and Taiji data analysis software were used to analyze transcription factor (TF)-gene networks. As an independent validation cohort, whole blood DNA samples from New Zealand Māori subjects (n = 13 patients with gout, n = 16 control subjects without gout) were analyzed.

RESULTS

Differentially methylated loci clearly separated gout patients from controls, as determined by hierarchical clustering and principal components analyses. IL23R, which mediates granuloma formation and cell invasion, was identified as one of the multiple differentially methylated gout risk genes. Epigenome-wide analyses revealed differential methylome pathway enrichment for B and T cell receptor signaling, Th17 cell differentiation and interleukin-17 signaling, convergent longevity regulation, circadian entrainment, and AMP-activated protein kinase signaling, which are pathways that impact inflammation via insulin-like growth factor 1 receptor, phosphatidylinositol 3-kinase/Akt, NF-κB, mechanistic target of rapamycin signaling, and autophagy. The gout cohorts overlapped for 37 (52.9%) of the 70 TFs with hypomethylated sequence enrichment and for 30 (78.9%) of the 38 enriched KEGG pathways identified via TFs. Evidence of shared differentially methylated gout TF-gene networks, including the NF-κB activation-limiting TFs MEF2C and NFATC2, pointed to osteoclast differentiation as the most strongly weighted differentially methylated pathway that overlapped in both gout cohorts.

CONCLUSION

These findings of differential DNA methylation of networked signaling, transcriptional, innate and adaptive immunity, and osteoclastogenesis genes and pathways suggest that they could serve as novel therapeutic targets in the management of flares, tophi, chronic synovitis, and bone erosion in patients with gout.

Unraveling the genetic causes in large pedigrees with gout by whole‑exome sequencing

Gout is a common type of inflammatory arthritis that is clinically and genetically heterogeneous. The genetic aetiology remains unclear, and mainly relies on previous genome-wide association studies focused on sporadic cases. The present study aimed to identify the genetic basis of gout in three families using whole-exome sequencing (WES). WES was performed in the probands, and family members were involved in the co-segregation analysis. In total, three deleterious rare or novel missense mutations were identified in ATP-binding cassette super-family G member 2 (ABCG2), protein kinase CGMP-dependent 2 (PRKG2) and adrenoceptor β3 (ADRB3) genes in three different families. In addition, certain gout-associated candidate genes were revealed to be shared among the co-expression and protein-protein interaction (PPI) networks of ABCG2, PRKG2 and ADRB3. Furthermore, the disease ontology analysis of the genes present in the co-expression network exhibited significant (P<0.05) enrichment in hyperuricemia, gout, cardiovascular system disease and metabolic disease. In addition, genes involved in the PPI network were significantly enriched in the purine nucleoside monophosphate biosynthetic process, urate transport and biological processes associated with glycose metabolism. Collectively, to the best of our knowledge, the present study was the first to use WES to identify three candidate rare or novel deleterious mutations in three families with gout. The present results provided novel insights that may improve the current understanding of the molecular genetic basis underlying gout. Importantly, the present results may facilitate the improvement of clinical diagnosis and the development of novel personalized therapies.

The comparison of dyslipidemia and serum uric acid in patients with gout and asymptomatic hyperuricemia: a cross-sectional study

BACKGROUND

Dyslipidemia often concurs with hyperuricemia. Our study was to discover different lipid levels of gout and asymptomatic hyperuricemia and the predictors of sUA (serum uric acid) levels.

METHODS

A cross-sectional study was performed to collect demographic, clinical variables, comorbidities and laboratory testing in patients with gout and asymptomatic hyperuricemia. Group comparison was performed with Student's t-test or Mann Whitney U test for continuous variables and chi-squared tests for categorical variables (Fisher's exact test where appropriate) and to screen potential risk factors. Correlation of sUA levels with demographic and biochemical variables were performed by using correlation analysis. The variable with s p-value less than 0.20 during the group comparison or clinical relevance was introduced into the stepwise multiple regression model.

RESULTS

Six hundred fifty-three patients with gout and 63 patients with asymptomatic hyperuricemia (> 420 μmol/L in male and > 360 μmol/L in female) were enrolled, including 553 (84.7%) males. The mean age was 47.8 ± 16.0 years old. Elevated total cholesterol (TC) was observed in 173 (26.5%) cases with gout. Increased triglycerides (TG) and low-density lipoprotein (LDL-C) levels were observed in 242 (37.1%) cases and 270 (41.3%) cases with gout, individually. In contrast, elevated TC, TG and LDL-C levels were observed in 10 (15.9%) cases, 30 (47.6%) cases and 22 (34.9%) cases with hyperuricemia, individually. Significant differences were found in age, serum creatine, TC and erythrocyte sedimentation rate (ESR) between gout and asymptomatic hyperuricemia groups (p < 0.05). In patients with asymptomatic hyperuricemia, 12 (19.0%) patients had hypertension and 5 (7.9%) suffered from coronary heart diseases. Male (B = -112.7, p < 0.001), high-density lipoprotein (HDL-C) (B = -60.797, p = 0.013), body mass index (BMI) (B = 5.168, p = 0.024), age (B = -3.475, p = 0.006), age of hyperuricemia onset (B = 2.683, p = 0.032), and serum creatine (B = 0.534, p < 0.001) were predictors of sUA levels in gout patients (adjusted R² = 28.7%).

CONCLUSIONS

Dyslipidemia is more commonly seen in patients with gout, compared to asymptomatic hyperuricemia. HDL-C is a protective predictor of sUA levels in gout.

Construction and expression of recombinant uricase‑expressing genetically engineered bacteria and its application in rat model of hyperuricemia

At present, the treatment of hyperuricemia is designed primarily to decrease the production of uric acid using xanthine oxidase inhibitors; however, the therapeutic effect is not satisfactory. Therefore, the key to the successful treatment of hyperuricemia is to increase the excretion of uric acid. The aim of present study was to construct uricase-expressing genetically engineered bacteria and analyze the effects of these engineered bacteria on the lowering of uric acid levels in a rat model of hyperuricemia. The uricase expression vector was constructed by gene recombination technology and transfected into Escherichia coli. The expression and activity of uricase were analyzed by SDS-PAGE analysis and Bradford assay. The water consumption, food intake, body weight, eosinophil count and intestinal histology, in addition to the levels of serum uric acid (SUA) and allantoin in the feces of the rats, were assessed. The intestinal contents of the rats were analyzed by 16S rDNA sequencing technology. The results demonstrated that uricase-expressing genetically engineered bacteria secreted active uricase. All rats exhibited a natural growth trend during the entire experiment, and the SUA of hyperuricemic rats treated with uricase-expressing engineered bacteria was significantly decreased. In conclusion, these results indicate that uricase secreted by recombinant uricase-expressing genetically engineered bacteria served an important role in decreasing SUA levels in a rat model of hyperuricemia.

Methods for measuring patient preferences: an update and future directions

PURPOSE OF REVIEW

The current review highlights the growing number of available methods used to measure patient preferences and discusses how this impacts preference research in rheumatology. Spurred by the growing role of preferences in regulatory decisions and drug development, researchers have begun applying preference methods to study questions beyond the clinical context. We explore these trends, provide case studies highlighting changes in measuring patient preferences, compare strengths and weaknesses of common stated-preference methods, and discuss considerations for the future use of these methods.

RECENT FINDINGS

Early literature on patient preferences often mimicked clinical practice, asking whether treatment A is better or worse than treatment B for a patient. Early applications of patient preference methods in rheumatology aimed to value different attributes of treatments, but remained focused on informing clinical questions. Spurred by interest in preferences by regulatory agencies and patient-centeredness throughout the product lifecycle, there are now a wide array of methods available to measure preference.

SUMMARY

Although these different preference methods have strengths and weaknesses, they serve to highlight the broad number of questions that could help rheumatology beyond the clinical context. Researchers in rheumatology now have the opportunity to better serve diverse stakeholders by considering how these methods could aid in clinical trial design, regulatory policy, and other elements of the medical product life cycle.

Whole-Exome Sequencing Reveals a Rare Missense Variant in SLC16A9 in a Pedigree with Early-Onset Gout

Gout is a common inflammatory arthritis triggered by monosodium urate deposition after longstanding hyperuricemia. In the general community, the disease is largely polygenic in genetic architecture, with many polymorphisms having been identified in gout or urate-associated traits. In a small proportion of cases, rare high penetrant mutations associated with monogenic segregation of the disease in families have been demonstrated to be disease causative. In this study, we recruited a two-generation pedigree with early-onset gout. To elucidate the genetic predisposition, whole-exome sequencing (WES) was performed. After comprehensive variant analyses and cosegregation testing, we identified a missense variant (c.277C>A, p.L93M) in SLC16A9, an extremely rare variant in genetic databases. Moreover, in silico assessments showed strong pathogenicity. This variant cosegregated with the disease phenotype perfectly in the family and is located in a highly conserved functional domain. A few studies supported our results of the association between SLC16A9 and gout and serum urate levels. In conclusion, we provide the first evidence for the association of rare missense in SLC16A9 with early-onset gout. These findings not only expand our current understanding of gout but also may have further implications for the treatment and prevention of gout.

Internalized and Anticipated Stigmatization in Patients With Gout

Objective

To investigate the relationship between stigma perception and demographic, clinical, and psychosocial variables.

Methods

A sample of 50 patients with gout and prescribed urate‐lowering medication (84% were males, mean serum urate 0.34 mmol/l) completed questionnaires on internalized and anticipated stigma, demographics, clinical gout‐related variables, and psychosocial variables (illness perceptions, illness‐related disability, illness‐related body satisfaction, intentional nonadherence). Serum urate level was obtained from the most recent blood test.

Results

In this sample, 26% experienced internalized stigma, 26% expected to be stigmatized by friends or family members, and 14% by health care workers. Univariate regression analyses showed that younger age, ethnicity other than New Zealand European, increased severity of gout pain, cognitive and emotional illness perceptions, greater illness‐related disability, and increased intentional nonadherence to urate‐lowering medication were associated with increased internalized and anticipated stigma. Younger age, emotional illness response, and intentional nonadherence were the only variables explaining incremental variance of the experience of anticipated stigma in a multivariate regression model.

Conclusion

Internalized and anticipated illness‐related stigma was reported by a subgroup of patients with gout. The experience of stigma is associated with younger age, a negative emotional illness response, and intentions to not adhere with a medical treatment.