Dual-energy CT in the differentiation of crystal depositions of the wrist: does it have added value?

OBJECTIVES

To evaluate the ability of dual-energy computed tomography (DECT) to improve diagnostic discrimination between gout and other crystal arthropathies such as calcium pyrophosphate deposition disease (CPPD) of the wrist in a clinical patient population.

MATERIALS AND METHODS

This retrospective case-control study included 29 patients with either gout (case group; n = 9) or CPPD (control group; n = 20) who underwent DECT of the wrist for clinically suspected crystal arthropathy. Color-coded urate and enhanced calcium as well as virtual 120 kVe blended images were reconstructed from the DECT datasets. Two independent and blinded readers evaluated each reconstructed dataset for the presence of depositions in 17 predefined regions. Additionally, a global diagnosis was made first for 120 kVe images only, based solely on morphologic criteria, and subsequently for all reconstructed images.

RESULTS

Sensitivity for the global diagnosis of gout was 1.0 (95% CI 0.63-1) for both DECT and 120 kVe images with specificities of 0.70 (95% CI 0.46-0.87) for DECT and 0.80 (95% CI 0.56-0.93) for 120 kVe images. Color-coded DECT images did not detect more depositions than monochrome standard CT images.

CONCLUSION

Discrimination of crystal arthropathies of the wrist is limited using DECT and primarily relying on color-coded images. Evaluation of morphologic criteria on standard CT images is essential for accurate diagnosis.

Gout

The treat to target strategy looks attractive for management of gout because it removes the causal mechanism inducing formation, growth, and aggregation of urate crystals. Further reduction of serum urate (sUA) levels below the threshold may dissolve crystals more rapidly. It is generally agreed that sUA less than 6 mg/dL is acceptable as a therapeutic and long-term preventive target, with <5 mg/dL for the most severe cases. The challenges that this approach in gout is facing include whether proposed targets are the best for desired outcomes, whether they fit patient-related outcomes, and whether they adequately balance effectiveness and safety.

Obstructive sleep apnea and the risk of gout: a population-based case-control study

Background

Patients with obstructive sleep apnea (OSA) might be at risk of gout because of pathophysiological mechanisms that can lead to hyperuricemia and eventually gout or because of shared risk factors between both diseases. The objective of the present study was to investigate the risk of gout in patients with OSA.

Methods

A population-based case-control study using the UK Clinical Practice Research Datalink GOLD including all patients aged 40 years and older with a first diagnosis of gout between 1987 and 2014. Gout cases were matched by year of birth, sex, and practice to non-gout controls. Conditional logistic regression estimated the risk of gout with an earlier diagnosis of OSA. Analyses were adjusted for lifestyle factors, comorbidities, and recent drug use.

Results

One hundred eleven thousand five hundred nine cases were matched with 210,241 controls. Patients with OSA were at increased risk of gout (OR 1.86; 95%CI (1.71–2.02). However, this association disappeared (OR 1.05; 95% CI 0.96–1.16) after adjustment for smoking status, body mass index (BMI), alcohol use, a history of heart failure, diabetes mellitus, renal function, and recent use of diuretics and other medications. Among females with OSA and patients with OSA associated with heart failure, renal impairment, or higher BMI, the risk of gout was however still increased when compared to the total control population.

Conclusion

This study showed that the observed association between OSA and gout disappeared after adjustment.

Determination of total purine and purine base content of 80 food products to aid nutritional therapy for gout and hyperuricemia

The aim of this work is to facilitate the nutritional therapy of gout and hyperuricemia. In Japan, patients with gout or hyperuricemia are recommended to consume less than 400 mg of dietary purines per day. When receiving nutritional therapy for gout or hyperuricemia, purine-rich foods (>200 mg/100 g) should be eaten in even lower quantities. The purine content of foods reported in this study are as follows: noodles, 0.6-12.1 mg/100 g; bread, 4.4 mg/100 g; peas or seeds, 19.6-67.1 mg/100 g; dairy, 0.0-1.4 mg/100 g; Japanese vegetables, 0.9-47.1 mg/100 g; seasonings, 0.7-847.1 mg/100 g; meat or fish, 19.0-385.4 mg/100 g; fish milt, 375.4-559.8 mg/100 g; and supplements, 81.9-516.0 mg/100 g. Foods containing very large amounts of purine (>300 mg/100 g) included anchovy, cutlassfish (hairtail), cod milt, globefish milt, dried Chinese soup stock, dried yeast, a Euglena supplement, and a Lactobacillus supplement. When eating these high-purine food or supplements, the quantity taken at one meal should be limited, especially milt because they typically consumed amount of 20-30 g is equivalent to 75-168 mg total purines. This is 20%-40% of the recommended daily amount (400 mg/day) for patients with gout or hyperuricemia. Thus, these patients should restrict the amount of purine-rich foods they consume. Good dietary habits with a good balance of nutrients are recommended.

Quality of gout care in the emergency departments: a multicentre study

BACKGROUND

To report on prevalence of gout flare in emergency departments and to report the quality of gout care in emergency departments and causes of admission at emergency departments.

METHODS

A retrospective chart review of visits that had a primary diagnosis in gout by the International Classification of Diseases, the tenth revision, at emergency departments from 6 universities in Thailand over a 5 year period from 1 January 2012 to 31 December 2016.

RESULTS

Six hundred thirty-two visits were included to the study. Prevalence of gout flare in emergency departments was 0.04. Only 29.3% of the visits had arthrocentesis. 628/632 (99.4%) and 519/585 (88.7%) of the visits were prescribed medications in emergency departments and had home medications, respectively. Although all visits that were prescribed colchicine in emergency departments received adequate doses of colchicine, it was also found that more than 2.4 mg/day of colchicine was prescribed (3/394, 0.8%) for home medications. In addition, 183/343 (53.4%) of the visits with normal renal function were prescribed non-steroidal anti-inflammatory drugs (NSAIDs). However, prescribed NSAIDs in abnormal renal function (42/343, 12.2%) was also found. The interruption of dosing, including increase, decrease, addition or discontinuance of urate lowing therapy in a gout flare period was 42/632 (6.6%). The most common cause of admission was acute gouty arthritis (31/47, 66.0%).

CONCLUSIONS

Quality of gout care in the emergency departments was not good. Inappropriate management of gout flare in emergency departments was demonstrated in our study, particularly with regard to investigations and pharmacological management. Gaps between clinicians and guidelines, the knowledge of clinicians, and overcrowding in emergency departments were hypothesized in the results.

Gout can increase the risk of periodontal disease in Taiwan

Objectives: To evaluate the risk of periodontal disease (PD) in gout patients. Methods: This retrospective cohort study was conducted using data from the Longitudinal Health Insurance Database 2000. The gout cohort included 31,759 patients newly diagnosed with gout from 2000 to 2012, and the comparison (nongout) cohort included 63,517 patients. Univariate and multivariable adjusted hazard ratios (aHRs), with corresponding 95% confidence intervals (CIs), were estimated using the Cox proportional hazard model for determining the occurrence of PD in both cohorts. We also measured the cumulative incidence of PD in these two cohorts using the Kaplan-Meier method and assessed the curve difference using the log-rank test. Results: The mean follow-up time was more than 6 years for both cohorts. The overall incidence rate of PD was significantly higher in the gout cohort than in the comparison cohort (5.04 vs 4.16 per 10,000 person-years; aHR = 1.13, 95% CI = 1.10-1.16). Only patients using colchicine had a significantly lower risk of PD (aHR = 0.85, 95% CI = 0.79-0.91). Conclusion: In our study, patients with gout showed an increased risk of PD, and treatment with colchicine could decrease the risk. Abbreviations: PD: periodontal disease; LHID: Longitudinal Health Insurance Research Database; NHIRD, National Health Insurance Research Database; ICD-9-CM: International Classification of Diseases, Ninth Revision, Clinical Modification; CI: confidence interval; HR: hazard ratio.

Gout is associated with an increased risk for incident heart failure among older adults: the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort study

Background

Gout has been associated with a higher risk for coronary heart disease (CHD) and stroke in some prior studies. Few studies have assessed the association of gout with incident heart failure (HF).

Methods

We analyzed data from 5713 black and white men and women ≥ 65.5 years of age in the population-based REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort study who had Medicare coverage without a history of HF, CHD, or stroke at baseline between 2003 and 2007. Gout was defined by ≥ 1 hospitalization or ≥ 2 outpatient visits with a diagnosis code for gout in Medicare claims prior to each participant’s baseline study examination. REGARDS study participants were followed for HF hospitalization, CHD, stroke, and all-cause mortality as separate outcomes through December 31, 2016. Analyses were replicated in a random sample of 839,059 patients ≥ 65.5 years of age with Medicare coverage between January 1, 2008, and June 30, 2015, who were followed through December 31, 2017.

Results

Among REGARDS study participants included in the current analysis, the mean age at baseline was 72.6 years, 44.9% were men, 31.4% were black, and 3.3% had gout. Over a median follow-up of 10.0 years, incidence rates per 1000 person-years among participants with and without gout were 13.1 and 4.4 for HF hospitalization, 16.0 and 9.3 for CHD, 9.3 and 8.2 for stroke, and 55.0 and 37.1 for all-cause mortality, respectively. After multivariable adjustment for sociodemographic variables and cardiovascular risk factors, hazard ratios (95% CI) comparing participants with versus without gout were 1.97 (1.22, 3.19) for HF hospitalization, 1.21 (0.79, 1.84) for CHD, 0.83 (0.48, 1.43) for stroke, and 1.08 (0.86, 1.35) for all-cause mortality. The multivariable-adjusted hazard ratio for HF hospitalization with reduced and preserved left ventricular ejection fraction among participants with versus without gout was 1.77 (95% CI 0.83, 3.79) and 2.32 (95% CI 1.12, 4.79), respectively. The multivariable-adjusted hazard ratio for heart failure hospitalization associated with gout among the 839,059 Medicare beneficiaries was 1.32 (95% CI 1.25, 1.39).

Conclusion

Among older adults, gout was associated with an increased risk for incident HF but not for incident CHD, incident stroke, or all-cause mortality.

The impact of the illness label 'gout' on illness and treatment perceptions in Māori (Indigenous New Zealanders)

Background

Despite contemporary advances in understanding pathogenesis and effective management of gout, beliefs about the disease continue to be focused on gout as a self-inflicted illness. The illness label itself may contribute to inaccurate perceptions of the disease and its management. In Aotearoa/New Zealand, Māori (Indigenous New Zealanders) have high prevalence of severe gout. The aim of this study was to examine the impact of the illness label ‘gout’ on perceptions of the disease and its management for Māori.

Methods

Māori supermarket shoppers (n = 172) in rural and urban locations were recruited into a study examining the perceptions about arthritis. Participants were randomised 1:1 to complete a questionnaire examining the perceptions of the same illness description labelled as either ‘gout’ or ‘urate crystal arthritis’. Differences between the two illness labels were tested using independent sample t-tests.

Results

‘Gout’ was most likely to be viewed as caused by diet, whereas ‘urate crystal arthritis’ was most likely to be viewed as caused by aging. ‘Urate crystal arthritis’ was seen as having a wider range of factors responsible for the illness, including stress or worry, hereditary factors and chance. ‘Gout’ was less likely to be viewed as having a chronic timeline, and was perceived as being better understood. Dietary management strategies were seen as more helpful for management of the gout-labelled illness.

Conclusions

This study has demonstrated that for Māori, Indigenous New Zealanders who are disproportionately affected by gout, the illness label influences perceptions about gout and beliefs about management.

Utility of Ultrasound and Dual Energy CT in Crystal Disease Diagnosis and Management

PURPOSE OF REVIEW

The objective of this review is to critically discuss the latest evidence on the use of ultrasound and dual energy computed tomography (DECT) for the assessment of microcrystalline arthritis.

RECENT FINDINGS

Both techniques have been included in the classification and diagnostic criteria for gout, while only ultrasound appears in the diagnostic recommendations for CPPD. Regarding the management of the diseases, there is encouraging evidence for the use of both techniques for the follow-up of gout patients, while very few or null data are available for CPPD. Ultrasound has been adequately validated for the diagnosis of CPPD, while some issues have still to be clarified regarding gout. DECT has also demonstrated to be accurate for gout diagnosis, but very few data are available regarding CPPD. Future research should aim to improve the reliability of both techniques and to create scoring systems for a more accurate follow-up of patients.

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.

Allopurinol hypersensitivity: Pathogenesis and prevention

Allopurinol, a first line urate-lowering therapy, has been associated with serious cutaneous reactions that have a high mortality. A number of risk factors for these serious adverse reactions have been identified including ethnicity, HLA-B∗5801 genotype, kidney impairment, allopurinol starting dose, and concomitant diuretic use. There is a complex interplay between these risk factors, which may (albeit rarely) lead to allopurinol-related serious adverse events. Although oxypurinol, the active metabolite of allopurinol, has been implicated, there is no defined drug concentration at which the reaction will occur. There is no specific treatment other than the cessation of allopurinol and supportive care. Whether hemodialysis, which rapidly removes oxypurinol, improves outcomes remains to be determined. Strategies to help reduce this risk are therefore important, which includes screening for HLA-B∗5801 in high-risk individuals, commencing allopurinol at low dose, and educating patients about the signs and symptoms of severe cutaneous adverse reactions, and what to do if they occur.

Management of hyperuricemia in asymptomatic patients: A critical appraisal

While there is consensus on starting urate-lowering therapy (ULT) in cases of symptomatic hyperuricemia, the frequent condition of asymptomatic hyperuricemia (AH) remains a challenge due to differences in the findings of studies that have addressed the issue. Uric acid has anti-oxidant properties, but high levels predispose to gout and may play a role in metabolic syndrome. We systematically evaluated randomized controlled trials (RCTs) addressing ULT in patients with AH, to assess the current evidence. We found broad heterogeneity among the studies (13 RCTs), in terms of study design and population, making findings challenging to interpret and generalize; hard end-points were not assessed. Allopurinol is often prescribed for AH despite the fact that its use is not backed by conclusive evidence from prospective RCTs, nor is it recommended by the guidelines. Its potential benefits, in terms of absolute risk reduction, must be weighed against its potential for harm since it can trigger severe adverse hypersensitivity reactions, sometimes even fatal. RCTs with hard end-points are needed to assess the risk/benefit of lowering uric acid in subjects with AH, particularly as secondary prevention for cardiovascular risk and in patients with different degrees of renal disease. To date, particularly after the result from the CARES trial, preventive treatment of asymptomatic and non-severe hyperuricemia is not recommended.

[Gout and Its Management in Clinical Practice]

Gout and Its Management in Clinical Practice Abstract. Resolution of an acute attack is usually the prime objective in routine clinical management of gout. Crystal identification in synovial fluid by polarised light microscopy is considered the diagnostic gold standard. Imaging procedures such as high-resolution ultrasonography are also useful. Non-steroidal anti-inflammatory drugs, steroids and colchicine (not approved in Switzerland, available from pharmacies) are used to treat an acute gout attack. Just as important as the diagnosis and treatment of an acute attack is the long-term management of hyperuricaemia in order to prevent further gout attacks as well as possible renal, cardiac or metabolic complications. Therefore, patients with a confirmed diagnosis of gout should, apart from non-pharmacologic interventions, receive hypouricaemic therapy with a target uric acid level of <360 µmol/l (<6 mg/dl). Drugs of first choice are xanthine oxidase inhibitors. Achievement of the therapeutic objective should be periodically reviewed, adjusting therapy as necessary.

Uric acid-mediated inflammasome activation in IL-6 primed innate immune cells is regulated by baricitinib

OBJECTIVES

Gout is an inflammatory arthropathy caused by the deposition of monosodium urate (MSU). The synthesis and release of IL-1β is crucial for MSU-induced synovial inflammation. The aim of the present study was to investigate the mechanism of MSU crystal-induced autoinflammatory processes.

METHODS

In vitro studies were used to evaluate the role of IL-6 in inflammasome activation in human neutrophils cultured with MSU crystals. Human neutrophils were stimulated with MSU in the presence or absence of IL-6 priming to determine NLRP3 inflammasome activation and subsequent cleaved caspase-1 induction or IL-1β production.

RESULTS

IL-6 or MSU stimulation alone did not result in the efficient IL-1β production from human neutrophils. However, MSU stimulation induced marked IL-1β production from IL-6-primed neutrophils. Pretreatment with baricitinib, which blocks IL-6 receptor signaling, prevented MSU-induced cleaved caspase-1 or IL-1β induction in IL-6-primed neutrophils. Tocilizumab pretreatment also inhibited MSU-mediated IL-1β production from IL-6-primed neutrophils.

CONCLUSION

Priming of human neutrophils with IL-6 promotes uric acid-mediated IL-1β secretion in the absence of microbial stimulation. These results suggest that an endogenous cytokine, IL-6, is involved in MSU-mediated NLRP3 inflammasome activation and subsequent IL-1β production from innate immune cells and has a crucial role in MSU crystal-induced synovial inflammation. These findings provide insights into uric acid-mediated autoinflammation in the innate immune system.

[Clinical study of staging operation for large gouty stone on the first metatarsophalangeal joint]

OBJECTIVE

To explore short-term curative effect of staging operation for large gouty stone on the first metatarsophalangeal joint.

METHODS

From January 2015 to December 2016, 12 patients with giant gout stone on the first metatarsophalangeal joint were treated with staging operation, including 12 males, aged from 45 to 73 years old, 6 cases on the right side and 6 cases on the left side. After conservative treatment for more than 2 years, the size and location of ventilator stone were detected by dual energy CT. The bone destruction of the first metatarsophalangeal joint was observed on X-ray examination. All patients underwent stageⅠgout radical removal and temporary fixation with Kirschner wire, and metatarsophalangeal joint fusion and internal fixation were performed after local soft tissue conditions were stabilized. The level of blood uric acid before and after hand were compared, and correction and complications of limb deformity were observed, VAS score was applied to evaluate pain relieved degree.

RESULTS

All patients were successfully completed two stages ' operation. Twelve patients were followed up for 9 to 13 months. VAS sco re and uric acid content at different time points were observed and recorded. VAS score before operation ranged from 6 to 9, and decreased to 0 to 1 at 7 weeks after operation; the level of blood uric acid ranged from 443 to 501 μmol/L before operation, and decreased to 307 to 330 μmol/L at 7 weeks after operation. The first metatarsophalangeal joint deformity of foot was corrected and the shape was recovered at 5 to 7 months after operation. One patient occurred incision infection and flap edgenecrosis, and the wound healed by debridement and dressing change.

CONCLUSION

Staged operation for the treatment of giant gout stone on the first metatarsophalangeal joint of foot could correct joint deformity, restore shape of the first metatarsophalangeal joint, relieve pain of the affected foot, and beneficial for control content of serum uric acid, and has less complications.

Speckle tracking echocardiography as a new diagnostic tool for an assessment of cardiovascular disease in rheumatic patients

Chronic inflammation represents the cornerstone of the raised cardiovascular (CV) risk in patients with inflammatory rheumatic diseases (IRD). Standardized mortality ratios are increased in these patients compared to the general population, which can be explained by premature mortality associated with early atherosclerotic events. Thus, IRD patients need appropriate CV risk management in view of this CV disease (CVD) burden. Currently, optimal CV risk management is still lacking in usual care, and early diagnosis of silent and subclinical CVD involvement is mandatory to improve the long-term prognosis of those patients. Although CV involvement in such patients is highly heterogeneous and may affect various structures of the heart, it can now be diagnosed earlier and promptly treated. CV imaging provides valuable information as a reliable diagnostic tool. Currently, different techniques are employed to evaluate CV risk, including transthoracic or trans-esophageal echocardiography, magnetic resonance imaging, or computed tomography, to investigate valve abnormalities, pericardial disease, and ventricular wall motion defects. All the above methods are reliable in investigating CV involvement, but more recently, Speckle Tracking Echocardiography (STE) has been suggested to be diagnostically more accurate. In recent years, the role of left ventricular ejection fraction (LVEF) as the gold standard parameter for the evaluation of systolic function has been debated, and many efforts have been focused on the clinical validation of new non-invasive tools for the study of myocardial contractility as well as to characterize the subclinical alterations of the myocardial function. Improvement in the accuracy of STE has resulted in a large amount of research showing the ability of STE to overcome LVEF limitations in the majority of primary and secondary heart diseases. This review summarizes the additional value that STE measurement can provide in the setting of IRD, with a focus in the different clinical stages.

[Gout]

Gout is a chronic disease due to the deposition of monosodium urate microcrystals in joints and tissues. Its incidence and prevalence are increasing worldwide in close relation with the epidemic of obesity and metabolic syndrome. Gout is related to chronic hyperuricemia that should be treated to ensure the reduction or even the disappearance of acute attacks ("gout flares") and to reduce the size and number of tophi. If arthritis of the first metatarsophalangeal joint is the most typical form, other joints may be affected, including the spine. Demonstration of urate microcrystals arthritis allows diagnosis of gout but, in the absence of possibility of performing joint puncture, imaging may be useful for providing complementary diagnostic elements. Appropriate care is essential to reduce the number of flares and the evolution towards gouty arthropathy but also in terms of public health in order to reduce costs related to this pathology.

Using electronic visits (E-visits) to achieve goal serum urate levels in patients with gout in a rheumatology practice: A pilot study

OBJECTIVE

Achieving goal serum urate levels in patients with gout remains difficult in primary care and rheumatology practices. This study measured the ability of an asynchronous electronic visit (E-visit) program to facilitate achieving a goal serum urate (SU) of less than 6.0 mg/dL.

METHODS

We performed a retrospective cohort study in a large academic medical center rheumatology practice between April 1, 2017 and May 31, 2018. Patients with gout and SU levels over 6.0 mg/dL were enrolled in an E-visit program and were compared with historical controls who received usual care, matched 1:1 for age and sex. The primary outcome of interest was the proportion of patients achieving SU target of less than 6.0 mg/dL at six months.

RESULTS

Sixty-two patients were enrolled by their rheumatologist in the gout asynchronous E-visit program and were compared to 62 historical controls who were seen within one year prior to E-visit program initiation. Baseline characteristics including age, sex, body mass index, renal function, and initial SU were similar among patients enrolled in the E-visit program and controls. At six months, a significantly higher proportion of patients in the E-visit program achieved goal SU of less than 6.0 mg/dL compared to controls (63.8% vs 33.9%, respectively, p < 0.01), and the E-visit patients had a lower mean SU level than historical controls (5.5 mg/dL versus 6.7 mg/dL, respectively, p < 0.01).

CONCLUSION

A physician-initiated E-visit program led to a substantial improvement in the rate of achieving goal SU among patients with gout within an academic rheumatology practice.

Pleiotropic effect of the ABCG2 gene in gout: involvement in serum urate levels and progression from hyperuricemia to gout

Background

The ABCG2 Q141K (rs2231142) and rs10011796 variants associate with hyperuricaemia (HU). The effect size of ABCG2 rs2231142 on urate is ~ 60% that of SLC2A9, yet the effect size on gout is greater. We tested the hypothesis that ABCG2 plays a role in the progression from HU to gout by testing for association of ABCG2 rs2231142 and rs10011796 with gout using HU controls.

Methods

We analysed 1699 European gout cases and 14,350 normouricemic (NU) and HU controls, and 912 New Zealand (NZ) Polynesian (divided into Eastern and Western Polynesian) gout cases and 696 controls. Association testing was performed using logistic and linear regression with multivariate adjusting for confounding variables.

Results

In Europeans and Polynesians, the ABCG2 141K (T) allele was associated with gout using HU controls (OR = 1.85, P = 3.8E^− 21 and OR_meta = 1.85, P = 1.3E^− 03, respectively). There was evidence for an effect of 141K in determining HU in European (OR = 1.56, P = 1.7E^− 18) but not in Polynesian (OR_meta = 1.49, P = 0.057). For SLC2A9 rs11942223, the T allele associated with gout in the presence of HU in European (OR = 1.37, P = 4.7E^− 06), however significantly weaker than ABCG2 rs2231142 141K (P_Het = 0.0023). In Western Polynesian and European, there was epistatic interaction between ABCG2 rs2231142 and rs10011796. Combining the presence of the 141K allele with the rs10011796 CC-genotype increased gout risk, in the presence of HU, 21.5-fold in Western Polynesian (P = 0.009) and 2.6-fold in European (P = 9.9E^− 06). The 141K allele of ABCG2 associated with increased gout flare frequency in Polynesian (P_meta = 2.5E^− 03).

Conclusion

These data are consistent with a role for ABCG2 141K in gout in the presence of established HU.

Does hyperuricemia correlate with intervertebral disc degeneration?

Gout is a form of crystal arthropathy associated with deposition of monosodium urate (MSU) crystals, and is directly related to hyperuricemia arising from abnormal purine metabolism and/or decreased uric acid excretion. Uric acid is the final oxidation product of purine metabolism and plays an important role as an in vivo antioxidant at physiological concentrations. Several case reports have described the presence of tophi in the intervertebral disc (IVD) or endplate of patients with hyperuricemia or gout, and these patients also exhibited severe intervertebral disc degeneration (IDD). We speculated that uric acid may have dual effects on an IVD. On the one hand, physiological concentrations of uric acid have powerful antioxidant activity and can effectively maintain the steady state of the IVD, while on the other hand, high concentrations of uric acid have strong oxidizing activity and the resulting high osmotic pressure can aggravate IDD. Moreover, when MSU crystals accumulate in the endplate and IVD, they lead to a series of mechanical damages and inflammatory reactions that further accelerate IDD. Further basic and clinical studies are needed to clarify the mechanism for the involvement of uric acid in the onset and development of IDD.

[Clinical value of artifact identification in ankle dual-energy CT for gout diagnosis]

Objective: To investigate the clinical value of artifact identification in ankle dual-energy CT for gout diagnosis. Methods: A total of 58 patients with gout, who were definitely diagnosed in Peking University Third Hospital from December 2018 to May 2019, were included in the case group, which were composed of 57 males and 1 female. And 37 individuals without gout were regarded as control group, which were composed of 36 males and 1 female. Dual-energy CT was performed for one foot, and the affected side or the more serious side was chosen in the case group. The dual-energy data were used in gout-recognition software to highlight the monosodium urate (MSU) with green-colored. And to compare the difference in MSU relevance ratio on the images of toenail, submillimeter spots, skins, movements and vascular calcification between two groups. Results: In the case group, 55 patients were revealed with MSU green-colored toenails (relevance ratio 94.8%), while 22 cases in the control groups (relevance ratio 59.5%). There was significantly statistical difference on the mean toenails numbers and the MSU distribution scores in the two groups (all P<0.01). In the case group, 47 patients were revealed with green-colored submillimeter spots (relevance ratio 81.0%),while 5 cases in the control group (relevance ratio 13.5%). The relevance ratio of submillimeter spots on tendon and ligament in the case group and control group were 75.9% (44/58) and 13.5%(5/37). There was also significantly statistical difference in the two groups on submillimeter spots (all P<0.01). And there was no significantly statistical difference in the two groups on MSU green-colored skins, movements and vascular calcification. Conclusion: There is great value for gout clinical diagnosis when green-colored MSU is detected on toenails and submillimeter spots, which should not be judged as artifact simply.

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.

Diseases of the Reptile Renal System

Renal disease accounts for a considerable amount of morbidity and mortality in reptiles, in part owing to inadequate husbandry practices, such as inappropriate temperature, humidity, and access to water. Inappropriate husbandry practices may lead to subclinical dehydration that can specifically impact the renal system, which relies on vascular perfusion to function. This article aims to highlight urinary pathophysiology and summarize infectious and noninfectious causes of renal disease in reptiles as a guide for differential diagnoses to consider during clinical evaluation.

Clinical Management of Reptile Renal Disease

Renal disease is one of the most common medical conditions encountered in captive reptiles. In most cases, signs of disease are nonspecific and often not present until the condition is advanced. Many factors contribute to the development of renal disease, and the etiology often is multifactorial. Diagnosis of renal disease by traditional methods used in small animals is not as straightforward as in reptiles; often many tests may be needed to reach a firm diagnosis. Prevention is preferred to treatment. Understanding the pathophysiology, potential causes, diagnostic tests available, and treatment options is essential for the reptile veterinarian to manage this condition.

A clinical pharmacology study of the novel, selective urate reabsorption inhibitor dotinurad in outpatients

BACKGROUND

Dotinurad is a novel, selective urate reabsorption inhibitor (SURI), which reduces serum uric acid levels by selective inhibition of the urate transporter 1 (URAT1). The Japanese guideline for the management of hyperuricemia and gout recommends that drug selection should be based on classification of hyperuricemia as a fundamental principle. However, there may be some cases where this principle is not observed. We investigated the pharmacodynamics and safety of dotinurad in outpatients with uric acid overproduction or uric acid underexcretion type.

METHODS

This was a multicenter, open-label, forced titration study. Patients were classified as uric acid overproduction or underexcretion type. Study treatment was initiated at 0.5 mg/day, followed by dose titration to the estimated maximum dose of 4 mg/day over 14 weeks. The primary endpoint was urinary uric acid excretion at each 24-h urine collection.

RESULTS

A total of 26 hyperuricemic patients with or without gout were enrolled in the study and assigned to the uric acid overproduction group (overproduction group) or the uric acid underexcretion group (underexcretion group). Although urinary uric acid excretion, the primary endpoint, tended to be slightly greater in the overproduction group, no notable difference was noted between the two hyperuricemic types. Neither type had noteworthy safety concerns associated with dotinurad.

CONCLUSION

The results of the study demonstrated no relevant differences between the hyperuricemic types in terms of pharmacodynamic action and safety of dotinurad.