GOSPEL: Prospective survey of gout in France. Part I: Design and patient characteristics (n=1003)

Validation of gout diagnosis in electronic primary care medical records: A population-based study

OBJECTIVE

The main objective of the study was to see the concordance between the diagnosis of gout recorded in primary care electronic medical records and the ACR/EULAR 2015 classification criteria.

METHODS

A cross-sectional study was conducted using electronic medicals records in 7 primary care centres of Barcelona. Patients' data to study clinical diagnose and management was gathered from the primary care electronic medical records of the Catalonian health institute (Institut Català de la Salut, ICS) and phone interview. Patients were considered to have gout if they scored 8 or more points on the EULAR/ACR 2015 classification criteria for gout.

RESULTS

In total, 70.9% of the patients with a gout diagnosis met ACR/EULAR 2015 criteria. Adding a hyperuricemia in a blood test in the EMR increased the percentage to 78.9%. 29.8% of the gout patients were not receiving urate-lowering therapy. 62.3% of the treated patients did not achieve the target uricemia (< 6mg/dL).

CONCLUSIONS

The majority of gout patients from primary care electronic medical records fulfil ACR/EULAR gout criteria. This database can be used for observational studies. In most of the gout patients the urate target was not achieved.

Simple Application and Adherence to Gout Guidelines Enables Disease Control: An Observational Study in French Referral Centres

Background: In a context of therapeutic inertia, the French Society of Rheumatology (SFR) published its first recommendations on gout in 2020, which were deliberately simple and concise. The objectives of the study were to determine the profile of patients referred to French gout-expert centres, and to examine the results of their management and the factors leading to those results. Methods: Three hundred patients attending a first visit for gout management in three French referral centres were retrospectively and randomly included in this multicentre observational study. Visits were performed at baseline (M0) and scheduled for month 6 (M6), month 12 (M12), and month 24 (M24). Results: Patients were 81% male and had a mean age 62.2 ± 15.2 years. Management followed French recommendations after the baseline visit in 94.9% of cases. SU levels were below 6.0 mg/dL in 59.4% of patients at M6, 67.9% at M12, and 78.6% at M24, with increasing clinical improvement (i.e., flare decrease) over 2 years of follow-up. At M24, 50% of patients were treated with allopurinol (313 ± 105 mg/d), which exceeded renal restrictions of doses in 61.5% of them, and 48.2% received febuxostat (84 ± 36 mg/d). The need for a sufficient dosage of ULT was the only predictive factor found for successful achievement of SU levels < 6.0 mg/dL at a given visit. Conclusions: Simple application of gout-management guidelines is feasible in clinical practice and is efficient, with a majority of patients achieving SU targets and clinical improvement.

Imaging of Crystal Disorders:: Calcium Pyrophosphate Dihydrate Crystal Deposition Disease, Calcium Hydroxyapatite Crystal Deposition Disease and Gout Pathophysiology, Imaging, and Diagnosis

Crystal arthropathies are a group of joint disorders due to deposition of crystals in and around joints that lead to joint destruction and soft tissue masses. Clinical presentation is variable and diagnosis might be challenging. In this article the pathophysiology is addressed, the preferred deposition of crystal arthropathies and imaging findings. Case studies of calcium pyrophosphate dihydrate crystal deposition disease, hydroxyapatite crystal deposition disease, and gout are shown. Guidelines for the use of dual-energy computed tomography are given to enable the diagnosis and follow-up of gout.

Crystal deposition measured with dual-energy computed tomography: association with mortality and cardiovascular risks in gout

Objectives

To determine whether the volume of monosodium urate (MSU) crystal deposition measured with dual-energy CT (DECT) is predictive of short-term mortality and development of cardiovascular comorbidities and diabetes mellitus.

Methods

Patients with a diagnosis of gout having had baseline DECT scans of their knees and feet to measure the volume of MSU crystal deposition were included to undergo a follow-up visit. Risk factors for mortality and a composite variable (onset of any cardio-metabolic event) were examined using multivariable Cox models.

Results

A total of 128 patients aged 66.1 (14.0) years with gout durations of 11.4 (10.4) years were included; most were naïve of urate lowering therapy (61.7%), with a follow-up visit at 24 (12, 36) months. Baseline serum urate (SU) level was 7.44 (2.29) mg/dl and DECT volume of MSU crystals was 0.2 (0, 0.9) cm3. A total of 14 patients died during follow-up, 6/14 from a cardiovascular cause, and 17 patients presented a new cardio-metabolic comorbidity. Factors associated with mortality risk were baseline DECT volume of MSU crystals [hazard ratio (HR) 1.02, 95% CI: 1.002, 1.03] and baseline SU level (HR 1.04, 95% CI: 1.003, 1.06). DECT volume of MSU crystals was the only factor associated with the onset of cardio-metabolic comorbidities with a HR of 1.014 (95% CI: 1.001, 1.03).

Conclusions

Volume of MSU crystals measured with DECT is a biomarker for the risk of developing new cardio-metabolic diseases and for all-cause mortality.

Genetic susceptibilities and prediction modeling of carbamazepine and allopurinol-induced severe cutaneous adverse reactions in Vietnamese

Aims: To determine genetic susceptibility markers for carbamazepine (CBZ) and allopurinol-induced severe cutaneous adverse reactions (SCARs) in Vietnamese. Methods: A case-control study was performed involving 122 patients with CBZ or allopurinol-induced SCARs and 120 drug tolerant controls. Results: HLA-B*58:01 was strongly associated with allopurinol-induced SCARs and strongly correlated with SNP rs9263726. HLA-B*15:02 was associated with CBZ-induced Stevens-Johnson syndrome/toxic epidermal necrolysis but not with drug-induced hypersensitivity syndrome/drug rash with eosinophilia and systemic symptoms. No association was found between HLA-A*31:01 and CBZ-induced SCARs. HLA-B*58:01 and rs3909184 allele A with renal insufficiency were shown to increase the risk of allopurinol-induced SCARs. Conclusion: HLA-B*58:01 and HLA-B*15:02 confer susceptibility to allopurinol-induced SCARs and CBZ-induced SJS/TEN in Vietnamese. SNP rs9263726 can be used as a surrogate marker in identifying HLA-B*58:01.

Ultrasonography and dual-energy computed tomography: impact for the detection of gouty deposits

Ultrasonography (US) and dual-energy computed tomography (DECT) are useful and sensitive diagnostic tools to identify monosodium urate deposits in joints and soft tissues. The purpose of this review is to overview the imaging findings obtained by US and DECT in patients with gout, to understand the strengths and weaknesses of each imaging modality, and to evaluate the added value of using both modalities in combination.

Association of Specific Comorbidities with Monosodium Urate Crystal Deposition in Urate-Lowering Therapy-Naive Gout Patients: A Cross-Sectional Dual-Energy Computed Tomography Study

(1) Background: To determine which factors are associated with the volume of monosodium urate (MSU) crystal deposition quantified by dual-energy computed tomography (DECT) in urate-lowering therapy (ULT)-naive gout patients. (2) Methods: In this multicenter cross-sectional study, DECT scans of knees and feet/ankles were prospectively obtained from ULT-naive gout patients. Demographic, clinical (including gout history and comorbidities), and biological data were collected, and their association with DECT MSU crystal volume was analyzed using bivariate and multivariate analyses. A second bivariate analysis was performed by splitting the dataset depending on an arbitrary threshold of DECT MSU volume (1 cm³). (3) Results: A total of 91 patients were included. In the bivariate analysis, age (p = 0.03), gout duration (p = 0.003), subcutaneous tophi (p = 0.004), hypertension (p = 0.02), diabetes mellitus (p = 0.05), and chronic heart failure (p = 0.03) were associated with the total DECT volume of MSU crystal deposition. In the multivariate analysis, factors associated with DECT MSU volumes ≥1 cm³ were gout duration (odds ratio (OR) for each 10-year increase 3.15 (1.60; 7.63)), diabetes mellitus (OR 4.75 (1.58; 15.63)), and chronic heart failure (OR 7.82 (2.29; 31.38)). (4) Conclusion: Specific comorbidities, particularly chronic heart failure and diabetes mellitus, are more strongly associated with increased MSU crystal deposition in knees and feet/ankles than gout duration, regardless of serum urate level.

Non-steroidal anti-inflammatory drugs in chronic kidney disease: a systematic review of prescription practices and use in primary care

BACKGROUND

Chronic kidney disease (CKD) management focuses on limiting further renal injury, including avoiding nephrotoxic medications such as non-steroidal anti-inflammatory drugs (NSAIDs). We performed a systematic review to evaluate the prevalence of primary care NSAID prescribing in this population.

METHODS

We systematically searched MEDLINE and Embase from inception to October 2017 for observational studies examining NSAID prescribing practices or use in CKD patients in a primary care setting. The methodological quality of included studies was assessed independently by two authors using a modified version of the Agency for Healthcare Research and Quality's Methodological Evaluation of Observational Research checklist.

RESULTS

Our search generated 8055 potentially relevant publications, 304 of which were retrieved for full-text review. A total of 14 studies from 13 publications met our inclusion criteria. There were eight cohort and three cross-sectional studies, two quality improvement intervention studies and one prospective survey, representing a total of 49 209 CKD patients. Cross-sectional point prevalence of NSAID use in CKD patients ranged from 8 to 21%. Annual period prevalence rates ranged from 3 to 33%. Meta-analysis was not performed due to important clinical heterogeneity across study populations.

CONCLUSIONS

Evidence suggests that NSAID prescriptions/use in primary care among patients with CKD is variable and relatively high. Future research should explore reasons for this to better focus knowledge translation interventions aimed at reducing NSAID use in this patient population.

Gout: state of the art after a decade of developments

This review article summarizes the relevant English literature on gout from 2010 through April 2017. It emphasizes that the current epidemiology of gout indicates a rising prevalence worldwide, not only in Western countries but also in Southeast Asia, in close relationship with the obesity and metabolic syndrome epidemics. New pathogenic mechanisms of chronic hyperuricaemia focus on the gut (microbiota, ABCG2 expression) after the kidney. Cardiovascular and renal comorbidities are the key points to consider in terms of management. New imaging tools are available, including US with key features and dual-energy CT rendering it able to reveal deposits of urate crystals. These deposits are now included in new diagnostic and classification criteria. Overall, half of the patients with gout are readily treated with allopurinol, the recommended xanthine oxidase inhibitor (XOI), with prophylaxis for flares with low-dose daily colchicine. The main management issues are related to patient adherence, because gout patients have the lowest rate of medication possession ratio at 1 year, but they also include clinical inertia by physicians, meaning XOI dosage is not titrated according to regular serum uric acid level measurements for targeting serum uric acid levels for uncomplicated (6.0 mg/dl) and complicated gout, or the British Society for Rheumatology recommended target (5.0 mg/dl). Difficult-to-treat gout encompasses polyarticular flares, and mostly patients with comorbidities, renal or heart failure, leading to contraindications or side effects of standard-of-care drugs (colchicine, NSAIDs, oral steroids) for flares; and tophaceous and/or destructive arthropathies, leading to switching between XOIs (febuxostat) or to combining XOI and uricosurics.

Patients With Early-Onset Gout and Development of Earlier Severe Joint Involvement and Metabolic Comorbid Conditions: Results From a Cross-Sectional Epidemiologic Survey

OBJECTIVE

Little is known of the clinical features and comorbidity profile of patients presenting with early-onset gout (EOG), although international guidelines recommend rapid treatment after diagnosis. The objective of this study was to assess specific characteristics and comorbidities of patients with gout who had an early onset.

METHODS

Patients from a cross-sectional French national cohort who experienced their first gout flare before age 40 years were included in the EOG group and compared to patients with an onset after age 40 years, the common gout group.

RESULTS

A total of 120 patients were included in the EOG group (mean ± SD age 49.5 ± 11.9 years) and 865 patients in the common gout group (mean ± SD age 64.4 ± 10.1 years). Patients with EOG more often presented with a history of polyarticular flares (P < 0.01), but had similar frequency of flares (P = 0.16), gout arthropathy (P = 0.79), and tophi (P = 0.53). Prevalence of each item comprising metabolic syndrome did not differ between groups. In patients with EOG, all cardiovascular comorbidities were diagnosed after gout onset. Greater age, low high-density lipoprotein, and excessive alcohol intake were associated in multivariate analysis with the common gout group, while a familial history of gout, longer duration of urate-lowering treatment, higher serum uric acid levels, and metabolic syndrome were associated with the EOG group.

CONCLUSION

Patients with EOG developed slightly more severe joint involvement and earlier metabolic disorders than patients with common gout.

Difficult-to-treat gout flares: eligibility for interleukin-1 inhibition in private practice is uncommon according to current EMA approval

Objective

The objective was to determine the proportion of patients with difficult-to-treat or difficult-to-prevent acute gout attacks eligible for IL-1 inhibition.

Methods

Participants included in the French cross-sectional GOSPEL cohort (n = 1003 gout patients) were examined for contraindications and intolerance to standard of care (SoC) drugs of gout flares (colchicine, non-steroidal anti-inflammatory drugs and systemic glucocorticoids). Patients were classified as definitely eligible for first-line IL-1 inhibition (canakinumab) according to European summary of product characteristics (contraindications/intolerance to SoC and at least three flares per year) without any other anti-inflammatory options (contraindications/intolerance only), or potentially eligible (precaution of use). Eligibility to receive IL-1 during an on-going flare related to insufficient efficacy was assessed (second-line eligibility).

Results

Definite first-line eligibility for IL-1 therapy was found in 10 patients (1%) and contraindication to all SoC therapies in nine patients who had presented <3 flares in the past 12 months. At least precaution of use for SoC therapies was noted for 218/1003 patients (21.7%). Of 487 patients experiencing flares at baseline, 114 (23.4%) were still experiencing pain scored ⩾4/10 numeric scale on day 3, one of whom could not receive further SoC drugs. Only nine of them had three or more flares in the past year and were eligible for second-line IL-1 inhibition.

Conclusion

Despite significant numbers of patients without any SoC anti-inflammatory therapeutic options for gout flares, eligibility for IL-1 inhibition therapy according to current European approval is rare.

Monosodium urate burden assessed with dual-energy computed tomography predicts the risk of flares in gout: a 12-month observational study : MSU burden and risk of gout flare

Background

Predicting the risk of flares in patients with gout is a challenge and the link between urate burden and the risk of gout flare is unclear. The objective of this study was to determine if the extent of monosodium urate (MSU) burden measured with dual-energy computed tomography (DECT) and ultrasonography (US) is predictive of the risk of gout flares.

Methods

This prospective observational study recruited patients with gout to undergo MSU burden assessment with DECT (volume of deposits) and US (double contour sign) scans of the knees and feet. Patients attended follow-up visits at 3, 6 and 12 months. Patients having presented with at least one flare at 6 months were compared to those who did not flare. Odds ratios (ORs) (95% confidence interval) for the risk of flare were calculated.

Results

Overall, 64/78 patients included attended at least one follow-up visit. In bivariate analysis, the number of joints with the double contour sign was not associated with the risk of flare (p = 0.67). Multivariate analysis retained a unique variable: DECT MSU volume of the feet. For each 1 cm³ increase in DECT MSU volume in foot deposits, the risk of flare increased 2.03-fold during the first 6 months after initial assessment (OR 2.03 (1.15–4.38)). The threshold volume best discriminating patients with and without flare was 0.81 cm³ (specificity 61%, sensitivity 77%).

Conclusions

This is the first study showing that the extent of MSU burden measured with DECT but not US is predictive of the risk of flares.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1714-9) contains supplementary material, which is available to authorized users.

Non-pharmacologic measures for gout management in the prospective GOSPEL cohort: Physicians' practice and patients' compliance profiles

OBJECTIVES

Gout management includes non-pharmacological measures (NPM). The main objective of this study was to describe the NPM proposed by physicians and their implementation by patients after 3-6 months. The secondary objective was to identify NPM compliance profiles among these patients.

METHODS

Ancillary observational study using the GOSPEL French cohort of 1003 patients with gout, based on questionnaires for physicians and patients at inclusion and then after 3-6 months. Patients were included by a representative sample of 398 general practitioners (GP) and 109 private-practice rheumatologists. Modifiable risk factors of hyperuricemia and proposed NPM were compared. Patient compliance profiles were identified by multiple correspondence and hierarchical clustering analysis.

RESULTS

The study included 630 patients: 80.7% were obese or overweight, 51% reported excessive alcohol consumption. Physicians identified fewer modifiable risk factors than their real prevalence in the cohort. Physicians proposed NPM to 57% of patients, particularly diet modifications (46.4%). Increasing physical activity (P < 0.0001) was the best followed NPM. The physician's influence in the decision of starting NPM was more frequent among GPs' patients (P = 0.01). Three patients' compliance profiles were identified. "Very good responders" (55.8%) implemented all the proposed NPM. "Good responders" (12.7%) had a more severe disease and followed the proposed NPM, but for alcohol consumption. "Bad responders" (31.5%) did not modify their life style: these were older patients with a very recent gout diagnosis.

CONCLUSION

More personalized care about NPM requires adapting the practitioner's approach to patients' compliance profiles, especially elderly patients with recent gout.

Multiple Tophaceous Gout of Hand with Extensor Tendon Rupture

A 45-year-old man presented with painless subcutaneous masses bilaterally on his hands and loss of motion or contracture of the fingers. Initially, drug therapy to reduce the serum uric acid was administered and was expected to reduce the tophi. However, during observation at the clinic, spontaneous rupture of an extensor tendon occurred, and surgical repair of the tendon and resection of the masses were performed. Surgical exploration of the right hand showed hypertrophic white-colored crystal deposits that both surrounded and invaded the extensor digitorum communis of the index finger, which was ruptured. Histopathologic examination of the specimen demonstrated findings consistent with gouty tophi. Tophaceous gout can induce a rupture of tendons during clinical observation, and surgical resection of the tophi might be needed to prevent ruptures.

Conventional Radiology in Crystal Arthritis: Gout, Calcium Pyrophosphate Deposition, and Basic Calcium Phosphate Crystals

This article reviews the main radiographic features of crystal deposition diseases. Gout is linked to monosodium urate crystals. Classic radiographic features include subcutaneous tophi, large and well-circumscribed paraarticular bone erosions, and exuberant bone hyperostosis. Calcium pyrophosphate deposition (CPPD) can involve numerous structures, such as hyaline cartilages, fibrocartilages, or tendons. CPPD arthropathy involves joints usually spared by osteoarthritis. Basic calcium phosphate deposits are periarticular or intraarticular. Periarticular calcifications are amorphous, dense, and round or oval with well-limited borders, and most are asymptomatic. When resorbing, they become cloudy and less dense with an ill-defined shape and can migrate into adjacent structures.

Critical revision of the medical treatment of gout in Brazil

Gout is considered the most common form of inflammatory arthritis in men over 40 years. The authors present a brief review of the current treatment of gout and discuss the existing pharmacological limitations in Brazil for the treatment of this disease. Although allopurinol is still the main drug administered for decreasing serum levels of uric acid in gout patients in this country, the authors also present data that show a great opportunity for the Brazilian drug market for the treatment of hyperuricemia and gout and especially for patients using private and public (SUS) health care systems.

GOSPEL 2 - Colchicine for the treatment of gout flares in France - a GOSPEL survey subgroup analysis. Doses used in common practices regardless of renal impairment and age

OBJECTIVES

The objective of this sub-study was to assess the use of colchicine for the treatment of gout flares in real life conditions in the GOSPEL cohort following the 2006 EULAR recommendations for gout management.

METHODS

This national cross-sectional epidemiologic survey included outpatients with gout suffering from acute flare followed by randomly selected primary care physicians (n=398) and private practice rheumatologists (n=109) between October 2008 and September 2009 in France. Data regarding patient characteristics and treatment prescription was collected by each physician. Glomerular filtration rate (eGFR) was estimated using the Cockroft-Gault formula. Patients included in the survey for a gout flare filled in a specific self-questionnaire including colchicine effective intake and pain relief (numeric scale).

RESULTS

This analysis focused on the 349 patients presenting with gout flare and treated with colchicine. Mean (±SD) prescribed dose of colchicine was 2.8 (±0.7) mg within the first 24hours and the cumulative dose over the first three days of treatment was 6.9 (±1.8) mg. Patients with mild decline in eGFR (eDFG 60-80mL/min) were prescribed an average initial dose of 2.8mg (±0.8) mg (n=58), 2.7 (±0.8) mg in chronic kidney disease (CKD) stage 3 (n=43) and 2.5 (±0.7) mg in CKD stage 4 (n=2). Cumulative doses of colchicine did not take into account either renal impairment or age.

CONCLUSIONS

This study draws attention to some misuse of colchicine in daily practice and the prescription of excessive doses especially in case of renal impairment. eGFR should be enforced in daily practice.

Hospital burden of gout, pseudogout and other crystal arthropathies in France

OBJECTIVE

To describe the hospital burden of microcrystal arthropathies in France.

METHODS

Data were extracted from the 2009-2011 French hospital national databases. We selected all hospital stays for microcrystal arthropathies (gout, chondrocalcinosis, other) encoded as primary or secondary diagnoses in patients older than 18. A descriptive analysis focused on number of patients and hospital stays, age, gender, comorbidities related to metabolic syndrome, and hospital costs based on 2012 public-sector costs.

RESULTS

132,275 hospitalizations involving 109,734 patients were related to microcrystal arthropathies encoded as primary or secondary diagnosis (61% related to gout, 34% to chondrocalcinosis, and 5% to other microcrystal arthropathies). 23,362 hospitalizations involving 25,105 patients were due to microcrystal diseases, encoded as primary diagnosis, (48% related to gout, 43% to chondrocalcinosis, and 9% to other microcrystal arthropathies). In this population, patients with chondrocalcinosis were older (mean 75.6±13.5 versus 71±16 years for other microcrystal arthropathies and 69.7±14.7 for gout). Men represented 70% of the patients with gout, 39% of those with chondrocalcinosis and 52% of the patients with other microcrystal arthropathies. Hypertension, diabetes, dyslipidemia, cardiac ischemia, and renal failure were more frequent in patients with gout than other patients. The hospital costs for microcrystal arthropathies encoded as primary diagnosis were 82.3 million Euros, 45% related to gout, 45% to chondrocalcinosis and 11% to other microcrystals.

CONCLUSION

In terms of hospital costs, gout and chondrocalcinosis represented the main part of the economic burden of crystal arthropathies and a high level of diseases belonging to the metabolic syndrome. Specific education programs favouring accurate microcrystal diagnosis and adherence to treatment could diminish this hospital economic burden.

Gout and risk of chronic kidney disease and nephrolithiasis: meta-analysis of observational studies

Introduction

To determine the prevalence of chronic kidney disease and nephrolithiasis in people with gout, and the association between gout and prevalent or incident chronic kidney disease and nephrolithiasis.

Methods

Systematic review and meta-analysis of epidemiological studies. Data sources; MEDLINE, EMBASE and CINAHL databases, hand-searched reference lists, citation history and contact with authors. Eligibility criteria: cohort, case–control or cross-sectional studies which examined the occurrence of chronic kidney disease or nephrolithiasis amongst adults with gout (with or without a non-gout comparator group) in primary care or general population samples. Prevalence and risk estimate meta-analyses were performed using a random-effects model.

Results

Seventeen studies were included in the meta-analysis (chronic kidney disease n = 7, nephrolithiasis n = 8, both n = 2). Pooled prevalence estimates of chronic kidney disease stage ≥3 and self-reported lifetime nephrolithiasis in people with gout were 24% (95% confidence interval 19% to 28%) and 14% (95% CI 12% to 17%) respectively. Gout was associated with both chronic kidney disease (pooled adjusted odds ratio 2.41, 95% confidence interval 1.86 to 3.11) and self-reported lifetime nephrolithiasis (1.77, 1.43 to 2.19).

Conclusions

Chronic kidney disease and nephrolithiasis are commonly found amongst patients with gout. Gout is independently associated with both chronic kidney disease and nephrolithiasis. Patients with gout should be actively screened for chronic kidney disease and its consequences.

Cost-effectiveness analysis of HLA-B5801 genotyping in the treatment of gout patients with chronic renal insufficiency in Korea

OBJECTIVE

Allopurinol-induced severe cutaneous adverse reactions (SCARs) are relatively rare but cause high rates of morbidity and mortality. Studies have shown that the HLA-B5801 allele and renal impairment are strongly associated with SCARs. Recent American College of Rheumatology guidelines recommend that, prior to treatment with allopurinol, the HLA-B5801 genotype of gout patients at high risk for SCARs, including Korean patients with chronic renal insufficiency, should be determined. However, whether such genotyping is cost-effective is unknown. This study evaluated the cost-effectiveness of HLA-B5801 genotyping for the treatment of gout in patients with chronic renal insufficiency in Korea.

METHODS

A decision analytical model over a time period of 12 months was employed to compare the cost and outcomes of treatment informed by HLA-B5801 genotyping with that of a conventional treatment strategy using a hypothetical cohort of gout patients with chronic renal insufficiency. Direct medical costs were obtained from real patients with SCARs from 2 tertiary hospitals. Outcomes were measured as a total expected cost and an incremental cost-effectiveness ratio.

RESULTS

In the base model, the total expected cost and probability of continuation of gout treatment without SCARs for the conventional and HLA-B5801 screening strategies were $1,193 and 97.8% and $1,055 and 100%, respectively. The results were robust according to sensitivity analyses.

CONCLUSION

Our model suggests that gout treatment informed by HLA-B5801 genotyping is less costly and more effective than treatment without genotyping, and HLA-B5801 genotyping could considerably reduce the occurrence of allopurinol-induced SCARs and related deaths.

Clinical manifestations and diagnosis of gout

Gout has been academically considered to be a step-up disease consisting of different stages: acute gout, intercritical gout, and chronic gout. This simple approach may lead to misinterpretation and misdiagnosis. In clinical practice, we should consider gout as a single disease with either or both acute (most commonly, episodes of acute inflammation) and persistent clinical manifestations, but not restricted to chronic synovitis. In this article, an innovative, practical, and rational approach to the clinical manifestations and diagnosis of gout is presented, which may be supportive for clinicians involved in everyday care and management of patients with gout.

Chronic kidney disease and the risk of incident gout among middle-aged men: a seven-year prospective observational study

OBJECTIVE

The kidney is the major organ that facilitates excretion of urate in humans. Surprisingly, few studies have assessed whether a reduced glomerular filtration rate (GFR) and/or kidney damage is associated with a higher incidence of gout, and this study was undertaken to address this question.

METHODS

Data from a 7-year followup of patients enrolled in the Multiple Risk Factor Intervention Trial, a primary prevention trial for cardiovascular disease among 12,866 men ages 35-57 years, were used for the present investigation. Presence of gout was determined by the study physicians from the original trial. Chronic kidney disease was defined using criteria similar to those proposed by the National Kidney Foundation. The Cox proportional hazards regression model was used to assess the association between gout and chronic kidney disease, after accounting for the effects of potential confounders.

RESULTS

Overall, there were 722 cases of physician- diagnosed incident gout over 76,602 person-years of followup. The standardized incidence ratio of gout among those with chronic kidney disease was 1,217 (95% confidence interval [95% CI] 1,191-1,244). The adjusted hazard ratio (HR) among those with chronic kidney disease was 1.61 (95% CI 1.60-1.61). Each standard deviation decline in the estimated GFR was associated with an HR of 1.43 (95% CI 1.35-1.51). Including the serum urate level, as well as the urate-chronic kidney disease interaction term, as variables in the second analysis did not attenuate the HR. Proteinuria and hematuria, two markers of kidney damage, were associated with an elevated risk of gout independent of the estimated GFR.

CONCLUSION

Chronic kidney disease manifesting as reduced glomerular function or as presence of blood or protein in the urine increases the risk of incident gout.

Revisiting comorbidities in gout: a cluster analysis

OBJECTIVES

The reciprocal links between comorbidities and gout are complex. We used cluster analysis to attempt to identify different phenotypes on the basis of comorbidities in a large cohort of patients with gout.

METHODS

This was a cross-sectional multicentre study of 2763 gout patients conducted from November 2010 to May 2011. Cluster analysis was conducted separately for variables and for observations in patients, measuring proximity between variables and identifying homogeneous subgroups of patients. Variables used in both analyses were hypertension, obesity, diabetes, dyslipidaemia, heart failure, coronary heart disease, renal failure, liver disorders and cancer.

RESULTS

Comorbidities were common in this large cohort of patients with gout. Abdominal obesity, hypertension, metabolic syndrome and dyslipidaemia increased with gout duration, even after adjustment for age and sex. Five clusters (C1-C5) were found. Cluster C1 (n=332, 12%) consisted of patients with isolated gout and few comorbidities. In C2 (n=483, 17%), all patients were obese, with a high prevalence of hypertension. C3 (n=664, 24%) had the greatest proportion of patients with type 2 diabetes (75%). In C4 (n=782, 28%), almost all patients presented with dyslipidaemia (98%). Finally, C5 (n=502, 18%) consisted of almost all patients with a history of cardiovascular disease and renal failure, with a high rate of patients receiving diuretics.

CONCLUSIONS

Cluster analysis of comorbidities in gout allowed us to identify five different clinical phenotypes, which may reflect different pathophysiological processes in gout.

When gout involves the spine: five patients including two inaugural cases

Spinal involvement is uncommon during gout and may raise diagnostic challenges. We describe five cases seen at a single center.

METHODS

We retrospectively reviewed the medical charts of the five patients with spinal gout seen over a 3-year period.

RESULTS

There were four men and one woman with an age range of 52 to 87 years. One patient presented with acute neck pain and visualization by imaging studies of a discovertebral tophus, another had febrile arthritis of a lumbar facet joint, and a third presented with a synovial cyst in a lumbar facet joint. The remaining two patients had acute febrile discitis confirmed by magnetic resonance imaging, at the cervical spine and lumbar spine, respectively. Laboratory tests showed systemic inflammation in four patients and marked serum uric acid elevation in two patients. Only three patients reported a previous history of peripheral acute gout attacks. Specimens of the spinal lesions were obtained in three patients and consistently showed monosodium urate crystals with tissue inflammation or a tophus. The outcome was rapidly favorable, either with colchicine therapy alone in four patients or after surgical resection of a facet joint cyst (during surgery to stabilize the lumbar spine) in the remaining patient. The patient with neck pain due to a tophus experienced nerve root pain at the acute phase. No other neurological manifestations were recorded.

CONCLUSION

These case reports illustrate the diagnostic challenges raised by spinal involvement due to gout. The spinal lesions can be inaugural, as seen in two of our five patients.

Reduced glomerular function and prevalence of gout: NHANES 2009-10

Background

The renal tubule is a major route of clearance of uric acid, a product of purine metabolism. The links between reduced glomerular filtration rate (GFR), hyperuricemia, and gout in the general population are not well understood. The objective of the present study was to estimate prevalence of gout and hyperuricemia among people with impaired GFR in the US general population.

Study Design

Cross-sectional, survey-weighted analyses of data on adults (age>20 years) in the 2009–10 cycle of the US National Health and Nutrition Examination Surveys (n = 5,589). Associations between self-reported physician diagnosis of gout and degrees of renal impairment were the primary focus of the present analyses.

Results

In the 2009–2010 period, there was an estimated 7.5 million people with gout in the US. There were 1.25 million men and 0.78 million women with moderate or severe renal impairment and gout. The age standardized prevalence of gout was 2.9% among those with normal GFR compared to 24% among those with GFR<60 ml/min/1.73 m².In multivariable logistic regression analyses that adjusted for age, gender, body mass index, hypertension, diabetes, hypertension medications, including diuretics, blood lead levels, and hyperlipidemia, the odds ratios of gout and hyperuricemia were 5.9 (2.2, 15.7) and 9.58 (4.3, 22.0) respectively among those with severe renal impairment compared to those with no renal impairment. Approximately 2–3 fold increase in prevalence of gout was observed for each 30 ml/min/1.73 m² decrease in GFR, after accounting for the above factors.

Conclusions

Renal glomerular function is an important risk factor for gout. The prevalence of hyperuricemia and gout increases with decreasing glomerular function independent of other factors. This association is non-linear and an eGFR of 60 ml/min/1.73 m² appears to be a threshold for the dramatic increase in the prevalence of gout.

ACTH as first line treatment for acute gout in 181 hospitalized patients

OBJECTIVE

We aimed at assessing the efficacy and safety of adrenocorticotropic hormone (ACTH) for the treatment of acute gout in hospitalized patients.

METHODS

We retrospectively reviewed our inpatient consultation records and identified 181 cases of gout where ACTH was used as first line treatment. The hospital medical records of these patients were fully reviewed. A total of 181 patients were treated with 1mg of synthetic ACTH intramuscularly.

RESULTS

A response was seen in 77.90% of patients and was evident the day following ACTH injection. The majority of non-responders (87.50%) were treated once more with ACTH the day following the first injection; 82.85% of these patients responded. A relatively small percentage of responders suffered a second gouty attack (11.34%) at a median of four days from the initial attack. They were retreated with a single ACTH course and all responded. Blood pressure and potassium levels remained stable 24 and 48 hours following ACTH administration. Diabetic patients showed an increase in fasting glucose levels 24 hours following the injection compared to baseline but this increase was not evident at 48 hours.

CONCLUSIONS

Our data indicate that ACTH is effective and safe for the treatment of gout in hospitalized patients. ACTH is an attractive therapeutic option for hospitalized patients since the use of non-steroidal anti-inflammatory drugs, steroids or colchicine in this patient population may be problematic.