Neoisoastilbin Ameliorates Acute Gouty Arthritis via Suppression of the NF-κB/NLRP3 Pathway

Acute gouty arthritis (AGA) is an acute inflammatory disease, whose occurrence and development mechanism are associated with inflammatory reaction of joint tissue. This study investigated the role of neoisoastilbin (NIA) in the treatment of AGA and explored the underlying mechanisms. C57BL/6 mice underwent intraarticular injection of monosodium urate (MSU) to establish an AGA model in vivo. Enzyme-linked immunosorbent assay, histopathological hematoxylin-eosin staining, western blotting, and other methods were used to observe the therapeutic effects of NIA on AGA and investigate the role of the NF-κB/NLRP3 pathway in the treatment. We found that NIA effectively reduced MSU-induced joint swelling and inflammatory cell infiltration in a concentration-dependent manner. NIA also significantly reduced interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels as compared with the respective values in the model mice group. In addition, administration of NIA significantly mitigated the phosphorylation of NF-κB-related proteins (IKKα, NF-κB, and IκBα) and the expression of NLRP3-related proteins (NLRP3, caspase-1, and ASC) in MSU-induced joint tissues. In conclusion, our research indicated that NIA significantly improved AGA, and its underlying mechanism was achieved by simultaneously inhibiting the NF-κB/NLRP3 pathway and the expression of inflammatory factors. This research preliminarily suggested the potential role of NIA in the treatment of AGA.

Gout Flare Burden, Diagnosis, and Management: Navigating Care in Older Patients with Comorbidity

Gout is the most common form of inflammatory arthritis, and its incidence is highest in middle-aged and older patients. Adding to the diagnostic complexity, up to 50% of patients aged > 65 years present atypically, with subacute oligo- or polyarticular flares. Comorbidity and polypharmacy, common in older populations, affect real-world treatment decisions in gout management, and no specific guidelines are available to address these issues in these at-risk groups. Despite the growing public health burden posed by gout, suboptimal management has led to increased morbidity and substantial healthcare utilization and cost burden, as reflected by an increased incidence of emergency department visits and hospitalizations in recent years. Colchicine, nonsteroidal anti-inflammatory drugs, or glucocorticoids (oral, intraarticular, or intramuscular) should be considered as first-line agents for gout flare management. Urate-lowering therapy, with the goal of lowering and maintaining serum urate concentrations at < 6 mg/dL (< 360 μmol/L), is recommended to achieve optimal outcomes, including regression of tophi, reduction (or elimination) of flares, and reductions in total urate burden. In this review, we summarize the current burden posed by gout and discuss best practices in its diagnosis and management, focusing on best practices in the context of gout flare in older patients with comorbid conditions.

The development of a targeted and more potent, anti-Inflammatory derivative of colchicine: Implications for gout

BACKGROUND

Colchicine is routinely used for its anti-inflammatory properties to treat gout and Familial Mediterranean fever. More recently, it was also shown to be of therapeutic benefit for another group of diseases in which inflammation is a key component, namely, cardiovascular disease. Whilst there is considerable interest in repurposing this alkaloid, it has a narrow therapeutic index and is associated with undesirable side effects and drug interactions. We, therefore, developed a derivatives of colchicine that preferentially target leukocytes to increase their potency and diminish their side effects. The anti-inflammatory activity of the colchicine derivatives was tested in experimental models of neutrophil activation by the etiological agent of gout, monosodium urate crystals (MSU).

METHODS

Using a rational drug design approach, the structure of colchicine was modified to increase its affinity for βVI-tubulin, a colchicine ligand preferentially expressed by immune cells. The ability of the colchicine analogues with the predicted highest affinity for βVI-tubulin to dampen neutrophil responses to MSU was determined with in vitro assays that measure MSU-induced production of ROS, release of IL-1 and CXCL8/IL-8, and the increase in the concentration of cytoplasmic calcium. The anti-inflammatory property of the derivatives was assessed in the air pouch model of MSU-induced inflammation in mice.

RESULTS

The most effective compound generated, CCI, is more potent than colchicine in all the in vitro assays. It inhibits neutrophil responses to MSU in vitro at concentrations 10-100-fold lower than colchicine. Similarly, in vivo, CCI inhibits the MSU-induced recruitment of leukocytes at a 10-fold lower concentration than colchicine when administered prior to or after MSU.

CONCLUSIONS

We provide evidence that colchicine can be rendered more potent atinhibiting MSU-induced neutrophil activation and inflammation using a rational drug design approach. The development of compounds such as CCI will provide more efficacious drugs that will not only alleviate gout patients of their painful inflammatory episodes at significantly lower doses than colchicine, but also be of potential therapeutic benefit for patients with other diseases treated with colchicine.

Fucoxanthin: A promising compound for human inflammation-related diseases

Fucoxanthin, a natural product of carotenoids, is a potential drug source obtained from marine algae. The special chemical structure of fucoxanthin has equipped it with a variety of biological activities. Several studies have indicated that fucoxanthin has a potential protective effect on a variety of inflammation-related diseases. This mechanism may be related to fucoxanthin's strong antioxidant capacity and gut microbiota regulation. The key molecules that require consideration include nuclear factor erythroid 2-related factor 2, Akt serine/threonine kinase/phosphatidylinositol-3-kinase, extracellular signal-regulated kinase, adenosine monophosphate (AMP)-dependent protein kinase, cAMP response element binding protein, and peroxisome proliferator-activated receptorγcoactivator-1α. The study summarizes the recent progress in the research based on the protective effect of fucoxanthin and its related molecular mechanism, in addition to the potential use of fucoxanthin as a promising compound for human inflammation-related diseases.

Effect of lemon water soluble extract on hyperuricemia in a mouse model

Lemon is a healthy fruit with high medicinal value.

Side Effects and Interactions of the Xanthine Oxidase Inhibitor Febuxostat

The paper addresses the safety of febuxostat and summarizes reports on side effects and interactions of febuxostat published by the cut-off date (last day of literature search) of 20 March 2018. Publications on side effects and the interactions of febuxostat were considered. Information concerning the occurrence of side effects and interactions in association with the treatment with febuxostat was collected and summarized in the review. The incidence of severe side effects was much less frequent than mild side effects (1.2–3.8% to 20.1–38.7%). The rate and range of febuxostat side effects are low at doses of up to 120 mg and only increase with a daily dose of over 120 mg. The publications reveal no age-dependent increase in side effects for febuxostat. In patients with impaired renal function, no increase in adverse events is described with a dose of up to 120 mg of febuxostat per day. Patients with impaired liver function had no elevated risk for severe side effects. A known allopurinol intolerance increases the risk of skin reactions during treatment with febuxostat by a factor of 3.6. No correlation between treatment with febuxostat and agranulocytosis has been confirmed. Possible interactions with very few medications (principally azathioprine) are known for febuxostat. Febuxostat is well tolerated and a modern and safe alternative to allopurinol therapy.

Crystal arthritides - gout and calcium pyrophosphate arthritis : Part 3: Treatment

The treatment of gout is based on several principles. Symptom control and termination of the inflammatory process are important early goals, whereas the urate level should be lowered in the long term to prevent further gout attacks and complications. The non-pharmacological approach is based on individually informing the patient on dietary measures and changes of life style. Besides physical measures, such as cold applications on the affected joint, various medications are available for treatment of an acute gout attack. The choice of drug depends on the individual risk profile. If non-steroidal anti-inflammatory drugs (NSAID) and coxibs are chosen it should be taken into account that the use is restricted in patients with renal insufficiency. Moreover, these drugs may have gastrointestinal side effects and are associated with increased cardiovascular morbidity and mortality. Colchicine has gastrointestinal side effects at high dosages but can also be used for differential diagnostics if there is a quick response to treatment. Steroids are an effective alternative and can be given orally or parenterally in patients with dysphagia. Moreover, steroids can be used in cases of renal insufficiency. After symptoms of the acute attack have subsided, urate lowering therapy should be initiated to prevent further attacks. Low-dose urate lowering therapy can be started during an acute gout attack when acute therapy is initiated. Allopurinol is still the medication of choice but its use is restricted in patients with renal insufficiency. A rare but serious side effect is allopurinol hypersensitivity syndrome. Febuxostat can be an alternative in patients who do not tolerate allopurinol. In February 2016, lesinurad, an URAT-1 and OAT-4 inhibitor, was approved in combination with allopurinol or febuxostat. Data on the effectiveness and safety of synthetic uricases and biologicals are still sparse for elderly patients. These substances are reserved for severe cases of gout.

Cost Comparison of Urate-Lowering Therapies in Patients with Gout and Moderate-to-Severe Chronic Kidney Disease

BACKGROUND

Patients with chronic kidney disease (CKD) are at increased risk for developing gout and having refractory disease. Gout flare prevention relies heavily on urate-lowering therapies such as allopurinol and febuxostat, but clinical decision making in patients with moderate-to-severe CKD is complicated by significant comorbidity and the scarcity of real-world cost-effectiveness studies.

OBJECTIVE

To compare total and disease-specific health care expenditures by line of therapy in allopurinol and febuxostat initiators after diagnosis with gout and moderate-to-severe CKD.

METHODS

A retrospective observational cohort study was conducted to compare mean monthly health care cost (in 2012 U.S. dollars) among gout patients with CKD (stage 3 or 4) who initiated allopurinol or febuxostat. The primary outcome was total mean monthly health care expenditures, and the secondary outcome was disease-specific (gout, diabetes, renal, and cardiovascular disease [CVD]) expenditures. Gout patients (ICD-9-CM 274.xx) aged ≥ 18 years with concurrent CKD (stage 3 or 4) were selected from the MarketScan databases (January 2009-June 2012) upon allopurinol or febuxostat initiation. Patients were followed until disenrollment, discontinuation of the qualifying study agent, or use of the alternate study agent. Patients initiating allopurinol were subsequently propensity score-matched (1:1) to patients initiating febuxostat. Five generalized linear models (GLMs) were developed, each controlling for propensity score, to identify the incremental costs (vs. allopurinol) associated with febuxostat initiation in first-line (without prior allopurinol exposure) and second-line (with prior allopurinol exposure) settings.

RESULTS

Propensity score matching yielded 2 cohorts, each with 1,486 patients (64.6% male, mean [SD] age 67.4 [12.8] years). Post-match, 74.6% of patients had stage 3 CKD; 82.9% had CVD; and 42.1% had diabetes. The post-match sample was well balanced on numerous comorbidities and medication exposures with the following exception: 50.0% of febuxostat initiators were treated in the second-line setting; that is, they had baseline exposure to allopurinol, whereas only 4.2% of allopurinol initiators had baseline exposure to febuxostat. Unadjusted mean monthly cost was $1,490 allopurinol and $1,525 febuxostat (P = 0.809). GLM results suggest that first-line febuxostat users incurred significantly (P = 0.009) lower cost than allopurinol users ($1,299 vs. $1,487), whereas second-line febuxostat initiators incurred significantly (P = 0.001) higher cost ($1,751 vs. $1,487). Febuxostat initiators in both settings had significantly (P < 0.001) higher gout-specific cost, due to higher febuxostat acquisition cost. Increased gout-specific cost in the first-line febuxostat cohort was offset by significantly (P < 0.001) lower CVD ($288 vs. $459) and renal-related cost ($86 vs. $216). There were no significant differences in either renal or CVD costs (adjusted) between allopurinol initiators treated almost exclusively in the first-line setting and second-line febuxostat patients.

CONCLUSIONS

Gout patients with concurrent CKD, initiating treatment with febuxostat in a first-line setting, incurred significantly less total cost than patients initiating allopurinol during the first exposure to each agent. Conversely, patients treated with second-line febuxostat following allopurinol incurred significantly higher total cost than patients initiating allopurinol. There was no significant difference in total cost between the agents across line of therapy. Although study findings suggest the potential for CVD and renal-related savings to offset febuxostat's higher acquisition cost in gout patients with moderate-to-severe CKD, this is the first such retrospective evaluation. Future research is warranted to both demonstrate the durability of study findings and to better elucidate the mechanism by which associated cost offsets occur.

DISCLOSURES

No outside funding supported this study. Turpin is an employee of Takeda Pharmaceuticals U.S.A. Mitri and Wittbrodt were employees of Takeda Pharmaceuticals U.S.A. at the time of this study. Tidwell and Schulman are employees of Outcomes Research Solutions, consultants to Takeda Pharmaceuticals U.S.A. All authors contributed to the design of the study and to the writing and review of the manuscript. All authors read and approved the final manuscript. Tidwell and Schulman collected the data, and all authors participated in data interpretation.

Optimizing current treatment of gout

Gout is the most common inflammatory arthritis worldwide. Although effective treatments exist to eliminate sodium urate crystals and to 'cure' the disease, the management of gout is often suboptimal. This article reviews available treatments, recommended best practice and barriers to effective care, and how these barriers might be overcome. To optimize the management of gout, health professionals need to know not only how to treat acute attacks but also how to up-titrate urate-lowering therapy against a specific target level of serum uric acid that is below the saturation point for crystal formation. Current perspectives are changing towards much earlier use of urate-lowering therapy, even at the time of first diagnosis of gout. Holistic assessment and patient education are essential to address patient-specific risk factors and ensuring adherence to individualized therapy. Shared decision-making between a fully informed patient and practitioner greatly increases the likelihood of curing gout.

Canakinumab: a guide to its use in acute gouty arthritis flares

Canakinumab (Ilaris®), an anti-interleukin-1β monoclonal antibody, is a novel approach to treat acute gouty arthritis flares in a targeted population of patients in whom treatment options are limited. Relative to on-demand treatment with intramuscular triamcinolone acetonide 40 mg, on-demand treatment with subcutaneous canakinumab 150 mg significantly relieved the pain and inflammation of a new gout flare, and reduced the risk of new flares in patients with acute gouty arthritis flares in whom standard treatment with non-steroidal anti-inflammatories and/or colchicine was inappropriate. Canakinumab has an acceptable tolerability profile in this difficult-to-treat population. The increased risk of infections and neutropenia associated with canakinumab treatment can be minimized by following the recommended precautions.

Pharmacodynamic, pharmacokinetic and tolerability evaluation of concomitant administration of lesinurad and febuxostat in gout patients with hyperuricaemia

OBJECTIVE

The aim of this study was to evaluate the pharmacodynamics (PDs), pharmacokinetics (PKs) and safety of lesinurad (selective uric acid reabsorption inhibitor) in combination with febuxostat (xanthine oxidase inhibitor) in patients with gout.

METHODS

This study was a phase IB, multicentre, open-label, multiple-dose study of gout patients with serum uric acid (sUA) >8 mg/dl following washout of urate-lowering therapy with colchicine flare prophylaxis. Febuxostat 40 or 80 mg/day was administered on days 1-21, lesinurad 400 mg/day was added on days 8-14 and then lesinurad was increased to 600 mg/day on days 15-21. sUA, urine uric acid and PK profiles were evaluated at the end of each week. Safety was assessed by adverse events, laboratory tests and physical examinations.

RESULTS

Initial treatment with febuxostat 40 or 80 mg/day monotherapy resulted in 67% and 56% of subjects, respectively, achieving a sUA level <6 mg/dl. Febuxostat 40 or 80 mg/day plus lesinurad 400 or 600 mg/day resulted in 100% of subjects achieving sUA <6 mg/dl and up to 100% achieving sUA <5 mg/dl. No clinically relevant changes in the PKs of either drug were noted. The combination was well tolerated.

CONCLUSION

The clinically important targets of sUA <6 mg/dl and <5 mg/dl are achievable in 100% of patients when combining lesinurad and febuxostat.

Trends in physician diagnosed gout and gout therapies in the US: results from the national ambulatory health care surveys 1993 to 2009

Introduction

Gouty arthritis (gout) is primarily cared for in ambulatory care settings. Although the prevalence of gout in the US is thought to be increasing, there have been few data on this as well as temporal changes in gout medication use.

Methods

We analyzed annual visit and drug utilization data from national sample surveys of physician practices and hospital outpatient clinics in the US from 1993 to 2009. Gout diagnosis was recorded by individual physicians.

Result

The frequency of visits for gout increased three-fold from 1993 through 2009; most of the increases were observed from 2003 onwards. The increase was only partly explained by changes in age and gender composition of the surveys over time. A concomitant increase in prescriptions for allopurinol and colchicine and decrease in prescriptions for anti-inflammatories was observed. Aspirin use, a putative risk factor for gout and gout flares, increased substantially over this period. Probenecid use was negligible. Frequency of systemic steroid use has not changed over time.

Conclusions

The number of ambulatory visits for gout has increased almost three-fold in the first decade of the millennium coinciding with increases in physician and patient awareness. This increase was primarily due to visits among the elderly. Uricosuric use remained negligible whereas the uses of allopurinol and colchicine have increased rapidly. Use of traditional non-steroidals has declined, possibly due to safety concerns whereas glucocorticoid use remains unchanged.

Chronic gout in the elderly

Gout is the most common cause of inflammatory arthritis in men over 40 years old; it is a debilitating disease and, if untreated, can result in a chronic progressive disease, including tophaceous gout. In the elderly it represents a special issue, with notable clinical and therapeutic differences from the classical form with a systemic involvement. The burden of the disease increases particularly in the very old people, in whom arthritis, impaired gait and eyesight problems may enhance the related disability. Chronic gout moreover could aggravate heart and kidney disease and increase overall mortality and organ-related damage. Early diagnosis and appropriate treatment are important goals for the clinician that should to rely on the cooperation of specialists working together through the methodology of comprehensive geriatric assessment. The aim of the present review was to analyze chronic gout in old people in terms of epidemiology, pathophysiology, risk factors, clinical approach, and current treatment.

How to manage patients with gout

OBJECTIVES

Recently, after almost 50 years of dormancy, new therapeutic agents for the management of gout have entered the market or are in clinical development. In this article, the current guidelines for the diagnosis and management of gout are reviewed.

METHODS

Key papers for inclusion were identified by a PubMed search, and articles were selected according to their relevance for the topic, according to the authors' judgment.

RESULTS AND CONCLUSIONS

Although our therapeutic arsenal is strong, and effective gout management with urate lowering therapy improves many patient-reported outcomes in clinical trials, major gaps exist in patient understanding of disease and adherence to long-term therapy. Research is required to identify the optimal models of care for patients with gout. However, quality of care in gout can be enhanced through better gout-centered education. To properly manage gout, education of the gout patient is critical, since only the patient who understands their gout will stay with their medication long-term.

Current status of inflammasome blockers as anti-inflammatory drugs

INTRODUCTION

The inflammasomes have emerged as key mediators of inflammation and immunity, yet clinical application of this knowledge has been limited by a lack of specific and drug-like antagonists. Recent studies using inflammasome knockout mice have shown that different inflammasomes control immunity in different pathologies. Drug-like antagonists acting up- or down-stream of the inflammasome pathway have been successfully used in clinics as important therapeutics to treat different inflammatory diseases.

AREAS COVERED

The current literature has been reviewed on the role of inflammasomes in inflammatory disease, focusing on potential therapeutic applications of selective inflammasome antagonists as anti-inflammatory agents. Particular emphasis has been placed on the potential role of the different inflammasomes in common inflammatory diseases. The latest clinical developments for drugs targeting inflammasome pathways are covered.

EXPERT OPINION

Recent studies using inflammasome knockout mice suggest its importance as a potential therapeutic target for the treatment of inflammatory disease. However, efficacious antagonists for the inflammasome for use in clinical studies are still at an early stage of development. Developing selective inflammasome antagonists is a challenge that if met, offers promise for the treatment of chronic inflammatory diseases. Major developments in this area will include the identification of reliable high-throughput screening methods for compounds directly targeting inflammasome assembly.

Recent advances in management of gout

Incidence and prevalence of gout have markedly increased over the last few decades in keeping with the rise in prevalence of obesity and metabolic syndrome. Until recently, management of gout in patients with associated metabolic syndrome and comorbid illnesses such as renal impairment was difficult because of limited treatment options. However, significant progress has been made in the last few years, with introduction of new treatments such as interleukin-1 antagonists for management of acute gout, and febuxostat and pegloticase for chronic gout. The association of gout with alcohol, dietary purines and fructose ingestion has been confirmed in large prospective studies, thus enabling the clinician to now provide evidence-based advice to patients. Recent efficacy and safety data favour lower over higher doses of colchicine, and oral corticosteroids over non-steroidal anti-inflammatory drugs for patients with acute gout. Local ice therapy might help to differentiate gout from other forms of inflammatory arthritis, and supplementation with vitamin C help to reduce risk of gout. Several other drugs with rational mechanisms of action are in the pipeline, and likely to be introduced over the next few years. A new era has thus begun in the field of gout.

The broad spectrum of urate crystal deposition: unusual presentations of gouty tophi

OBJECTIVES

Gout is typically described as an inflammatory arthropathy that affects the peripheral joints. Our aim was to describe atypical and rare clinical presentations of gouty tophi to help increase physician awareness and aid in patient care.

METHODS

The relevant English literature of unusual gout manifestations was searched using the keywords gout, toph*, monosodium urate, uric acid, unusual, and rare. Well-described case reports, case series, and review articles were evaluated and included, if relevant, in the literature review.

RESULTS

Review of the literature revealed many unusual manifestations of gouty tophi involving the head and neck, skin, viscera, bones, tendons, ligaments, nerves, and axial skeleton. Transplant recipients, women, and elderly people are particularly susceptible to developing tophi. Furthermore, gout can cause diagnostic dilemmas, as it can be a great mimicker of and can coexist with infection, malignancy, and other connective tissue diseases. Imaging modalities can help detect tophi in atypical locations.

CONCLUSIONS

Tophi can present in unexpected locations, even as the first sign of gout, and vigilance is required when unusual symptoms or signs occur in a patient with gout.

Pegloticase: A Novel Agent for Treatment-Refractory Gout

Objective:

To evaluate efficacy and safety of pegloticase, approved by the Food and Drug Administration in September 2010 for treatment of patients with chronic treatment-refractory gout.

Data Sources:

Literature searches were conducted using PubMed (1948–January 2012), TOXLINE, international Pharmaceutical Abstracts (1970-January 2012), and Google Scholar using the terms pegloticase, puricase, PEG-uricase, gout, uricase, and Krystexxa. Results were limited to English-language publications. References from selected articles were reviewed to identify additional citations.

Study Selection and Data Extraction:

Studies evaluating the pharmacology, pharmacokinetics, safety, and efficacy of pegloticase for the treatment of chronic treatment-refractory gout were included.

Data Synthesis:

Pegloticase represents a novel intravenous treatment option for patients who have chronic gout refractory to other available treatments. Pegloticase is a recombinant uricase and achieves therapeutic effects by catalyzing oxidation of uric acid to allantoin, resulting in decreased uric acid concentrations. Results of published trials demonstrate the ability of pegloticase to maintain uric acid concentrations below 7 mg/dL in patients with chronic gout, Data supporting reduction of gout flares are limited. Pegloticase is well tolerated but associated with gout flares and infusion reactions. Other adverse events include nausea, dizziness, and back pain. During Phase 3 trials, 2 patients in the pegloticase biweekly group and 1 in the monthly group experienced heart failure exacerbation; another patient in the monthly group experienced a nonfatal myocardial infarction. Providers should exercise caution before administering pegloticase to patients with cardiovascular disease. The cost burden and safety profile may limit its use in practice, in addition to limited data available to support decreases in patient-centered outcomes (eg, gouty attacks).

Conclusions:

Pegloticase is an effective option for patients with symptomatic gout for whom current uric acid-lowering therapies are ineffective or contraindicated.