The challenges of gout flare reporting: mapping flares during a randomized controlled trial

Investigating gout flares: beyond a definition

PURPOSE OF REVIEW

Gout flares are a paramount component of disease burden inflicted by gout onto the patient. Furthermore, they are included in the core domain set for long-term gout studies recognized by Outcome Measures in Rheumatology. Along with a validated classification criterion for gout, gout investigators have turned their efforts into defining and characterizing the gout flare. This brief review will summarize the efforts that have been done to define and characterize a gout flare in clinical studies.

RECENT FINDINGS

Recent findings include a validated definition of a gout flare that has been utilized in novel clinical studies, use of technology to monitor for gout flares and their effects on patient life, and qualitative analyses into the disease burden that a patient undergoes.

SUMMARY

Although guidelines for core outcome domains have been well established, there is question in methods of measuring and reporting gout flares in long-term trials. Furthermore, there is question as to the effectiveness of the agreed upon instruments' abilities to fully capture the disease burden experienced by patients with gout. A combination of outcome measurements including binary data (gout flare present or absent) along with a comprehensive measurement of disease burden over time would theoretically provide a more accurate description of the disease and serve as a basis for intervention development.

The effect of exercise rehabilitation with exergames combined with ice therapy in the treatment of obese patients with gout: protocol for a clinical trial

BACKGROUND

Gout remains a leading cause of inflammatory arthritis worldwide, and the main risk factor for gout is persistent hyperuricemia. The clinical management of gout is mostly drug-based, and other treatment options are often ignored. This research proposal will explore whether exergames combined with ice therapy can help patients with gout to lose weight, relieve pain, improve the range of movement, improve quality of life, decrease uric acid level, decrease kinesiophobia and improve mental health of patients with gout.

METHODS

This experiment will use a two-arm randomized controlled design. The study setting is at the Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia (USM). Obese patients with gout (N = 30) will be randomly assigned to the control group (receive an exergames intervention) and intervention group (receive an exergames intervention combined with ice therapy). The outcomes measurement will be conducted before (baseline) and after intervention (4 weeks). Then, it will be followed up at 12 weeks.

DISCUSSION

To our knowledge, no study has investigated the effect of exergames and ice therapy among gout patients. This study is expected to demonstrate that exercise rehabilitation facilitated by exergames with ice therapy is more effective in gout management compared to a conventional rehabilitation intervention.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2300070029). Registered on 31 March 2023.

Effective xanthine oxidase inhibitor urate lowering therapy in gout is linked to an emergent serum protein interactome of complement activation and inflammation modulators

Background

Urate-lowering treatment (ULT) to target with xanthine oxidase inhibitors (XOIs) paradoxically causes early increase in gouty arthritis flares. Because delayed reduction in flare burden is mechanistically unclear, we tested for ULT inflammation responsiveness markers.

Methods

Unbiased proteomics analyzed blood samples (baseline, 48 weeks ULT) in two, independent ULT out trial cohorts (n = 19, n = 30). STRING-db and multivariate analyses supplemented determinations of altered proteins via Wilcoxon matched pairs signed rank testing in XOI ULT responders. Mechanistic studies characterized proteomes of cultured XOI-treated murine bone marrow macrophages (BMDMs).

Results

At 48 weeks ULT, serum urate normalized in all gout patients, and flares declined, with significantly altered proteins (p < 0.05) in clustering and proteome networks in sera and peripheral blood mononuclear cells. Serum proteome changes included decreased complement C8 heterotrimer C8A and C8G chains and chemokine PPBP/CXCL7, and increased urate crystal phagocytosis inhibitor sCD44. In both cohorts, a treatment-emergent serum interactome included key gouty inflammation mediators (C5, IL-1B, CXCL8, IL6). Last, febuxostat inhibited complement activation pathway proteins in cultured BMDMs.

Conclusions

Reduced gout flares are kinked with a XOI-treatment emergent complement- and inflammation-regulatory serum protein interactome. Serum and leukocyte proteomes could help identify onset of anti-inflammatory responsiveness to ULT in gout.

Trial registration

ClinicalTrials.gov Identifier: NCT02579096, posted October 19, 2015.

Sustained xanthine oxidase inhibitor treat to target urate lowering therapy rewires a tight inflammation serum protein interactome

Background

Effective xanthine oxidoreductase inhibition (XOI) urate-lowering treatment (ULT) to target significantly reduces gout flare burden and synovitis between 1-2 years therapy, without clearing all monosodium urate crystal deposits. Paradoxically, treat to target ULT is associated with increased flare activity for at least 1 year in duration on average, before gout flare burden decreases. Since XOI has anti-inflammatory effects, we tested for biomarkers of sustained, effective ULT that alters gouty inflammation.

Methods

We characterized the proteome of febuxostat-treated murine bone marrow macrophages. Blood samples (baseline and 48 weeks ULT) were analyzed by unbiased proteomics in febuxostat and allopurinol ULT responders from two, independent, racially and ethnically distinct comparative effectiveness trial cohorts (n=19, n=30). STRING-db and multivariate analyses supplemented determinations of significantly altered proteins via Wilcoxon matched pairs signed rank testing.

Results

The proteome of cultured IL-1b-stimulated macrophages revealed febuxostat-induced anti-inflammatory changes, including for classical and alternative pathway complement activation pathways. At 48 weeks ULT, with altered purine metabolism confirmed by serum metabolomics, serum urate dropped >30%, to normal (<6.8 mg/dL) in all the studied patients. Overall, flares declined from baseline. Treated gout patient sera and peripheral blood mononuclear cells (PBMCs) showed significantly altered proteins (p<0.05) in clustering and proteome networks. CRP was not a useful therapy response biomarker. By comparison, significant serum proteome changes included decreased complement C8 heterotrimer C8A and C8G chains essential for C5b-9 membrane attack complex assembly and function; increase in the NLRP3 inflammasome activation promoter vimentin; increased urate crystal phagocytosis inhibitor sCD44; increased gouty inflammation pro-resolving mediator TGFB1; decreased phagocyte-recruiting chemokine PPBP/CXCL7, and increased monocyte/macrophage-expressed keratin-related proteins (KRT9,14,16) further validated by PBMC proteomics. STRING-db analyses of significantly altered serum proteins from both cohorts revealed a tight interactome network including central mediators of gouty inflammation (eg, IL-1B, CXCL8, IL6, C5).

Conclusions

Rewiring of inflammation mediators in a tight serum protein interactome was a biomarker of sustained XOI-based ULT that effectively reduced serum urate and gout flares. Monitoring of the serum and PBMC proteome, including for changes in the complement pathway could help determine onset and targets of anti-inflammatory changes in response to effective, sustained XOI-based ULT.Trial Registration: ClinicalTrials.gov Identifier: NCT02579096.

Cohort study investigating gout flares and management in UK general practice

BACKGROUND

Gout is the most common inflammatory arthritis and is almost exclusively managed in primary care, however the course and severity of the condition is variable and poorly characterised. This research aims improve understanding about the frequency of, and factors associated with, gout flares in the UK and characterise the factors associated with the initiation of ULT.

METHODS

Using the Clinical Practice Research Database, patients with a coded incident gout diagnosis without a prior prescription for urate-lowering therapy (ULT) were identified. Gout flares post diagnosis and ULT initiation were identified through prescribing and coded data. Patient characteristics, co-morbidities and co-prescribing were co-variants. Factors associated with gout flares and ULT initiation were analysed using cox-proportional hazard model and logistic regression.

RESULTS

Fifty-one thousand seven hundred eighty-four patients were identified: 18,605 (35.9%, 95%CI 35.5-36.3%) had experienced ≥ 1 recurrent flare, 17.4% (95%CI 17.1-17.8%) within 12 months of diagnosis. Male sex, black ethnicity, higher BMI, heart failure, CKD, CVD and diuretic use were associated with flares, with the highest HR seen with high serum urate levels (≥ 540 µmol/L HR 4.63, 95%CI 4.03-5.31). ULT initiation was associated with similar variables, although higher alcohol intake and older age were associated with lower odds of ULT initiation but were not associated with flares. ULT was initiated in 27.7% (95%CI 27.3-28.0%): 5.7% (95%CI 5.5-5.9%) within 12 months of diagnosis. ULT initiation rates were higher in patients with recurrent flares.

CONCLUSION

Approximately one in six people with incident gout had a second flare within 12 months. Factors associated with flare recurrence and ULT initiation were similar, but ULT initiation occurred later after diagnosis than previously thought.

One- and 2-year flare rates after treat-to-target and tight-control therapy of gout: results from the NOR-Gout study

OBJECTIVES

To explore the frequency and predictors of flares over 2 years during a treat-to-target strategy with urate-lowering therapy (ULT) in patients with gout.

METHODS

In the treat-to-target, tight control NOR-Gout study patients started ULT with escalating doses of allopurinol. Flares were recorded over 2 years. Baseline predictors of flares during months 9-12 in year 1 and during year 2 were analyzed by multivariable logistic regression.

RESULTS

Of 211 patients included (mean age 56.4 years, disease duration 7.8 years, 95% males), 81% (150/186) of patients experienced at least one gout flare during the first year and 26% (45/173) during the second year. The highest frequency of flares in the first year was seen during months 3-6 (46.8% of patients). Baseline crystal depositions detected by ultrasound and by dual-energy computed tomography (DECT) were the only variables which predicted flares both during the first period of interest at months 9-12 (OR 1.033; 95% CI 1.010-1.057, and OR 1.056; 95% CI 1.007-1.108) and also in year 2. Baseline subcutaneous tophi (OR 2.42, 95% CI 1.50-5.59) and prior use of colchicine at baseline (OR 2.48, 95% CI 1.28-4.79) were independent predictors of flares during months 9-12, whereas self-efficacy for pain was a protective predictor (OR 0.98 per unit, 95% CI 0.964-0.996).

CONCLUSIONS

In patients with gout, flares remain frequent during the first year of a treat-to-target ULT strategy, especially during months 3-6, but are much less frequent during year 2. Baseline crystal depositions predict flares over 2 years, supporting ULT early during disease course.

TRIAL REGISTRATION

ACTRN12618001372279.

Tofacitinib for the treatment of rheumatoid arthritis: a real-world study in China

Tofacitinib has only been available in China for 2 years to treat rheumatoid arthritis (RA). Our purpose was to compare real-world effectiveness of tofacitinib with that of disease-modifying anti-rheumatic drugs (DMARDs) in Chinese patients with RA. The records of patients with RA treated at Guangdong Provincial People's Hospital between July 2017 and September 2019 were retrospectively reviewed. Patients were divided into those treated with tofacitinib, biological DMARDs (bDMARDs), and conventional synthetic DMARDs (csDMARDs). Clinical disease activity index (CDAI), simplified disease activity index (SDAI), health assessment questionnaire-disability index (HAQ-DI), visual analog scale (VAS) pain score, patient global assessment of disease activity (PtGA), physician global assessment of disease activity (PhGA), and swollen joint and tender joint count were compared among the groups up to 12 months of treatment. A total of 150 patients were included: 63 were treated with tofacitinib, 48 with bDMARDs, and 39 with csDMARDs. Tofacitinib was first-line treatment in 26.98% of patients, second-line treatment in 49.21%, and third-line treatment in 26.98%. Patients in the tofacitinib group had significantly higher disease duration (6.11 ± 6.97 years) than those in the other groups. All disease indices in the three groups decreased with time, indicating improvement of symptoms, with no differences among the groups at 12 months. Tofacitinib appeared to improve symptoms more rapidly than other treatments; however, differences in disease indices were not significant. This real-world study suggests that tofacitinib is rapidly effective and that the effects are sustained after 12 months in Chinese patients with RA.

Remission in Gout: Concepts From a Patient Perspective

Any human who has ever experienced an acute gout flare understands how painful and debilitating this condition is. Unfortunately, due to the episodic nature of these acute flares that occur randomly due to transient fluctuations in urate levels, patients often underreport these attacks.

Association between serum urate and flares in people with gout and evidence for surrogate status: a secondary analysis of two randomised controlled trials

BACKGROUND

Use of serum urate as a treatment target and outcome measure has become controversial in view of the 2017 American College of Physicians guidelines, which advocated a treat-to-symptom rather than a treat-to-target serum urate approach to gout management. The relevance of serum urate as a treatment target measure implies that achievement of target serum urate is causally associated with improvement in patient-important outcomes such as reduction in the number of gout flares. The aim of this study was to assess the causal relationship between achieving target serum urate and the occurrence of gout flares.

METHODS

We analysed individual patient-level data from two randomised trials on urate-lowering therapies in people with gout conducted in Nottingham, UK, and New Zealand. We included participants randomly assigned to immediate dose escalation in the New Zealand study and all participants in the Nottingham study (a nurse-led gout care group and a general practitioner-led usual care group). Individuals who on average achieved a serum urate concentration less than 6 mg/dL (0·36 mmol/L) based on data at 6, 9, and 12 months post-baseline were defined as serum urate responders. The primary outcome was the proportion of participants having at least one gout flare, and the secondary outcome was the mean number of flares per participant per month, from 12 to 24 months after baseline, compared between serum urate responders and non-responders. In adjusted logistic regression models, serum urate at baseline, previous flare history (in the year preceding study entry), presence of tophi at baseline, and, for the Nottingham dataset, the original randomisation group, were included as covariates. The Nottingham study was registered with ClinicalTrials.gov, NCT01477346. The New Zealand study was registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000845932.

FINDINGS

From the combined individual data from both trials, we identified 343 serum urate responders and 245 serum urate non-responders. Significantly fewer serum urate responders had a gout flare than did serum urate non-responders between 12 and 24 months (91 [27%] of 343 vs 156 [64%] of 245; adjusted odds ratio [OR] 0·29 [95% CI 0·17 to 0·51], p<0·0001). The mean number of flares per participant per month between 12 and 24 months was significantly lower in serum urate responders than in serum urate non-responders (adjusted mean difference -1·41 [95% CI -1·77 to -1·04], p<0·0001). This association was independent of the original randomised treatment allocation.

INTERPRETATION

Achieving an average serum urate concentration less than 6 mg/dL is associated with an absence of gout flares and a reduction in the number of flares in the subsequent 12 months in people with gout. These results support a treat-to-target serum urate approach in the management of gout.

FUNDING

None.

Which Attributes Are Most and Least Important to Patients When Considering Gout Flare Burden Over Time? A Best-worst Scaling Choice Study

OBJECTIVE

Several factors contribute to the patient experience of gout flares, including pain intensity, duration, frequency, and disability. It is unknown which of these factors are most important to patients when considering flare burden over time, including those related to the cumulative experience of all flares, or the experience of a single worst flare. This study aimed to determine which flare attributes are the most and least important to the patient experience of flare burden over time.

METHODS

Participants with gout completed an anonymous online survey. Questions were aimed at identifying which attributes of gout flares, representing both individual and cumulative flare burden, were the most and least important over a hypothetical 6-month period. A best-worst scaling method was used to determine the importance hierarchy of the included attributes.

RESULTS

Fifty participants were included. Difficulty doing usual activities during the worst flare and pain of the worst flare were ranked as the most important, whereas average pain of all flares was considered the least important. Overall, attributes related to the single worst gout flare were considered more important than attributes related to the cumulative impact of all flares.

CONCLUSION

When thinking about the burden of gout flares over time, patients rank activity limitation and pain experienced during their worst gout flare as the most important contributing factors, whereas factors related to the cumulative impact of all flares over time are relatively less important.

The challenge of gout flare measurement

Gout flares are central to the patient experience of gout and are included in the Outcome Measures in Rheumatology (OMERACT) core outcome domain set for long-term gout studies. Although a valid definition for gout flare has been developed, there is no consensus around how flare outcomes are measured and reported in long-term clinical studies. Current methods of flare measurement, which are centered on measuring flares as a binary outcome (i.e., present vs absent), do not reflect the variable pattern of flares over time, nor the multidimensional patient experience of gout flares which include factors related to pain severity, functional disability, impact on family and social life, and psychological wellbeing. This review will discuss the importance and challenges of gout flare measurement.

What Represents Treatment Efficacy in Long-term Studies of Gout Flare Prevention? An Interview Study of People With Gout

OBJECTIVE

The patient experience of gout flares is multidimensional, with several contributing factors including pain intensity, duration, and frequency. There is currently no consistent method for reporting gout flare burden in long-term studies. This study aimed to determine which factors contribute to patient perceptions of treatment efficacy in long-term studies of gout flare prevention.

METHODS

This study involved face-to-face interviews with people with gout using visual representations of gout flare patterns. Participants were shown different flare scenarios over a hypothetical 6-month treatment period that portrayed varying flare frequency, pain intensity, and flare duration. The participants were asked to indicate and discuss which scenario they believed was most indicative of successful treatment over time. Quantitative data relating to the proportion of participants selecting each scenario were reported using descriptive statistics. A qualitative descriptive approach was used to code and categorize the data from the interview transcripts.

RESULTS

Twenty-two people with gout participated in the semistructured interviews. All 3 factors of pain intensity, flare duration, and flare frequency influenced participants' perception of treatment efficacy. However, a shorter flare duration was the most common indicator of successful treatment, with half of participants (n = 11, 50%) selecting the scenario with a shorter flare duration over those with less painful flares.

CONCLUSION

Flare duration, flare frequency, and pain severity are all taken into account by patients with gout when considering treatment efficacy over time. Long-term studies of gout should ideally capture all these factors to better represent patients' experience of treatment success.

Cost-Effectiveness of Colchicine Prophylaxis for Gout Flares When Commencing Allopurinol

OBJECTIVE

Colchicine prophylaxis to prevent gout flares when commencing urate-lowering therapy is recommended by international rheumatology society guidelines. Whether this is a cost-effective intervention is currently unknown. Our objective was to perform a cost-effectiveness analysis using both a US cost input model and an Australian cost input model.

METHODS

This cost-effectiveness analysis was completed from the point of view of the third-party payer. We used a 2-arm decision tree with 1 arm commencing allopurinol with no colchicine prophylaxis and the other with colchicine prophylaxis. Model inputs were drawn from published literature where available. We completed a univariate and probabilistic sensitivity analysis to confirm the robust nature of the modeling. The time frame for the model was 6 months.

RESULTS

The colchicine prophylaxis arm resulted in a cost of $1,276 and 0.49 quality-adjusted life-years (QALYs), while in the placebo arm the cost was $516 and 0.47 QALYs, with an incremental cost-effectiveness ratio of $34,004 per QALY gained. In Australia, where cost of colchicine was much lower, the colchicine arm dominated the placebo ($208 [Australian] in the colchicine arm versus $415 [Australian] in the placebo). Univariate and probability sensitivity analysis demonstrated that results were robust to changes in input parameters. In the probabilistic sensitivity analysis, the probability of colchicine prophylaxis being the most cost-effective option was 93% in the US and 100% in the Australian setting.

CONCLUSION

Colchicine prophylaxis to prevent gout flares while commencing allopurinol in gout is very cost-effective.

Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) common language definition of gout

Objective

To develop a Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) common language definition of gout, with the goal of increasing public understanding and awareness, and ensure consistent and understandable messages about gout.

Methods

A G-CAN working group that included patients, physicians and nongovernmental organisation (NGO) representatives was formed to develop a common language definition of gout for use with the public, media, healthcare providers and stakeholders. A literature search and interviews with patients, healthcare workers and stakeholders informed development of the definition. Following consultation with G-CAN members and partners, the definition was endorsed by the G-CAN board.

Results

The G-CAN common language definition of gout describes the epidemiology, pathophysiology, symptoms and impact, risk factors, comorbidities, management and healthcare and workforce considerations. Detailed information is provided to support the content of the definition. After the publication of the English-language version, the definition will be available for translation into other languages by G-CAN members.

Conclusion

G-CAN has developed a concise and easily understandable statement describing gout in language that can be used in conversations with the lay public, media, NGOs, funders, healthcare providers and other stakeholders.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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