Nicola Dalbeth

2012 American College of Rheumatology Guidelines for Management of Gout. Part 1: Systematic Nonpharmacologic and Pharmacologic Therapeutic Approaches to Hyperuricemia

DINESH KHANNA, JOHN D. FITZGERALD, PUJA P. KHANNA, SANGMEE BAE, MANJIT K. SINGH, TUHINA NEOGI, MICHAEL H. PILLINGER, JOAN MERILL, SUSAN LEE, SHRADDHA PRAKASH, MARIAN KALDAS, MANEESH GOGIA, FERNANDO PEREZ-RUIZ, WILL TAYLOR, FREDERIC LIOTE, HYON CHOI, JASVINDER A. SINGH, NICOLA DALBETH, SANFORD KAPLAN, VANDANA NIYYAR, DANIELLE JONES, STEVEN A. YAROWS, BLAKE ROESSLER, GAIL KERR, CHARLES KING, GERALD LEVY, DANIEL E. FURST, N. LAWRENCE EDWARDS, BRIAN MANDELL, H. RALPH SCHUMACHER, MARK ROBBINS, NEIL WENGER, AND ROBERT TERKELTAUB

2012 American College of Rheumatology guidelines for management of gout. Part 2: Therapy and antiinflammatory prophylaxis of acute gouty arthritis

In response to a request for proposal from the American College of Rheumatology (ACR), our group was charged with developing non-pharmacologic and pharmacologic guidelines for treatments in gout that are safe and effective, i.e., with acceptable risk-benefit ratio. These guidelines for the management and anti-inflammatory prophylaxis of acute attacks of gouty arthritis complements our manuscript on guidelines to treat hyperuricemia in patients with evidence of gout (or gouty arthritis) (1). Gout is the most common cause of inflammatory arthritis in adults in the USA. Clinical manifestations in joints and bursa are superimposed on top of local deposition of monosodium urate crystals. Acute gout characteristically presents as self-limited, attack of synovitis (also called “gout flares”). Acute gout attacks account for a major component of the reported decreased health-related quality of life in patients with gout (2, 3). Acute gout attacks can be debilitating and are associated with decreased work productivity (4, 5). Urate lowering therapy (ULT) is a cornerstone in the management of gout, and, when effective in lowering serum urate (SUA), is associated with decreased risk of acute gouty attacks (6). However, during the initial phase of ULT, there is an early increase in acute gout attacks, which has been hypothesized due to remodeling of articular urate crystal deposits as a result of rapid and substantial lowering of ambient urate concentrations (7). Acute gout attacks attributable to the initiation of ULT may contribute to non-adherence in long-term gout treatment, as reported in recent studies (8). In order to systematically evaluate a broad spectrum of acute gouty arthritis, we generated multifaceted case scenarios to elucidate decision making based primarily on clinical and laboratory test-based data that can be obtained in a gout patient by both non-specialist and specialist health care providers in an office practice setting. This effort was not intended to create a novel classification system of gout, or new gout diagnostic criteria, as such endeavors are beyond the scope of this work. Prior gout recommendations and guidelines, at the independent (i.e, non pharmaceutical industry-sponsored) national or multinational rheumatology society level, have been published by EULAR (9, 10), the Dutch College of General Practitioners (11), and the British Society for Rheumatology (BSR)(12). The ACR requested new guidelines, in view of the increasing prevalence of gout (13), the clinical complexity of management of gouty arthritis imposed by co-morbidities common in gout patients (14), and increasing numbers of treatment options via clinical development of agents(15–17). The ACR charged us to develop these guidelines to be useful for both rheumatologists and other health care providers on an international level. As such, this process and resultant recommendations, involved a diverse and international panel of experts. In this manuscript, we concentrate on 2 of the 4 gout domains that the ACR requested for evaluation of pharmacologic and non-pharmacologic management approaches: (i) analgesic and anti-inflammatory management of acute attacks of gouty arthritis, and (ii) pharmacologic anti-inflammatory prophylaxis of acute attacks of gouty arthritis. Part I of the guidelines focused on systematic non-pharmacologic measures (patient education, diet and lifestyle choices, identification and management of co-morbidities) that impact on hyperuricemia, and made recommendations on pharmacologic ULT in a broad range of case scenarios of patients with disease activity manifested by acute and chronic forms of gouty arthritis, including chronic tophaceous gouty arthropathy(1). Each individual and specific statement is designated as a “recommendation”, in order to reflect the non-prescriptive nature of decision making for the hypothetical clinical scenarios. So that the voting panel could focus on gout treatment decisions, a number of key assumptions were made, as described in Part I of the guidelines (1). Importantly, each proposed recommendation assumed that correct diagnoses of gout and acute gouty arthritis attacks had been made for the voting scenario in question. For treatment purposes, it was also assumed that treating clinicians were competent, and considered underlying medical comorbidities (including diabetes, gastrointestinal disease, hypertension, and hepatic, cardiac, and renal disease), and potential drug toxicities and drug-drug interactions, when making both treatment choicesand dosing decisions on chosen pharmacologic interventions. The RAND/UCLA methodology used here emphasizes level of evidence, safety, and quality of therapy, and excludes analyses of societal cost of health care. As such, the ACR gout guidelines are designed to reflect best practice, supported either by level of evidence or consensus-based decision-making. These guidelines cannot substitute for individualized, direct assessment of the patient, coupled with clinical decision making by a competent health care practitioner. The motivation, financial circumstances, and preferences of the gout patient also need to be considered in clinical practice, and it is incumbent on the treating clinician to weigh the issues not addressed by this methodology, such as treatment costs, when making management decisions. Last, the guidelines for gout management presented herein were not designed to determine eligibility for health care cost coverage by third party payers.

Starting dose is a risk factor for allopurinol hypersensitivity syndrome: A proposed safe starting dose of allopurinol

OBJECTIVE Allopurinol is the most commonly used urate-lowering therapy in gout. Allopurinol hypersensitivity syndrome (AHS) is a rare but potentially fatal adverse event. Dosing guidelines based on creatinine clearance have been proposed based on the recognition that dosages of ≥300 mg/day may be associated with AHS, particularly in patients with renal impairment. However, the relationship between the allopurinol starting dose and AHS is unknown. This study was undertaken to determine the relationship between allopurinol dosing and AHS. METHODS A retrospective case-control study of patients with gout who developed AHS between January 1998 and September 2010 was undertaken. For each case, 3 controls with gout who were receiving allopurinol but did not develop AHS were identified. Controls were matched with cases for sex, diuretic use at the time of initiating allopurinol, age (±10 years), and estimated glomerular filtration rate (estimated GFR). Starting dose and dose at the time of the reaction in cases were compared between cases and controls. RESULTS Fifty-four AHS cases and 157 controls were identified. There was an increase in the risk of AHS as the starting dose of allopurinol corrected for the estimated GFR increased. For the highest quintile of starting dose per estimated GFR, the odds ratio was 23.2 (P < 0.01). Receiver operating characteristic analysis indicated that 91% of AHS cases and 36% of controls received a starting dose of allopurinol of ≥1.5 mg per unit of estimated GFR (mg/ml/minute). CONCLUSION Our findings indicate that starting allopurinol at a dose of 1.5 mg per unit of estimated GFR may be associated with a reduced risk of AHS. In patients who tolerate allopurinol, the dose can be gradually increased to achieve the target serum urate level.

Cellular characterization of the gouty tophus: A quantitative analysis

OBJECTIVE To characterize the cellular architecture of the tophus and to determine the presence of cytokines implicated in the initiation and resolution of gouty inflammation. METHODS Sixteen fixed, paraffin-embedded, uninfected tophus samples were surgically obtained from 12 patients with microscopically proven gout and were analyzed by quantitative immunohistochemistry. The number of cells present in the corona and fibrovascular zones of the tophus was analyzed by Genmod mixed models analysis. RESULTS Numerous CD68+ mononucleated and multinucleated cells were present within the corona zone. Mast cells were identified in all tophus samples and at similar densities throughout the corona and fibrovascular zones. In contrast, neutrophils were rarely observed. Plasma cells were present in very high numbers within the corona zone. The overall number of CD20+ B cells was much lower. However, in 6 of 12 patients (50%), at least 1 B cell aggregate was present in the fibrovascular zone. Large numbers of cells expressing interleukin-1beta (IL-1beta) were observed in the corona zone. Transforming growth factor beta1 (TGFbeta1)-expressing mononucleated cells were also identified. The number of CD68+ cells correlated with the number of cells expressing IL-1beta (r = 0.691, P = 0.009) and the number expressing TGFbeta1 (r = 0.518, P = 0.04). CONCLUSION The tophus represents a complex and organized chronic inflammatory tissue response to monosodium urate monohydrate crystals involving both innate and adaptive immune cells. The coexpression of IL-1beta and TGFbeta1 suggests that both proinflammatory and antiinflammatory factors present within the tophus contribute to a cycle of chronic inflammation, attempted resolution, and tissue remodeling.

Allopurinol Dosing in Renal Impairment: Walking the Tightrope Between Adequate Urate Lowering and Adverse Events

Allopurinol is the mainstay of urate‐lowering therapy for patients with gout and impaired renal function. Although rare, a life‐threatening hypersensitivity syndrome may occur with this drug. The risk of this allopurinol hypersensitivity syndrome (AHS) is increased in renal impairment. The recognition that AHS may be because of delayed‐type hypersensitivity to oxypurinol, the main metabolite of allopurinol, and that oxypurinol concentrations are frequently elevated in patients with renal impairment prescribed standard doses of allopurinol has led to the widespread adoption of allopurinol‐dosing guidelines. These guidelines advocate allopurinol dose reduction according to creatinine clearance in patients with renal impairment. However, recent studies have challenged the role of these guidelines, suggesting that AHS may occur even at low doses of allopurinol, and that these guidelines lead to under‐treatment of hyperuricemia, a key therapeutic target in gout. Based on current data, we advocate gradual introduction of allopurinol according to current treatment guidelines, with close monitoring of serum uric acid concentrations. In patients with severe disease and persistent hyperuricemia, allopurinol dose escalation above those recommended by the guidelines should be considered, with careful evaluation of the benefits and risks of therapy. Further work is needed to clarify the safety and efficacy of allopurinol dose escalation, particularly in patients with renal impairment.

Mechanisms of bone erosion in gout; a quantitative analysis using plain radiography and computed tomography.

Objective: The underlying basis of bone erosion in gout remains speculative. The aim of this study was to understand the mechanisms of bone erosion in gout using non-invasive imaging techniques. Methods: Paired plain radiographs and computed tomography (CT) scans of 798 individual hand and wrist joints from 20 patients with gout were analysed. Radiographs were scored for erosion (0–5) using the Sharp/van der Heijde method. CT scans were scored for the presence and diameter of bone erosions and tophi. The presence of intraosseous tophus (tophus visualised within bone) was recorded. The relationships between radiographic erosion, CT erosion and tophus scores were analysed. Results: With increasing radiographic erosion scores, the percentage of joints with intraosseous tophus increased (p<0.001). For those joints with a radiographic erosion score of 4 or 5, 96/98 (98%) had CT evidence of intraosseous tophus. There was a significant relationship between the radiographic erosion scores and intraosseous tophus size (p<0.001). For those joints with CT erosion, 194/237 (81.8%) had visible intraosseous tophus. Of the joints with CT erosions greater than 5 mm, 106/112 (94.6%) had visible intraosseous tophus and all (56/56) erosions greater than 7.5 mm had intraosseous tophus. There was a strong correlation between CT erosion diameter and intraosseous tophus diameter (r  =  0.93, p<0.001). Intraosseous tophi were larger than non-intraosseous tophi, but had similar density and calcification. Conclusion: There is a strong relationship between bone erosion and the presence of intraosseous tophus. These results strongly implicate tophus infiltration into bone as the dominant mechanism for the development of bone erosion and joint damage in gout.

Cellular characterisation of magnetic resonance imaging bone oedema in rheumatoid arthritis; implications for pathogenesis of erosive disease

OBJECTIVES Magnetic resonance imaging (MRI) bone oedema is an important predictor of bone erosion in rheumatoid arthritis (RA). This study aimed to determine the cellular components of MRI bone oedema, and clarify the relationship between bone erosion and MRI bone oedema. METHODS Twenty-eight bones from 11 patients with RA undergoing orthopaedic surgery were analysed by quantitative and semi-quantitative immunohistochemistry. Pre-operative contrast-enhanced MRI scans were analysed for bone oedema. RESULTS The density of osteoclasts was higher in those samples with MRI bone oedema than those without MRI bone oedema (p = 0.01). Other cells identified within bone marrow included macrophages and plasma cells, and these were more numerous in samples with MRI bone oedema (p = 0.02 and 0.05 respectively). B cells were present in lower numbers, but B cell aggregates were identified in some samples with MRI bone oedema. There was a trend to increased RANKL expression in samples with MRI bone oedema (p = 0.09). Expression of RANKL correlated with the number of osteoclasts (r = 0.592, p = 0.004). CONCLUSIONS The increased number of osteoclasts and RANKL expression in samples with MRI bone oedema supports the hypothesis that bone erosion in RA occurs through activation of local bone resorption mechanisms within subchondral bone as well as through synovial invasion into bone.

2015 Gout Classification Criteria: An American College of Rheumatology/European League Against Rheumatism Collaborative Initiative

Existing criteria for the classification of gout have suboptimal sensitivity and/or specificity, and were developed at a time when advanced imaging was not available. The current effort was undertaken to develop new classification criteria for gout.

The genetic basis of hyperuricaemia and gout

Gout results from elevated urate concentrations in the blood (hyperuricaemia). When super-saturation of urate is reached, monosodium urate crystals form within the joint. In some individuals, these crystals elicit a painful self-limiting inflammatory response that is characteristic of acute gouty arthritis. The most important cause of hyperuricaemia is reduced excretion of uric acid in the urine. Uric acid excretion is coordinated by a suite of urate transport molecules expressed in the renal collecting tubules, and is a key physiological checkpoint in gout. Other checkpoints in gout are hepatic production of urate, monosodium urate crystal formation, and initiation of the acute inflammatory response. Genome-wide association scans for genes regulating serum urate concentrations have identified two major regulators of hyperuricaemia- the renal urate transporters SLC2A9 and ABCG2. The risk variants at each gene approximately double the risk for gout in people of Caucasian ancestry, with SLC2A9 also resulting in higher risk for gout in people of Polynesian ancestry, a diverse population characterized by a high prevalence of gout. Ongoing genetic association studies are identifying and confirming other genes controlling serum urate concentrations; although genome-wide association studies in gout per se await recruitment of suitable case sample sets.

The Experience and Impact of Living With Gout A Study of Men With Chronic Gout Using a Qualitative Grounded Theory Approach

Background:Gout is commonly undertreated and can lead to significant disability. Few data are available about the lived experience of gout or the barriers to effective urate-lowering therapy in men with gout. Aims:This study aims to understand the experience of men living with chronic gout using a qualitative grounded theory approach. Methods:Eleven English-speaking men with chronic gout participated in an in-depth semistructured interview about their experiences of living with gout. Interviews were recorded and transcribed. Consensus groups were used to analyze and validate the themes arising from the transcripts. Results:Three major themes related to the experience of gout emerged from the interviews: the impact of disease (pain, dependency on family members during flares, isolation, work disability), the progressiveness of untreated gout (increasing number of affected joints and frequency of flares, increase in food type triggers, escalating treatment required to control flares due to reducing efficacy of anti-inflammatory medication), and the lack of knowledge of gout (a community wide lack of understanding of the causes or prevention of gout, stoicism/tolerance to symptoms and disability, personal and social stigma related to gout). Discussion:Chronic gout has an important impact on both the patient and his family. This work provides previously hidden perspectives of the experience of gout, which may be generalized to other men with gout, suggesting that shame, embarrassment, and stigma lead to trivialization of the impact of disease despite its severity. These experiences may lead to undertreatment of gout because of lack of disclosure of symptom severity and lack of expectation of treatment effectiveness, which in turn could contribute to the development of progressive gout.