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Item does not contain fulltext OBJECTIVE: To determine whether a gout polygenic risk score (PRS) is associated with age at gout onset and tophaceous disease in European, East Polynesian, and West Polynesian men and women with gout. METHODS: A 19-variant gout PRS was produced in 7 European gout cohorts (N = 4,016), 2 East Polynesian gout cohorts (N = 682), and 1 West Polynesian gout cohort (N = 490). Sex-stratified regression models were used to estimate the relationship between the PRS and age at gout onset and tophaceous disease. RESULTS: The PRS was associated with earlier age at gout onset in men (β = -3.61 in years per unit PRS [95% confidence interval (95% CI) -4.32, -2.90] in European men; β = -6.35 [95% CI -8.91, -3.80] in East Polynesian men; β = -3.51 [95% CI -5.46, -1.57] in West Polynesian men) but not in women (β = 0.07 [95% CI -2.32, 2.45] in European women; β = 0.20 [95% CI -7.21, 7.62] in East Polynesian women; β -3.33 [95% CI -9.28, 2.62] in West Polynesian women). The PRS showed a positive association with tophaceous disease in men (odds ratio [OR] for the association 1.15 [95% CI 1.00, 1.31] in European men; OR 2.60 [95% CI 1.66, 4.06] in East Polynesian men; OR 1.53 [95% CI 1.07, 2.19] in West Polynesian men) but not in women (OR for the association 0.68 [95% CI 0.42, 1.10] in European women; OR 1.45 [95% CI 0.39, 5.36] in East Polynesian women). The PRS association with age at gout onset was robust to the removal of ABCG2 variants from the PRS in European and East Polynesian men (β = -2.42 [95% CI -3.37, -1.46] and β = -6.80 [95% CI -10.06, -3.55], respectively) but not in West Polynesian men (β = -1.79 [95% CI -4.74, 1.16]). CONCLUSION: Genetic risk variants for gout also harbor risk for earlier age at gout onset and tophaceous disease in European and Polynesian men. Our findings suggest that earlier gout onset involves the accumulation of gout risk alleles in men but perhaps not in women, and that this genetic risk is shared across multiple ancestral groups.

The genetic determinants of the allopurinol dose-concentration relationship have not been extensively studied. We aimed to clarify what factors, including genetic variation in urate transporters, influence oxypurinol pharmacokinetics (PKs). A population PK model for oxypurinol was developed with NONMEM (version 7.3). The influence of urate transporter genetic variants for ABCG2 (rs2231142 and rs10011796), SLC2A9/GLUT9 (rs11942223), SLC17A1/NPT1 (rs1183201), SLC22A12/URAT1 (rs3825018), SLC22A11/OAT4 (rs17300741), and ABCC4/MRP4 (rs4148500), as well as other participant factors on oxypurinol PKs was assessed. Data from 325 people with gout were available. The presence of the T allele for ABCG2 (rs2231142) and SLC17A1/NPT1 (rs1183201) was associated with a 24% and 22% increase in oxypurinol clearance, respectively, in univariate analysis. This effect was not significant in the multivariate analysis. In the final model, oxypurinol PKs were predicted by creatinine clearance, diuretic use, ethnicity, and body weight. We have found that genetic variability in the transporters examined does not appear to influence oxypurinol PKs.

OBJECTIVE: Classification criteria for calcium pyrophosphate deposition disease (CPPD) will facilitate clinical research on this common crystalline arthritis. We report on the first two phases of a four-phase process for developing CPPD classification criteria. METHODS: CPPD classification criteria development is overseen by a 12-member Steering Committee. Item generation (Phase I) included a scoping literature review of five literature databases and contributions from a 35-member Combined Expert Committee and two Patient Research Partners. Item reduction and refinement (Phase II) involved a Combined Expert Committee meeting, discussions among Clinical, Imaging, and Laboratory Advisory Groups, and an item rating exercise to assess the influence of individual items toward classification. The Steering Committee reviewed the modal rating score for each item (range -3 [strongly pushes away from CPPD] to +3 [strongly pushes toward CPPD]) to determine items to retain for future phases of criteria development. RESULTS: Item generation yielded 420 items (312 from the literature, 108 from experts/patients). The Advisory Groups eliminated items they agreed were unlikely to distinguish between CPPD and other forms of arthritis, yielding 127 items for the item rating exercise. Fifty-six items, most of which had a modal rating of +/- 2 or 3, were retained for future phases. As numerous imaging items were rated +3, the Steering Committee recommended focusing on imaging of the knee, wrist, and one additional affected joint for calcification suggestive of CPP crystal deposition. CONCLUSION: A data- and expert-driven process is underway to develop CPPD classification criteria. Candidate items comprise clinical, imaging, and laboratory features.

Gout is of particularly high prevalence in the Māori and Pacific (Polynesian) populations of Aotearoa New Zealand (NZ). Here, we investigated the contribution of common population-specific copy number variation (CNV) to gout in the Aotearoa NZ Polynesian population. Microarray-generated genome-wide genotype data from Aotearoa NZ Polynesian individuals with (n = 1196) and without (n = 1249) gout were analyzed. Comparator population groups were 552 individuals of European ancestry and 1962 of Han Chinese ancestry. Levels of circulating major histocompatibility complex (MHC) class I polypeptide-related sequence A (MICA) were measured by enzyme-linked immunosorbent assay. Fifty-four CNV regions (CNVRs) appearing in at least 10 individuals were detected, of which seven common (>2%) CNVRs were specific to or amplified in Polynesian people. A burden test of these seven revealed associations of insertion/deletion with gout (odds ratio (OR) 95% confidence interval [CI] = 1.80 [1.01; 3.22], P = 0.046). Individually testing of the seven CNVRs for association with gout revealed nominal association of CNVR1 with gout in Western Polynesian (Chr6: 31.36–31.45 Mb, OR = 1.72 [1.03; 2.92], P = 0.04), CNVR6 in the meta-analyzed Polynesian sample sets (Chr1: 196.75–196.92 Mb, OR = 1.86 [1.16; 3.00], P = 0.01) and CNVR9 in Western Polynesian (Chr1: 189.35–189.54 Mb, OR = 2.75 [1.15; 7.13], P = 0.03). Analysis of European gout genetic association data demonstrated a signal of association at the CNVR1 locus that was an expression quantitative trait locus for MICA. The most common CNVR (CNVR1) includes deletion of the MICA gene, encoding an immunomodulatory protein. Expression of MICA was reduced in the serum of individuals with the deletion. In summary, we provide evidence for the association of CNVR1 containing MICA with gout in Polynesian people, implicating class I MHC-mediated antigen presentation in gout.

The gouty tophus is an organized structure composed of monosodium urate (MSU) crystals and chronic inflammatory soft tissue. This dual energy CT (DECT) study aimed to determine whether the composition of the tophus changes during urate-lowering therapy.Serial DECT scans from 32 people with gout were obtained over two years of allopurinol therapy, dose-escalated to serum urate0.36mmol/L. Up to five index tophi were selected for each patient, with 103 separate tophi included in the analysis. Using manual outlining methods of conventional CT and DECT scans, the same index tophi were serially measured for total tophus volume and urate volume. For each tophus, the soft tissue volume was then calculated by subtracting the urate volume from the total tophus volume.The mean (SD) serum urate reduced from 0.43 (0.03) mmol/L at baseline to 0.31 (0.02) mmol/L at Year 2. The mean (SD) total tophus volume reduced over the two-year period; from 5.17 (5.55) cmThe composition of the tophus is dynamic and changes during urate-lowering therapy for gout management. The soft tissue component of the tophus is slower to respond and may persist without measurable MSU crystal deposition.

This study aimed to develop and evaluate an allopurinol adherence tool based on steady-state oxypurinol plasma concentrations, allopurinol's active metabolite.Plasma oxypurinol concentrations were simulated stochastically from an oxypurinol pharmacokinetic model for allopurinol doses of 100-800 mg daily, accounting for differences in renal function, diuretic use and ethnicity. For each scenario, the 20th percentile for peak and trough concentrations defined the adherence threshold, below which imperfect adherence was assumed. Predictive performance was evaluated using both simulated low adherence and against data from 146 individuals with paired oxypurinol plasma concentrations and adherence measures. Sensitivity and specificity (SS), negative and positive predictive values (NPV, PPV) and receiver operating characteristic (ROC) area under the curve (AUC) were determined. The predictive performance of the tool was evaluated using adherence data from an external study (CKD-FIX).The allopurinol adherence tool produced SS values for trough thresholds of 89-98% and 76-84%, respectively, and 90%-98% and 76-83% for peak thresholds. PPV and NPV were 79-84% and 88-94%, respectively, for trough and 80-85% and 89-98%, respectively, for peak concentrations. The ROC AUC values ranged from 0.84 to 0.88 and from 0.86 to 0.89 for trough and peak concentrations, respectively. SS values for the external evaluation were found to be 75.8% and 86.5%, respectively, producing an ROC AUC of 0.8113.A tool to identify people with gout who require additional support to maintain adherence using plasma oxypurinol concentrations was developed and evaluated. The predictive performance of the tool is suitable for adherence screening in clinical trials and may have utility in some clinical practice settings.

BackgroundThe Pacific-specific minor allele of rs373863828, a missense variant in CREB3 Regulatory Factor (CREBRF), is associated with several cardiometabolic phenotypes in Polynesian peoples, but the variant’s function remains poorly understood. To broaden our understanding of this variant, we used joint multivariate and network analyses to examine the relationships between rs373863828 and a panel of correlated anthropometric and lipid phenotypes.MethodsWe tested the association of rs373863828 with a panel of phenotypes (body mass index [BMI], weight, height, HDL cholesterol, triglycerides, and total cholesterol) under a multivariate Bayesian association model in a cohort from Samoa (N = 1 632), a Māori and Pacific Island (Polynesian) cohort from Aotearoa New Zealand (N = 1 419), and the combined cohort (N = 2 976). An expanded set of phenotypes (adding estimated fat and fat-free mass, abdominal circumference, hip circumference, and abdominal-hip ratio) was also tested in the Samoa cohort (N = 1 496). Bayesian networks were learned to further understand the structure of the relationships.ResultsIn the Samoa cohort, significant associations (log10 Bayes factor ≥5.0) were found between rs373863828 and the overall phenotype panel (7.97), weight (8.35) and BMI (6.39). In the Aotearoa New Zealand cohort, suggestive associations (log10 Bayes factor between 1.5 and 5) were found between rs373863828 and the overall phenotype panel (3.64), weight (3.30), and BMI (1.79). In the combined cohort, concordant signals with stronger magnitudes were observed. In the expanded phenotype analyses among the Samoa cohort, significant associations were also observed between rs373863828 and fat mass (5.68), abdominal circumference (5.37), and hip circumference (5.15).Bayesian networks provided evidence for a direct association of rs373863828 with weight and indirect associations with height and BMI.ConclusionsWhen correlation structures were considered, multivariate Bayesian analyses provided additional evidence of rs373863828’s pleiotropic effects and highlighted a strong direct effect only on weight.

Current understanding of lipid genetics has come mainly from studies in European-ancestry populations; limited effort has focused on Polynesian populations, whose unique population history and high prevalence of dyslipidemia may provide insight into the biological foundations of variation in lipid levels. Here we performed an association study to fine map a suggestive association on 5q35 with high-density lipoprotein cholesterol (HDL-C) seen in Micronesian and Polynesian populations. Fine-mapping analyses in a cohort of 2,851 Samoan adults highlighted an association between a stop-gain variant (rs200884524; c.652C>T, p.R218*; posterior probability = 0.9987) in BTNL9 and both lower HDL-C and greater triglycerides (TG). Meta-analysis across this and several other cohorts of Polynesian ancestry from Samoa, American Samoa, and Aotearoa New Zealand confirmed the presence of this association (βHDL-C = -1.60 mg/dL, pHDL-C = 7.63 × 10−10; βTG = 12.00 mg/dL, pTG = 3.82 × 10−7). While this variant appears to be Polynesian-specific, there is also evidence of association from other multi-ancestry analyses in this region. This work provides evidence of a previously unexplored contributor to the genetic architecture of lipid levels and underscores the importance of genetic analyses in understudied populations.

Current understanding of lipid genetics has come mainly from studies in European-ancestry populations; limited effort has focused on Polynesian populations, whose unique population history and high prevalence of dyslipidemia may provide insight into the biological foundations of variation in lipid levels. Here, we performed an association study to fine map a suggestive association on 5q35 with high-density lipoprotein cholesterol (HDL-C) seen in Micronesian and Polynesian populations. Fine-mapping analyses in a cohort of 2,851 Samoan adults highlighted an association between a stop-gain variant (rs200884524; c.652CT, p.R218∗; posterior probability = 0.9987) in

ObjectiveTo determine the long-term use of and adherence to urate-lowering therapy (ULT), serum urate (SU) control, and self-reported flares in participants from a randomized controlled trial of allopurinol dose escalation, in order to achieve target SU concentration (< 0.36 mmol/L) in people with gout.MethodsFor surviving study participants, ULT dispensing and SU testing within the preceding 12 months was obtained by medical record review. A phone interview was conducted to determine self-reported flares and adherence.ResultsOver a mean follow-up of 6.5 (SD 2.5) years since enrollment, 60 out of 183 (33%) participants had died. Review of the 119 surviving participants showed that 98 (82%) were receiving allopurinol, 5 (4%) were receiving febuxostat, and 10 (8%) were not receiving ULT; for the remaining 6 (5.0%), ULT use could not be determined. In those receiving allopurinol, the mean dose was 28.1 (range −600 to 500) mg/day lower than at the last study visit; 49% were receiving the same dose, 18% were on a higher dose, and 33% were on a lower dose than at the last study visit. SU values were available for 86 of the 119 (72%) participants; 50 out of 86 (58%) participants had an SU concentration of < 0.36 mmol/L. Of the 89 participants who participated in the phone interview, 19 (21%) reported a gout flare in the preceding 12 months and 79 (89%) were receiving allopurinol; 71 (90%) of those receiving allopurinol reported 90% or greater adherence.ConclusionMost of the surviving participants in the allopurinol dose escalation study had good real-world persistence with allopurinol, remained at target SU, and had a low number of self-reported flares.

Clinical questionsWhat is the role of plasma exchange and what is the optimal dose of glucocorticoids in the first 6 months of therapy of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)? This guideline was triggered by the publication of a new randomised controlled trial.Current practiceExisting guideline recommendations vary regarding the use of plasma exchange in AAV and lack explicit recommendations regarding the tapering regimen of glucocorticoids during induction therapy.RecommendationsThe guideline panel makes a weak recommendation against plasma exchange in patients with low or low-moderate risk of developing end stage kidney disease (ESKD), and a weak recommendation in favour of plasma exchange in patients with moderate-high or high risk of developing ESKD. For patients with pulmonary haemorrhage without renal involvement, the panel suggests not using plasma exchange (weak recommendation). The panel made a strong recommendation in favour of a reduced dose rather than standard dose regimen of glucocorticoids, which involves a more rapid taper rate and lower cumulative dose during the first six months of therapy.How this guideline was createdA guideline panel including patients, a care giver, clinicians, content experts, and methodologists produced these recommendations using GRADE and in adherence with standards for trustworthy guidelines. The recommendations are based on two linked systematic reviews. The panel took an individual patient perspective in the development of recommendations.The evidenceThe systematic review of plasma exchange identified nine randomised controlled trials (RCTs) that enrolled 1060 patients with AAV. Plasma exchange probably has little or no effect on mortality or disease relapse (moderate and low certainty). Plasma exchange probably reduces the one year risk of ESKD (approximately 0.1% reduction in those with low risk, 2.1% reduction in those with low-moderate risk, 4.6% reduction in those with moderate-high risk, and 16.0% reduction in those with high risk or requiring dialysis) but increases the risk of serious infections (approximately 2.7% increase in those with low risk, 4.9% increase in those with low-moderate risk, 8.5% increase in those with moderate-high risk, to 13.5% in high risk group) at 1 year (moderate to high certainty). The guideline panel agreed that most patients with low or low-moderate risk of developing ESKD would consider the harms to outweigh the benefits, while most of those with moderate-high or high risk would consider the benefits to outweigh the harms. For patients with pulmonary haemorrhage without kidney involvement, based on indirect evidence, plasma exchange may have little or no effect on death (very low certainty) but may have an important increase in serious infections at 1 year (approximately 6.8% increase, low certainty). The systematic review of different dose regimens of glucocorticoids identified two RCTs at low risk of bias with 704 and 140 patients respectively. A reduced dose regimen of glucocorticoid probably reduces the risk of serious infections by approximately 5.9% to 12.8% and probably does not increase the risk of ESKD at the follow-up of 6 months to longer than 1 year (moderate certainty for both outcomes).Understanding the recommendationThe recommendations were made with the understanding that patients would place a high value on reduction in ESKD and less value on avoiding serious infections. The panel concluded that most (50-90%) of fully informed patients with AAV and with low or low-moderate risk of developing ESKD with or without pulmonary haemorrhage would decline plasma exchange, whereas most patients with moderate-high or high risk or requiring dialysis with or without pulmonary haemorrhage would choose to receive plasma exchange. The panel also inferred that the majority of fully informed patients with pulmonary haemorrhage without kidney involvement would decline plasma exchange and that all or almost all (≥90%) fully informed patients with AAV would choose a reduced dose regimen of glucocorticoids during the first 6 months of therapy.

Two recent randomized clinical trials of escalating doses of allopurinol for the progression of chronic kidney disease (CKD) reported no benefits but potentially increased risk for death. Whether the risk could occur in patients with gout and concurrent CKD remains unknown.To examine the relation of allopurinol initiation, allopurinol dose escalation, and achieving target serum urate (SU) level after allopurinol initiation to all-cause mortality in patients with both gout and CKD.Cohort study.The Health Improvement Network U.K. primary care database (2000 to 2019).Patients aged 40 years or older who had gout and concurrent moderate-to-severe CKD.The association between allopurinol initiation and all-cause mortality over 5-year follow-up in propensity score (PS)-matched cohorts was examined. Analysis of hypothetical trials were emulated: achieving target SU level (0.36 mmol/L) versus not achieving target SU level and dose escalation versus no dose escalation for mortality over 5-year follow-up in allopurinol initiators.Mortality was 4.9 and 5.8 per 100 person-years in 5277 allopurinol initiators and 5277 PS-matched noninitiators, respectively (hazard ratio [HR], 0.85 [95% CI, 0.77 to 0.93]). In the target trial emulation analysis, the HR of mortality for the achieving target SU level group compared with the not achieving target SU level group was 0.87 (CI, 0.75 to 1.01); the HR of mortality for allopurinol in the dose escalation group versus the no dose escalation group was 0.88 (CI, 0.73 to 1.07).Residual confounding cannot be ruled out.In this population-based data, neither allopurinol initiation, nor achieving target SU level with allopurinol, nor allopurinol dose escalation was associated with increased mortality in patients with gout and concurrent CKD.Project Program of National Clinical Research Center for Geriatric Disorders.

Background Features of new bone formation (NBF) are common in tophaceous gout. The aim of this project was to develop a plain radiographic scoring system for NBF in gout. Methods Informed by a literature review, scoring systems were tested in 80 individual 1st and 5th metatarsophalangeal joints. Plain radiography scores were compared with computed tomography (CT) measurements of the same joints. The best-performing scoring system was then tested in paired sets of hand and foot radiographs obtained over 2 years from an additional 25 patients. Inter-reader reproducibility was assessed using intraclass correlation coefficients (ICC). NBF scores were correlated with plain radiographic erosion scores (using the gout-modified Sharp-van der Heijde system). Results Following a series of structured reviews of plain radiographs and scoring exercises, a semi-quantitative scoring system for sclerosis and spur was developed. In the individual joint analysis, the inter-observer ICC (95% CI) was 0.84 (0.76–0.89) for sclerosis and 0.81 (0.72–0.87) for spur. Plain radiographic sclerosis and spur scores correlated with CT measurements (r = 0.65–0.74, P < 0.001 for all analyses). For the hand and foot radiograph sets, the inter-observer ICC (95% CI) was 0.94 (0.90–0.98) for sclerosis score and 0.76 (0.65–0.84) for spur score. Sclerosis and spur scores correlated highly with plain radiographic erosion scores (r = 0.87 and 0.71 respectively), but not with change in erosion scores over 2 years (r = −0.04–0.15). Conclusion A semi-quantitative plain radiographic scoring method for the assessment of NBF in gout is feasible, valid, and reproducible. This method may facilitate consistent measurement of NBF in gout.

IntroductionRheumatoid arthritis (RA) affects approximately 0.5%–1% of the general population. Clinically significant interstitial lung diseases (ILD) develops in just under 10% of people with RA, and subclinical disease is more common. Little is known about RA-ILD in New Zealand (NZ), or the number of persons with RA in Canterbury, NZ. This study aims to determine: (1) incidence and prevalence of RA, (2) incidence and prevalence of RA-ILD, (3) clinical characteristics and risk factors for the development of RA-ILD, (4) long-term outcomes of RA-ILD, in the population resident within the Canterbury District Health Board (CDHB) catchment area.Methods and analysisPersons aged 18 years of age and older, and resident in the region covered by the CDHB with RA as well as RA-ILD will be identified by retrospective review of medical records. Prevalent as well as incident cases of RA between 1 January 2006 and 31 December 2008 and between 1 January 2011 and 31 December 2013 will be identified, and followed until 30 June 2019. Existing as well as incident cases of RA-ILD during this time will be identified. The association between the development of ILD and clinical characteristics and environmental exposures will be examined using Cox-proportional hazard models. Kaplan-Meier methods will be used to estimate survival rates for patients with RA-ILD. Mortality for people with RA and RA-ILD will also be compared with the general population of the CDHB.Ethics and disseminationData will be obtained by retrospective review of medical records. Deidentified patient data will be stored in a secure online database. Data on individual patients will not be released, and all results will only be published in aggregate. Ethical approval has been obtained from the University of Otago Human Research Ethics Committee (REF HD18/079). Results will be published in peer-reviewed medical journals and presented at conferences.Trial registration numberACTRN12619001310156; Pre-results.

The purpose of gout treatment is to alleviate symptoms of flares, prevent flares from recurring by lowering serum urate, and minimize structural joint damage and functional impairment. In recent years, several new medications to treat gout have been developed, and novel agents continue to be investigated, in addition to several long-established treatments. Although a number of effective therapies are available, optimal management and outcomes are frequently not achieved due to physician under prescribing of urate-lowering therapy (ULT) and poor adherence with therapy when it is prescribed. This article reviews recent developments in the management of gout with reference to recently published clinical guidelines, outlines some important questions regarding the safety and efficacy of particular agents, and remaining gaps in our knowledge about the most effective strategies for using currently available treatments.