Risk of urolithiasis associated with allopurinol versus benzbromarone among patients with gout: a population-based cohort study.

OBJECTIVES: To compare the risk of urolithiasis in gout patients initiating allopurinol, a xanthine oxidase inhibitor, vs benzbromarone, a uricosuric. METHODS: Using the 2011-2020 Korea National Health Insurance Service database, we conducted a cohort study on gout patients initiating allopurinol vs benzbromarone as the 1st-line urate-lowering treatment (ULT). The primary outcome was a new onset urinary stone. The secondary outcome was a stone requiring intervention. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazard models with a 5:1 ratio propensity-score matching on > 80 variables. Subgroup analyses were done by age, sex, thiazide use, and cardiovascular (CV) risk. RESULTS: 61 300 allopurinol initiators PS-matched on 12 260 benzbromarone initiators were included (mean age 59 years, 79% male). During a mean follow-up of 322 days, 619 urolithiasis cases occurred with an incidence rate of 0.87 per 100 person-years in allopurinol and 1.39 in benzbromarone initiators, showing a HR of 0.64 (95% CI, 0.51-0.80). ∼44% of urinary stones required intervention with a HR of 0.61 (95% CI 0.43-0.88). The lower risk associated with allopurinol compared with benzbromarone persisted across subgroups but was greater in the high than non-high CV risk subgroup (p for interaction = 0.02). CONCLUSION: This population-based cohort study found that allopurinol compared with benzbromarone was associated with a substantially lower risk of urolithiasis particularly in the presence of the high CV risk. This finding provides important safety information for clinicians' decision-making on ULTs of different mechanisms of action.

All-cause and cause-specific mortality in patients with Behçet disease versus the general population.

BACKGROUND: The comparative risk of cause-specific mortality in patients with Behçet disease (BD) vs. the general population is not known. OBJECTIVES: To compare the risk of all-cause and cause-specific mortality in patients with BD vs. the general population. METHODS: Using data from the Korea National Health Insurance Service database for the period 2002-20, we conducted a cohort study comparing patients with BD with the general population, matched according to age and sex (1 : 4 ratio). We used Cox proportional hazard models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality. Subgroup analyses by age and sex were done. RESULTS: We included 24 669 patients with BD and 98 676 age- and sex-matched controls [mean (SD) age 40.5 (12.9) years; 34% male]. During a mean follow-up of 11.9 years, the incidence rate (IR) of death per 100 person-years was 0.36 in patients with BD and 0.29 in controls [hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.20-1.38]. The risk of mortality was highest in the first year after BD diagnosis (HR 2.66, 95% CI 2.09-3.40). Patients with BD died more often in this period as a result of malignancy (HR 1.96, 95% CI 1.30-2.98); cardiovascular (HR 2.68, 95% CI 1.45-4.97), gastrointestinal (HR 3.50, 95% CI 1.35-9.07) and respiratory disease (HR 5.00, 95% CI 1.34-18.62); and infection (HR 3.33, 95% CI 1.02-10.92). Mortality as a result of neurological (HR 1.58, 95% CI 1.06-2.35) or genitourinary disease (HR 2.20, 95% CI 1.43-3.37) was also more common in patients with BD during the overall follow-up. Subgroup analyses showed consistent results. The risk of cardiovascular mortality vs. the general population was higher in younger patients (P = 0.006) and the risk of gastrointestinal mortality was increased in women vs. men (P = 0.04). CONCLUSIONS: This population-based cohort study revealed that the first year after diagnosis is the highest risk period for excess mortality in people with BD. The mortality burden in BD derives from a wide spectrum of organ involvement and should serve as a warning to clinicians about the systemic nature of the disease.

Behçet disease (BD) is a multisystem vasculitis (inflammation of the blood vessels) of unknown origin that commonly results in oral and genital ulcers, uveitis (eye inflammation) and skin lesions. BD is most prevalent in people from the Mediterranean to East Asia, affecting 0.4% of people in this area. Most lesions go away with time, but more severe forms that involve the cardiovascular and neurological systems can lead to death. It is estimated that people with BD have 1.4 times the risk of dying than the general population. Using large insurance databases in Korea, we investigated the risk of death in people with BD versus age- and sex-matched controls (i.e. people without the disease) from the general population. We found that patients with BD had a 28% greater risk of death than controls over 11.9 years of follow-up, with the highest risk being in first year after diagnosis. Top causes of death in people with BD included cancer, and cardiovascular, gastrointestinal, neurological, genitourinary, respiratory and infectious disease. Further analyses of the data showed that the risk of death in BD is affected by age and sex. In particular, younger patients were more susceptible to death as a result of cardiovascular disease and women were more susceptible to dying of gastrointestinal disease. Our study suggests that there could be an increased risk of death within the first year of being diagnosed with BD and highlights how BD is a systemic disease (i.e. the involvement of any internal organ system could lead to an increase in mortality). Finally, there were unique patterns of cause-specific deaths across subgroups of people with BD.

Comparative risk of blindness and vision-threatening ocular comorbidities in patients with Behçet's disease versus the general population.

OBJECTIVE: To compare the risk of blindness and vision-threatening ocular comorbidities in patients with Behçet's disease (BD) vs the general population. METHODS: Using 2002-2017 Korea National Health Insurance Service database, we did a population-based cohort study comparing newly diagnosed BD patients and age- and sex-matched non-BD controls at a 1:5 ratio. The primary outcome was blindness, defined as a best-corrected visual acuity of ≤20/500 in the better-seeing eye. Secondary outcomes were vision-threatening ocular comorbidities (cataract, glaucoma and retinal disorders) that require surgical interventions and incident uveitis. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs. We performed subgroup analyses by sex and BD diagnosis age. RESULTS: We included 31 228 BD patients and 156 140 controls. During a follow-up of 9.39 years, the incidence rate of blindness per 1000 person-years was 0.24 in BD and 0.02 in controls with an HR of 10.73 (95% CI 7.10, 16.22). The HR for secondary outcomes was 2.06 (95% CI 1.98, 2.15) for cataract surgery, 5.43 (4.57, 6.45) for glaucoma surgery and 2.71 (2.39, 3.07) for retinal surgery. The HR of incident uveitis was 6.19 (95% CI 5.83, 6.58). Males suffered a disproportionately higher risk of blindness than females due to greater severity rather than a lower incidence of uveitis. The risk of uveitis and blindness decreased as BD diagnosis age increased. CONCLUSIONS: In this large population-based cohort study, BD patients compared with the general population have a 10.73-fold risk of blindness in 10 years and also a substantially higher risk of diverse ocular comorbidities that pose potential threats to vision.

Performance of cut-offs adjusted with positive control band intensity in line-blot assays for myositis-specific antibodies.

The diagnostic performance of band intensity (BI) cut-offs, adjusted by a positive control band (PCB) in a line-blot assay (LBA) for myositis-related autoantibodies (MRAs) is investigated. Sera from 153 idiopathic inflammatory myositis (IIM) patients with available immunoprecipitation assay (IPA) data and 79 healthy controls were tested using the EUROLINE panel. Strips were evaluated for BI using the EUROLineScan software, and the coefficient of variation (CV) was calculated. Sensitivity and specificity, area under the curve (AUC), and the Youden's index (YI) were estimated at non-adjusted or PCB-adjusted cut-off values. Kappa statistics were calculated for IPA and LBA. Although inter-assay CV for PCB BI was 3.9%, CV was 12.9% in all samples, and a significant correlation was found between BIs of PCB and seven MRAs (all P < 0.05). At adjusted BI (aBI) > 10, the negative conversion rate of myositis-specific autoantibody (MSA)-positivity at BI > 10 was 11.5% in controls and 1.3% in patients. The specificity, AUC, and YI for MSAs at aBI > 10 or > 20 were higher than those at non-adjusted cut-off values. Additionally, AUC (0.720), YI (0.440), and the prevalence of MRAs with kappa > 0.60 (58.3%) were the highest at aBI > 20. The overall sensitivity and specificity for MSAs were 50.3% and 93.7% at aBI > 20, respectively, and 59.5% and 65.8% with BI > 10, respectively. The diagnostic performance of LBA can be improved using PCB-adjusted BIs. aBI > 20 is the optimal cut-off for IIM diagnosis using the EUROLINE LBA panel.

Anterior and Lateral Femoroacetabular Excursion Angles Are Helpful for Assessing Femoroacetabular Impingement Syndrome: A Cross-Sectional Cohort Study.

PURPOSE: To develop a radiographic measurement to evaluate the femoroacetabular space using 3-dimensional (3D) hip models in asymptomatic hips, and to evaluate the reliability and validity of the femoroacetabular excursion angle (FAEA) in symptomatic patients. METHODS: From January 2020 to December 2020, we recruited patients with healthy hips to establish 3D models. Through the simulation of 14 activities of daily living (ADLs), anterior and lateral impingement-free FAEAs were measured. Another cross-sectional cohort was formed from consecutive symptomatic subjects with impingement signs during the same period. In the validation cohort, anterior and lateral FAEAs were assessed on modified Dunn's and anteroposterior views of the hip, respectively. We evaluated the reliability and clinical implications of the FAEAs. RESULTS: In the discovery cohort (n = 33), hips with collisions tended to have smaller computed tomography-based FAEAs than collision-free hips, although alpha and lateral center-edge (CE) angles were comparable. Additionally, hips with a lower quartile of FAEAs had a significantly higher number of ADLs with collisions. In the validation cohort (n = 411), the FAEA measurement was highly reliable (kappa statistics >0.95 for both interobserver and intraobserver reliabilities). The femoroacetabular impingement syndrome (FAIS) group (n = 165) showed significantly smaller anterior and lateral FAEAs than the non-FAIS group (all P < .001, Cramer V = .420). The optimal cut-off values for anterior and lateral FAEAs were 32.6° and 48.9°, respectively. In univariate regression, anterior (odds ratio [OR] = 0.91; 95% confidence interval [CI] = 0.89-0.94) and lateral (OR = 0.91; 95% CI = 0.89-0.93) FAEAs were significantly associated with FAIS. Moreover, in multivariate regression adjusted for alpha and lateral CE angles, anterior FAEA remained a significant predictor (OR = 0.96; 95% CI = 0.93-0.99), and small FAEA was an independent risk factor for FAIS (OR = 1.99; 95% CI = 1.06-3.71) for any small FAEA (OR = 2.88; 95% CI = 1.32-6.31) for both small FAEAs. CONCLUSION: The FAEA is a valid measurement for FAIS with high reliability. Small FAEA was an independent risk factor for FAIS in the multivariate regression model, even after adjusting for alpha and lateral CE angles. LEVEL OF EVIDENCE: Level III, diagnostic study.

The 2021 Association Research Circulation Osseous Classification for Early-Stage Osteonecrosis of the Femoral Head to Computed Tomography-Based Study.

BACKGROUND: The Association Research Circulation Osseous developed a novel classification for early-stage (precollapse) osteonecrosis of the femoral head (ONFH). We hypothesized that the novel classification is more reliable and valid when compared to previous 3 classifications: Steinberg, modified Kerboul, and Japanese Investigation Committee classifications. METHODS: In the novel classification, necrotic lesions were classified into 3 types: type 1 is a small lesion, where the lateral necrotic margin is medial to the femoral head apex; type 2 is a medium-sized lesion, with the lateral necrotic margin being between the femoral head apex and the lateral acetabular edge; and type 3 is a large lesion, which extends outside the lateral acetabular edge. In a derivation cohort of 40 early-stage osteonecrotic hips based on computed tomography imaging, reliabilities were evaluated using kappa coefficients, and validities to predict future femoral head collapse by chi-squared tests and receiver operating characteristic curve analyses. The predictability for future collapse was also evaluated in a validation cohort of 104 early-stage ONFH. RESULTS: In the derivation cohort, interobserver reliability (k = 0.545) and intraobserver agreement (63%-100%) of the novel method were higher than the other 3 classifications. The novel classification system was best able to predict future collapse (P < .05) and had the best discrimination between non-progressors and progressors in both the derivation cohort (area under the curve = 0.692 [0.522-0.863], P < .05) and the validation cohort (area under the curve = 0.742 [0.644-0.841], P = 2.46 × 10-5). CONCLUSION: This novel classification is a highly reliable and valid method of those examined. Association Research Circulation Osseous recommends using this method as a unified classification for early-stage ONFH. LEVEL OF EVIDENCE: Level III, diagnostic study.

Baseline disease activity influences subsequent achievement of patient acceptable symptom state in Sjögren's syndrome.

OBJECTIVES: To investigate longitudinal changes of the EULAR SS Patient-Reported Index (ESSPRI) and EULAR SS Disease Activity Index (ESSDAI), and identify factors associated with patient acceptable symptom state (PASS) in patients with primary SS (pSS). METHODS: We assessed ESSPRI, ESSDAI, clinical ESSDAI (ClinESSDAI), EULAR Sicca Score, EuroQoL 5-dimension (EQ-5D), Fatigue Severity Score, Beck Depression Inventory, and patient global assessment (PGA) for pSS, and visual analogue scale (VAS) scores for glandular and extra-glandular symptoms at baseline and follow-up. The responses to the currently available standards of care were evaluated by the PASS, the minimal clinically important improvement (MCII) of ESSPRI and ESSDAI, and a modified SS Responder Index-30 (mSSRI-30) response. RESULTS: Among 115 patients enrolled, 102 (88.7%) completed a median 3-year follow-up. The ESSPRI, ClinESSDAI and EQ-5D levels remained stable, although the PGA and ESSDAI significantly improved (both P <0.05). Of the 102 patients, 52 (51.0%) patients achieved the PASS at the follow-up and tended to attain the ESSPRI-MCII and mSSRI-30 (both P < 0.001) more frequently than the non-PASS group. Multivariate analysis revealed that the PASS was significantly associated with baseline ESSPRI negatively [odds ratio (OR) 0.609] and ESSDAI positively (OR 1.224). When categorized using baseline ESSPRI and ESSDAI, a subgroup of low ESSPRI and high ESSDAI reached a PASS achievement rate of 79.3%. CONCLUSION: Although longitudinal changes in ESSPRI and ClinESSDAI are stable in pSS, baseline ESSPRI and ESSDAI could provide prognostic information on the subsequent achievement of PASS, using currently available treatments. A categorization model using ESSPRI and ESSDAI may have clinical implications.

Tuberculosis risk with biologics by screening-guided preventive strategy in rheumatoid arthritis under intermediate tuberculosis burden.

OBJECTIVES: We aimed to compare tuberculosis (TB) risk during biologics treatment between patients with RA who did (prophylaxis) and did not (non-prophylaxis) undergo chemoprophylaxis following pre-biologic latent TB screening in Korea of an intermediate TB burden. METHODS: Using the 2002-16 Korea National Health Insurance database, we conducted a cohort study examining TB risk, defined by International Classification of Diseases Tenth Revision codes plus anti-TB drugs, among RA patients initiating a biologic drug with and without chemoprophylaxis after screening triage for latent TB. To control baseline confounding, we used propensity score-based fine stratification (PSS) and weighting. Cox proportional hazards models estimated hazard ratios and 95% CIs comparing TB risk between the prophylaxis vs non-prophylaxis groups. RESULTS: The PSS-weighted study cohort (mean age 57.0 years; 81.3% female) included 2249 and 7225 RA patients in the prophylaxis and non-prophylaxis groups, respectively. During 2.42 years of biologics treatment, 118 patients developed TB with the incidence rate per 100 person-years of 0.33 in the prophylaxis and 0.63 in the non-prophylaxis groups. The PSS-weighted hazard ratio (95% CI) for TB associated with the prophylaxis was 0.52 (0.32, 0.86). During the follow-up time, the incidence rate of TB remained consistently low in the prophylaxis group but it was highest in the first year, then time-dependently declined in the non-prophylaxis group. CONCLUSION: This population-based cohort study warns that the current screening-based preventive strategy generates a substantially higher TB risk after biologics initiation among screening-negative patients compared with screening-positive patients receiving chemoprophylaxis, when the background TB burden is not low.

A clinical comparison of an endothelin receptor antagonist and phosphodiesterase type 5 inhibitors for treating digital ulcers of systemic sclerosis.

OBJECTIVES: To assess the efficacy of an endothelin receptor antagonist (ERA) and phosphodiesterase type5 inhibitors (PDE5is) for treating SSc-related digital ulcers (DUs). METHODS: This prospective, multicentre, observational cohort study recruited patients with active SSc-related DUs from 13 medical centres in South Korea. The primary outcome was time to cardinal ulcer (CU) healing. A secondary outcome was time to new DU occurrence. Patients were followed up 4, 8, 12 and 24 weeks after treatment initiation. RESULTS: Sixty-three patients were analysed. Their mean age was 49.9 years (s.d. 11.4) and 49 were female. Twenty-eight had limited SSc. Forty-nine patients received ERA, 11 received a PDE5i (9 sildenafil, 1 udenafil and 1 tadalafil) and 3 received other medication. The hazard ratio (HR) for time to CU healing in the ERA group vs the PDE5i group was 0.75 (95% CI 0.35, 1.64; P = 0.47) in an unadjusted model and 0.80 (95% CI 0.36, 1.78; P = 0.59) in a model adjusted for age, sex, use of calcium channel blockers (CCBs), total DU number and initial CU area. The HR for new DU development in the ERA group vs the PDE5i group was 0.39 (95% CI 0.16, 0.93; P = 0.03) in an unadjusted model and 0.32 (95% CI 0.13, 0.81; P = 0.02) in an adjusted model. No patients receiving CCBs developed new DUs at 24 weeks. CONCLUSION: Time to CU healing is comparable for ERA and PDE5i. ERAs are more effective in reducing new DU occurrence than PDE5is. CCBs may be effective as a background medication.

Clinical usefulness of anti-muscarinic type 3 receptor autoantibodies in patients with primary Sjögren's syndrome.

OBJECTIVES: To elucidate the clinical values of anti-M3R in Sjögren's syndrome (SS) in the largest cohort for an anti-M3R study. METHODS: The plasma of 361 subjects (156 primary SS [pSS], 62 non-SS-sicca [SICCA], 40 systemic lupus erythematosus [SLE], 50 rheumatoid arthritis [RA], and 53 healthy controls [HC]) was screened using our modified On-Cell-Western assay. Saliva from pSS (n=37) compared to SICCA (n=26) was also analysed. The sensitivity and specificity of anti-M3R and its association with comprehensive clinical and laboratory features were determined. RESULTS: Plasma-anti-M3R was higher in pSS compared to other groups, differentiating pSS with good-to-excellent diagnostic power with a specificity of 85% and a sensitivity between 75% and 98%. pSS plasma-anti-M3R was positively correlated with ocular staining scores, anti-Ro/SSA, IgG, ß2-microglobulin, ESR, and ESSDAI. It was negatively correlated with WBC, C4, and salivary scintigraphic indices. Saliva-anti-M3R was 3.59 times higher in pSS than in SICCA. Interestingly, the agreement between the 2002 American European Consensus Group criteria and the criteria substituted with plasma-anti-M3R for the lip biopsy reached 92%, with a significant kappa of 0.824. CONCLUSIONS: Anti-M3R enhances sensitivity and specificity for SS diagnosis, correlating with ocular dryness and glandular hypofunction, and the haematological/biological domains of the ESSDAI. Our findings also highlight the clinical significance of anti-M3R in SS diagnosis, especially where clinical assessments, such as lip biopsy, sialometry, or ocular evaluation, by multi-disciplinary specialists are limited.

Fucoxanthin Suppresses Osteoclastogenesis via Modulation of MAP Kinase and Nrf2 Signaling.

Fucoxanthin (FX), a natural carotenoid present in edible brown seaweed, is known for its therapeutic potential in various diseases, including bone disease. However, its underlying regulatory mechanisms in osteoclastogenesis remain unclear. In this study, we investigated the effect of FX on osteoclast differentiation and its regulatory signaling pathway. In vitro studies were performed using osteoclast-like RAW264.7 cells stimulated with the soluble receptor activator of nuclear factor-κB ligand or tumor necrosis factor-alpha/interleukin-6. FX treatment significantly inhibited osteoclast differentiation and bone resorption ability, and downregulated the expression of osteoclast-specific markers such as nuclear factor of activated T cells 1, dendritic cell-specific seven transmembrane protein, and matrix metallopeptidase 9. Intracellular signaling pathway analysis revealed that FX specifically decreased the activation of the extracellular signal-regulated kinase and p38 kinase, and increased the nuclear translocation of phosphonuclear factor erythroid 2-related factor 2 (Nrf2). Our results suggest that FX regulates the expression of mitogen-activated protein kinases and Nrf2. Therefore, FX is a potential therapeutic agent for osteoclast-related skeletal disorders including osteoporosis and rheumatoid arthritis.

Predictors of a placebo response in patients with hand osteoarthritis: post-hoc analysis of two randomized controlled trials.

BACKGROUND: Placebo can have a significant therapeutic effect in patients with hand osteoarthritis (OA). This aim of the study is to identify factors associated with a clinically meaningful placebo response in patients with hand OA. METHODS: This post-hoc analysis of two double-blind, placebo-controlled, randomized trials (RCTs) investigating the efficacy of GCSB-5 or diacerein as treatments for hand OA analyzed the efficacy of a placebo. Clinical and laboratory factors associated with a clinically meaningful response, defined as an improvement in the Australian/Canadian Osteoarthritis Hand Index (AUSCAN) pain score > 10 at 4 weeks relative to baseline, were identified. RESULTS: The mean improvement in the AUSCAN pain score was - 6.0 ± 20.3, with marked variation between 143 hand OA patients (range: - 76.4 to 33.2). A clinically meaningful improvement was observed in 54 (37.8%) patients. Placebo responders had worse AUSCAN pain scores (55.7 ± 19.7 vs. 43.6 ± 21.6, p = 0.001) and a worse AUSCAN stiffness (68.2 ± 20.5 vs. 57.5 ± 24.5, p = 0.008) at baseline than non-responders. Improvements in pain correlated with the baseline pain level (Pearson r = - 427, p < 0.001). Structural joint changes such as tender, swollen, enlarged, or deformed joint counts did not differ between placebo responders and non-responders. In a multivariable analysis, only baseline AUSCAN pain was associated with a clinically meaningful placebo response (OR: 1.054, 95% CI [1.019-1.089], p = 0.002). CONCLUSIONS: High levels of pain at baseline are predictive of a clinically meaningful placebo response in patients with hand OA. Further studies are needed to optimize and utilize the benefit of placebo responses in patients with hand OA.

ARCO Consensus on the Pathogenesis of Non-traumatic Osteonecrosis of the Femoral Head.

Osteonecrosis of the femoral head (ONFH) is a devastating disease frequently leading to femoral head collapse and hip arthritis. Specifically, non-traumatic ONFH primarily affects young and middle-aged adults. Although compromised local circulation of the femoral head seems to be pathognomonic for the disease, the pathogenesis is perplexing and continues to be an area of scrutiny and research. Comprehension of the pathogenesis is of crucial importance for developing and guiding treatments for the disease. Therefore, we provide an up-to-date consensus on the pathogenesis of non-traumatic ONFH.

Diffuse large B-cell lymphoma involving the left sternoclavicular joint mimicking rheumatoid arthritis flare: a case-based review.

Rheumatoid arthritis (RA) is a chronic autoimmune disease affecting primarily joints and an increased risk of developing malignant lymphomas in RA has been well reported. However, primary lymphoma in a joint in RA patient is rare. We report the case of a 65-year-old man with RA suffering from pain and swelling of left sternoclavicular (SC) joint, which was not relieved by adding low-dose glucocorticoid. Magnetic resonance imaging (MRI) showed a para-osseous soft tissue swelling around the SC joint and a fracture of proximal clavicle. Histology of the soft tissue demonstrated diffuse large B-cell lymphoma and the patient subsequently underwent R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy. He was successfully treated with six cycles of R-CHOP chemotherapy, with discontinuation of MTX, resulting in a complete response. We performed a literature review and identified nine cases of lymphoma which involved joints in patients with rheumatoid arthritis. This is the first described case of a primary large B-cell lymphoma involving the unilateral SC joint in a patient with RA, which was initially confused with aggravation of RA. Therefore, malignant lymphoma should be considered in the differential diagnosis when a RA patient develops monoarthritis with spontaneous fracture, even without B symptoms.

The 2019 Revised Version of Association Research Circulation Osseous Staging System of Osteonecrosis of the Femoral Head.

BACKGROUND: The Association Research Circulation Osseous (ARCO) presents the 2019 revised staging system of osteonecrosis of the femoral head (ONFH) based on the 1994 ARCO classification. METHODS: In October 2018, ARCO established a task force to revise the staging system of ONFH. The task force involved 29 experts who used a web-based survey for international collaboration. Content validity ratios for each answer were calculated to identify the levels of agreement. For the rating queries, a consensus was defined when more than 70% of the panel members scored a 4 or 5 rating on a 5-point scale. RESULTS: Response rates were 93.1%-100%, and through the 4-round Delphi study, the 1994 ARCO classification for ONFH was successfully revised. The final consensus resulted in the following 4-staged system: stage I-X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II-X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III-fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV-X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. This revised staging system does not incorporate the previous subclassification or quantitation parameters, but the panels agreed on the future development of a separate grading system for predicting disease progression. CONCLUSION: A staging system has been developed to revise the 1994 ARCO classification for ONFH by an expert panel-based Delphi survey. ARCO approved and recommends this revised system as a universal staging of ONFH.

Autoantibody Biomarkers in Rheumatic Diseases.

Autoantibodies encountered in patients with systemic rheumatic diseases bear clinical significance as a biomarker to help or predict diagnosis, clinical phenotypes, prognosis, and treatment decision-making. Furthermore, evidence has accumulated regarding the active involvement of disease-specific or disease-associated autoantibodies in the pathogenic process beyond simple association with the disease, and such knowledge has become essential for us to better understand the clinical value of autoantibodies as a biomarker. This review will focus on the current update on the autoantibodies of four rheumatic diseases (rheumatoid arthritis, myositis, systemic sclerosis, and anti-neutrophil cytoplasmic antibody associated vasculitis) where there has been a tremendous progress in our understanding on their biological effects and clinical use.

Association between socioeconomic status and comorbidities among patients with rheumatoid arthritis: results of a nationwide cross-sectional survey.

OBJECTIVES: We examined the association between socioeconomic status (SES) and comorbidity distribution among patients with RA. METHODS: Information on comprehensive health status of 1088 RA patients (weighted n = 612 303) was obtained from the 2007-2015 Korea National Health and Nutrition Examination Survey database. SES components were household equivalence income, education and area of residence. To minimize confounding by age, patients were stratified by median age (63 years). Age-adjusted odds ratio (OR) with 95% confidence interval (95% CI) was estimated, comparing weighted prevalence of individual comorbidities between low and high SES groups in each age stratum. RESULTS: Among RA patients aged <63 years (mean 49 years, 70% female), we observed age-adjusted associations of depression (OR 2.13, 95% CI 1.01, 4.53), depressive mood (OR 2.68, 95% CI 1.54, 4.65), suicide ideation (OR 3.01, 95% CI 1.79, 5.07), diabetes (OR 3.09, 95%CI 1.31, 7.29), obesity (OR 2.04, 95% CI 1.30, 3.20), hypertriglyceridemia (OR 2.36, 95% CI 1.28, 4.34) and osteoarthritis (OR 2.12, 95% CI 1.13, 3.99) with low income, of suicide ideation with low education (OR 2.25, 95% CI 1.14, 4.44), but no association of any comorbidities with area of residence. Unhealthy behavior patterns were comparable between low- and high-income groups but patients with low income reported a numerically higher rate of failed access to necessary healthcare services. We did not find any association between SES and comorbidities among those aged ⩾63 years (mean 72 years, 83% female). CONCLUSION: Among Korean RA patients aged <63 years, socioeconomic inequalities of multiple comorbidities in mental, cardiometabolic and musculoskeletal systems were found.

Comparative cardiovascular risk of allopurinol versus febuxostat in patients with gout: a nation-wide cohort study.

OBJECTIVE: To compare cardiovascular (CV) risk among gout patients initiating allopurinol vs febuxostat. METHODS: Using 2002-2015 Korean National Health Insurance Service data for the entire Korean population, we conducted a cohort study on gout patients initiating allopurinol or febuxostat. The primary outcome was a composite CV end point of myocardial infarction, stroke/transient ischaemic attack, or coronary revascularization. Secondary outcomes were individual components of the primary outcome, and all-cause mortality. We used propensity score-matching with a 4:1 ratio for allopurinol and febuxostat initiators to control for confounding. Competing risk analyses were done for non-fatal outcomes accounting for deaths. RESULTS: We included 39 640 allopurinol initiators propensity score-matched on 9910 febuxostat initiators. The mean age was 59.1 years and 78.4% were male. The incidence rate per 100 person-years for the primary outcome was 1.89 for allopurinol and 1.84 for febuxostat initiators. The corresponding hazard ratio comparing allopurinol vs febuxostat initiators was 1.09 (95% CI: 0.90, 1.32). No significant difference was found for the secondary outcomes, including all-cause mortality (hazard ratio 0.96; 95% CI: 0.79, 1.16). Subgroup analyses limited to those at high CV risk and to equipotent-dose initiators (i.e. allopurinol ⩾300 mg/day vs febuxostat ⩾40 mg/day) showed similar results. CONCLUSION: Overall, this large Korean population-based study suggests no difference in the risk of non-fatal CV events and all-cause mortality between allopurinol and febuxostat initiators. These findings are consistent with the recent US Medicare population study, although the current study population consisted of younger Asians.

PIM-1 kinase is a novel regulator of proinflammatory cytokine-mediated responses in rheumatoid arthritis fibroblast-like synoviocytes.

Objectives: This study investigated the expression of proviral-integration site for Moloney murine leukaemia virus (PIM) -1 kinase in RA synovium and RA fibroblast-like synoviocytes (FLSs) along with its impact on RA-FLS aggressiveness. Methods: The expression of PIM kinases was assessed in synovial tissues by immunohistochemistry and double IF. After PIM-1 inhibition using either small-interfering RNA or the chemical inhibitor AZD1208, we performed proliferation and migration assays and measured the levels of MMPs and IL-6 released from RA-FLSs under stimulation with proinflammatory cytokines (TNF-α, S100A4 and IL-6/soluble IL-6 receptor). Additionally, PIM-1-associated downstream signalling pathways were analysed by immunoblotting. Results: Three isoforms of PIM kinases were immunodetected in the synovial tissues from patients with RA or OA. Specifically, PIM-1 and PIM-3 were upregulated in RA synovium and PIM-1 was expressed in T cells, macrophages and FLSs. Additionally, upon stimulation of RA-FLSs with TNF-α, S100A4 and IL-6/sIL-6R, PIM-1 and PIM-3, but not PIM-2, were significantly inducible. Moreover, PIM-1 knockdown or AZD1208 treatment significantly suppressed basal or cytokine-induced proliferation and migration of RA-FLS and the secretion of MMPs from stimulated RA-FLSs. PIM-1 knockdown significantly affected the phosphorylation levels of extracellular signal-regulated kinase and cAMP responsive element binding protein in RA-FLSs. Conclusion: PIM-1 was upregulated in RA synovial tissues and RA-FLSs and its inhibition significantly reduced the proliferation, migration and MMP production of RA-FLSs in vitro. These findings suggest PIM-1 as a novel regulator of the aggressive and invasive behaviour of RA-FLSs and indicate its potential as a target for RA treatment.

Performance of the 2015 American College of Rheumatology/European League against Rheumatism Classification Criteria for Gout in Korean Patients with Acute Arthritis.

BACKGROUND: We aimed to assess the performance of the 2015 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria for gout in Korean patients with acute arthritis and to compare the performance of the ACR/EULAR criteria to that of other sets of criteria for gout classification. METHODS: Patients with acute arthritis who underwent diagnostic arthrocentesis at one of the four participating rheumatology clinics were consecutively enrolled between February and December 2017. Crystal-proven gout was diagnosed upon confirming the presence of monosodium urate (MSU) crystals in patients with a clinical impression of gout as judged by the rheumatologist. The performance of the ACR/EULAR and other gout classification criteria, including the Rome, New York, American Rheumatism Association (ARA), Mexico, and Netherlands criteria, was analyzed regardless of the presence/absence of MSU crystals. RESULTS: The study enrolled 118 gout patients (all crystal-proven) and 95 non-gout patients. According to the area under the curve, the diagnostic performance was the highest for the ACR/EULAR classification criteria (sensitivity, 80.5%; specificity, 95.8%; area under the curve, 0.966), followed by the Netherlands, Rome, ARA, New York, and Mexico criteria. All six sets of criteria demonstrated lower sensitivity in patients exhibiting the first episode of acute arthritis. CONCLUSION: In Korean patients with acute arthritis, the ACR/EULAR classification criteria outperformed other sets of gout classification criteria even in the absence of information regarding the presence of MSU crystals. However, to enhance diagnostic sensitivity, synovial fluid analysis should be considered in patients with the first episode of acute arthritis.