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We aimed to develop evidence-based recommendations for treating axial spondylarthritis (axSpA) in Korea. The development committee was constructed, key clinical questions were determined, and the evidence was searched through online databases including MEDLINE, Embase, Cochrane, KoreaMed, and Kmbase. Systematic literature reviews were conducted, quality of evidence was determined, and draft recommendations were formulated according to the Grading of Recommendations Assessment, Development, and Evaluations methodology. Recommendations that reached 80% consensus among a voting panel were finalized. Three principles and 21 recommendations were determined. Recommendations 1 and 2 pertain to treatment strategies, regular disease status assessment, and rheumatologist-steered multidisciplinary management. Recommendations 3 and 4 strongly recommend patient education, exercise, and smoking cessation. Recommendations 5–12 address pharmacological treatment of active disease using nonsteroidal anti-inflammatory drugs, glucocorticoids, sulfasalazine, biologics, and Janus kinase inhibitors. Recommendations 13–16 address treatment in stable disease. We suggest against spa and acupuncture as therapies (Recommendation 17). Recommendations 18 and 19 pertain to total hip arthroplasty and spinal surgery. Monitoring of comorbidities and drug toxicities are recommended (Recommendations 20 and 21). Recommendations for axSpA treatment in a Korean context were developed based on comprehensive clinical questions and evidence. These are intended to guide best practice in the treatment of axSpA.

We compared two interferon gamma release assays (IGRAs), QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB, for diagnosis of latent tuberculosis infection (LTBI) in patients before and while receiving tumor necrosis factor (TNF)-α antagonist therapy. This study evaluated the significance of sensitive IGRAs for LTBI screening and monitoring.Before starting TNF-α antagonist therapy, 156 consecutive patients with rheumatic diseases were screened for LTBI using QFT-GIT and T-SPOT.TB tests. According to our study protocol, QFT-GIT-positive patients received LTBI treatment. Patients positive by any IGRAs were subjected to follow-up IGRA tests after completing LTBI-treatment and/or during TNF-α antagonist therapy.At the initial LTBI screening, 45 (28.9%) and 70 (44.9%) patients were positive by QFT-GIT and T-SPOT.TB, respectively. The agreement rate between IGRA results was 78.8% (k = 0.56; 95% confidence interval [95% CI] = 0.43 to 0.68). Of 29 patients who were positive only by T-SPOT.TB in the initial screening, 83% (19/23) were persistently positive by T-SPOT.TB, while QFT-GIT testing showed that 36% (9/25) had conversion during TNF-α antagonist therapy. By the end of the follow-up period (218 to 1,264 days), four patients (4/137, 2.9%) developed active tuberculosis (TB) diseases during receiving TNF-α antagonist therapy. Among them, one was Q-T+, one was Q+T-, and the remaining two were Q-T- at the initial screening (Q, QuantiFERON-TB Gold In-Tube; T, T-SPOT.TB; +, positive; -, negative). Two (2/4, 50%) patients with TB reactivation had at least one prior risk factor consistent with previous TB infection.This study demonstrated the need to capitalize on sensitive IGRAs to monitor for LTBI in at-risk patients for a more sensitive diagnosis in countries with an intermediate TB burden.

Abstract Background Previous studies have shown that the incidence and risk factors of gout differs according to sex. However, little research has been done on the association between reproductive factors and gout. We conducted an analysis of a large nationwide population-based cohort of postmenopausal women to determine whether there is an association between reproductive factors and the incidence of gout. Methods A total of 1,076,378 postmenopausal women aged 40–69 years who participated in national health screenings in 2009 were included in the study. The outcome was the occurrence of incident gout, which was defined using the ICD-10 code of gout (M10) in the claim database. Cox proportional hazard models were used for the analyses and stratified analyses according to body mass index (BMI) and the presence/absence of chronic kidney disease (CKD) were performed. Results The mean follow-up duration was 8.1 years, and incident cases of gout were 64,052 (incidence rate 7.31 per 1000 person-years). Later menarche, earlier menopause, and a shorter reproductive span were associated with a high risk of gout. No association between parity and gout incidence was observed. Use of oral contraceptives (OC) and hormone replacement therapy (HRT) were associated with an increased risk of gout. The association between reproductive factors and gout was not statistical significant in the high BMI group. The effects of OC and HRT usage on gout were not significant in the CKD group. Conclusion Shorter exposure to endogenous estrogen was associated with a high risk of gout. Conversely, exposure to exogenous estrogen such as OC and HRT was associated with an increased risk of gout.

Abstract Background This study aimed to classify the distinct group of patients with axial spondyloarthritis (SpA) on tumour necrosis factor alpha inhibitors (TNFi) according to the baseline characteristics using a clustering algorithm. Methods The clinical characteristics and demographic data of patients with axial SpA included in the Korean College of Rheumatology Biologics and Targeted Therapy registry were investigated. The patterns of disease manifestations were examined using divisive hierarchical cluster analysis. After clustering, we compared the clinical characteristics of patients and the drug survival of TNFi between the classified groups. Results A total of 1042 patients were analysed. The cluster analysis classified patients into two groups: axial group predominantly showing isolated axial manifestations (n = 828) and extra-axial group more frequently showing extra-axial symptoms (n = 214). Almost all extra-axial symptoms (peripheral arthritis, enthesitis, uveitis, and psoriasis) were more frequently observed in the extra-axial group than in the axial group. Moreover, patients in the extra-axial group had shorter disease duration, later disease onset, and higher disease activity than those in the axial group. The disease activity was comparable between the two groups after 1 year of treatment with TNFi. Interestingly, the extra-axial group had a lower drug survival with TNFi than the axial group (p = 0.001). Conclusions Cluster analysis of patients with axial SpA using TNFi classified two distinct clinical phenotypes. These clusters had different TNFi drug survival, clinical characteristics, and disease activity.

Abstract Background Few studies on rheumatoid arthritis (RA) have generated machine learning models to predict biologic disease-modifying antirheumatic drugs (bDMARDs) responses; however, these studies included insufficient analysis on important features. Moreover, machine learning is yet to be used to predict bDMARD responses in ankylosing spondylitis (AS). Thus, in this study, machine learning was used to predict such responses in RA and AS patients. Methods Data were retrieved from the Korean College of Rheumatology Biologics therapy (KOBIO) registry. The number of RA and AS patients in the training dataset were 625 and 611, respectively. We prepared independent test datasets that did not participate in any process of generating machine learning models. Baseline clinical characteristics were used as input features. Responders were defined as those who met the ACR 20% improvement response criteria (ACR20) and ASAS 20% improvement response criteria (ASAS20) in RA and AS, respectively, at the first follow-up. Multiple machine learning methods, including random forest (RF-method), were used to generate models to predict bDMARD responses, and we compared them with the logistic regression model. Results The RF-method model had superior prediction performance to logistic regression model (accuracy: 0.726 [95% confidence interval (CI): 0.725–0.730] vs. 0.689 [0.606–0.717], area under curve (AUC) of the receiver operating characteristic curve (ROC) 0.638 [0.576–0.658] vs. 0.565 [0.493–0.605], F1 score 0.841 [0.837–0.843] vs. 0.803 [0.732–0.828], AUC of the precision-recall curve 0.808 [0.763–0.829] vs. 0.754 [0.714–0.789]) with independent test datasets in patients with RA. However, machine learning and logistic regression exhibited similar prediction performance in AS patients. Furthermore, the patient self-reporting scales, which are patient global assessment of disease activity (PtGA) in RA and Bath Ankylosing Spondylitis Functional Index (BASFI) in AS, were revealed as the most important features in both diseases. Conclusions RF-method exhibited superior prediction performance for responses of bDMARDs to a conventional statistical method, i.e., logistic regression, in RA patients. In contrast, despite the comparable size of the dataset, machine learning did not outperform in AS patients. The most important features of both diseases, according to feature importance analysis were patient self-reporting scales.

Abstract Ankylosing spondylitis is a male-predominant disease and previous study revealed that estrogens have an anti-inflammatory effect on the spondyloarthritis (SpA) manifestations in zymosan-induced SKG mice. This study aimed to evaluate the effect of selective estrogen receptor modulator (SERM) lasofoxifene (Laso) on disease activity of SpA. Mice were randomized into zymosan-treated, zymosan + 17β-estradiol (E2)-treated, and zymosan + Laso-treated groups. Arthritis was assessed by 18F-fluorodeoxyglucose (18F-FDG) small-animal positron emission tomography/computed tomography and bone mineral density (BMD) was measured. Fecal samples were collected and 16S ribosomal RNA gene sequencing was used to determine gut microbiota differences. Both zymosan + E2-treated mice and zymosan + Laso-treated mice showed lower arthritis clinical scores and lower 18F-FDG uptake than zymosan-treated mice. BMD was significantly higher in zymosan + E2-treated mice and zymosan + Laso-treated mice than zymosan-treated mice, respectively. Fecal calprotectin levels were significantly elevated at 8 weeks after zymosan injection in zymosan-treated mice, but it was not significantly changed in zymosan + E2-treated mice and zymosan + Laso-treated mice. Gut microbiota diversity of zymosan-treated mice was significantly different from zymosan + E2-treated mice and zymosan + Laso-treated mice, respectively. There was no significant difference in gut microbiota diversity between zymosan + E2-treated mice and zymosan + Laso -treated mice. Laso inhibited joint inflammation and enhanced BMD in SKG mice, a model of SpA. Laso also affected the composition and biodiversity of gut microbiota. This study provides new knowledge regarding that selected SpA patients could benefit from SERM treatment.

Behcet’s disease (BD) is an immune disease characterized by chronic and relapsing systemic vasculitis of unknown etiology, which can lead to blindness and even death. Despite continuous efforts to discover biomarkers for accurate and rapid diagnosis and optimal treatment of BD, there is still no signature marker with high sensitivity and high specificity. As the link between glycosylation and the immune system has been revealed, research on the immunological function of glycans is being actively conducted. In particular, sialic acids at the terminus of glycoconjugates are directly implicated in immune responses, cell–cell/pathogen interactions, and tumor progression. Therefore, changes in sialic acid epitope in the human body are spotlighted as a new indicator to monitor the onset and progression of immune diseases. Here, we performed global profiling of N-glycan compositions derived from the sera of 47 healthy donors and 47 BD patients using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) to preferentially determine BD target glycans. Then, three sialylated biantennary N-glycans were further subjected to the separation of linkage isomers and quantification using porous graphitized carbon-liquid chromatography (PGC-LC)/multiple reaction monitoring (MRM)-MS. We were able to successfully identify 11 isomers with sialic acid epitopes from the three glycan compositions consisting of Hex5HexNAc4NeuAc1, Hex5HexNAc4Fuc1NeuAc1, and Hex5HexNAc4NeuAc2. Among them, three isomers almost completely distinguished BD from control with high sensitivity and specificity with an area under the curve (AUC) of 0.945, suggesting the potential as novel BD biomarkers. In particular, it was confirmed that α2,3-sialic acid at the terminus of biantennary N-glycan was the epitope associated with BD. In this study, we present a novel approach to elucidating the association between BD and glycosylation by tracing isomeric structures containing sialic acid epitopes. Isomer-specific glycan profiling is suitable for analysis of large clinical cohorts and may facilitate the introduction of diagnostic assays for other immune diseases.

Abstract Background To evaluate the long-term efficacy, safety and immunogenicity of continuing LBEC0101; the etanercept (ETN) biosimilar; or switching from the ETN reference product (RP) to LBEC0101 in patients with rheumatoid arthritis (RA). Methods This multicentre, single-arm, open-label extension study enrolled patients who had completed a 52-week randomised, double-blind, parallel phase III trial of LBEC0101 vs ETN-RP. Patients treated with ETN-RP during the randomised controlled trial switched to LBEC0101; those treated with LBEC0101 continued to receive LBEC0101 in this study. LBEC0101 (50 mg) was administered subcutaneously once per week for 48 weeks with a stable dose of methotrexate. Efficacy, safety and immunogenicity of LBEC0101 were assessed up to week 100. Results A total of 148 patients entered this extension study (70 in the maintenance group and 78 in the switch group). The 28-joint disease activity scores (DAS28)-erythrocyte sedimentation rate (ESR) were maintained in both groups from week 52 to week 100 (from 3.068 to 3.103 in the maintenance group vs. from 3.161 to 3.079 in the switch group). ACR response rates at week 100 for the maintenance vs. switch groups were 79.7% vs. 83.3% for ACR20, 65.2% vs. 66.7% for ACR50 and 44.9% vs. 42.3% for ACR70. The incidence of adverse events and the proportion of patients with newly developed antidrug antibodies were similar in the maintenance and switch groups (70.0% and 70.5%, 1.4% and 1.3%, respectively). Conclusions Administration of LBEC0101 showed sustained efficacy and acceptable safety in patients with RA after continued therapy or after switching from ETN-RP to LBEC0101. Trial registration ClinicalTrials.gov, NCT02715908. Registered 22 March 2016.

In the urinary metabolomics for finding biomarkers in urine, owing to high concentrations of urea, for chromatography-based metabolomic analysis, urea needed to be degraded by urease. This urease pretreatment has been the key step of sample preparation for standard urinary metabolomics until today even for mass spectrometry-based analysis. The urease pretreatment involving incubation of urine with urease contradicts the concept of metabolome sampling, which should immediately arrest metabolic reactions to prevent alterations of a metabolite profile. Nonetheless, the impact of urease pretreatment has not been clearly elucidated yet. We found that activities of urease and endogenous urinary enzymes and metabolite contaminants from the urease preparations introduce artefacts into metabolite profiles, thus leading to misinterpretation.

Background: Magnetic resonance imaging (MRI) is important for the early detection of axial spondyloarthritis (axSpA). We developed an artificial intelligence (AI) model for detecting sacroiliitis in patients with axSpA using MRI. Methods: This study included MRI examinations of patients who underwent semi-coronal MRI scans of the sacroiliac joints owing to chronic back pain with short tau inversion recovery (STIR) sequences between January 2010 and December 2021. Sacroiliitis was defined as a positive MRI finding according to the ASAS classification criteria for axSpA. We developed a two-stage framework. First, the Faster R-CNN network extracted regions of interest (ROIs) to localize the sacroiliac joints. Maximum intensity projection (MIP) of three consecutive slices was used to mimic the reading of two adjacent slices. Second, the VGG-19 network determined the presence of sacroiliitis in localized ROIs. We augmented the positive dataset six-fold. The sacroiliitis classification performance was measured using the sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC). The prediction models were evaluated using three-round three-fold cross-validation. Results: A total of 296 participants with 4,746 MRI slices were included in the study. Sacroiliitis was identified in 864 MRI slices of 119 participants. The mean sensitivity, specificity, and AUROC for the detection of sacroiliitis were 0.725 (95% CI, 0.705-0.745), 0.936 (95% CI, 0.924-0.947), and 0.830 (95%CI, 0.792- 0.868), respectively, at the image level and 0.947 (95% CI, 0.912-0.982), 0.691 (95% CI, 0.603-0.779), and 0.816 (95% CI, 0.776-0.856), respectively, at the patient level. In the original model, without using MIP and dataset augmentation, the mean sensitivity, specificity, and AUROC were 0.517 (95% CI, 0.493-0.780), 0.944 (95% CI, 0.933-0.955), and 0.731 (95% CI, 0.681-0.780), respectively, at the image level and 0.806 (95% CI, 0.729-0.883), 0.617 (95% CI, 0.523-0.711), and 0.711 (95% CI, 0.660-0.763), respectively, at the patient level. The performance was improved by MIP techniques and data augmentation. Conclusion: An AI model was developed for the detection of sacroiliitis using MRI, compatible with the ASAS criteria for axSpA, with the potential to aid MRI application in a wider clinical setting. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the association of knee osteoarthritis (OA) with comorbidities and health-related quality of life (HRQOL).A total of 8,907 (weighted n = 13,687,058) participants aged ≥50 years who had undergone knee radiography were selected from the 2010-2012 Korea National Health and Nutrition Examination Survey. OA was classified into four subgroups based on the presence or absence of pain and radiographic OA (ROA): non-OA (Pain-/ROA-), pain only (Pain+/ROA-), ROA only (Pain-/ROA+), and painful ROA (Pain+/ROA+). ROA was defined as Kellgren-Lawrence grade ≥ 2. HRQOL measurements including EuroQOL visual analogue scale (EQ-VAS) scores and the five dimensions and summary index of the EuroQOL-5 dimension (EQ-5D index) were also analyzed. Multivariable logistic regression and linear regression analyses were performed.After adjustment for socioeconomic and lifestyle characteristics, cardiovascular disease, malignancy, and other comorbidities were not significantly associated with OA. Pain only and painful ROA were each significantly associated with limitations in physical activity (odds ratio (OR) 2.66, 95% CI 2.07-3.44, p < 0.001 and OR 2.83, 95% CI 2.25-3.58, p < 0.001, respectively), lower EQ-VAS (β-coefficient = -10.95, p < 0.001 and β-coefficient = -9.75, p < 0.001, respectively), and EQ-5D index (β-coefficient = -0.10, p < 0.001 and β-coefficient = -0.13, p < 0.001) compared with the non-OA group, whereas ROA only was not associated with limitations in physical activity or lower HRQOL score.Comorbidities were not significantly associated with knee OA after adjustment. Knee OA was associated with physical activity and HRQOL. Painful knee OA, with or without ROA, was more strongly associated with decreased physical activity and lower quality of life than ROA without pain.

Behcet's disease (BD) with arthritis is often confused with seronegative arthritis (SNA) because of shared clinical symptoms and the lack of definitive biomarkers for BD. To investigate possible metabolic patterns and potential biomarkers of BD with arthritis, metabolomic profiling of synovial fluid (SF) from 6 patients with BD with arthritis and 18 patients with SNA was performed using gas chromatography/time-of-flight mass spectrometry in conjunction with univariate and multivariate statistical analyses. A total of 123 metabolites were identified from samples. Orthogonal partial least square-discriminant analysis showed clear discrimination between BD with arthritis and SNA. A set of 11 metabolites were identified as potential biomarkers for BD using variable importance for projection values and the Wilcoxon-Mann-Whitney test. Compared with SNA, BD with arthritis exhibited relatively high levels of glutamate, valine, citramalate, leucine, methionine sulfoxide, glycerate, phosphate, lysine, isoleucine, urea, and citrulline. There were two markers identified, elevated methionine sulfoxide and citrulline, that were associated with increased oxidative stress, providing a potential link to BD-associated neutrophil hyperactivity. Glutamate, citramalate, and valine were selected and validated as putative biomarkers for BD with arthritis (sensitivity, 100%; specificity, 61.1%). This is the first report to present potential biomarkers from SF for discriminating BD with arthritis from SNA. The metabolomics of SF may be helpful in searching for potential biomarkers and elucidating the clinicopathogenesis of BD with arthritis.

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease characterized by synovial inflammation and joint disability. Curcumin is known to be effective in ameliorating joint inflammation in RA. To obtain new insights into the effect of curcumin on primary fibroblast-like synoviocytes (FLS, N = 3), which are key effector cells in RA, we employed gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS)-based metabolomics. Metabolomic profiling of tumor necrosis factor (TNF)-α-stimulated and curcumin-treated FLS was performed using GC/TOF-MS in conjunction with univariate and multivariate statistical analyses. A total of 119 metabolites were identified. Metabolomic analysis revealed that metabolite profiles were clearly distinct between TNF-α-stimulated vs. the control group (not stimulated by TNF-α or curcumin). Treatment of FLS with curcumin showed that the metabolic perturbation by TNF-α could be reversed to that of the control group to a considerable extent. Curcumin-treated FLS had higher restoration of amino acid and fatty acid metabolism, as indicated by the prominent metabolic restoration of intermediates of amino acid and fatty acid metabolism, compared with that observed in TNF-α-stimulated FLS. In particular, the abundance of glycine, citrulline, arachidonic acid, and saturated fatty acids in TNF-α-stimulated FLS was restored to the control level after treatment with curcumin, suggesting that the effect of curcumin on preventing joint inflammation may be elucidated with the levels of these metabolites. Our results suggest that GC/TOF-MS-based metabolomic investigation using FLS has the potential for discovering the mechanism of action of curcumin and new targets for therapeutic drugs in RA.

Patients undergoing anti-tumor necrosis factor (TNF) treatment are at an increased risk of reactivating a latent tuberculosis infection (LTBI). This study evaluated the effectiveness of the QuantiFERON-TB Gold In-Tube (QFT) assay for diagnosing LTBI in arthritis patients undergoing anti-TNF treatment.We enrolled 342 consecutive patients from August 2007 to October 2013: 176 (51.5%) patients with ankylosing spondylitis and 166 (48.5%) with rheumatoid arthritis. Screening tests included tuberculin skin test (TST) and QFT assay. Positive QFT results, regardless of TST results, were considered an indicator for LTBI treatment.Bacillus Calmette-Guérin scars were found in 236 (69.0%) patients. Of 342 patients, TST and QFT were positive in 122 (35.7%) and 103 (30.1%) patients, respectively, and discordant in 101 (29.5%) patients. During a median follow-up duration of 41.7 months, five patients (1.5%) developed TB in a median of 20.8 months after initiation of anti-TNF treatment (428/100,000 person-years). TB did not occur in 62 TST+/QFT+ patients who received LTBI treatment. Of 41 TST-/QFT+ patients who received LTBI treatment, one (2.4%) developed TB 20.5 months after starting anti-TNF treatment (705/100,000 person-years). Of 60 TST+/QFT- patients who did not receive LTBI treatment, two (3.3%) developed TB 20.8 and 22.0 months after starting anti-TNF treatment (871/100,000 person-years). Of 179 TST-/QFT- patients, two (1.1%) developed TB 7.2 and 22.7 months, respectively, after initiating anti-TNF treatment (341/100,000 person-years). TB incidence rate during the follow-up period did not differ among TST-/QFT+, TST+/QFT-, and TST-/QFT- patients (P = 0.661).QFT might be used instead of TST for diagnosing LTBI in patients before starting anti-TNF therapy in countries, such as Korea, where the TB prevalence is intermediate and the BCG vaccination is mandatory at birth. In the absence of a true gold standard test for LTBI, however, there is still a risk of TB development during anti-TNF treatment.

Background: A small number of studies have suggested an association between systemic lupus erythematosus (SLE) and Parkinson's disease (PD). Objectives: This study aimed to determine the risk of incident PD among Korean patients with SLE. Design: A nationwide retrospective cohort study using the claims database of the National Health Insurance Service of Korea was conducted. Methods: Patients above 40 years of age diagnosed with SLE between 2010 and 2015 were included in the study. The primary outcome of the study was incident PD, defined by registration in the rare intractable diseases program for PD and an ICD-10 code of G20. Subjects were followed until PD diagnosis or the end of 2017. We estimated the cumulative incidence of PD among the SLE cohort and compared this to that in a 1:5 age- and sex- matched control group. Results: Totals of 11,615 SLE cases and 58,075 matched controls were identified. The cumulative incidence rate of PD was 0.7 per 1000 person-years in the SLE cohort. The crude hazard ratio (HR) of incident PD was 1.71 (95% CI: 1.25-2.36) among the SLE cohort compared to the control group. The HR was 1.59 (95% CI: 1.15-2.20) after adjustment for age, sex, income, and baseline comorbidities. Conclusion: This study demonstrated that patients with SLE had an increased risk of incident PD compared to non-SLE controls. Further research is required to determine the mechanism underlying this and to elucidate the precise role of systemic inflammation in the development of PD in patients with SLE. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to examine the effects of tocilizumab therapy on serum levels of interleukin (IL)-33 and IL-6 in rheumatoid arthritis (RA) patients. Patients and methods: Interleukin-33 and IL-6 levels in serum samples from 83 RA patients (10 males, 73 females; mean age 51.9 years; range, 26 to 77 years) and 12 healthy controls (2 males, 10 females; mean age 52.2 years; range, 39 to 62 years) were compared by cross-sectional, case control analysis. Of the RA patients, 40 received 24 weeks of tocilizumab therapy and were assigned to the prospective cohort. These 40 patients were then divided into two subgroups as responders and non-responders according to the American College of Rheumatology (ACR) 20. The remaining 43 RA patients did not receive tocilizumab therapy. Serum cytokine levels were analyzed at baseline and after 24 weeks of tocilizumab therapy in these patients. Results: Interleukin-33 and IL-6 concentrations were significantly higher in RA patients than in healthy controls (p<0.001 for both). Serum IL-33 levels in RA patients showed a significant correlation with rheumatoid factor titer (r=0.660, p<0.001), and IL-6 levels showed a significant correlation with high-sensitivity C-reactive protein levels (Spearman's rank correlation coefficient=0.482, p<0.001). Serum IL-33 levels decreased significantly after 24 weeks of tocilizumab therapy (p<0.001); this was particularly marked in ACR20 responders (p<0.001). However, the decrease in non-responders was not significant (p=0.066). Changes in serum IL-6 levels after 24 weeks of tocilizumab therapy were not significant in either ACR20 responders or non-responders. Conclusion: Serum IL-33 levels in RA patients receiving tocilizumab therapy decreased significantly, particularly in ACR20 responders. Thus, IL-33 may be a useful marker for m onitoring responses to tocilizumab therapy. [ABSTRACT FROM AUTHOR]

Osteopoikilosis is an autosomal dominant bone disorder characterized by symmetric multiple osteosclerotic lesions throughout the axial and appendicular skeleton. Pathogenic variants in the LEMD3 have been identified as the cause of osteopoikilosis. LEMD3 encodes an inner nuclear membrane protein that interacts with bone morphogenetic protein (BMP) and transforming growth factor (TGF)-β pathways. We report the case of a 19-yearold man presenting with lower back pain and sciatica. His radiograph revealed bilateral and symmetrical multiple osteosclerotic bone lesions in both scapular areas. Sanger sequencing of LEMD3 revealed a four-base-pair deletion in intron 2 (c.1560+3_1560+6del), which was inherited from his father. We found that this four-base-pair deletion in intron 2 causes aberrant splicing and consequent deletion of exon 2. To the best of our knowledge, this is the first report of genetically confirmed osteopoikilosis in Korea. [ABSTRACT FROM AUTHOR]

Diagnosing Behcet's disease (BD) is challenging because of the lack of a diagnostic biomarker. The purposes of this study were to investigate distinctive metabolic changes in urine samples of BD patients and to identify urinary metabolic biomarkers for diagnosis of BD using gas chromatography/time-of-flight-mass spectrometry (GC/TOF-MS). Metabolomic profiling of urine samples from 44 BD patients and 41 healthy controls (HC) were assessed using GC/TOF-MS, in conjunction with multivariate statistical analysis. A total of 110 urinary metabolites were identified. The urine metabolite profiles obtained from GC/TOF-MS analysis could distinguish BD patients from the HC group in the discovery set. The parameter values of the orthogonal partial least squared-discrimination analysis (OPLS-DA) model were R2X of 0.231, R2Y of 0.804, and Q2 of 0.598. A biomarker panel composed of guanine, pyrrole-2-carboxylate, 3-hydroxypyridine, mannose, L-citrulline, galactonate, isothreonate, sedoheptuloses, hypoxanthine, and gluconic acid lactone were selected and adequately validated as putative biomarkers of BD (sensitivity 96.7%, specificity 93.3%, area under the curve 0.974). OPLS-DA showed clear discrimination of BD and HC groups by a biomarker panel of ten metabolites in the independent set (accuracy 88%). We demonstrated characteristic urinary metabolic profiles and potential urinary metabolite biomarkers that have clinical value in the diagnosis of BD using GC/TOF-MS. [ABSTRACT FROM AUTHOR]

Background: The gold standard for antinuclear antibody (ANA) screening is the indirect immunofluorescence (IIF) assay with human epithelial cells (HEp-2). However, a number of substantial disadvantages of manual IIF assays have highlighted the need for the automation and standardization of fluorescent ANA (FANA) testing. We evaluated the performance of EUROPattern Suite (Euroimmun AG, Germany), an automated FANA image analyzer, with regard to ANA detection and pattern recognition compared with conventional manual interpretation using the fluorescence microscopic IIF assay. Methods: A total of 104 samples including 70 ANA-positive sera and 34 ANA-negative sera collected from September to October 2015 were included. The sensitivity, specificity, and pattern recognition function were evaluated to determine the performance of EUROPattern Suite compared with the manual IIF assay results. Results: The sensitivity and specificity of EUROPattern Suite for ANA detection were 94.3% and 94.1%, respectively. The concordance rate between the two methods was 94.2%. For pattern recognition, 45.7% of the samples were assigned identical ANA patterns including simple and mixed. When major pattern matching was considered, 83.7% (41/49) and 95.2% (20/21) of the samples with simple and mixed patterns, respectively, showed concordant results between the two methods. Conclusions: EUROPattern Suite, an automated FANA image analyzer, provides a viable option for distinguishing between positive and negative results, although the ability to assign specific patterns is insufficient to replace manual microscopic interpretation. This automated system may increase efficiency in laboratories, in which a large number of samples need to be processed. [ABSTRACT FROM AUTHOR]

Objective: To identify the level of agreement between patients with rheumatoid arthritis (RA) and physicians in the global assessment of disease activity and to explore factors influencing their discordance. Methods: A total of 4368 patients with RA were analyzed from the KORean Observational study Network for Arthritis (KORONA) database. Patients were divided into four subgroups according to difference from their physicians in the assessment of disease activity by substracting physician's visual analog scale (VAS) from patient's VAS as follows: positive discordance group I (10mm≤discordance < 25 mm), positive discordance group II (≥25 mm), concordance (<|10| mm), and negative discordance (≤-10mm). Multinomial logistic regression analysis was performed to identify factors associated with discordance. Results: Only 1350 (29.2%) patients were classified in the concordance group. Positive discordance was found in 52.3% of the patients (n = 2425), with 33.7% (n = 1563) showing marked discordance (≥25 mm). The high disease activity (OR =1.41), gastrointestinal (GI) disease (OR = 1.28), pain (OR = 1.12), fatigue (OR = 1.07) were consistently associated with positive discordance. Conclusion: More than half of patients with RA thought their disease more severe than their physicians. In addition to high disease activity, pain, fatigue, and sleep disturbance or GI disease were associated with the discordance between physicians and patients with RA. [ABSTRACT FROM AUTHOR]

Purpose: Some patients with interstitial lung disease (ILD) related to connective tissue disease (CTD) have a delayed diagnosis of the underlying CTD when the ILD is categorized as idiopathic. In this study, we evaluated the frequency of myositis autoantibodies in patients diagnosed with idiopathic ILD and investigated the clinical significance stemming from the presence of the antibodies. Materials and Methods: A total 32 patients diagnosed with idiopathic ILD were enrolled in this study. We analyzed a panel of 11 myositis autoantibody specificities in the patients using a line blot immunoassay. Then, we divided them into myositis autoantibodypositive and -negative groups and compared the clinical features and laboratory data between the two groups. Results: Of the 32 idiopathic ILD patients, 12 patients had myositis autoantibodies encompassing 9 specificities, except for anti-Mi-2 and anti- PM-Scl 100 (12/32, 38%). Anti-synthetase autoantibodies including Jo-1, EJ, OJ, PL-7, and PL-12 were present in 7 patients (7/32, 22%). The group with myositis autoantibodies presented more frequently with the symptom of mechanic's hand and showed abnormal pulmonary function test results with low forced vital capacity, diffusing capacity for carbon monoxide, total lung capacity, and high lactate dehydrogenase values in blood when compared with the group without myositis antibodies. Conclusion: We strongly suggest that patients undergo an evaluation of myositis autoantibodies, if they are diagnosed with idiopathic ILD in the presence of clinical characteristics including mechanic's hand, arthralgia, and autoantibodies which are insufficient to make a diagnosis of a specific CTD category. [ABSTRACT FROM AUTHOR]

We sought to evaluate the frequency of cervical spine (C-spine) involvement, and associated risk factors for this disorder and its progression in Korean patients with rheumatoid arthritis (RA). From 1995 to 2008, we recruited patients with RA attending the rheumatology clinic of a single tertiary care hospital, and evaluated 1,120 of the patients who had neck pain for C-spine involvement. A diagnosis of C-spine involvement was made in 28.6% of patients evaluated, and within this group, anterior atlantoaxial subluxation (AAS) and subaxial subluxation were found in 89.7 and 15%, respectively. Of the 1,120 patients, 570 patients were followed for more than 3 years. Comparing the clinical characteristics of 193 patients with C-spine involvement and 377 patients without C-spine involvement, we found the associations with female gender, RA diagnosis at or before age 45, erosive changes in hand or foot radiographs, C-reactive protein levels and erythrocyte sedimentation rates at the time of first visit, and combination disease-modifying anti-rheumatic drug (DMARD) therapy. We found using logistic regression analysis that significant predictors of C-spine involvement included erosion in hand or foot radiographs (OR = 2.22, p = 0.001) and RA diagnosis at or before age 45 (OR = 2.26, p < 0.001). Among 137 patients followed for more than 3 years, for whom at least two consecutive X-rays were available, we observed radiographic progression in 60.4%. Patients with and without radiologic evidence for cervical progression did not differ significantly in clinical characteristics. In conclusion, Korean patients with RA frequently show radiographic evidence for progressive involvement of the cervical spine. Significant risk factors for C-spine involvement may be associated with erosive peripheral joint disease and RA diagnosis at an early age. [ABSTRACT FROM AUTHOR]

a measure of healthcare cost containment, the total number of vials of entanercept (25 mg) that can be prescribed for patients with inflammatory arthritis is restricted in Korea. Consequently, attempts to extend the dosing interval while maintaining the efficacy have not been an uncommon clinical practice. The aim of this study was to determine if extended doing interval of etanercept can be effective in patients with ankylosing spondylitis (AS). We performed a retrospective analysis using medical records at a single tertiary hospital. One hundred and nine patients with AS and 79 patients with rheumatoid arthritis (RA) started on etanercept between November 2004 and November 2009 were indentified. Etanercept (25 mg) was started with twice-weekly dosing schedule. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), C-reactive protein (CRP), and etanercept dosing interval for AS patients at 0, 3, 9, 15, 21 months were reviewed. Dosing interval for RA patients was analyzed for comparison. In AS, mean dosing interval was 4.7 ± 2.1 days at 3 months and was increased to 12.1 ± 7.0 days at 21 months. Despite the progressive increase in the dosing interval, the mean BASDAI declined rapidly at 3 months, and continued to decrease over 21 months. Mean CRP declined after 3 months of therapy and remained low thereafter. In RA, mean dosing interval was 4.0 ± 1.2 days at 3 months and 5.1 ± 1.8 days at 21 months. In conclusion, in AS, extended dosing of etanercept can be effective without compromising clinical and laboratory markers of disease activity as measured by BASDAI and CRP, respectively. Tapering of etanercept was less accommodating in RA when compared to AS. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the clinical characteristics of Behcet’s disease (BD) complicated with malignancy in Korea. Of 1,769 patients with BD in our hospital, 32 patients (1.8%, 21 in solid cancer, 11 in hematologic malignancy) developed cancer. In 10 of the 32 subjects (31.3%), malignancy was diagnosed before or concomitantly with BD. Twelve cases (37.5%) occurred within the first 2 years of disease and 9 cases (28.1%) occurred 5 years after the diagnosis of BD. Myelodysplastic syndrome (MDS) was the most common disease ( n = 7) followed by thyroid cancer ( n = 4), breast cancer, cervix cancer, stomach cancer, rectal cancer, hepatoma, aplastic anemia ( n = 3, each), renal cell cancer, endometrial cancer, lymphoma ( n = 1, each). There were no significant differences in the clinical characteristic between patients with or without malignancy. Intestinal involvement were more frequent in patients with malignancy than those without, but was not statistically significant ( p = 0.083). Our results demonstrate that MDS and thyroid cancer are the most common hematologic disease and solid cancer associated with BD, respectively. Further studies will be required to ascertain the pathogenic link between BD and malignancy and the prevalence of malignancy in BD. [ABSTRACT FROM AUTHOR]

Adult onset Still's disease (AOSD) is an inflammatory disease of unknown etiology, characterized by spiking fever, evanescent salmon pink maculopapular rash, arthritis, and leukocytosis with neutrophilia. Malignant lymphoma is one of the most important differential diagnoses of AOSD. AOSD has been reported as one of paraneoplastic syndromes associated with breast cancer. We report a rare case of occult papillary thyroid cancer (PTC) diagnosed coincidently with AOSD. A 32-year-old woman was diagnosed with AOSD according to the diagnostic criteria of Yamaguchi as follows: leukocytosis with neutrophilia, high fever with 39°C and above, arthralgia/arthritis, sore throat, liver dysfunctions, and lymphadenopathy. Excisional biopsy of cervical lymph node showed metastatic papillary carcinoma, and immunohistochemical staining for thyroglobulin and thyroid transcription factor-1 was strongly positive. There was no evidence of focal lesion in the thyroid glands. To our knowledge, this is the first report of adult onset Still's disease diagnosed concomitantly with occult PTC. [ABSTRACT FROM AUTHOR]

The authors report an unusual case of myelodysplastic syndrome (MDS) associated with ankylosing spondylitis (AS). A 40-year-old-man with MDS presented with chronic low back pain for 6 years. Four years ago, MDS was diagnosed during routine blood analysis for the work-up of his articular complaints. His initial articular complaints were attributed to extramedullary manifestations of MDS. Persistent low back pain with increasing intensity finally led the patient to seek medical attention. Radiograph of the pelvis showed bilateral asymmetric sacroiliitis. A diagnosis of AS was established on the basis of modified New York criteria. Although various autoimmune phenomena associated with MDS have been described, this is the first report of AS in the setting of MDS. Causal relationship between these two disorders is currently unknown. Increased risk of hematological diseases as well as AS in individuals with a positive HLA-B27 provides a feasible explanation for this rare observation. [ABSTRACT FROM AUTHOR]

Hughes–Stovin syndrome is an exceedingly rare disorder of unknown etiology, and it is characterized by multiple pulmonary artery aneurysms and peripheral venous thrombosis. We report a case of Hughes–Stovin syndrome with complete resolution of pulmonary artery aneurysm after treatment with cyclophosphamide. A 48-year-old man presented with massive hemoptysis, fever, and weight loss of 4-month duration. Computed tomography angiography revealed multiple pulmonary arterial aneurysms of variable sizes in both lung fields. Inferior vena caval thrombosis was also noted. Despite multiple surgical procedures including embolectomy and lobectomy combined with steroid therapy, new aneurysms continued to appear with persistent hemoptysis. Thorough history and physical examination did not suggest any evidence of Behcet’s disease. Hughes–Stovin syndrome was subsequently diagnosed. High-dose prednisolone combined with oral cyclophosphamide therapy was initiated. Chest radiography follow-up in 3 months revealed complete resolution of pulmonary aneurysm. No new aneurysm was detected at 15 months of follow-up. [ABSTRACT FROM AUTHOR]

Although p53 is overexpressed in rheumatoid arthritis (RA) synovial tissue (ST), few synoviocytes undergo apoptosis. This could be partly due to low expression of proapoptotic genes. Deficient p53 up‐regulated modulator of apoptosis (PUMA), which is a major effector of p53‐mediated cell death, could contribute to this phenomenon. To evaluate a method to induce apoptosis, the expression and function of PUMA was investigated in ST and cultured fibroblast‐like synoviocytes (FLS).PUMA expression in ST was measured by immunohistochemistry, Western blot analysis, and quantitative polymerase chain reaction analysis. Ad‐p53 and plasmids encoding hemagglutinin‐tagged, full‐length PUMA expression vector (HA‐PUMA), PUMA lacking the Bcl‐2 homology 3 domain, or pCEP4 were used to transfect FLS. Apoptosis was quantified by trypan blue exclusion, DNA fragmentation, and caspase 3 activation.PUMA protein was detected in RA ST, although most of the immunoreactive protein was localized to sublining cells rather than the intimal lining synoviocytes. Western blot analysis showed no difference between RA ST and osteoarthritis (OA) ST. PUMA messenger RNA was detected in RA and OA ST, although the amounts were markedly lower than in the spleen and FLS. To determine if PUMA was inducible, FLS were transduced with Ad‐p53. Even though p53 protein was produced and p21 expression was increased, PUMA expression was not enhanced. Consistent with this observation, Ad‐p53 did not induce apoptosis in FLS. However, HA‐PUMA transfection into FLS resulted in rapid apoptosis with the activation of caspase 3.PUMA can induce apoptosis by FLS and represents a potential target in RA. [ABSTRACT FROM AUTHOR]

Macrophages play a crucial role in the perpetuation of inflammation and irreversible cartilage damage during the development of rheumatoid arthritis (RA). LIGHT (TNFSF14) and its receptor TR2 (TNFRSF14) are known to have pro-inflammatory activities in foam cells of atherosclerotic plaques. We tested a hypothesis that LIGHT and TR2 are involved in activation of monocyte/macrophages in RA synovium. Immunohistochemical analysis of RA synovial tissue samples revealed that both LIGHT and TR2 are expressed in CD68 positive macrophages. In contrast, synovial tissue samples from osteoarthritis (OA) patients failed to reveal the expression of LIGHT. Expression of TR2 in RA synovial macrophages was also detected using flow cytometry analysis. To identify the role of LIGHT in the functioning of macrophages in RA, we isolated macrophage enriched cells from RA synovial fluid and stimulated them with LIGHT. LIGHT induced expression of matrix metalloproteinase-9 and pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8. These data indicate that LIGHT and TR2 expressed in macrophages are involved in the pathogenesis of RA by inducing the expression pro-inflammatory cytokines and matrix degrading enzymes. [ABSTRACT FROM AUTHOR]

Human soluble Fas ligand (sFasL) has an apoptotic activity in contrast to murine sFasL. The physiological function of human sFasL is not known, while the pathological consequence of sFasL overproduction has been reported. To understand the physiological function of (human) sFasL, murine and human lymphocytes were treated with sFasL. sFasL treatment significantly decreased CD45RB lo "memory" CD4+ lymphocyte fraction and increased propidium iodide (PI)+ apoptotic CD45RB lo CD4+ lymphocytes among murine peripheral lymphocytes. However, sFasL treatment neither decreased CD45RO+ "memory" CD4+ lymphocyte fraction nor increased PI+ CD45RO+CD4+ lymphocytes among human peripheral lymphocytes, suggesting that the deletion of memory cells by sFasL had already occurred in vivo . Patients with systemic lupus erythematosus had sFasL-susceptible "memory" cell fraction suggesting an incomplete deletion of such "memory" cells. These results suggest that the physiological function of human sFasL is to delete the potentially auto-reactive "memory" lymphocytes, which complements membrance FasL (mFasL)-mediated deletion of auto-reactive cells in human beings but not in mice. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Non-traumatic fracture of the femoral shaft in a patient taking long-term bisphosphonate therapy," that was published in the April 10, 2010 issue.

A letter to the editor on treatment outcomes in patients with non-infectious aortic valvulitis undergoing aortic valve replacement is presented.

Abstract Background We aimed to investigate whether there are sex differences in disease activity measures among patients with axial spondyloarthritis (axSpA) and to determine any potential impact on the assessment of treatment responses to tumor necrosis factor alpha inhibitors (TNFi). Methods Using the Korean College of Rheumatology Biologics and Targeted Therapy (KOBIO) registry data, we compared sex differences in changes in the Bath Ankylosing Spondylitis Disease Activity Score (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS) levels at baseline and one year after TNFi initiation in patients with axSpA. Results This study included 1,753 patients with axSpA who started or changed TNFi, of whom 1,343 (76.6%) were male. At baseline, the mean BASDAI and ASDAS scores of all patients were 5.98 and 3.6, respectively. The BASDAI changes between baseline and the one-year follow-up were independently associated with sex (𝛽 = 0.343, p = 0.011), whereas ASDAS was not (𝛽 = 0.079, p = 0.235). When judging the effect of TNFi at one-year of treatment, male patients were more likely to be assessed as effective by the BASDAI-based criterion (ΔBASDAI ≥ 50% or ≥ 2; OR 1.700, 95% CI 1.200–2.406), while the ASDAS-based criterion (ΔASDAS ≥ 1.1) showed no significant difference between sexes (OR 0.993, 95% CI 0.678–1.455), after adjusting for other baseline characteristics. Conclusions The changes in disease activity before and after TNFi use were significantly different between sexes when measured by BASDAI, but not ASDAS. TNFi treatment effects may be interpreted differently between sexes depending on the disease activity measure used.

Objectives Summarise the evidence of the performance of the machine learning algorithm in discriminating sacroiliitis features on MRI and compare it with the accuracy of human physicians.Methods MEDLINE, EMBASE, CIHNAL, Web of Science, IEEE, American College of Rheumatology and European Alliance of Associations for Rheumatology abstract archives were searched for studies published between 2008 and 4 June 2023. Two authors independently screened and extracted the variables, and the results are presented using tables and forest plots.Results Ten studies were selected from 2381. Over half of the studies used deep learning models, using Assessment of Spondyloarthritis International Society sacroiliitis criteria as the ground truth, and manually extracted the regions of interest. All studies reported the area under the curve as a performance index, ranging from 0.76 to 0.99. Sensitivity and specificity were the second-most commonly reported indices, with sensitivity ranging from 0.56 to 1.00 and specificity ranging from 0.67 to 1.00; these results are comparable to a radiologist’s sensitivity of 0.67–1.00 and specificity of 0.78–1.00 in the same cohort. More than half of the studies showed a high risk of bias in the analysis domain of quality appraisal owing to the small sample size or overfitting issues.Conclusion The performance of machine learning algorithms in discriminating sacroiliitis features on MRI varied owing to the high heterogeneity between studies and the small sample sizes, overfitting, and under-reporting issues of individual studies. Further well-designed and transparent studies are required.

Abstract This study aimed to evaluate the relative risk of malignancy in patients with Takayasu’s arteritis compared to that in the general population. This retrospective nationwide cohort study used data from the Korean Health Insurance Review and Assessment Service database. All newly diagnosed patients with Takayasu’s arteritis were identified between January 2009 and December 2019. They were observed until the diagnosis of malignancy, death, or end of the observational period, December 2020. The standardized incidence ratios (SIRs) of the overall and site-specific malignancies were estimated and compared with the incidence of cancer in the general population retrieved from the National Cancer Registry. We identified 1449 newly diagnosed patients with Takayasu’s arteritis during the observational period (9196 person-years). A total of 74, 66, and 8 patients had overall, solid, and hematologic malignancies, respectively. The risks of overall [SIR, 1.62; 95% confidence interval (CI) 1.27–2.03], solid (SIR, 1.51; 95% CI 1.17–1.92), and hematologic (SIR, 4.05; 95% CI 1.75–7.98) malignancies were increased compared to those in the general population. In solid malignancies, breast (SIR, 2.07; 95% CI 1.16–3.42) and ovarian (SIR, 4.45; 95% CI 1.21–11.39) cancers had an increased risk. In hematologic malignancies, the risk of myelodysplasia increased (SIR, 18.02; 95% CI 3.72–52.66). Immunosuppressive agent use was not associated with malignancy. There was no specific period when cancer more frequently occurred. An increased risk of malignancy was observed in patients with Takayasu’s arteritis compared to that in the general population in this large-scale nationwide population study of Korean health insurance data.

BackgroundTo date, few studies have focused on risk factors for gout in young people, and large-scale studies on the relationship between metabolic syndrome (MetS) and gout are lacking. We aimed to investigate the association between gout and MetS in a large nationwide population-based cohort of young men who participated in national health examination.Materials and methodsCohort included men aged 20–39 years who participated in a health check-up in 2009–2012. A total of 3,569,104 subjects was included in the study, excluding those who had a previous diagnosis of gout or had renal impairment. The outcome was the occurrence of gout, which was defined using the diagnosis code of gout in the claims database. Cox proportional hazard model was used to evaluate the association between MetS and incident gout.ResultsMean follow-up duration was 7.35 ± 1.24 years and the incidence rate of gout was 3.36 per 1,000 person-years. The risk of gout in subjects with MetS was 2.4-fold higher than subjects without MetS. Among the components of MetS, hypertriglyceridemia and abdominal obesity showed the greatest association with gout. As the number of MetS components increased, the risk of gout increased. The association between gout and MetS was more pronounced in relatively young subjects and in low- or normal-weight subjects.ConclusionMetabolic syndrome is an important risk factor for the gout in young men. In particular, the association between MetS and gout was greater in young and non-obese men. Management of MetS in young men will be important for future gout prevention.

Background: In previous studies, cardiovascular (CV) risk was increased in patients with gout. The effects of uric acid–lowering therapy on CV risk in gout patients have been investigated in numerous studies; however, allopurinol and benzbromarone have rarely been compared. Objectives: To compare CV risk based on allopurinol and benzbromarone treatment in Korean gout patients. Design: A nationwide population-based retrospective cohort study. Methods: We used South Korea database of the Health Insurance Review and Assessment (HIRA) service to identify gout patients ⩾18 years of age who newly started allopurinol or benzbromarone between 2009 and 2015. The primary outcome of the study was the occurrence of a composite CV endpoint, which included coronary revascularization, hospitalization due to myocardial infarction, ischemic stroke, and transient ischemic attack. Cox proportional hazard regression analysis and Kaplan–Meier curves were used for analysis. Results: The study included 257,097 allopurinol initiators and 7868 benzbromarone initiators. Compared with allopurinol initiators, the adjusted hazard ratio (aHR) of the composite CV endpoint of benzbromarone initiators was 1.01 [95% confidence interval (CI): 0.83−1.21], which was not significantly different. The results did not change even when 1:3 propensity score matching was performed for baseline characteristics. In subgroup analysis of high-risk patients with CV disease, significant difference was not observed between allopurinol and benzbromarone initiators. Conclusion: In this study, significant difference was not found in CV risk between allopurinol and benzbromarone initiators. In the high-CV-risk group, the incidence of CV events did not differ between allopurinol and benzbromarone initiators.

Background/Aims The objective of this study was to compare changes in the simplified disease activity index (SDAI) between biologic (b) and conventional (c) disease-modifying antirheumatic drugs (DMARD) users with seropositive rheumatoid arthritis (RA) in daily clinical practice. Methods This was a nationwide multicenter observational study. Patients who had three or more active joint counts and abnormal inf lammatory marker in blood test were enrolled. The selection of DMARDs was determined by the attending rheumatologist. Clinical parameters, laboratory findings, and Health Assessment Questionnaire (HAQ) scores were obtained at baseline and at 6 and 12 months. Serial SDAI changes and clinical remission rate at 6 and 12 months were assessed. Results A total of 850 patients participated in this study. The mean baseline SDAI score in bDMARD group was higher than that in cDMARD group (32.08 ± 12.98 vs 25.69 ± 10.97, p < 0.0001). Mean change of SDAI at 12 months was –19.0 in the bDMARD group and –12.6 in the cDMARD group (p < 0.0001). Clinical remission rates at 12 months in bDMARD and cDMARD groups were 15.4% and 14.6%, respectively. Patient global assessment and HAQ at 12 months were also significantly improved in both groups. Multivariate logistic regression showed that baseline HAQ score was the most notable factor associated with remission. Conclusions There was a significant reduction in SDAI within 12 months after receiving DMARDs in Korean seropositive RA patients irrespective of bDMARD or cDMARD use in real-world practice. Clinical remission was achieved in those with lower baseline HAQ scores.

Background/Aims To investigate the efficacy and safety of tocilizumab (TCZ) humanized anti-interleukin-6 receptor monoclonal antibody, in Korean patients with active rheumatoid arthritis (RA) refractory to conventional disease modifying anti-rheumatic drugs (DMARDs) including methotrexate (MTX) Methods The main study was a 24-week, randomized, double-blind, controlled trial that was followed by a 48-week, open-labeled, extension phase. TCZ (8 mg/kg) or placebo was intravenously administered every 4 weeks. Results Those treated with TCZ showed more favorable outcomes in terms of 20% according to the American College of Rheumatology response criteria (ACR20) and ACR50 responses, individual parameters of ACR core set, disease activity score in 28 joints (DAS28) remission, and European League Against Rheumatism (EULAR) response at week 24. These improvements were maintained or increased during the extension period. DAS28 remission at week 72 was associated with EULAR good response at week 12. The patients who experienced any adverse event (AE) were more frequent in the TCZ group compared to the placebo group. Most AEs were mild or moderate in intensity, although TCZ therapy had possible AEs including serious infection, abnormal liver function, and atherogenic lipid profile. Conclusions TCZ infusion add-on is highly efficacious and well-tolerated in Korean patients with active RA refractory to conventional DMARDs including MTX. EULAR good response at week 12 could predict DAS28 remission at week 72.

Objective: The aim of this study was to examine the impact of fat mass alteration on serum uric acid (SUA) levels in apparently clinically healthy men. Methods: We evaluated 27,387 men who consecutively underwent health check ups between 2015 and 2017. We assessed the likelihood of achieving a SUA level of

Background and objectives: Hyperuricemia is one of the well-known cardiovascular risk factors. There is a growing interest in the association between hyperuricemia and arrhythmia. We used the representative sample data of Korean population to study the association between hyperuricemia and heart rate irregularity (HRI) that reflects total arrhythmia. Materials and Methods: We performed weighted multivariate logistic regression analysis to assess the association between hyperuricemia and HRI. Results: Of the 10,827 subjects, 1308 (13.2%) had hyperuricemia and 130 (1%) had HRI. In the presence of hyperuricemia, HRI was three times higher than that in the absence of hyperuricemia (OR 2.98, 95% CI 1.71–5.18). The risk of HRI was highest in subjects with both hypertension and hyperuricemia. In the subgroup analysis, the association of hyperuricemia with HRI was most pronounced in the smoker group. Conclusions: Hyperuricemia was highly correlated with HRI in adult Korean representative sample data. Hyperuricemia was associated with a nearly tripled risk for HRI. Hypertension has a synergistic effect with hyperuricemia on HRI. Further research is warranted to clarify the relationship between hyperuricemia and arrhythmia and its mechanism.

This study aimed to evaluate the prevalence of comorbidities in patients with rheumatoid arthritis (RA) compared with the non-RA population. The 2010-2012 Korea National Health and Nutrition Examination Survey (KNHANES), which assesses the general health status of populations in South Korea using interviews and basic health assessment, was analyzed retrospectively. Weighted prevalence and odds ratio (OR) of comorbidities were analyzed in patients with RA compared with the non-RA population. The overall weighted (n = 37,453,158) prevalence of RA was 1.5%. Patients with RA were older and more female predominant than subjects without RA. The prevalence of living in an urban area, college graduation, alcohol consumption and smoking was lower in patients with RA than non-RA. Patients with RA had more comorbidities including hypertension, dyslipidemia, myocardial infarction (MI) or angina, stoke, osteoarthritis, lung cancer, colon cancer, pulmonary tuberculosis, asthma, diabetes, depression, thyroid disease and chronic kidney disease. After adjusting socioeconomic and lifestyle characteristics, RA was associated with an increased prevalence of MI or angina (OR 1.86, 95% CI 1.17-2.96, p = 0.009), pulmonary TB (OR 1.95, 95% CI 1.24-3.09, p = 0.004), asthma (OR 1.97, 95% CI 1.05-3.71, p = 0.036), thyroid disease (OR 1.71, 95% CI 1.05-2.77), depression (OR 2.38, 95% CI 1.47-3.85, p < 0.001) and hepatitis B (OR 2.34, 95% CI 1.15-4.80, p = 0.020) compared with the non-RA population. Prevalence of solid cancer was not significantly associated with RA after adjustment.

[This corrects the article DOI: 10.1371/journal.pone.0176260.].