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.

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.

Impact of socioeconomic status on biologics utilization in rheumatoid arthritis: revealing inequalities and healthcare efficiency

Background/Aims

This cross-sectional study aimed to investigate biologics treatment disparities in rheumatoid arthritis (RA) patients based on socioeconomic status (SES).

Methods

Data from the KOrean Observational Study Network for Arthritis (KORONA) database were analyzed to assess various factors associated with SES, health behaviors, and biologics use. Logistic regression and structured equation modeling (SEM) were utilized for data analysis.

Results

Among 5,077 RA patients included, 393 (7.7%) patients were identified as biologics users. Within the entire cohort, 31.8% of the participants were in the low-income and low-education groups, and 39.3% of the participants were in the high-income and high-education groups. Despite the patients with low income or low education experienced higher disease activity at diagnosis, had more comorbidities, exhibited higher medication compliance, underwent more check-ups, and had more hospital admissions than their counterparts, the odds of patients with low-income receiving biologics were 34% lower (adjusted odds ratio = 0.76, 95% confidence interval: 0.60-0.96, p = 0.021) after adjustment for demographics and comorbidities. SEM and pathway analyses confirmed the negative impact of low SES on biologics use.

Conclusions

The findings suggest that SES plays a significant role in biologics use among RA patients, indicating potential healthcare inefficiencies for low SES patients. Moreover, adverse healthcare habits negatively affect biologics use in RA patients. The study highlights the importance of considering socioeconomic factors while discussing biologics use and promoting equitable access to biologics for optimal RA management.

Corrigendum: Korean treatment recommendations for patients with axial spondyloarthritis

[This corrects the article on p. 151 in vol. 30, PMID: 37476674.].

Risk-Benefit Analysis of Primary Prophylaxis Against Pneumocystis Jirovecii Pneumonia in Patients With Rheumatic Diseases Receiving Rituximab

OBJECTIVE

To identify a specific population of patients with rheumatic diseases receiving rituximab treatment for whom the benefit from primary prophylaxis against Pneumocystis jirovecii pneumonia (PJP) outweighs the risk of adverse events (AEs).

METHODS

This study included 818 patients treated with rituximab for rheumatic diseases, among whom 419 received prophylactic trimethoprim/sulfamethoxazole (TMP/SMX) with rituximab, while the remainder did not. Differences in 1-year PJP incidence between the groups were estimated using Cox proportional hazards regression. Risk-benefit assessment was performed in subgroups stratified according to risk factors based on the number needed to treat (NNT) to prevent 1 case of PJP and the number needed to harm (NNH) due to severe AEs. Inverse probability of treatment weighting was applied to minimize the confounding by indication.

RESULTS

During the 663.1 person-years, there were 11 PJP cases, with a mortality rate of 63.6%. Concomitant use of high-dose glucocorticoids (≥30 mg/day of prednisone or equivalent during 4 weeks after rituximab administration) was the most important risk factor. The PJP incidence (per 100 person-years) was 7.93 (95% confidence interval [95% CI] 2.91-17.25) in the subgroup receiving high-dose glucocorticoids compared with 0.40 (95% CI 0.01-2.25) in the subgroup without high-dose glucocorticoid use. Although prophylactic TMP/SMX significantly reduced the overall PJP incidence (HR 0.11 [95% CI 0.03-0.43]), the NNT to prevent 1 case of PJP (146) was higher than the NNH (86). In contrast, the NNT fell to 20 (95% CI 10.7-65.7) in patients receiving concomitant high-dose glucocorticoids.

CONCLUSION

The benefit associated with primary PJP prophylaxis outweighs the risk of severe AEs in patients with rheumatic diseases receiving rituximab and concomitant high-dose glucocorticoid treatment.

Recurrent focal myofasciitis of Behçet syndrome mimics infectious myofasciitis: a case report

Behçet syndrome (BS) is a chronic inflammatory disease with multiorgan manifestations. However, muscular involvement in BS has rarely been reported. Herein, we report the case of a 30-year-old male with BS who had recurring pain and swelling of the lower legs. The patient was administered antibiotics on several occasions as the condition was misinterpreted to be infectious myositis. Magnetic resonance imaging revealed myofascial involvement with focal necrotic lesions, and muscle biopsy revealed acute suppurative myositis with perivascular infiltration of polymorphonuclear leukocytes. His symptoms improved after treatment with corticosteroids. Azathioprine and colchicine therapy was beneficial for preventing further relapse after short-term corticosteroid treatment. Therefore, BS should be considered in the differential diagnosis of focal suppurative myofasciitis.

Korean treatment recommendations for patients with axial spondyloarthritis

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.

Lung function trajectory of rheumatoid arthritis-associated interstitial lung disease

OBJECTIVES

To explore the course of lung function and RA disease activity and predictive factors for deteriorating lung function in patients with RA-interstitial lung disease (ILD).

METHODS

The Korean Rheumatoid Arthritis-Interstitial Lung Disease cohort is a multicentre, prospective observational cohort. Patients with RA-ILD were enrolled and followed up annually for 3 years for RA disease activity and ILD status assessment. Group-based modelling was used to cluster a similar predicted percentage of forced vital capacity (FVC%) patterns into trajectories.

RESULTS

This study included 140 patients who underwent at least two pulmonary function tests. Four distinctive trajectories for predicted FVC% were 'improving' [n = 11 (7.9%)], 'stable' [n = 68 (38.4%)], 'slowly declining' [n = 54 (48.6%)] and 'rapidly declining' [n = 7 (5.0%)]. Most (77.7%) patients maintained or improved to low RA disease activity. The lung function trajectory was not comparable to the RA disease activity trajectory. Age ≥70 years [relative risk (RR) 10.8 (95% CI 1.30, 89.71)] and early RA diagnosed within the preceding 2 years [RR 10.1 (95% CI 1.22, 84.2)] were associated with increased risk for rapidly declining predicted FVC%. The risk for deterioration or mortality increased in patients with a simultaneous diagnosis of RA and ILD within 24 weeks [RR 9.18 (95% CI 2.05, 41.0)] and the extent of lung involvement [RR 3.28 (95% CI 1.12, 9.60)].

CONCLUSION

Most patients with RA-ILD experienced stable or slowly declining lung function. In 5% of patients, predicted FVC% deteriorated rapidly, especially in older adults with early RA. The lung function trajectory was not comparable to the RA disease activity trajectory.

Comparative risk of infections between JAK inhibitors versus TNF inhibitors among patients with rheumatoid arthritis: a cohort study

BACKGROUND

To compare infectious risk between JAK inhibitors (JAKis) versus TNF inhibitors (TNFis) among rheumatoid arthritis (RA) patients in Korea.

METHODS

Using 2009-2019 Korea National Health Insurance Service database, we conducted a cohort study on RA patients initiating a JAKi or TNFi. The primary outcomes were herpes zoster (HZ), serious bacterial (SBI), and opportunistic infections (OI). Propensity-score fine-stratification (PSS) and weighting were applied to adjust for > 70 baseline covariates. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard models comparing JAKi versus TNFi users.

RESULTS

We included 2963 JAKi initiators PSS-weighted on 5169 TNFi initiators. During a follow-up of 1.16 years, the most frequent type of infections was HZ with incidence rate (IR) per 100 person-years of 11.54 and 4.88 in JAKi and TNFi users, respectively. The IR of SBI was 1.39 and 1.32, respectively. The OI was rare with a majority being tuberculosis and showed an IR of 0.11 and 0.49 in JAKi and TNFi users, respectively. The PSS-weighted HR (95% CI) for individual types of infections was 2.37 (2.00-2.80) for HZ, 1.04 (0.71-1.52) for SBI, and 0.25 (0.09-0.73) for OI.

CONCLUSIONS

This population-based cohort study on RA patients treated with JAKi or TNFi in Korea showed an exceptionally high IR of HZ in both treatment groups compared to that from Western countries, with an approximately doubled risk associated with JAKi versus TNFi use. The risk of SBI was comparable, but the risk of OI, particularly tuberculosis, was less among JAKi than TNFi initiators.

Methotrexate, leflunomide and tacrolimus use and the progression of rheumatoid arthritis-associated interstitial lung disease

OBJECTIVE

To examine the association between MTX, LEF and tacrolimus use and the progression of RA-associated interstitial lung disease (ILD).

METHODS

The Korean RA-ILD cohort prospectively enrolled patients with RA-associated ILD at multiple centres from 2015 to 2018 and followed up with them for 3 years. ILD progression was defined by any of the followings: a decrease of ≥10% in forced vital capacity, a decrease of ≥15% in the diffusing capacity of the lung for carbon monoxide, or death from respiratory failure.

RESULTS

Of 143 patients, 64 patients experienced ILD progression during a median follow-up period of 33 months. The use of MTX [adjusted hazard ratio (aHR), 1.06; 95% CI, 0.59, 1.89], LEF (aHR, 1.75; 95% CI, 0.88, 3.46) and tacrolimus (aHR, 0.94; 95% CI, 0.52, 1.72) did not increase the risk of ILD progression. However, the association between LEF use and the risk of ILD progression was significant in subgroups with poor lung function (aHR, 8.42; 95% CI, 2.61, 27.15). Older age, male sex, a shorter RA duration, higher RA disease activity and extensive disease at baseline were independently associated with ILD progression.

CONCLUSION

None of the three treatments increased the risk of RA-associated ILD progression, except for LEF, which increased the risk of ILD progression in patients with severe ILD. The appropriate use of conventional synthetic disease-modifying antirheumatic drugs considering RA disease activity and ILD severity would be important for the management of RA-associated ILD.

Korean treatment recommendations for patients with axial spondyloarthritis

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.

Ophthalmic manifestations and visual outcomes of granulomatosis with polyangiitis: a retrospective multicentre study in Korea

OBJECTIVES

To analyse the ophthalmic manifestations and treatment outcomes of Korean patients with granulomatosis with polyangiitis (GPA).

METHODS

One hundred twenty patients diagnosed with GPA by rheumatologists from January 1984 to March 2019 at three referral centres were retrospectively reviewed. Patients with ophthalmic symptoms were examined by ophthalmologists and underwent orbital imaging. Ophthalmic manifestations were divided into ocular involvement and ocular adnexal involvement. Multivariable logistic regression was used to examine the factors related to ocular, ocular adnexal, and optic nerve involvement. Visual improvement was defined as a best-corrected visual acuity gain of ≥2 Snellen lines, accompanied by improvements in optic nerve function.

RESULTS

Ophthalmic manifestations were observed in 50 patients (41.7%) during the median follow-up period of 6.7 years. Proteinase 3-anti-neutrophil cytoplasmic antibody (PR3-ANCA) positivity (odds ratio 3.19, 95% confidence interval 1.18-8.60) was an independent risk factor for ocular involvement, while sinonasal involvement (21.94, 2.54-189.69) and brain involvement (5.38, 1.50-19.31) were independent risk factors for ocular adnexal involvement. Antinuclear antibody (ANA) positivity was associated with optic nerve involvement (12.8, 1.80-90.5). Visual improvement occurred in 5 of 14 patients with optic nerve involvement, all of whom received intravenous (IV) immunosuppressive treatments beyond oral steroids within 2 months of visual impairment.

CONCLUSIONS

Ophthalmic involvement is common in Korean GPA patients and should be considered in the presence of PR3-ANCA, sinonasal or brain involvement. Patients with positive ANA have an increased risk of optic nerve involvement, and early IV immunosuppressive treatments beyond oral steroids are necessary to improve the visual outcome.

Safety and Effectiveness of Etanercept Biosimilar SB4 for Rheumatic Diseases in South Korea: Real-World Post-marketing Surveillance Data

INTRODUCTION

SB4 is the first approved biosimilar of etanercept, a biologic tumor necrosis factor inhibitor, to treat various autoimmune diseases including axial spondylarthritis (axSpA), rheumatoid arthritis (RA), psoriatic arthritis (PsA), and plaque psoriasis (PsO). This post-marketing surveillance (PMS) study of SB4 investigated safety and effectiveness in routine clinical practice and is part of the drug approval process in Korea.

METHODS

This prospective, multi-center, open-label, observational, phase IV PMS study was designed to enroll patients with axSpA, RA, PsA, and PsO in Korea from September 2015 to September 2019. Both etanercept-naïve patients or patients switched from reference etanercept were included. SB4 was administered weekly via subcutaneous injections using pre-filled syringes. Safety was assessed by the incidence of adverse events (AEs), adverse drug reactions (ADRs) and serious adverse events (SAE). Effectiveness was assessed by the change from baseline of investigator-rated Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in patients with ankylosing spondylitis (AS) and disease activity score-28 (DAS28) in patients with RA.

RESULTS

Among 316 enrolled patients, 314 were included in the safety analysis (176 with AS and 138 with RA). The overall incidence of AEs, ADRs and serious AEs were 17.8, 9.9, and 1.3%, respectively. Most AEs were mild (66.7%) or moderate (31.1%) and not related to SB4 (58.9%). Most common AEs were injection site pruritus (1.9%) and injection site rash (1.3%). At week 24, mean disease activity scores significantly decreased compared to baseline in naïve patients with AS and RA (BASDAI 2.7 vs. 6.2, p < 0.0001; DAS28 3.8 vs. 5.7, p < 0.0001) and in switched patients with AS and RA (BASDAI 1.0 vs. 1.3, p = 0.0018; DAS28 2.4 vs. 2.9, p = 0.0893).

CONCLUSION

This first real-world evidence of SB4 from a phase IV PMS study in Korea shows comparable effectiveness to historical SB4 real-world evidence without any new significant safety signals.

Impact of early age at menopause on disease outcomes in postmenopausal women with rheumatoid arthritis: a large observational cohort study of Korean patients with rheumatoid arthritis

OBJECTIVES

To assess the differences in clinical outcomes between patients with rheumatoid arthritis (RA) with early menopause (EM) (<45 years) and usual menopause (UM) (≥45 years) and to identify the impact of EM on longitudinal changes in RA activity and patient-reported outcomes (PROs).

METHODS

We recruited 2878 postmenopausal women with RA from the Korean Observational Study Network for Arthritis. Patients were examined at baseline and for 5 consecutive years using the Simplified Disease Activity Index (SDAI), Health Assessment Questionnaire-Disability Index (HAQ-DI) and other PROs. Generalised estimating equation (GEE) analyses were performed among patients with a baseline SDAI of >11 to evaluate the impact of EM on longitudinal changes in RA activity and PROs.

RESULTS

The EM group (n=437) was younger than the UM group (n=2441), but the RA duration was similar between the two groups. The EM group was more educated and more likely to be seronegative at enrolment. Moreover, the EM group demonstrated higher disease activity and worse PROs for global assessment, fatigue, sleep disturbance and health-related quality of life (HRQoL) (all p<0.05) at baseline. The GEE model revealed that EM significantly influenced the rate of SDAI change (β=1.265, p=0.004) after adjusting for age, RA duration, biologics use and SDAI at baseline. The EM group was also significantly associated with increased HAQ-DI scores and decreased EQ-5D-utility values during the 5-year follow-up period.

CONCLUSION

Patients with RA and EM demonstrate higher disease activity and poorer HRQoL. Furthermore, EM significantly affects the longitudinal changes in disease activity and PROs in patients with RA.

A Multicenter, Prospective, Randomized, Parallel-Group Trial on the Effects of Temporary Methotrexate Discontinuation for One Week Versus Two Weeks on Seasonal Influenza Vaccination in Patients With Rheumatoid Arthritis

OBJECTIVE

This clinical trial was conducted to investigate whether discontinuing methotrexate (MTX) for 1 week after seasonal influenza vaccination is noninferior to discontinuing for 2 weeks after vaccination in patients with rheumatoid arthritis (RA).

METHODS

In this multicenter, prospective, randomized, parallel-group noninferiority trial, RA patients receiving a stable dose of MTX were randomly assigned at a ratio of 1:1 to discontinue MTX for 1 week or for 2 weeks after they received the quadrivalent 2021-2022 seasonal influenza vaccine containing H1N1, H3N2, B/Yamagata, and B/Victoria strains. The primary outcome measure was the proportion of patients with a satisfactory vaccine response, which was defined as ≥4-fold increase in antibody titers, as determined with the hemagglutination inhibition assay, against ≥2 of the 4 vaccine strains at 4 weeks after vaccination.

RESULTS

The modified intent-to-treat population included 90 patients in the 1-week MTX hold group and 88 patients in the 2-week MTX hold group. The mean ± SD MTX doses were 12.6 ± 3.4 mg/week in the 1-week MTX hold group and 12.9 ± 3.3 mg/week in the 2-week MTX hold group. The proportion of satisfactory vaccine responses did not differ between the groups (68.9% versus 75.0%; P = 0.364). The rate of seroprotection and the fold increase in antibody titers for each of the 4 influenza antigens were similar between the groups.

CONCLUSION

A temporary discontinuation of MTX for 1 week after vaccination was noninferior to a discontinuation of MTX for 2 weeks after vaccination, regarding induction of a satisfactory vaccine response to a seasonal influenza vaccine in patients with RA receiving a stable dose of MTX.

The effect of rebamipide on non-steroidal anti-inflammatory drug-induced gastro-enteropathy: a multi-center, randomized pilot study

BACKGROUND/AIMS

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly-used medications, and ailments such as arthritis or heart disease, require long-term use of these drugs, which can induce gastroenteropathy with bleeding and ulcers. This study investigated the associations between efficacy, safety, and gastrointestinal symptoms linked to rebamipide and proton pump inhibitor administration in patients requiring long-term NSAID use.

METHODS

This study was a multi-center, randomized, open-labeled, pilot design.

RESULTS

Thirty-three patients were included. Of these, 15 were included in the study group and 18 were in the control group. NSAID-induced gastric ulcers, which were the primary outcome of this study, did not occur in either the study or control group. Changes in the number of small bowel erosions and ulcers were -0.6 ± 3.06 in the study group and 1.33 ± 4.71 in the control group. The number of subjects with mucosal breaks (defined as multiple erosions and/or ulcers) was three (20%) in the study group and six (40%) in the control group (p = 0.427). No serious adverse events occurred in either group. However, dyspepsia and skin rashes occurred in six patients (31.58%) in the study group and 13 (65%) in the control group (p = 0.036).

CONCLUSION

Although statistically significant differences were not generated, possibly as a result of the small sample size, mucosal breaks observed via capsule endoscopy revealed that rebamipide was likely to be more effective than lansoprazole in preventing small intestine damage caused by NSAIDs. Furthermore, fewer side-effects emerged with rebamipide.

Comparative risk of blindness and vision-threatening ocular comorbidities in patients with Behcet’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 hazard models estimated hazard ratios (HRs) and 95% confidence intervals (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 the HR [95% CI] of 10.73 [7.10–16.22]. The HR [95% CI] for secondary outcomes was 2.06 [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 [95% CI] of incident uveitis was 6.19 [5.83–6.58]. Males suffered a disproportionately higher risk of blindness than females due to greater severity than lower incidence of uveitis. The risk of uveitis and blindness decreased as BD diagnosis ages increased.

Conclusion

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.

Electrochemical detection of uric acid in undiluted human saliva using uricase paper integrated electrodes

In this study, we introduce a uricase-immobilized paper (UOx­-paper) integrated electrochemical sensor for detection of uric acid (UA) in saliva. The UOx was immobilized on the detection zone in the wax-patterned paper substrate. This UOx-paper was integrated with a Prussian blue­-modified, screen-printed carbon electrode after electropolymerization of o-phenylenediamine to construct an electrochemical cell for small-volume (20 μL) of samples. First, we optimized the fabrication conditions of UOx-paper. Next, the amperometric response of the UOx-paper-based electrochemical UA sensor was analyzed using a known concentration of UA standard solution in artificial saliva at an applied potential of − 0.1 V (versus Ag pseudo-reference electrode). The UOx-­paper based electrochemical UA sensor showed a sensitivity of 4.9 μA·mM⁻¹ in a linear range of 50 to 1000 μM (R² = 0.998), high selectivity and good reproducibility, as well as a limit of detection of 18.7 μM (0.31 mg/dL) UA. Finally, we quantified the UA levels in undiluted saliva samples of healthy controls (n = 20) and gout patients (n = 8). The levels were correlated with those measured with conventional salivary UA enzymatic assays as well as serum UA levels. The UOx-paper-based electrochemical UA sensor is a user-friendly and convenient tool to assess salivary UA levels.

A Case of Macrophage Activation Syndrome During the Treatment of Adult-onset Still's Disease With Tocilizumab

Macrophage activation syndrome (MAS) is a fatal complication of adult-onset Still's disease (AOSD). Although anti-cytokine agents have been recommended for refractory AOSD or complicated with MAS, MAS cases have been rarely reported during anti-cytokine treatment. Herein, we describe the first AOSD case complicated with MAS during the treatment with tocilizumab in Korea. Two years after tocilizumab maintenance therapy, high fever and hypertransaminasemia recurred. MAS was diagnosed based on hyperferritinemia, elevated soluble IL-2 receptor levels, and the presence of hemophagocytic histiocytes in the bone marrow. However, she had normal white blood cell counts and acute phase reactant levels. High-dose glucocorticoid and anakinra therapies were not effective, but her disease improved with etoposide. This case shows that tocilizumab may not prevent MAS development and can modify clinical features making it challenging to diagnose. Cytotoxic therapy such as etoposide may be required in MAS cases that develop during anti-cytokine therapy.

Assessment on Treatments With Conventional Synthetic Disease-modifying Drugs Before Initiating Biologics in Patients With Rheumatoid Arthritis in Korea: A Population-based Study

Objective

To assess pre-biologic treatments with conventional synthetic disease-modifying drugs (csDMARDs) prior to biologics initiation among patients with rheumatoid arthritis (RA).

Methods

Using Korea National Health Insurance database, we examined pre-biologic treatments of RA patients on the following four items whether 1) initial methotrexate (MTX) therapy was given, 2) MTX dose was escalated up to ≥15 mg/week within 1-year post-diagnosis, 3) prednisone-equivalent glucocorticoid was used at a dose of ≤7.5 mg/day, and 4) glucocorticoid was discontinued within 6 months of treatment. Multivariable logistic regressions identified predictors of items 2) and 4) fulfillment.

Results

Among 6,986 biologics initiators with RA, 54.9% used MTX as the 1st csDMARD. Within 1-year post-diagnosis, 85.2% used MTX with half of them achieving a dose of ≥15 mg/week. The majority (75.2%) of patients used glucocorticoids initially and 64.5% were still on glucocorticoids at 6 months, mostly at a dose of ≤7.5 mg/day. csDMARD combination was observed in 85.7%. Item 2) fulfillment was associated with males, younger age, glucocorticoid, combination therapy, cyclo-oxygenase-2 inhibitors, and viral hepatitis. Item 4) fulfillment was associated with males, MTX dose of ≥15 mg/week, combination therapy, viral hepatitis, and hospitalizations.

Conclusion

RA patients in Korea were predominantly treated with MTX-based csDMARD combination plus glucocorticoids before initiating biologics, without sufficient MTX dose escalation or glucocorticoid discontinuation. Items 2) and 4) fulfillments were associated with patient age and gender, concomitant treatments, and comorbidities.

Extracellular pyruvate kinase M2 promotes osteoclastogenesis and is associated with radiographic progression in early rheumatoid arthritis

Extracellular PKM2 (exPKM2) levels have been reported to be increased in several cancers and inflammatory diseases, including rheumatoid arthritis (RA). This study aimed to investigate the association of circulating exPKM2 levels with radiographic progression in RA patients and the effect of exPKM2 on osteoclastogenesis. Plasma and synovial fluid exPKM2 levels were significantly elevated in RA patients. Plasma exPKM2 levels were correlated with RA disease activity and were an independent predictor for radiographic progression in RA patients with a disease duration of ≤ 12 months. CD14⁺ monocytes but not RA fibroblast-like synoviocytes secreted PKM2 upon stimulation with inflammatory mediators. Recombinant PKM2 (rPKM2) increased the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells and resorption pit in osteoclast precursors, dose-dependently, even in the absence of receptor activator of nuclear factor-kappa B ligand (RANKL). rPKM2 treatment upregulated the expression of dendrocyte-expressed seven transmembrane protein (DC-STAMP) and MMP-9 via the ERK pathway. Although rPKM2 did not directly bind to RAW264.7 cells, extracellular application of pyruvate, the end-product of PKM2, showed effects similar to those seen in rPKM2-induced osteoclastogenesis. These results suggest that exPKM2 is a potential regulator of RA-related joint damage and a novel biomarker for subsequent radiographic progression in patients with early-stage RA.

High Estimated 24-Hour Urinary Sodium Excretion Is Related to Symptomatic Knee Osteoarthritis: A Nationwide Cross-Sectional Population-Based Study

OBJECTIVES

High salt intake results in various harmful effects on human health including hypertension, cardiovascular disease, and reduced bone density. Despite this, there are very few studies in the literature that have investigated the association between sodium intake and osteoarthritis (OA). Therefore, we aimed to explore these associations in a Korean population.

METHODS

This study used cross-sectional data from adult subjects aged 50-75 years from two consecutive periods of the Korean National Health and Nutrition Examination Survey V-VII (2010-2011 and 2014-2016). The estimated 24-hour urinary sodium excretion (24HUNa) was used as a surrogate marker of salt intake. In the 2010-2011 dataset, knee OA (KOA) was defined as the presence of the radiographic features of OA and knee pain. The association between KOA and salt intake was analysed using univariable and multivariable logistic regression methods. For the sensitivity analysis, the same procedures were conducted on subjects with self-reported OA (SR-OA) with knee pain in the 2010-2011 dataset and any site SR-OA in the 2014-2016 dataset.

RESULTS

Subjects with KOA had significantly lower energy intake, but higher 24HUNa than those without KOA. The restricted cubic spline plots demonstrated a J-shaped distribution between 24HUNa and prevalent KOA. When 24HUNa was stratified into five groups (<2, 2-3, 3-4, 4-5 and ≥5 g/day), subjects with high sodium intake (≥5 g/day) had a higher risk of KOA (odds ratio [OR] = 1.64, 95% confidence interval [CI] 1.03-2.62) compared to the reference group (3-4 g/day) after adjusting for covariates. The sensitivity analysis based on SR-OA with knee pain showed that high sodium intake was also significantly associated with increased prevalence of OA (OR = 1.84, 95% CI 1.10-3.10) compared with the reference group. Regarding SR-OA at any site in the 2014-2016 dataset, estimated 24HUNa showed a significantly positive association with the presence of SR-OA after adjusting for potential confounders.

CONCLUSIONS

This nationwide Korean representative study showed a significant association between symptomatic KOA and high sodium intake (≥5 g/day). Avoidance of a diet high in salt might be beneficial as a non-pharmacologic therapy for OA.

Association of rheumatoid arthritis and high sodium intake with major adverse cardiovascular events: a cross-sectional study from the seventh Korean National Health and Nutrition Examination Survey

OBJECTIVES

High salt intake has a harmful effect on hypertension; however, the association between major adverse cardiovascular events (MACE) and salt intake is still controversial. Rheumatoid arthritis (RA) is also characterised by excess cardiovascular risk. However, few studies have investigated the combined role of salt intake and RA in MACE in the general Korean population. Here, we evaluated this relationship among the Korean adult population.

DESIGN

Retrospective, cross-sectional.

SETTING

Population-based survey in Korea.

METHODS

This study was based on the data of the seventh Korean National Health and Nutrition Examination Survey (2016-2018). The estimated 24-hour urinary sodium excretion (24HUNa), a surrogate marker for daily sodium intake, was calculated using the Tanaka equation and was stratified into five groups (<3, 3-3.999, 4-4.999, 5-5.999 and ≥6 g/day). Finally, data from 13 464 adult participants (weighted n=90 425 888) were analysed; all analyses considered a complex sampling design. Multivariable logistic regression for MACE as primary dependent variable was performed and adjusted for potential covariates.

RESULTS

Participants with MACE had higher 24HUNa levels and RA proportion than those without MACE (p<0.001). The association of MACE with 24HUNa was J-shaped with a gradual increase from about 3 g/day. The highest 24HUNa (≥6 g/day) group was significantly associated with increased prevalence of MACE compared with the reference group (3-3.999 g/day) after adjusting for all associated covariates (OR 6.75, 95% CI 1.421 to 32.039). In the multivariate logistic regression analysis, RA (OR 2.05, 95% CI 1.283 to 3.264) and the highest 24HUNa group (OR 6.35, 95% CI 1.337 to 30.147) were significantly associated with MACE even after adjusting for baseline covariates.

CONCLUSIONS

These nationally representative data suggest that RA and extremely high sodium intake are associated with MACE in the general adult Korean population. Avoiding extremely high salt intake and considering RA as an important risk factor for MACE might help promote public cardiovascular health.

Cardiovascular risk associated with allopurinol vs. benzbromarone in patients with gout

Aims 

With the high prevalence of gout and associated cardiovascular (CV) diseases, information on the comparative CV safety of individual urate-lowering drugs becomes increasingly important. However, few studies examined the CV risk of uricosuric agents. We compared CV risk among patients with gout who initiated allopurinol vs. benzbromarone.

Methods and results 

Using the Korean National Health Insurance claims data (2002–17), we conducted a cohort study of 124 434 gout patients who initiated either allopurinol (n = 103 695) or benzbromarone (n = 20 739), matched on propensity score at a 5:1 ratio. The primary outcome was a composite CV endpoint of myocardial infarction, stroke/transient ischaemic attack, or coronary revascularization. To account for competing risk of death, we used cause-specific hazard models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the outcomes comparing allopurinol initiators with benzbromarone. Over a mean follow-up of 1.16 years, 2258 patients developed a composite CV event. The incidence rate of the composite CV event was higher in allopurinol initiators (1.81 per 100 person-years) than benzbromarone (1.61 per 100 person-years) with a HR of 1.22 (95% CI 1.05–1.41). The HR for all-cause mortality was 1.66 (95% CI 1.43–1.93) among allopurinol initiators compared with benzbromarone.

Conclusion 

In this large population-based cohort of gout patients, allopurinol was associated with an increased risk of composite CV events and all-cause mortality compared to benzbromarone. Benzbromarone may reduce CV risk and mortality in patients with gout, although more studies are necessary to confirm our findings and to advance our understanding of the underlying mechanisms.

Association of Serum Biomarkers With Pulmonary Involvement of Rheumatoid Arthritis Interstitial Lung Disease: From KORAIL Cohort Baseline Data

Objective

The increase in mortality in rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) is well known However, there are few studies on serum markers that can evaluate acute exacerbation or prognosis in RA-ILD patients The purpose of this study was to identify the association between biomarkers and lung lesions in patients with RA-ILD.

Methods

We analyzed 153 patients with serum samples in a prospective, multicenter cohort of Korean RA-ILD patients The serum levels of biomarkers, matrix metalloproteinase (MMP-7), surfactant protein-D (SP-D), and Krebs von den Lungen-6 (KL-6) were measured and correlated with forced vital capacity (FVC), diffusing capacity for carbon monoxide (DLCO) and the results of computed tomography (CT) CT results were interpreted semi-quantitatively according to the extent of lung lesions (grade 1, 0%∼25%; grade 2, 26%∼50%; grade 3, 51%∼75%; grade 4, 76%∼100%).

Results

MMP-7, SP-D, and KL-6 were negatively correlated with FVC (MMP-7, r=-0267, p=0001; SP-D, r=-0250, p=0002; KL-6, r=-0223, p=0006) and DLCO (MMP-7, r=-0404, p<0001; SP-D, r=-0286, p=0001; KL-6, r=-0226, p=0007) In addition, MMP-7, SP-D, and KL-6 tended to increase with higher grades of lung lesions on CT (MMP-7, p=0013; SP-D, p<0001; KL-6, p<0001).

Conclusion

MMP-7, SP-D, and KL-6 can be used to evaluate the functional and anatomical status of lung involvement in the RA-ILD patients.

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.

Quality Indicators for Evaluating the Health Care of Patients with Rheumatoid Arthritis: a Korean Expert Consensus

BACKGROUND

There is increasing interest in the quality of health care and considerable efforts are being made to improve it. Rheumatoid arthritis (RA) is a disease that can result in favorable outcomes when appropriate diagnosis and treatment are provided. However, several studies have shown that RA is often managed inappropriately. Therefore, the Korean College of Rheumatology aimed to develop quality indicators (QIs) to evaluate and improve the health care of patients with RA.

METHODS

Preliminary QIs were derived based on the existing guidelines and QIs for RA. The final QIs were determined through two separate consensus meetings of experts. The consensus was achieved through a panel of experts who voted using the modified Delphi method.

RESULTS

Fourteen final QIs were selected among 70 preliminary QIs. These included early referral to and regular follow-up with a rheumatologist, radiographs of the hands and feet, early initiation and maintenance of disease-modifying anti-rheumatic drug (DMARD) therapy, periodic assessment of disease activity, screening for drug safety and comorbidities, including viral hepatitis and tuberculosis before biologic DMARD therapy, periodic laboratory testing, supplementation with folic acid, assessment of the risk for cervical spine instability before general anesthesia, patient education, and specialized nurse.

CONCLUSION

These QIs can be used to assess and improve the quality of health care for patients with RA.

Pharmacological Interventions for Pulmonary Involvement in Rheumatic Diseases

Among the diverse forms of lung involvement, interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are two important conditions in patients with rheumatic diseases that are associated with significant morbidity and mortality. The management of ILD and PAH is challenging because the current treatment often provides only limited patient survival benefits. Such challenges derive from their common pathogenic mechanisms, where not only the inflammatory processes of immune cells but also the fibrotic and proliferative processes of nonimmune cells play critical roles in disease progression, making immunosuppressive therapy less effective. Recently, updated treatment strategies adopting targeted agents have been introduced with promising results in clinical trials for ILD ad PAH. This review discusses the epidemiologic features of ILD and PAH among patients with rheumatic diseases (rheumatoid arthritis, myositis, and systemic sclerosis) and the state-of-the-art treatment options, focusing on targeted agents including biologics, antifibrotic agents, and vasodilatory drugs.

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.

Sex differences in clinical characteristics and their influence on clinical outcomes in an observational cohort of patients with rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is more prevalent in women, but sex differences remain incompletely understood. This study aimed to elucidate sex differences in clinical characteristics and their potential impact on clinical outcomes in a large Korean cohort of patients with RA.

METHODS

In total, 5376 RA patients from the KORean Observational study Network for Arthritis (KORONA) database were examined at baseline and for 3 consecutive years using the disease activity score 28 (DAS28), health assessment questionnaire (HAQ), and patient-reported outcomes (PROs). Within a subgroup with active disease (DAS28≥3.2) at baseline, sex impacts on clinical outcome during follow-up were analyzed using generalized estimating equation (GEE) models. The factors related to achieving clinical remission were analyzed using Cox-proportional hazard regression.

RESULTS

At baseline, women (n=4574) were younger and had more erosive disease and longer disease duration than men (n=802) with higher scores in DAS28, HAQ, and PROs. The prevalence of interstitial lung disease, cardiovascular disease, and diabetes in men was higher than that of women. In a RA subgroup with active disease at baseline, GEE analyses demonstrated that women RA significantly influenced the rate of change of DAS28 over time. In that group, men are associated with achieving DAS28 sustained remission and point remission.

CONCLUSIONS

Women with RA in Korea report higher levels of disease activity and PROs compared to men, whereas most comorbidities were more prevalent in men. The longitudinal change in disease activity and the rate of achieving clinical remission were found to be worse in women with RA.

[Clinicopathological features and differential diagnosis of eosionphilic chromophobe renal cell carcinoma]

Objective: To investigate the clinicopathological characteristics of eosionphilic Chromophobe renal cell carcinoma (eChRCC), and differences in morphology, immunophenotype and clinical prognosis betweeneChRCC, renal oncocytoma(RO) and classic Chromophobe renal cell carcinoma (cChRCC). Methods: The clinicopathologic data of 17 patients diagnosed as eChRCC from the Affiliated Hospital of Qingdao University (13 cases) and 971 Hospital of PLA Navy (4 cases) from October 2006 to February 2019 were collected. Immunohistochemical analysis was carried out to compare the immunophenotypes between 17 cases with ChRCC, 27 cases with RO and 30 cases with cChRCC. Resuls: Among the 17 patients, seven were males and ten were females, and the age ranged from 40 to 75 years (median 54 years). Clinically, 15 cases of 17 were found accidentally by physical examination. The tumor size ranged from 1.8 cm to 10.0 cm (average 5.7 cm) and the cut surface of 15 cases were solid, one case was solicl and cystic, and one was cystic. Most showed gray to red, and partially soft, gray to yellow appearances. Microscopically, most tumors presented solid growth pattern with vary number of alveolar structures (12 cases). Some were predominately characterized by cystic structure (3 cases), alveolar structure(1 case) and microcapsule structure (1 case). There were boundaries with varying degrees of clarity between tumor cells in 16 cases. The cytoplasm of tumor cells was eosinophilic and the nuclei were small round or irregular with focal perinuclear haloes in 14 cases. Large polygonal cells with light-stained cytoplasm appeared focally in 9 cases, and edematous areas with scarce tumor cells were found in 4 cases. Among 7 cases, 4 cases focally invaded peripheral renal parenchyma, 2 cases invaded adipose tissues outside the renal capsule, and 1 case presented invasion of renal sinus. Immunohistochemically, all cases were moderate to strong positive for EMA and claudin-7. CK7, CD117 and Ksp-cad were highly expressed with the expression rates of 12/17, 15/17, 14/17, respectively. Cyclin D1, AMACR, CD10, S100A1, and RCC were rarely expressed with the expression rates of 4/17, 3/17, 4/17, 1/17 and 1/17, respectively. On the contrary, all cases were negative for vimentin, CAⅨ, HMB45 and Melan A. The Ki-67 proliferation index of the 17 cases was 1%‒5%. Follow-up data were available for all 17 patients from 7 to 154 months. Among them, 15 patients were alive without tumor recurrence or metastasis, one patient died of pulmonary metastasis after 31 months of surgery and one patient died of hepatic metastasis after 38 months of surgery. Conclusion: eChRCC has overlapping morphology and immunophenotype with RO. eChRCC is characterized by solid nest or alveolar structure, distinct border between tumor cells, perinuclear halos and lacking of interstitial looseness and edema. Scattered large polygonal cells with light-stained cytoplasm in tumor tissue play a significant role in the diagnosis of eChRCC. The positive expression of CK7, CD117, claudin-7 and Ksp-cad, and negative expression of cyclin D1, S100A1 are helpful to the diagnosis and differential diagnosis of eChRCC. The prognosis of eChRCC after complete surgical resection is excellent and few cases may have long-term metastasis. There is no significant difference in prognosis between eChRCC and cChRCC, but eChRCC shows better outcome than RO.

Risk of Serious Infection Among Initiators of Tumor Necrosis Factor Inhibitors Plus Methotrexate Versus Triple Therapy for Rheumatoid Arthritis: A Cohort Study

OBJECTIVE

To compare the risk of serious infections between the use of tumor necrosis factor inhibitors (TNFi) plus methotrexate (MTX) versus triple therapy among rheumatoid arthritis (RA) patients in a real-world setting.

METHODS

Using claims data from Truven MarketScan (2003-2014), we conducted a cohort study to compare RA patients receiving MTX who added a TNFi (TNFi plus MTX group) versus MTX plus hydroxychloroquine and sulfasalazine (triple therapy group). The primary outcome was any serious infection (i.e., a composite end point of hospitalized bacterial and opportunistic infections or herpes zoster). Secondary outcomes were individual components of the composite end point. To adjust for baseline confounding, we used propensity score (PS)-based fine stratification and weighting. A weighted Cox proportional hazards model estimated the hazard ratio (HR) and 95% confidence interval (95% CI) of the outcomes.

RESULTS

After PS stratification (PSS) and weighting, we included a total of 45,208 TNFi plus MTX initiators and 1,387 triple therapy initiators. Mean age was 53 years and 70% were female. The incidence rate of any serious infection per 100 person-years was 2.46 in the TNFi plus MTX group and 2.03 in the triple therapy group. The PSS-weighted HR for any serious infection comparing TNFi plus MTX versus triple therapy was 1.23 (95% CI 0.87-1.74). For the secondary outcomes, the PSS-weighted HR was 1.41 (95% CI 0.85-2.34) for bacterial infection and 0.80 (95% CI 0.55-1.18) for herpes zoster.

CONCLUSION

In this real-world cohort of RA patients, we noted no substantially different risk of any serious infection, bacterial infection, or herpes zoster after initiating TNFi plus MTX versus triple therapy, although CIs were wide.

Comparative risk of osteoporotic fracture among patients with rheumatoid arthritis receiving TNF inhibitors versus other biologics: a cohort study

In this population-based cohort study on comparative osteoporotic fracture risks between different biologic disease-modifying drugs among patients with rheumatoid arthritis (RA), we did not find a significant difference in the risk of osteoporotic fractures between RA patients receiving TNF inhibitors versus abatacept or tocilizumab.

INTRODUCTION

We aimed to investigate the comparative risk of osteoporotic fractures between rheumatoid arthritis (RA) patients who initiated TNF inhibitors (TNFis) versus abatacept or tocilizumab.

METHODS

Using the Korea National Health Insurance Service datasets from 2002 to 2016, RA patients who initiated TNFis, abatacept, or tocilizumab were identified. The primary outcome was a composite end point of non-vertebral fractures and hospitalized vertebral fractures; secondary outcomes were two components of the primary outcome and fractures occurring at the humerus/forearm. Propensity score (PS) matching with a variable ratio up to 10 TNFi initiators per 1 comparator drug initiator was used to adjust for > 50 baseline confounders. We estimated hazard ratios (HRs) and 95% confidence interval (CI) of fractures comparing TNFi initiators to abatacept and to tocilizumab by Cox proportional hazard models stratified by a matching ratio.

RESULTS

After PS-matching, 2307 TNFi initiators PS-matched on 588 abatacept initiators, and 2462 TNFi initiators on 640 tocilizumab initiators were included. A total of 77 fractures occurred during a mean follow-up of 454 days among TNFi and abatacept initiators and 83 fractures during 461 days among TNFi and tocilizumab initiators. The PS-matched HR (95% CI) was 0.91 (0.48-1.71) comparing TNFi versus abatacept initiators, and 1.00 (0.55-1.83) comparing TNFi versus tocilizumab initiators. Analysis on vertebral and non-vertebral fractures showed similar results.

CONCLUSIONS

In this nationally representative cohort, we did not find a significant difference in the risk of fractures between TNFi initiators versus abatacept or tocilizumab among RA patients.

Risk factors associated with initiation of a biologic disease modifying anti-rheumatic drug in patients with rheumatoid arthritis: A nested case-control study on 34,925 patients

OBJECTIVE

To identify risk factors of biological disease-modifying anti-rheumatic drugs (bDMARDs) initiation in patients with rheumatoid arthritis (RA).

METHODS

Using the 2002-2016 Korea National Health Insurance database, we conducted a nested case-control study on seropositive RA patients. Cases (bDMARD users) and controls (users of conventional synthetic DMARDs only) were 1:4 matched on the calendar year/month of RA diagnosis and index dates (bDMARD initiation dates). Potential risk factors from two time periods, 1-year post-RA-diagnosis and 1-year pre-index, were separately assessed on the association with bDMARD initiation by conditional logistic regression analyses.

RESULTS

The study included 6985 cases and 27,940 controls. Older age, female gender, use of methotrexate (MTX), leflunomide, or tacrolimus as a first csDMARD, higher initial MTX dose, and initial csDMARD combination during 1-year post-diagnosis were negatively associated with later bDMARD initiation, while use of sulfasalazine as a first csDMARD, corticosteroid therapy, and higher maximal MTX dose were positively associated. Among covariates from 1-year period before bDMARD initiation, use of leflunomide, sulfasalazine, or tacrolimus, parenteral MTX, higher maximal MTX dose, corticosteroid, and csDMARD combination were positively associated with subsequent bDMARD initiation. Effects of comorbidities on bDMARD initiation were heterogenous across involved systems.

CONCLUSION

In this population-based nationwide study, we identified period-specific risk factors of bDMARD initiation among RA patients in Korea. Overall, initial aggressive RA treatment after diagnosis was associated with less use of later bDMARD, while highly intensive therapy observed just before bDMARD initiation rather reflects refractory nature of RA during this period, and did not prevent bDMARD use.

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.

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.

Risk of exacerbation of pulmonary comorbidities in patients with rheumatoid arthritis after initiation of abatacept versus TNF inhibitors: A cohort study

BACKGROUND

Biologic agents may pose a potential risk for exacerbations of pulmonary comorbidities in rheumatoid arthritis (RA) patients.

METHODS

Using U.S. Medicare and Truven MarketScan databases, we identified three cohorts of RA patients with interstitial lung disease (ILD), chronic obstructive pulmonary disease (COPD), or asthma who initiated abatacept or a TNF inhibitor (TNFi). The primary outcome was a composite exacerbation of individual pulmonary comorbidities based on inpatient or emergency department (ED) visits due to exacerbation of the given pulmonary comorbidity. To adjust for >60 baseline confounders, we used propensity-score fine stratification (PSS) and weighting. Negative binomial regression model estimated a cohort-specific incidence rate ratio (IRR) and 95% confidence interval (CI) of the primary outcome per database, comparing abatacept versus TNFi. Database-specific IRRs were combined using a random-effects meta-analysis.

RESULTS

We identified 3,295 ILD, 7,161 COPD, and 5,613 asthma patients with RA who initiated either abatacept or a TNFi. IR of composite exacerbation was high in all three pulmonary cohorts but highest in COPD cohort (3.59-11.80 per 100 person-years in ILD, 20.68-34.97 in COPD, and 4.66-13.78 in asthma). After PSS weighting, the combined IRR (95%CI) in abatacept initiators versus TNFi initiators was 0.44 (0.18-1.09) for ILD exacerbation, 0.91 (0.80-1.03) for COPD exacerbation, and 0.81 (0.54-1.22) for asthma exacerbation.

CONCLUSION

Among patients with RA and pulmonary comorbidities, exacerbations requiring inpatient or ED visits occurred frequently after initiating abatacept or TNFi. Overall, we found no significant difference in the risk of ILD, COPD or asthma exacerbation between abatacept and TNFi initiators, but precision of our estimates is limited.

Assessment of Cardiovascular Risk in Older Patients With Gout Initiating Febuxostat Versus Allopurinol: Population-Based Cohort Study

BACKGROUND

Hyperuricemia and gout are associated with an increased risk of cardiovascular disease. Xanthine oxidase inhibitors, allopurinol and febuxostat, are the mainstay of urate-lowering treatment for gout and may have different effects on cardiovascular risk in patients with gout.

METHODS

Using US Medicare claims data (2008-2013), we conducted a cohort study for comparative cardiovascular safety of initiating febuxostat versus allopurinol among patients with gout ≥65 years of age. The primary outcome was a composite end point of hospitalization for myocardial infarction or stroke. Secondary outcomes were individual end points of hospitalization for myocardial infarction, stroke, coronary revascularization, new and recurrent heart failure, and all-cause mortality. We used propensity score matching with a ratio of 1:3 to control for confounding. We estimated incidence rates and hazard ratios for primary and secondary outcomes in the propensity score-matched cohorts of febuxostat and allopurinol initiators.

RESULTS

We included 24 936 febuxostat initiators propensity score-matched to 74 808 allopurinol initiators. The median age was 76 years, 52% were male, and 12% had cardiovascular disease at baseline. The incidence rate per 100 person-years for the primary outcome was 3.43 in febuxostat and 3.36 in allopurinol initiators. The hazard ratio for the primary outcome was 1.01 (95% CI, 0.94-1.08) in the febuxostat group compared with the allopurinol group. Risk of secondary outcomes including all-cause mortality was similar in both groups, except for a modestly decreased risk of heart failure exacerbation (hazard ratio, 0.94; 95% CI, 0.91-0.99) in febuxostat initiators. The hazard ratio for all-cause mortality associated with long-term use of febuxostat (>3 years) was 1.25 (95% CI, 0.56-2.80) versus allopurinol. Subgroup and sensitivity analyses consistently showed similar cardiovascular risk in both groups.

CONCLUSIONS

Among a cohort of 99 744 older Medicare patients with gout, overall there was no difference in the risk of myocardial infarction, stroke, new-onset heart failure, coronary revascularization, or all-cause mortality between patients initiating febuxostat compared with allopurinol. However, there seemed to be a trend toward an increased, albeit not statistically significant, risk for all-cause mortality in patients who used febuxostat for >3 years versus allopurinol for >3 years. The risk of heart failure exacerbation was slightly lower in febuxostat initiators.

Clinical features and risk factors for gout attacks during anti-tuberculosis treatment: A case-control study in South Korea

AIM

This study aimed to investigate the clinical features and risk factors of gout attacks during anti-tuberculosis (TB) treatment in South Korea.

METHOD

We investigated the clinical characteristics of 49 patients who suffered from gout attacks while taking anti-TB medications. Among them, 25 TB patients having newly developed gout attacks without prior history of gout were set to the gout group. Seventy-five age- and sex-matched TB patients without gout attacks during anti-TB therapy were randomly selected as the control group. The demographics, clinical features, and laboratory findings between the two groups were compared to establish risk factors of gout attack during anti-TB treatment.

RESULTS

The gout patients had a mean age of 67.7 ± 13.2 years and 39 patients (79.6%) were male. Approximately half of the patients experienced an attack within 2 months of treatment initiation. The attacks typically involved lower extremity joints (87.8%). The serum uric acid (SUA) levels were significantly elevated at 2 and 6 months after starting anti-TB medication compared with those at baseline. In the case-control study, the factors associated with gout attack were higher body mass index (BMI), higher pre-treatment SUA levels, dyslipidemia, and reduced renal function. In the multivariate model, higher BMI, chronic kidney disease (CKD), and pre-treatment hyperuricemia (SUA ≥ 6.8 mg/dL) were independent risk factors of gout attack while taking anti-TB medication.

CONCLUSIONS

Patients with high BMI, CKD, and pre-treatment hyperuricemia are at a higher risk of gout attack during TB treatment.

Impact of sleep quality on clinical features of primary Sjögren's syndrome

BACKGROUND/AIMS

This study aimed to investigate the inf luence of poor sleep quality on clinical features of primary Sjögren's syndrome (pSS).

METHODS

Sleep quality was cross-sectionally assessed using the Pittsburgh Sleep Quality Index (PSQI), and demographic, clinical, and laboratory data were collected from 115 Korean patients with pSS. The patients completed questionnaires on the European League Against Rheumatism (EULAR) SS Patient Reported Index (ESSPRI), quality of life (EuroQOL five dimensions questionnaire [EQ-5D]), fatigue (fatigue severity score [FSS]), and depression (Beck Depression Inventory [BDI] II]). Symptoms and patient global assessment (PGA) were evaluated with a 100-mm visual analogue scale (VAS). The EULAR sicca score (ESS), ESSPRI, and EULAR SS Disease Activity Index (ESSDAI) were calculated at study enrollment.

RESULTS

Fifty-three patients (46.1%) had poor sleep quality and 32.4% of 71 patients without depression were poor sleepers. Poor sleepers had a significantly lower EQ-5D or ESSDAI and a significantly higher FSS, BDI-II, PGA, ESS, ESSPRI, or VAS scores for extra-glandular symptoms than good sleepers. Neutrophil and lymphocyte counts were significantly higher and immunoglobulin G levels tended to decrease in poor sleepers. Additionally, PSQI was negatively correlated with EQ-5D and ESSDAI and positively with ESS, FSS, BDI-II, PGA, VAS scores for their symptoms, and ESSPRI. Multivariate analysis revealed that poor sleep quality remained the independent determinants of the unsatisfactory symptom state (ESSPRI ≥ 5).

CONCLUSION

Our results showed that poor sleep quality could significantly affect the patient-oriented outcomes and physician-reported activity index of pSS patients through the various effects of sleep quality on the psychological or somatic symptoms and the immune system.