Epidemiology of Rheumatoid Arthritis in Korea

Global RA treatment recommendations: An update from the various international societies

Rheumatoid arthritis is a chronic inflammatory arthritis with many extra-articular manifestations and is associated with an increased risk of morbidity and mortality. This review attempts to provide an update on the treatment recommendations from various global societies and discuss some of the challenges and solutions to caring for people with rheumatoid arthritis across the world. A search was conducted on PubMed, Google Scholar, and EMBASE from 2000 to 2024 using rheumatoid arthritis, treatment, recommendations, guidelines, management, disparities, and access as the search terms. Emphasis was placed on pertinent recommendations published in the last five years. Recent available recommendations of the American College of Rheumatology (ACR), European Alliance of Associations for Rheumatology (EULAR), Asia-Pacific League of Associations for Rheumatology (APLAR), Pan-American League of Rheumatology (PANLAR) and African League of Associations for Rheumatology (AFLAR) were concentrated on. The latest recommendations from various societies are discussed.

Sex-Specific Trends in the Prevalence of Osteoarthritis and Rheumatoid Arthritis From 2005 to 2021 in South Korea: Nationwide Cross-Sectional Study

BACKGROUND

Osteoarthritis and rheumatoid arthritis (RA) are prevalent chronic joint disorders, with prevalence rates varying by sex. However, few studies have comprehensively documented the factors contributing to the sex-specific prevalence of osteoarthritis and RA, including sociological factors and the impact of the COVID-19 pandemic.

OBJECTIVE

This study aims to identify long-term trends in the sex-specific prevalence of osteoarthritis and RA from 2005 to 2021 while examining the factors that serve as vulnerabilities specific to each sex within the context of the COVID-19 pandemic.

METHODS

Data were collected from a nationally representative sample of 110,225 individuals through the Korea National Health and Nutrition Examination Survey from 2005 to 2021. The study included patients aged 19 years and older diagnosed with osteoarthritis or RA in South Korea. Data were analyzed using weighted trends to accurately represent the sample population, with a 95% CI. Weighted logistic and regression models were used to identify vulnerable groups at risk of osteoarthritis or RA during the pandemic to assess sex-specific trends.

RESULTS

In total, 110,225 individuals (n=48,410, 43.92% male participants) were analyzed from 2005 to 2021, with prevalence rates remaining stable over time and higher in female than in male participants. Notably, during the pandemic, female participants aged 60 years and older exhibited a prevalence of osteoarthritis that was 4.92 times greater than male participants and a prevalence of RA that was 6.44 times greater (osteoarthritis: prevalence ratio [PR] 69.78, 95% CI 41.66-116.88; RA: PR 17.27, 95% CI 8.75-34.07). In terms of osteoarthritis, male participants did not show a significant association with BMI (PR 1.40, 95% CI 1.21-1.61; P=.47), whereas female participants exhibited a significantly higher vulnerability within the obese group (PR 1.68, 95% CI 1.55-1.83; P<.001). Regarding RA, lower education levels were associated with increased vulnerability, with male participants showing a greater risk than female participants (male participants: PR 2.29, 95% CI 1.61-3.27 and female participants: PR 1.50, 95% CI 1.23-1.84).

CONCLUSIONS

This study reveals that women in South Korea have a higher prevalence of osteoarthritis and RA than men. Understanding these sex-specific trends and identifying vulnerability factors can enhance preventive efforts and patient care.

Application of disease activity index in rheumatoid arthritis management in Korea

Effective management of rheumatoid arthritis (RA) necessitates the accurate measurement of disease activity using a treat-to-target strategy established as a cornerstone approach. Disease activity assessment tools such as the Disease Activity Score in 28 joints (DAS28), Simplified Disease Activity Index, Clinical Disease Activity Index, and Routine Assessment of Patient Index Data 3 have been internationally validated and recognised. In Korea, the government initiated a quality assessment program mandating routine measurement of DAS28 to ensure high-quality RA management. However, whether the DAS28 is the most suitable disease activity measurement tool in the Korean clinical environment is a topic worth considering. In this review, we comprehensively examined disease activity measurement tools and their performance in the Korean context. We also propose a new strategy for measuring RA disease activity, tailored to the different situations encountered by physicians in routine clinical practice. This review may contribute to the improvement of the quality of care for patients with RA in Korea.

The Relationship between Seropositive Rheumatoid Arthritis and Congestive Heart Failure: A Nationwide Longitudinal Cohort Study in Korea

Objectives: The aim of this nationwide longitudinal cohort study is to determine the risk of congestive heart failure (CHF) associated with a seropositive rheumatoid arthritis (RA) population in Korea. Methods: In this study, National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) data from 2002 to 2003 were used. The cohort was followed up with for 12 years until December of 2015. Seropositive RA was defined as a patient prescribed with a disease-modifying anti-rheumatic drug (DMARD) among patients with the International Classification of Diseases code M05 (seropositive RA). Patients who were diagnosed before 2004 were excluded. The seropositive RA group consisted of 2765 patients, and a total of 13,825 patients were in the control group. The Kaplan-Meier method was used to calculate the 12-year CHF incidence rate for each group. A Cox proportional hazards regression analysis was used to estimate the hazard ratio of CHF. Results: The hazard ratio of CHF in the seropositive RA group was 2.41 (95% confidence interval (CI): 1.40-4.14) after adjusting for age and sex. The adjusted hazard ratio of CHF in the seropositive RA group was 2.50 (95% CI: 1.45-4.30) after adjusting for age, sex, income, and comorbidities. In females aged ≥65 and aged <65, the incidence rates in the non-hypertension, non-diabetes mellitus, and non-dyslipidemia subgroups were significantly higher in the seropositive RA group than in the control group. Conclusions: This nationwide longitudinal cohort study shows an increased risk of CHF in patients with seropositive RA.

Serum and urine lipidomic profiles identify biomarkers diagnostic for seropositive and seronegative rheumatoid arthritis

Objective

Seronegative rheumatoid arthritis (RA) is defined as RA without circulating autoantibodies such as rheumatoid factor and anti-citrullinated protein antibodies; thus, early diagnosis of seronegative RA can be challenging. Here, we aimed to identify diagnostic biomarkers for seronegative RA by performing lipidomic analyses of sera and urine samples from patients with RA.

Methods

We performed untargeted lipidomic analysis of sera and urine samples from 111 RA patients, 45 osteoarthritis (OA) patients, and 25 healthy controls (HC). These samples were divided into a discovery cohort (n = 97) and a validation cohort (n = 84). Serum samples from 20 patients with systemic lupus erythematosus (SLE) were also used for validation.

Results

The serum lipidome profile of RA was distinguishable from that of OA and HC. We identified a panel of ten serum lipids and three urine lipids in the discovery cohort that showed the most significant differences. These were deemed potential lipid biomarker candidates for RA. The serum lipid panel was tested using a validation cohort; the results revealed an accuracy of 79%, a sensitivity of 71%, and a specificity of 86%. Both seropositive and seronegative RA patients were differentiated from patients with OA, SLE, and HC. Three urinary lipids showing differential expression between RA from HC were identified with an accuracy of 84%, but they failed to differentiate RA from OA. There were five lipid pathways that differed between seronegative and seropositive RA.

Conclusion

Here, we identified a panel of ten serum lipids as potential biomarkers that can differentiate RA from OA and SLE, regardless of seropositivity. In addition, three urinary lipids had diagnostic utility for differentiating RA from HC.

The Association of Chronic Periodontitis as a Potential Risk Factor with Rheumatoid Arthritis: A Nested Case-Control Study Using a Korean National Health Screening Cohort

Growing research has proposed that rheumatoid arthritis (RA) and chronic periodontitis (CP) share similar pathophysiological mechanisms involving inflammation and tissue destruction. However, the potential correlation of CP as a contributing factor for the occurrence of RA warrants validation in the Korean population, where both diseases are prevalent, especially considering the increasingly aging demographic in Korea. This study examined 5139 RA cases and 509,727 matched controls from a Korean national cohort dataset (2002-2019) by carefully employing propensity score matching to ensure comparability between groups. Baseline characteristics were compared using standardized differences, and logistic regression was employed to estimate the impact of CP history on RA likelihood while controlling for covariates. We fully examined medical records documenting CP occurrences within the two-year period leading up to the index date, conducting comprehensive subgroup analyses. While a 1-year history of CP did not show a significant association with likelihood of RA, a 2-year history of CP increased RA likelihood by 12%, particularly among older adults, females, rural residents, and those with certain comorbidities such as hypercholesterolemia. Interestingly, this association persisted even among individuals with non-smoking habits, normal weight, and infrequent alcohol consumption. These findings suggest that chronic CP exposure for at least 2 years may independently elevate RA risk in Korean adults. The association in certain subgroups appears to suggest a predisposition toward genetic susceptibilities over lifestyle and environmental factors. Predicting RA in CP patients may be challenging, emphasizing the importance of regular RA screening, especially in high-risk subgroups.

Medication utilisation trends during pregnancy and factors influencing adverse pregnancy outcomes in patients with rheumatoid arthritis

OBJECTIVES

We aimed to investigate medication utilisation trends during pregnancy and identify factors associated with adverse pregnancy outcomes (APOs) in patients with rheumatoid arthritis (RA).

METHODS

Female patients with RA aged 20-50 years were identified from the Korean national health insurance database between 2010 and 2020. Pregnancy episodes were divided into two groups according to pregnancy outcome: the delivery group and the APO group (abortion and stillbirth). The characteristics and medication utilisation patterns were compared between the two groups, and multivariable logistic regression analysis was conducted to identify the factors associated with APOs.

RESULTS

A total of 5728 pregnancy episodes were included, comprising 4576 delivery episodes and 1152 APO episodes. The mean maternal age for all pregnancy episodes was 33.7 years; 33.3 years in the delivery group and 33.7 years in the APO group. Hydroxychloroquine was the most commonly used conventional synthetic disease-modifying antirheumatic drug (DMARD) during the preconception period and pregnancy in both groups. The prescription rate of all DMARDs decreased rapidly during pregnancy. In the multivariable analysis, use of methotrexate (adjusted OR (aOR): 2.14, 95% CI 1.57 to 2.92) and leflunomide (aOR: 2.68, 95% CI 1.39 to 5.15) within 3 months before conception was associated with APOs.

CONCLUSION

Methotrexate and leflunomide are associated with an increased possibility of APOs, emphasising the importance of appropriate medication adjustment when planning for pregnancy.

Clinical course of nontuberculous mycobacterial pulmonary disease in patients with rheumatoid arthritis

OBJECTIVES

The impact of rheumatoid arthritis (RA) on nontuberculous mycobacterial pulmonary disease (NTM-PD) has not been well established. In this study, we investigated the clinical course of NTM-PD in patients with RA and the impact of RA on the prognosis of NTM-PD.

METHODS

We analyzed patients who developed NTM-PD after being diagnosed with RA from January 2004 to August 2023 at a tertiary referral hospital in South Korea. The patient's baseline characteristics, clinical course, and prognosis were evaluated. An optimal matching analysis was performed to measure the impact of RA on the risk of mortality.

RESULTS

During the study period, 18 patients with RA [median age, 68 years; interquartile range (IQR) 59-73; female, 88.9%] developed NTM-PD. The median interval between RA diagnosis and subsequent NTM-PD development was 14.8 years (IQR, 8.6-19.5). At a median of 30 months (IQR, 27-105) after NTM-PD diagnosis, 10 of 18 (55.6%) patients received anti-mycobacterial treatment for NTM-PD and 5 (50.0%) patients achieved microbiological cure. When matched to patients with NTM-PD but without RA, patients with both RA and NTM-PD had a higher risk of mortality (adjusted hazard ratio, 8.14; 95% confidence interval, 2.43-27.2).

CONCLUSION

NTM-PD occurring after RA is associated with a higher risk of mortality than NTM-PD in the absence of RA.

A meta-analysis of the association between the ATIC 347 C/G polymorphism and methotrexate responsiveness and toxicity in rheumatoid arthritis

OBJECTIVES

The purpose of this study was to determine whether the 347 C/G polymorphism in the 5-aminoimidazole-4-carboxamide ribonucleotide transformylase (ATIC) gene predicts the responsiveness to or toxicity of methotrexate (MTX) in patients with rheumatoid arthritis (RA).

METHOD

To identify relevant publications, we searched the Medline, Embase, Cochrane, and Web of Science databases. We performed a meta-analysis of studies on the relationship between the ATIC 347 C/G polymorphism and MTX toxicity or non-responsiveness in patients with RA.

RESULTS

Thirteen studies consisting of 3,185 patients with RA satisfied our inclusion criteria. The analysis included 10 studies on MTX responsiveness and seven studies on MTX toxicity in patients with RA in connection with ATIC 347C/G polymorphism. According to our meta-analysis, the ATIC 347 GG genotype and failure to respond to MTX treatment were significantly associated (OR = 0.741, 95% CI = 0.591-0.929, p=0.009). According to stratification by ethnicity, this genotype was significantly associated with non-responsiveness to MTX in Europeans (OR=0.548, 95% CI=0.377-0.796, p=0.002) but not in Asian populations (OR=0.882, 95% CI=0.665-1.1172, p=0.388). However, analyses employing allelic, dominant, and homozygous contrast models failed to detect any relationship between the polymorphism and the failure to respond to MXT. However, the ATIC 347GG genotype and MTX toxicity were not associated (OR=1.278, 95% CI=0.937-1.745, p=0.121). Asian and European populations showed no evidence of a relationship between the ATIC 347GG genotype and MTX toxicity (OR=1.252, 95% CI=0.905-1.732, p=0.175 and OR =1.617, 95% CI=0.549-4.765, p=0.383, respectively).

CONCLUSIONS

This meta-analysis revealed that ATIC 347 C/G polymorphism was related to non-responsiveness to MTX in European populations with RA. However, no significant correlation was found with MTX toxicity.

Comparison of the efficacy and safety of olokizumab at different dosages in patients with active rheumatoid arthritis: a network meta-analysis of randomized controlled trials

OBJECTIVE

This study aimed to assess the relative efficacy and safety of olokizumab at different dosages in patients with active rheumatoid arthritis (RA).

METHODS

We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) to examine the efficacy and safety of olokizumab administered intravenously to RA patients at 64 mg/kg every 2 or 4 weeks (Q2 or Q4W).

RESULTS

Five RCTs comprising 2609 patients met the inclusion criteria. Both olokizumab Q2 and Q4W treatments achieved a significant American College of Rheumatology 20% response (ACR20) compared with the placebo (odds ratio [OR] 3.21, 95% credible interval [CrI] 2.53-4.09; OR 3.05, 95% CrI 2.43-3.86). However, olokizumab Q2W was associated with the most favorable surface using the cumulative ranking curve (SUCRA) for the ACR20 response rate. The ranking probability based on the SUCRA indicated that olokizumab Q2W had the highest probability of being considered the best treatment option for achieving the ACR20 response rate, followed by olokizumab Q4W, adalimumab, and placebo. The ACR50 and 70 response rates showed a similar distribution pattern to the ACR20 response rate, except that olokizumab Q4W had a higher-ranking probability than olokizumab Q2W for ACR50. The SUCRA rating likelihood of adverse events (AEs) and withdrawal due to AEs showed that a placebo was likely to be the best intervention.

CONCLUSION

Both olokizumab Q2 and Q4W were efficacious and well-tolerated treatments for active RA.

Comparison of the efficacy and safety of tocilizumab, sarilumab, and olokizumab in patients with active rheumatoid arthritis: a network meta-analysis of randomized controlled trials

OBJECTIVE

This study compared the relative efficacy and safety of olokizumab, tocilizumab, and sarilumab in rheumatoid arthritis (RA) patients who were intolerant or responding inadequately to methotrexate (MTX).

METHODS

We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) to examine the efficacy and safety of olokizumab, tocilizumab, and sarilumab in RA patients who were intolerant or responding inadequately to MTX.

RESULTS

Six RCTs comprising 4439 patients met the inclusion criteria. Tocilizumab, sarilumab, olokizumab, and adalimumab treatments achieved a significant American College of Rheumatology 20% (ACR20) response rate compared with placebo. However, tocilizumab was associated with the most favorable surface area using the cumulative ranking curve (SUCRA) for the ACR20 response rate. The ranking probability based on the SUCRA indicated that tocilizumab treatment had the highest probability of providing the best ACR20 response rate, followed by sarilumab, olokizumab every 2 weeks (Q2W), olokizumab Q4W, adalimumab 40 mg, and placebo. The ACR50 and 70 response rates showed a distribution pattern similar to that of the ACR20 response rate. However, olokizumab Q4W had a higher ranking probability than olokizumab Q2W. The SUCRA rating showed that the placebo was the best intervention with the least adverse events (AEs) and withdrawal due to AEs, followed by interleukin‑6 inhibitors.

CONCLUSION

Tocilizumab, sarilumab, and olokizumab are more effective than adalimumab and have similar efficacy and safety in RA patients with inadequate responses to MTX.

Relative remission rates of Janus kinase inhibitors in comparison with adalimumab in patients with active rheumatoid arthritis: a network meta-analysis

OBJECTIVES

The relative remission rates of tofacitinib, baricitinib, upadacitinib, and filgotinib compared with those of adalimumab were assessed in patients with rheumatoid arthritis (RA) who responded poorly to methotrexate (MTX).

METHODS

We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) to examine the Disease Activity Score in 28 joints with C‑reactive protein (DAS28-CRP), the Clinical Disease Activity Index (CDAI), the Simplified Disease Activity Index (SDAI), and the Boolean remission of tofacitinib, baricitinib, upadacitinib, filgotinib, and adalimumab in RA patients with inadequate responses to MTX.

RESULTS

Four RCTs, comprising 3507 patients, met the inclusion criteria. The filgotinib 200 mg + MTX and upadacitinib 15 mg + MTX groups showed a significantly higher DAS28-CRP < 2.6 than adalimumab 40 mg + MTX. Upadacitinib 15 mg + MTX showed a significantly higher CDAI (≤ 2.8) than adalimumab 40 mg + MTX (odds ratio [OR]: 1.62; 95% credible interval [CrI]: 1.16-2.29). The ranking probability based on the surface under the cumulative ranking curve (SUCRA) indicated that upadacitinib 15 mg + MTX had the highest probability of being the best treatment as it achieved a CDAI ≤ 2.8, followed by filgotinib 200 mg + MTX, baricitinib 4 mg + MTX, tofacitinib 5 mg + MTX, and adalimumab 40 mg + MTX. The Boolean remission showed the same distribution pattern as that of the CDAI ≤ 2.8. Upadacitinib 15 mg + MTX showed a significantly higher SDAI ≤ 3.3 than adalimumab 40 mg + MTX (OR: 1.62; 95% CrI: 1.16-2.28). SUCRA ranking based on SDAI ≤ 3.3 indicated that upadacitinib 15 mg + MTX had the highest probability of being the best treatment for achieving an SDAI ≤ 3.3, followed by baricitinib 4 mg + MTX, filgotinib 200 mg + MTX, tofacitinib 5 mg + MTX, and adalimumab 40 mg + MTX.

CONCLUSIONS

In RA patients with an inadequate response to MTX, remission rates with JAK inhibitors were significantly higher; there is evidence for differences in efficacy regarding remission among the different JAK inhibitors.

Risk factors for interstitial lung disease in rheumatoid arthritis: a cohort study from the KOBIO registry

Background

Interstitial lung disease (ILD) is a critical extra-articular manifestation of rheumatoid arthritis (RA). However, little is known about the risk factors of RA-ILD.

Objectives

Here, we examined the effect of demographic, clinical, therapeutic, and environmental factors on the incidence of ILD in RA patients using the Korean College of Rheumatology Biologics and Targeted Therapy (KOBIO) registry.

Design

We used data from the KOBIO registry, a multi-center, prospective, observational cohort that included RA patients in South Korea.

Methods

RA patients who used biologic or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) or conventional synthetic (cs)DMARDs, and were enrolled in the KOBIO registry, were examined. Demographic, clinical, and radiographic characteristics, as well as medications, were recorded at baseline and annually thereafter. Kaplan-Meier curves and the log-rank test were used to compare the incidence of ILD between RA patients taking different b/tsDMARDs. Hazard ratios (HRs) were calculated by Cox regression analyses.

Results

In total, 2492 patients (1967 in the b/tsDMARDs group and 525 in the csDMARDs group) were analyzed. The b/tsDMARDs group showed longer disease duration, higher erythrocyte sedimentation rate/C-reactive protein, and higher disease activity score-28 (DAS28) than the csDMARDs group. The incidence of ILD was significantly higher in those taking tumor necrosis factor inhibitors and abatacept than in those taking csDMARDs (log ranked p < 0.001). Multivariate Cox regression analysis identified older age (HR = 1.057, p = 0.001), male sex (HR = 2.824, p = 0.007), time-averaged DAS28 (HR = 2.241, p < 0.001), and rheumatoid factor titer (HR = 1.009, p = 0.007) as having a significantly increased HR for ILD occurrence.

Conclusion

ILD is a rare but critical extra-articular symptom of RA patients. Therefore, RA patients with the above risk factors should be monitored carefully for ILD development.

Effects of a self-determination theory-based physical activity programme for postmenopausal women with rheumatoid arthritis: A randomized controlled trial

AIMS

The study aimed to develop and evaluate the effects of a self-determination theory-based, nurse-led, physical activity programme for postmenopausal women with rheumatoid arthritis.

METHODS

Between December 2019 and April 2020, this randomized controlled trial recruited 62 postmenopausal women with rheumatoid arthritis from a university-affiliated hospital in South Korea. The intervention group participated in a self-determination theory-based, nurse-led, physical activity programme that consisted of Tai Chi-based physical activity, a supportive psychosocial strategy, and interactive counselling for 16 weeks, and the control group continued to undergo their usual care.

RESULTS

There were statistically significant group-by-time interactions in physical activity and perceived sarcopenia, which favoured the intervention group. Additionally, the intervention group showed significant improvements in the perceived therapeutic efficacy of physical activity, grip strength, walking speed, disease activity score, and health-related quality of life.

CONCLUSIONS

The programme developed in this study can be an effective and feasible approach for postmenopausal women with rheumatoid arthritis in improving physical activity, selected osteosarcopenic outcomes, and health-related quality of life. Further research is required to investigate the long-term effects of this theory-based programme for postmenopausal women in diverse settings.

Predicting physical activity and sarcopenia-related health outcomes in women with rheumatoid arthritis: A test of the self-determination theory

AIM

This study aimed to examine a hypothetical model of physical activity (PA) and health outcomes related to sarcopenia in women with rheumatoid arthritis (RA) based on self-determination theory.

DESIGN

Cross-sectional study.

METHODS

This study included 214 women diagnosed with RA from the outpatient rheumatology department of a university-affiliated hospital in South Korea. Data were collected from September 2019 to August 2020 through structured questionnaires and anthropometric measurements and analysed using path analysis to test the hypothesized model. The primary health outcomes were perceived health status and sarcopenia-related health (thigh circumference, handgrip strength and sarcopenia risk).

RESULTS

The final model's fit indices were adequate. Physical activity was directly affected by motivation for PA, while depression, self-efficacy for PA, health care provider's autonomy support and basic psychological needs satisfaction indirectly affected PA. Physical activity directly affected perceived health status and thigh circumference, while perceived sarcopenia risk and handgrip strength were directly affected by disease activity and age.

PATIENT OR PUBLIC CONTRIBUTION

Patients were involved in a questionnaire-based survey.

Relative Remission and Low Disease Activity Rates of Tofacitinib, Baricitinib, Upadacitinib, and Filgotinib versus Methotrexate in Patients with Disease-Modifying Antirheumatic Drug-Naive Rheumatoid Arthritis

BACKGROUND

The relative efficacy of Janus kinase (JAK) inhibitors in producing remission and low disease activity (LDA) states remains unknown since there are currently no trials that provide direct comparisons among JAK inhibitors in disease-modifying antirheumatic drug (DMARD)-naive patients with rheumatoid arthritis (RA).

OBJECTIVES

This study aimed to assess the relative remission and LDA rates of tofacitinib, baricitinib, upadacitinib, and filgotinib compared to those of methotrexate (MTX) in DMARD-naive patients with RA.

METHOD

We conducted Bayesian network meta-analysis and included information from direct and indirect comparisons from randomized controlled trials that examined remission (Disease Activity Score in 28 Joints using C-reactive protein level [DAS28-CRP] <2.6) and LDA (DAS28-CRP ≤ 3.2) produced by tofacitinib, baricitinib, upadacitinib, filgotinib monotherapy, and MTX in patients with DMARD-naive RA.

RESULTS

Four randomized controlled trials, comprising 2,185 patients, met the inclusion criteria. This network meta-analysis showed that treatment with tofacitinib, baricitinib, upadacitinib, and filgotinib achieved a significantly higher remission rate than that with MTX (odds ratio [OR] = 4.13, 95% CI = 2.88-6.02; OR = 2.12, 95% CI = 1.17-4.13; OR = 1.95, 95% CI = 1.10-3.50; OR = 1.79, 95% CI = 1.27-3.53). The ranking probability based on the surface under the cumulative ranking curve indicated that upadacitinib 15 mg had the highest probability of achieving remission (SUCRA = 0.985), followed by tofacitinib 5 mg (SUCRA = 0.574), baricitinib 4 mg (SUCRA = 0.506), filgotinib 200 mg (SUCRA = 0.431), and MTX (SUCRA = 0.004). Moreover, treatment with tofacitinib, baricitinib, upadacitinib, and filgotinib achieved significantly higher LDA rate than that with MTX. The ranking probability for LDA was similar to that for remission; upadacitinib 15 mg had the highest probability of achieving LDA, followed by tofacitinib 5 mg, baricitinib 4 mg, filgotinib 200 mg, and MTX.

CONCLUSIONS

Upadacitinib seems to be one of most effective interventions for achieving remission and LDA in DMARD-naive patients with RA based on the comparative analysis, and there are differences in remission and LDA rates induced by different JAK inhibitors.

Risk of all-cause and cause-specific mortality associated with immune-mediated inflammatory diseases in Korea

Objective

Immune-mediated inflammatory disease (IMID) is associated with an increased risk of mortality. It is unclear whether the higher mortality is attributable to the IMIDs themselves or to the higher prevalence of comorbidities in IMIDs. We aimed to investigate whether IMIDs per se confer a higher risk of mortality.

Methods

From the Korean National Health Insurance Service-National Sample Cohort database, this population-based cohort study included 25,736 patients newly diagnosed with IMIDs between January 2007 and December 2017, and 128,680 individuals without IMIDs who were matched for age, sex, income, hypertension, type 2 diabetes, dyslipidemia, and the Charlson comorbidity index. All individuals were retrospectively observed through December 31, 2019. The outcomes included all-cause and cause-specific mortalities. Adjustments for age, sex, and comorbidities were performed using multivariable Cox proportional hazard regression analyses, and adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) for the outcomes were estimated.

Results

The adjusted risk of all-cause mortality was significantly lower in patients with IMIDs than that in those without (aHR, 0.890; 95% CI, 0.841-0.942). Regarding cause-specific mortality, cancer-specific (aHR, 0.788; 95% CI, 0.712-0.872) and cardiovascular disease-specific (aHR, 0.798; 95% CI, 0.701-0.908) mortalities were the two causes of death that showed significantly lower risks in patients with IMIDs. A similar trend was observed when organ based IMIDs were analyzed separately (i.e., gut, joint, and skin IMIDs).

Conclusion

After adjusting for comorbidities, IMIDs were associated with a lower risk of all-cause mortality compared to those without IMIDs. This was attributable to the lower risks of cancer-and cardiovascular disease-specific mortalities.

Pregnancy Outcomes Associated With Biologic Agent Exposure in Patients With Several Rheumatic Diseases and Inflammatory Bowel Diseases

BACKGROUND

This study aimed to analyze pregnancy outcomes based on biologic agents use in women using the nationwide population-based database.

METHODS

The study used the claims database to identify women of childbearing age with several rheumatic (rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, psoriatic arthritis) and inflammatory bowel diseases (Crohn's disease and ulcerative colitis) who had pregnancy-related codes between January 2010 and December 2019. We analyzed live births and adverse pregnancy outcomes based on the previous use of biologics. We also stratified the patients according to duration of biologic agent exposure before pregnancy and the use of biologics during pregnancy to analyze the pregnancy outcomes by subgroups.

RESULTS

We identified 4,787 patients with pregnancy events. Among them, 1,034 (21.6%) used biologics before pregnancy. Live birth rate was not different between the biologics group and biologics naïve group (75.0% vs. 75.2%). Multivariate analyses showed that biologics use was associated with higher risk of intrauterine growth retardation (odds ratio [OR], 1.780) and lower risk of gestational diabetes mellitus (OR, 0.776) compared with biologics naïve. Biologics use during pregnancy was associated with higher risk of preterm delivery (OR, 1.859), preeclampsia/eclampsia (OR, 1.762), intrauterine growth retardation (OR, 3.487), and cesarean section (OR, 1.831), but lower risk of fetal loss (OR, 0.274) compared with biologics naïve.

CONCLUSIONS

Although there was no difference in live birth rate between the biologics group and biologics naïve group, biologics use seems to be associated with several adverse pregnancy outcomes, especially in patients with biologics during pregnancy. Therefore, patients with biologics during pregnancy need to be carefully observed for adverse pregnancy outcomes.

Association between the functional FCGR3A F158V and FCGR2A R131H polymorphisms and responsiveness to biologics in rheumatoid arthritis patients: A meta-analysis

OBJECTIVES

This study aimed to investigate the association between functional Fc gamma receptor 3A (FCGR3A) V158F and FCGR2A R131H polymorphisms and biologic therapy in rheumatoid arthritis (RA) patients.

METHODS

We searched Medline, Embase, and Cochran databases for available articles. This study is a meta-analysis of the association between the FCGR3A V158F and FCGR2A R131H polymorphisms and their responsiveness to biologics in RA patients.

RESULTS

Seventeen studies involving RA patients with FCGR3A V158F (n = 1884) and FCGR2A R131H (n = 1118) polymorphisms were considered. This meta-analysis showed that the FCGR3A V allele was associated with responsiveness to rituximab (odds ratio [OR] = 1.431, 95% CI = 1.081-1.894, P = 0.012), but not with tumor necrosis factor (TNF) blockers, tocilizumab, or abatacept. A significant association was also found between the FCGR3A V158F polymorphism and responsiveness to biologics using the dominant-recessive model. Additionally, the FCGR3A V158F polymorphism was associated with responsiveness to TNF blockers in the homozygous contrast model. Meta-analysis revealed an association between the FCGR2A RR + RH genotype and responsiveness to biologics (OR = 1.385, 95% CI = 1.007-1.904, P = 0.045).

CONCLUSIONS

This meta-analysis demonstrates that FCGR3A V allele carriers show better responsiveness to rituximab, and FCGR2A R allele carriers may show a better response to biologics in RA treatment. Genotyping of these polymorphisms could be a useful tool to find associations with the responsiveness of personalized medicine to biologics.

Clinical characteristics of rheumatoid arthritis patients with interstitial lung disease: baseline data of a single-center prospective cohort

BACKGROUND

To introduce a prospective cohort for rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) and to identify their clinical features in comparison with RA patients without ILD.

METHODS

Using a multidisciplinary collaborative approach, a single-center cohort for RA patients with ILD (RA-ILD) was established in May 2017, and enrolment data from May 2017 to March 2021 were used to compare the clinical features of RA patients without ILD (RA-non ILD). Multivariable logistic regression analysis was used to identify factors associated with ILD in RA patients.

RESULTS

Among 148 RA-ILD and 410 RA-non ILD patients, participants in the RA-ILD group were older (65.8 ± 9.9 vs. 58.0 ± 10.4 years, P < 0.001) and included more males (35.8% vs. 14.6%, P < 0.001) than in the RA-non ILD group. The RA-ILD group had a higher proportion of late-onset RA patients (age ≥ 60 years) than in the comparator group (43.9% vs. 14.2%, P < 0.001). Multivariable logistic regression analysis showed that higher age at RA onset (OR 1.056, 95% CI 1.021-1.091), higher body mass index (BMI; OR 1.65, 95% CI 1.036-2.629), smoking history (OR 2.484, 95% CI 1.071-5.764), and oral glucocorticoid use (OR 3.562, 95% CI 2.160-5.874) were associated with ILD in RA patients, whereas methotrexate use was less likely to be associated with ILD (OR 0.253, 95% CI 0.155-0.412).

CONCLUSIONS

Higher age at RA onset, smoking history, and higher BMI were associated with the presence of ILD among RA patients. Oral glucocorticoids were more frequently used whereas methotrexate was less likely to be used in RA-ILD patients.

Comparative efficacy and safety of infliximab and its biosimilars in patients with rheumatoid arthritis presenting an insufficient response to methotrexate : A network meta-analysis

OBJECTIVE

To assess the relative efficacy and safety of infliximab and its biosimilars in patients with active rheumatoid arthritis (RA) who showed an inadequate response to methotrexate (MTX).

METHODS

We performed a Bayesian network meta-analysis combining direct and indirect evidence from randomized controlled trials (RCTs), comparing the efficacy and safety of infliximab biosimilars versus the originator product in patients with active RA despite receiving MTX.

RESULTS

Overall, 7 RCTs involving 3168 patients, including 7 biologic agents, met the inclusion criteria. The NI-071 was listed at the top left of the diagonal of the league table because it was associated with the most favorable surface under the cumulative ranking curve (SUCRA) for the American College of Rheumatology 20 (ACR20) response rate. SB2 was listed at the bottom right of the diagonal of the league table because it was associated with the least favorable results. Based on SUCRA, NI-071 had the highest probability of being the best treatment agent in terms of the ACR20 response rate (SUCRA = 0.731), followed by ABP 710, CT-P13, BCD-055, infliximab, Exemptia, PF-06438179, and SB2 (SUCRA = 0.311). Although statistically non-significant differences in safety ranking were observed for serious adverse events (SAEs) among the treatment options, ABP 710 presented the highest safety probability (SUCRA = 0.739) while BCD-055 showed the lowest safety profile (SUCRA = 0.289).

CONCLUSION

No significant difference in ACR20 response rates and SAEs were detected between infliximab biosimilars and the originator in the investigated study populations.

Association of Oral Health with Risk of Rheumatoid Arthritis: A Nationwide Cohort Study

Periodontitis and rheumatoid arthritis (RA) are inflammatory diseases that share many similarities. We aimed to investigate the associations of periodontitis and oral hygiene status and behaviors with RA in a nationwide general population cohort. Participants from the National Health Screening cohort database of Korea who underwent oral health screening by dentists between 2003 and 2004 were included. The occurrence of RA was analyzed according to the presence of periodontitis, oral health examination findings, and behaviors. Overall, 2,239,586 participants were included. During a median of 16.7 years, RA occurred in 27,029 (1.2%) participants. The risk for incident RA was higher when participants had periodontitis (hazard ratio (HR) 1.2, 95% confidence interval (CI), 1.08-1.24) and an increased number of missing teeth (HR 1.5, 95% CI, 1.38-1.69). In contrast, better oral hygiene behaviors, such as a higher frequency of daily tooth brushing (HR 0.76, 95% CI 0.73-0.79, p for trend <0.001) and a recent history of dental scaling (HR 0.96, 95% CI 0.94-0.99), were associated with a lower occurrence of RA. Periodontitis and increased missing teeth were associated with an increased risk of RA. Maintaining good oral hygiene through frequent tooth brushing and regular dental scaling may reduce the risk of RA occurrence.

A green-lipped mussel prevents rheumatoid arthritis via regulation of inflammatory response and osteoclastogenesis

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by progressive joint destruction. Green-lipped mussel (GLM) has chondro-modulatory and anti-inflammatory properties, but the mechanism underlying the effect of GLM on RA is unclear. To investigate the roles of GLM on the pathogenesis of RA, we examined the effects of GLM in collagen-induced arthritis (CIA) mice and osteoclast differentiation. GLM was orally administrated CIA mice at 3 weeks after chicken type II collagen (CII) immunizations. GLM reduced arthritis severity and the histologic score of CIA mice compared to vehicle. The expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-17) was decreased in the ankle joints of GLM-treated CIA mice. The expression of CD4+ IL-17+ cells decreased in ex vivo splenocytes and the spleens of GLM-treated CIA mice. Moreover, GLM inhibited TRAP+ multinucleated cells among mouse bone marrow-derived monocytes/macrophages (BMM), and the expression of osteoclast-related genes in mouse BMMs and human monocytes in vitro. These results suggest that GLM has potential as a therapeutic agent that can improve disease by controlling pathologic immune cells and osteoclastogenesis.

The lessebo effect in randomized controlled trials of rituximab in patients with rheumatoid arthritis: a meta-analysis

OBJECTIVE

The goal of this study was to assess the impact of negative expectations associated with receiving a placebo (the lessebo effect) on efficacy outcomes in randomized clinical trials (RCTs) of rituximab in patients with rheumatoid arthritis (RA).

METHODS

We performed a meta-analysis on the American College of Rheumatology 20%, 50%, and 70% (ACR20, 50, 70) response rates in the placebo and active (biosimilar)-controlled groups (reference-pbo and reference-bs) of rituximab showing an insufficient response to methotrexate or tumor necrosis factor. We evaluated the difference in ACR20, 50, 70 response rates between the two groups (reference-bs vs. reference-pbo).

RESULTS

Nine RCTs included a total of 2734 patients with RA. The pooled incidence of ACR20 response rate in the placebo- and active-controlled groups of the rituximab RCTs for RA was 53.1% (95% confidence interval [CI] 49.9-56.3%) and 75.0% (95% CI 71.2-78.4%), respectively. The difference in the ACR20 response rate between the placebo- and active-controlled groups was -20.9% (95% CI -26.9 to 61.9%, p < 0.001). The pooled incidence of ACR50 response rate in the placebo- and active-controlled groups of the rituximab RCTs for RA was 29.0% (95% CI 26.2-32.0%) and 47.4% (95% CI 43.2-51.6%), respectively. The ACR50 response rates were significantly higher in the active-controlled groups than in the placebo-controlled groups (-18.4%; 95% CI -18.4 to -13.4%, p < 0.001). The difference in the ACR70 response rate between the placebo- and active-controlled groups was -14.9% (95% CI -22.2 to -7.6%, p < 0.001). The ACR20, 50, 70 response rates were significantly higher in the active-controlled groups than in the placebo-controlled group.

CONCLUSION

This study shows that the use of a placebo can be associated with a clinically significant reduction in the magnitude of change of the ACR20, 50, 70 response rates in rituximab RCTs for RA. The lessebo effect has potential implications for the development of new treatments and appraisal of current treatment options for RA.

Associations between the interleukin-6 rs1800795 G/C and interleukin-6 receptor rs12083537 A/G polymorphisms and response to disease-modifying antirheumatic drugs in rheumatoid arthritis: A meta-analysis

OBJECTIVE

We aimed to investigate the association between interleukin-6 (IL-6) rs1800795 G/C, IL-6 receptor (IL-6R) rs12083537 A/G, and rs4329505 T/C polymorphisms and responsiveness to disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA).

METHODS

We searched Medline, Embase, and Web of Science databases. We conducted a meta-analysis of studies on the association between the IL-6 rs1800795 G/C, IL-6R rs12083537 A/G and rs4329505 T/C polymorphisms and responsiveness to DMARDs in RA patients.

RESULTS

Fourteen studies from eight published articles involving 982 patients were included in this meta-analysis. The meta-analysis showed a significant association between the IL-6 rs1800795 G allele and response to DMARDs in RA (P = 0.008). Stratification by DMARD class showed that the IL-6 rs1800795 G allele was significantly associated with responsiveness to biological DMARDs (bDMARDs) (P = 0.022), but not conventional synthetic DMARDs (P = 0.145). A significant association was also found between the IL-6 rs1800795 G/C polymorphism and response to DMARDs. The meta-analysis revealed a significant association between the IL-6R rs12083537 A allele and response to tocilizumab in RA patients (P = 0.001). A significant association was also found between the IL-6R rs12083537 AA genotype and response to tocilizumab in RA patients (P = 0.001). However, no association was found between the IL-6R rs4329505 T/C polymorphism and response to tocilizumab.

CONCLUSIONS

This meta-analysis revealed associations between treatment response to bDMARDs and the IL-6 rs1800795 G/C polymorphism, and between response to tocilizumab and the IL-6R rs12083537 A/G polymorphism in RA.

Diagnostic Value of Neutrophil-to-Lymphocyte, Platelet-to-Lymphocyte, and Monocyte-to-Lymphocyte Ratios for the Assessment of Rheumatoid Arthritis in Patients with Undifferentiated Inflammatory Arthritis

Background: To investigate the diagnostic performance of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) in the diagnosis of rheumatoid arthritis (RA) in subjects with undifferentiated inflammatory arthritis (UIA). Methods: This retrospective cohort study investigated 201 female patients with UIA (≥1 swollen joint) and 280 age-matched, healthy female controls. “Clinical RA” was defined based on the clinical judgment of a rheumatologist and “disease-modifying anti-rheumatic drugs (DMARDs) RA” was defined as a case of initiating DMARDs treatment within 6 months after the first visit. “Classified RA” was defined as fulfilling the 2010 classification criteria for RA. Receiver operating characteristics were used to determine the optimal cut-off value. Results: UIA patients had a significantly higher NLR, PLR, and MLR than the controls. Among the 201 UIA patients, 65 (32.3%), 63 (31.3%), and 61 (30.3%) subjects were classified as clinical RA, DMARDs RA, and classified RA, respectively. At a cut-off of 0.24, MLR showed moderate accuracy for the diagnosis of DMARDs RA (sensitivity, 65.1%; specificity, 62.3%; area under the curve [AUC], 0.701; p < 0.001). However, the diagnostic accuracies of NLR and PLR were low. Conclusions: MLR may be used as a complementary diagnostic indicator for RA diagnosis in patients with UIA.

A positive faecal immunochemical test result and its association with the incidence of rheumatoid arthritis, systemic lupus erythematosus, and psoriatic arthritis: an analysis of one-million national colorectal cancer screening programme results

BACKGROUND

Accumulating evidence now indicates that the presence of faecal haemoglobin, in the absence of gastrointestinal bleeding, may be an indicator of systemic inflammation and is linked to the development of human diseases. We evaluated whether a positive faecal immunochemical test (FIT) is associated with the development of immune-mediated inflammatory diseases (IMIDs).

METHODS

Data from the nationwide colorectal cancer screening programme from 2009 to 2013 were used. Participants (n=8,646,887) were divided into FIT (+) and FIT (-) groups by performing a 1:1 random sampling matched by age and sex. Participants with concurrent haemorrhoids, colorectal cancer (CRC), inflammatory bowel disease (IBD), and missed CRC and IBD were excluded using the colonoscopy results, ICD-10 codes, and the special exemption code (V code). Endpoints were the incidence of IMIDs (rheumatoid arthritis [RA], systemic lupus erythematosus [SLE], and psoriatic arthritis [PsA]) after FIT.

RESULTS

Of the 1,044,955 eligible participants, 229,594 and 815,361 individuals were included in the FIT (+) and the FIT (-) groups, respectively. During the mean follow-up period of 7.59 years, a total of 7645 (incidence rate [IR] 9.56/10,000 person-years [PY]), 208 (IR 0.26/10,000 PY), and 101 (IR 0.13/10,000 PY) patients were diagnosed with RA, SLE, and PsA, respectively. An adjusted Cox analysis demonstrated that FIT positivity conferred a 1.16 (95% confidence interval [CI] 1.09-1.24, p<0.001) times greater risk of developing RA. Kaplan-Meier analysis in the 1:2 propensity-score matched population also confirmed these results (hazard ratio [HR] 1.18, 95% CI 1.10-1.27, p<0.001).

CONCLUSIONS

Positive FIT is associated with increased risk of RA in the general population, corroborating that aberrancies of gut mucosa are associated with the development of IMIDs. Vigilant monitoring and early referral to a specialist upon medical suspicion is required in this population.

TRIAL REGISTRATION

Retrospectively registered.

Associations of Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio and Monocyte-to-Lymphocyte Ratio with Osteoporosis and Incident Vertebral Fracture in Postmenopausal Women with Rheumatoid Arthritis: A Single-Center Retrospective Cohort Study

Background and Objectives: We investigated whether nutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphoycte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) are associated with the presence of osteoporosis (OP) and vertebral fractures in patients with rheumatoid arthritis (RA). Materials and Methods: This retrospective cohort study included 413 postmenopausal patients with RA and 200 healthy controls who underwent dual-energy X-ray absorptiometry (DEXA) between January 2005 and December 2017. DEXA examination data were defined as the index date, and all laboratory values were measured within one month from the index date. OP was defined as a T-score < −2.5, and incident vertebral fractures were defined as the first occurrence of non-traumatic fractures after the index date. NLR, PLR, and MLR measures were dichotomized by a median split (low vs. high). Results: The median NLR, PLR, and MLR in RA patients were significantly higher than those in controls. The frequencies of OP of the lumbar spine, hip, and either site in postmenopausal patients with RA were 24.7%, 15.5%, and 32%, respectively, and were significantly higher than those in controls. After adjusting for confounding factors, a high baseline NLR was significantly associated with OP at either site (OR = 1.61, p = 0.041). In addition, high baseline NLR (OR = 2.11, p = 0.025) and PLR (OR = 2.3, p = 0.011) were related with the presence OP at hip. During the follow-up period, 53 (12.8%) patients with RA developed vertebral fractures incidentally. In multivariable Cox regression models, a high baseline NLR (HR = 4.72, p < 0.001), PLR (HR = 1.96, p = 0.024), and MLR (HR = 2.64, p = 0.002) were independently associated with a higher risk of incidental vertebral fractures. Conclusions: Our data suggest that NLR, PLR, and MLR can be used as potential markers of systemic bone loss among individuals with RA.

Time-integrated Cumulative Parameters Predictive of Radiographic Progression of Rheumatoid Arthritis: Real-world Data From a Prospective Single-center Cohort

Objective

With many chronic inflammatory diseases, outcomes are determined by assessing both disease activity at presentation and cumulative activity over time. Here, we investigated whether cumulative activity better reflects the radiographic progression (RP) of rheumatoid arthritis (RA) than measurement of activity at a single time point.

Methods

From a prospective cohort of RA patients, most of whom were treated with anti-rheumatic drugs, we selected 117 subjects for whom laboratory, clinical, and radiographic parameters potentially influencing RP were monitored serially for more than 1 year. X-ray images of both hands and both feet were scored using the van der Heijde modified total Sharp score (mTSS). In addition to cross-sectional values at baseline, longitudinal and cumulative values for each parameter were calculated in a time-integrated and averaged manner.

Results

Among the values measured at baseline, mTSS, but not the baseline erythrocyte sedimentation rate (ESR) or C-reactive protein level, was associated with RP. By contrast, multivariate analyses identified cumulative values such as the cumulative ESR, cumulative tender joint count, cumulative swollen joint count (SJC), and cumulative Disease Activity Score 28-ESR as major determinants of RP. In particular, the cumulative SJC showed the best predictive performance for RP.

Conclusion

This study highlights the importance of cumulative indices for predicting progression of RA. Specifically, dynamic and cumulative values of RA activity-related factors, particularly the cumulative SJC, may be the major determinants of RP in the current practice.

Incident Rheumatoid Arthritis Following Statin Use: From the View of a National Cohort Study in Korea

Safety issues regarding the potential risk of statins and incident rheumatoid arthritis (RA) have been raised, but the existing data are largely based on Caucasian populations, and continue to have biases and require further validation in Asian populations. Here, we aimed to verify the risk of RA depending on the duration of previous statin use and statin types using a large-scale, nationwide database. This study enrolled 3149 patients with RA and 12,596 matched non-RA participants from the national health insurance database (2002−2015), and investigated their statin prescription histories for two years before the index date. Propensity score overlap-weighted logistic regression was applied after adjusting for multiple covariates. The prior use of any statins and, specifically, the long-term use of lipophilic statins (>365 days) were related to a lower likelihood of developing RA ((odds ratio (OR) = 0.73; 95% confidence intervals (CI) = 0.63−0.85, p < 0.001) and (OR = 0.71; 95% CI = 0.61−0.84, p < 0.001), respectively). Subgroup analyses supported these preventive effects on RA in those with dyslipidemia, independent of sex, age, smoking, alcohol use, hypertension, and hyperglycemia. Hydrophilic statin use or short-term use showed no such associations. Our study suggests that prior statin use, especially long-term lipophilic statin use, appears to confer preventive benefits against RA.

Impact of lifestyle and comorbidities on seropositive rheumatoid arthritis risk from Korean health insurance data

Rheumatoid arthritis (RA) is a systemic inflammatory arthritis in which primary prevention is key. However, the impact of lifestyle and comorbidities on RA development is unknown. Data from the Korean National Health Insurance Service (NHIS)-national sample cohort from 2002 to 2016 were used. At baseline, demographic characteristics, socioeconomic status, type of residential area, lifestyle behaviours (including exercise), and comorbidities (including the Charlson Comorbidity Index, CCI) were included. Cox regression analysis and Kaplan-Meier curves were used to evaluate the impact of lifestyle and comorbidities on seropositive RA occurrence. A total of 517,053 participants were included in the analysis for seropositive RA occurrence. Mean follow up duration was 71.5 and 142.3 person-month for seropositive RA occurrence group and non-occurrence group, respectively. Seropositive RA was diagnosed in 1,948 participants (0.37%) during follow-up. Cox regression analysis revealed that being aged between 40 and 79, a higher CCI, and hyperlipidemia resulted in elevated hazard ratios (HRs) for seropositive RA, whereas male gender, city residence, moderate alcohol consumption, high regular exercise and a BMI between 23 and 34.9 kg/m2 resulted in lower HRs. Using Korean NHIS data, the present study demonstrates that high-intensity regular physical exercise and moderate alcohol consumption are negatively associated with seropositive RA occurrence, which are modifiable lifestyle habits that might aid the primary prevention of seropositive RA.

Acetylated Diacylglycerol 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol in Autoimmune Arthritis and Interstitial Lung Disease in SKG Mice

Acetylated diacylglycerol 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) is a lipid molecule from the antlers of sika deer that might reduce inflammation by effectively controlling neutrophil infiltration, endothelial permeability and inflammatory chemokine production. Therefore, we evaluated the modulatory effect of PLAG on arthritis and interstitial lung disease (ILD) in an autoimmune arthritis model. We injected curdlan into SKG mice and PLAG was orally administered every day from 3 weeks to 20 weeks after the curdlan injection. The arthritis score was measured every week after the curdlan injection. At 20 weeks post-injection, the lung specimens were evaluated with H&E, Masson's trichrome and multiplexed immunofluorescent staining. Serum cytokines were also analyzed using a Luminex multiple cytokine assay. PLAG administration decreased the arthritis score until 8 weeks after the curdlan injection. However, the effect was not sustained thereafter. A lung histology revealed severe inflammation and fibrosis in the curdlan-induced SKG mice, which was attenuated in the PLAG-treated mice. Furthermore, immunofluorescent staining of the lung tissue showed a GM-CSF+ neutrophil accumulation and a decreased citrullinated histone 3 expression after PLAG treatment. PLAG also downregulated the levels of IL-6 and TNF-α and upregulated the level of sIL-7Rα, an anti-fibrotic molecule. Our results indicate that PLAG might have a preventative effect on ILD development through the resolution of NETosis in the lung.