Rheumatoid arthritis prevalence, incidence, and mortality rates: a nationwide population study in Taiwan

Major adverse cardiovascular events or venous thromboembolism in patients with rheumatoid arthritis initiating biological or targeted synthetic disease-modifying antirheumatic drugs: a nationwide, population-based cohort study

Background

Rheumatoid arthritis (RA) is complicated by a high risk of cardiovascular disease and requires the initiation of biological or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) for persistently active disease despite first-line therapies. The influence of b/tsDMARDs, especially tsDMARDs, on cardiovascular risk in Taiwanese patients with RA remains unclear.

Objectives

To compare the risk of major cardiovascular adverse events (MACEs) or venous thromboembolism (VTE) amongst RA patients initiating approved b/tsDMARDs for up to 5 years.

Design

A nationwide, population-based, retrospective cohort study.

Methods

Using Taiwan National Health Insurance (NHI) Research Database, we identified patients with RA initiating NHI-reimbursed b/tsDMARDs indicated for RA between 2001 and 2020. Study outcomes were newly developed MACEs or VTE within 5 years of the first b/tsDMARD initiation. Time-dependent Cox regression analysis was performed to determine the association between b/tsDMARDs and MACEs or VTE and independently associated or protective factors. Subgroup analyses by age at b/tsDMARD initiation and cardiovascular risk levels, as well as sensitivity analyses of b/tsDMARD initiation after 2012, were performed.

Results

We enrolled 12,332 adults with RA initiating the first b/tsDMARD during pre-determined period. The incidence rates of MACE and VTE were 894 and 283 per 100,000 person-years, respectively. After adjustment, other b/tsDMARDs were not associated with a higher risk of MACEs or VTE than tumour necrosis factor inhibitors (TNFis) up to 5 years after initiation. Subgroup analyses by age at b/tsDMARD initiation and cardiovascular risk levels revealed consistent findings. Factors associated with or protective against MACEs or VTE were identified.

Conclusion

No non-TNFi b/tsDMARD had a higher risk of MACEs or VTE than TNFis up to 5 years after initiation amongst patients with RA, and this remained consistent for those initiating their b/tsDMARD at age 65 years and older or with high cardiovascular risk.

Incidence and prevalence of autoimmune diseases in China: A systematic review and meta-analysis of epidemiological studies

Background

Autoimmune diseases account for a substantial burden of disease in high-income countries, including Europe and North America. However, their epidemiology remains under-researched in other regions. We examined the incidence and prevalence of eight autoimmune diseases in the adult Chinese population through a systematic review of epidemiological studies.

Methods

We searched OvidSP MEDLINE and Google Scholar from 1995 to 2023 (inclusive) for articles on the incidence or prevalence of autoimmune thyroiditis (AT), Graves' disease (GD), type 1 diabetes mellitus (T1D), multiple sclerosis (MS), Crohn's disease (CD), ulcerative colitis (UC), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We included studies from mainland China, Taiwan, Hong Kong or Macau. The study is registered with PROSPERO (CRD42021225842).

Findings

We retrieved 2278 records, of which 62 studies (161 estimates) were included in the systematic review, and 42 studies (101 estimates) were included in the meta-analysis. Pooled fixed-effects estimates for incidence of CD, UC, MS, T1D and SLE were 0.22 (95% CI 0.21-0.23), 1.13 (1.10-1.17), 0.28 (0.26-0.30), 2.20 (1.70-2.84) and 4.87 (4.21-5.64) per 100,000 persons, respectively. For RA, one study estimate was included, with an incidence of 15.8 per 100,000 persons. Fixed-effects estimates for the prevalence of CD, UC, MS, SLE, RA, GD and AT were 3.73 (95% CI 3.68-3.78), 16.11 (15.93-16.29), 4.08 (3.95-4.21), 93.44 (92.27-94.63), 104 (103-106), 450 (422-481) and 2322 (2057-2620), respectively, per 100,000 persons. Across all conditions, women were almost twice as likely as men to be diagnosed with an autoimmune disease.

Interpretation

There is marked variation in the frequency of autoimmune diseases among Chinese adults. We estimate that 2.7-3.0% (>31 million people) of the adult Chinese population have one or more autoimmune diseases, comparable to Western populations, with the majority of the burden from autoimmune thyroid diseases and rheumatoid arthritis.

Short- and Long-Term Mortality of Hospitalized Patients With Autoimmune Rheumatic Diseases and Serious Infections: A National Cohort Study

OBJECTIVE

Infectious conditions are a significant cause of mortality in autoimmune rheumatic diseases (ARD). Among patients hospitalized with an infection, we compared in-hospital and long-term (3-year) mortality between those with and without ARD.

METHODS

This retrospective analysis included members of the largest health maintenance organization in Israel, aged > 18 years at the first episode of infection, who required hospitalization during 2003-2019. We compared in-hospital mortality and the results of a 3-year landmark analysis of those who survived the index hospitalization between patients with ARD, according to disease subgroups, and patients without ARD. Additionally, we compared mortality outcomes among patients with ARD, according to subgroup diagnosis, matched in a 1:3 ratio by age, sex, and ethnicity to patients without ARD.

RESULTS

Included were 365,247 patients who were admitted for the first time with the diagnosis of a serious infection. Of these, we identified 9755 with rheumatoid arthritis (RA), 1351 with systemic lupus erythematosus, 2120 with spondyloarthritis (SpA), 584 with systemic sclerosis, and 3214 with vasculitis. In a matched multivariate analysis, the risk for in-hospital mortality was lower among patients with RA (odds ratio [OR] 0.89, 95% CI 0.81-0.97) and SpA (OR 0.77, 95% CI 0.63-0.94). In a similar analysis, the risk of 3-year mortality was lower among patients with RA (hazard ratio [HR] 0.82, 95% CI 0.78-0.86) and vasculitis (HR 0.86, 95% CI 0.80-0.93).

CONCLUSION

Among patients hospitalized for an infection, the risk of in-hospital and 3-year mortality was not increased among those with ARD compared to those without ARD.

Temporal trends in mortality in patients with rheumatoid arthritis: a Danish population-based matched cohort study

OBJECTIVES

To investigate the 5-year all-cause mortality in patients with RA compared with the general population.

METHODS

This was a nationwide population-based matched cohort study. RA patients diagnosed between 1996 and the end of 2015 were identified using administrative heath registries and followed until the end of 2020 allowing 5 years of follow-up. Patients with incident RA were matched 1:5 on year of birth and sex with non-RA individuals from the Danish general population. Time-to-event analyses were performed using the pseudo-observation approach.

RESULTS

Compared with matched controls in 1996-2000, the risk difference for RA patients ranged from 3.5% (95% CI 2.7%, 4.4%) in 1996-2000 to -1.6% (95% CI -2.3%, -1.0%) in 2011-15, and the relative risk from 1.3 (95% CI 1.2, 1.4) in 1996-2000 to 0.9 (95% CI 0.8, 0.9) in 2011-15. The age-adjusted 5-year cumulative incidence proportion of death for a 60-year-old RA patient decreased from 8.1% (95% CI 7.3%, 8.9%) when diagnosed in 1996-2000 to 2.9% (95% CI 2.3%, 3.5%) in 2011-15, and for matched controls from 4.6% (95% CI 4.2%, 4.9%) to 2.1% (95% CI 1.9%, 2.4%). Excess mortality persisted in women with RA throughout the study period, while the mortality risk for men with RA in 2011-15 was similar to their matched controls.

CONCLUSIONS

Enhanced improvement in mortality was found in RA patients compared with matched controls, but for sex-specific differences excess mortality was only persistent in women with RA.

Incidence and disease burden of autoimmune inflammatory rheumatic diseases after non-pharmaceutical interventions in the COVID-19 era: A nationwide observational study in Korea

BACKGROUND

Infections are considered risk factors for autoimmune inflammatory rheumatic diseases (AIRDs), the incidence of which is considered to have been impacted by the COVID-19 pandemic. The impact of non-pharmaceutical interventions (NPIs) on the incidence of AIRDs and their associated health care services and medical expenses in Korea was investigated.

METHODS

We included all AIRD cases reported between January 2016 and February 2021 based on the National Health Insurance Service data. We evaluated changes in incidence trends for each AIRD before and after NPI implementation (Feb 2020 to Feb 2021) using segmented regression analysis. Changes in health care utilization and medical costs for each AIRD before and after NPI implementation were also investigated.

RESULTS

After NPI implementation, monthly incidence rates declined significantly by 0.205 per 1 000 000 (95% confidence interval [CI], -0.308 to -0.101, p < .001) in patients with systemic lupus erythematosus (SLE). No significant changes in the incidence of all AIRDs other than SLE were observed before and after implementation. Further, annual outpatient department visits per patient were lower during implementation for all diseases, except juvenile idiopathic arthritis (JIA). The prescription days per outpatient visit increased significantly during implementation for all diseases, except JIA and ankylosing spondylitis. During implementation, the total annual medical costs per patient tended to decrease for all diseases, except JIA and mixed connective tissue disease.

CONCLUSION

Implementation of NPIs to contain the pandemic led to a reduction in the incidence of SLE and changed patterns of medical care utilization and treatment cost for most AIRDs.

Peptide-Coated Bacteriorhodopsin-Based Photoelectric Biosensor for Detecting Rheumatoid Arthritis

An effective early diagnosis is important for rheumatoid arthritis (RA) management. This study reveals a novel RA detection method using bacteriorhodopsin as a photoelectric transducer, a light-driven proton pump in purple membranes (PMs). It was devised by covalently conjugating a PM monolayer-coated electrode with a citrullinated-inter-alpha-trypsin inhibitor heavy chain 3 (ITIH3)542-556 peptide that recognizes the serum RA-associated autoantibodies. The direct serum coating decreased the photocurrents in the biosensor, with the reduction in the photocurrent caused by coating with an RA-patient serum that is significantly larger than that with a healthy-control serum (38.1% vs. 20.2%). The difference in the reduction in the photocurrent between those two serum groups widened after the serum-coated biosensor was further labeled with gold nanoparticle (AuNP)-conjugated anti-IgA (anti-IgA-AuNP) (53.6% vs. 30.6%). Both atomic force microscopic (AFM) and Raman analyses confirmed the sequential peptide, serum, and anti-IgA-AuNP coatings on the PM-coated substrates. The reductions in the photocurrent measured in both the serum and anti-IgA-AuNPs coating steps correlated well with the results using commercial enzyme-linked immunosorbent assay kits (Spearman rho = 0.805 and 0.787, respectively), with both a sensitivity and specificity close to 100% in both steps. It was shown that an RA diagnosis can be performed in either a single- or two-step mode using the developed biosensor.

Rheumatoid Arthritis Associated with Dry Eye Disease and Corneal Surface Damage: A Nationwide Matched Cohort Study

Rheumatoid arthritis is potentially connected to ocular disorders, such as corneal inflammation and lacrimal gland destruction. This study aimed to evaluate the risk of dry eye disease (DED) and corneal surface damage among patients with rheumatoid arthritis. In a nationwide cohort study, we utilized Taiwan’s National Health Insurance research database and conducted propensity score matching to compare the risks of DED and corneal surface damage between patients with and without rheumatoid arthritis. Proportional hazards regression analyses were used to calculate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) for the outcomes of interest. The matching procedure generated 33,398 matched pairs with 501,377 person-years of follow-up for analyses. The incidence of DED was 23.14 and 10.25 per 1000 person-years in patients with and without rheumatoid arthritis, respectively. After adjusting for covariates, rheumatoid arthritis was significantly associated with DED (aHR: 2.03, 95% CI: 1.93−2.13, p < 0.0001). The association was generally consistent across the subgroups of age, sex, use of systemic corticosteroids, and different comorbidity levels. In addition, patients with rheumatoid arthritis had a higher risk of corneal surface damage (aHR: 1.36, 95% CI: 1.21−1.51, p < 0.0001) compared to control subjects. Other independent factors for corneal surface damage were age and sleeping disorders. Rheumatoid arthritis was associated with an increased risk of DED and corneal surface damage. Ophthalmological surveillance is required to prevent vision-threatening complications in this susceptible population.

Traditional Chinese Medicine Compound Preparations Are Associated with Low Disease-Related Complication Rates in Patients with Rheumatoid Arthritis: A Retrospective Cohort Study of 11,074 Patients

Objective

To evaluate whether traditional Chinese medicine compound preparations (TCMCPs) are associated with rheumatoid arthritis- (RA-) related complications (including readmission, Sjogren's syndrome, surgical treatment, and all-cause death) in patients with RA.

Methods

Clinical outcome data were retrospectively collected from patients with RA discharged from the Department of Rheumatology and Immunology of the First Affiliated Hospital of Anhui University of Chinese Medicine from January 2009 to June 2021. The propensity score matching method was used to match baseline data. Multivariate analysis was conducted to analyze sex, age, the incidence of hypertension, diabetes, and hyperlipidemia and identify the risk of readmission, Sjogren's syndrome, surgical treatment, and all-cause death. Users of TCMCP and nonusers of TCMCP were defined as the TCMCP and non-TCMCP groups, respectively.

Results

A total of 11,074 patients with RA were included in the study. The median follow-up time was 54.85 months. After propensity score matching, the baseline data of TCMCP users corresponded with those of non-TCMCP users, with 3517 cases in each group. Retrospective analysis revealed that TCMCP significantly reduced clinical, immune, and inflammatory indices in patients with RA, and these indices were highly correlated. Notably, the composite endpoint prognosis for treatment failure in TCMCP users was better than that in non-TCMCP users (HR = 0.75 (0.71-0.80)). The risk of RA-related complications in TCMCP users with high-exposure intensity (HR = 0.669 (0.650-0.751)) and medium-exposure intensity (HR = 0.796 (0.691-0.918)) was significantly lower than those in non-TCMCP users. An increase in exposure intensity was associated with a concomitant decrease in the risk of RA-related complications.

Conclusion

The use of TCMCPs, as well as long-term exposure to TCMCPs, may lower RA-related complications, including readmission, Sjogren's syndrome, surgical treatment, and all-cause death, in patients with RA.

Autoantibodies against complement factor B in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder affecting the joints. Many patients carry anti-citrullinated protein autoantibodies (ACPA). Overactivation of the complement system seems to be part of the pathogenesis of RA, and autoantibodies against the pathway initiators C1q and MBL, and the regulator of the complement alternative pathway, factor H (FH), were previously reported. Our aim was to analyze the presence and role of autoantibodies against complement proteins in a Hungarian RA cohort. To this end, serum samples of 97 ACPA-positive RA patients and 117 healthy controls were analyzed for autoantibodies against FH, factor B (FB), C3b, C3-convertase (C3bBbP), C1q, MBL and factor I. In this cohort, we did not detect any patient with FH autoantibodies but detected C1q autoantibodies in four patients, MBL autoantibodies in two patients and FB autoantibodies in five patients. Since the latter autoantibodies were previously reported in patients with kidney diseases but not in RA, we set out to further characterize such FB autoantibodies. The isotypes of the analyzed autoantibodies were IgG2, IgG3, IgGκ, IgGλ and their binding site was localized in the Bb part of FB. We detected in vivo formed FB-autoanti-FB complexes by Western blot. The effect of the autoantibodies on the formation, activity and FH-mediated decay of the C3 convertase in solid phase convertase assays was determined. In order to investigate the effect of the autoantibodies on complement functions, hemolysis assays and fluid phase complement activation assays were performed. The autoantibodies partially inhibited the complement-mediated hemolysis of rabbit red blood cells, inhibited the activity of the solid phase C3-convertase and C3 and C5b-9 deposition on complement activating surfaces. In summary, in ACPA-positive RA patients we identified FB autoantibodies. The characterized FB autoantibodies did not enhance complement activation, rather, they had inhibitory effect on complement. These results support the involvement of the complement system in the pathomechanism of RA and raise the possibility that protective autoantibodies may be generated in some patients against the alternative pathway C3 convertase. However, further analyses are needed to assess the exact role of such autoantibodies.

Implementation of automated behavior metrics to evaluate voluntary wheel running effects on inflammatory-erosive arthritis and interstitial lung disease in TNF-Tg mice

BACKGROUND

Although treatment options and algorithms for rheumatoid arthritis (RA) have improved remarkably in recent decades, there continues to be no definitive cure or pharmacologic intervention with reliable long-term efficacy. For this reason, the combination of medications and healthy lifestyle modifications are essential for controlling joint disease, and extra-articular manifestations of RA, such as interstitial lung disease (ILD) and other lung pathologies, which greatly impact morbidity and mortality. Generally, exercise has been deemed beneficial in RA patients, and both patients and clinicians are motivated to incorporate effective non-pharmacologic interventions. However, there are limited evidence-based and specific exercise regimens available to support engagement in such activities for RA patients. Here, we provided the continuous opportunity for exercise to mice and implemented automated recording and quantification of wheel running behavior. This allowed us to describe the associated effects on the progression of inflammatory-erosive arthritis and ILD in the tumor necrosis factor transgenic (TNF-Tg) mouse model of RA.

METHODS

Wild-type (WT; males, n=9; females, n=9) and TNF-Tg (males, n=12; females, n=14) mice were singly housed with free access to a running wheel starting at 2 months until 5 to 5.5 months of age. Measures of running included distance, rate, length, and number of run bouts, which were derived from continuously recorded data streams collected automatically and in real-time. In vivo lung, ankle, and knee micro-computed tomography (micro-CT), along with terminal micro-CT and histology were performed to examine the association of running behaviors and disease progression relative to sedentary controls.

RESULTS

TNF-Tg males and females exhibited significantly reduced running distance, rate, length, and number of run bouts compared to WT counterparts by 5 months of age (p<0.0001). Compared to sedentary controls, running males and females showed increased aerated lung volumes (p<0.05) that were positively correlated with running distance and rate in female mice (WT: Distance, ρ=0.705/rate, ρ=0.693 (p<0.01); TNF-Tg: ρ=0.380 (p=0.06)/ρ=0.403 (p<0.05)). Talus bone volumes were significantly reduced in running versus sedentary males and negatively correlated with running distance and rate in TNF-Tg mice (male: ρ=-903/ρ=-0.865; female: ρ=-0.614/ρ=-0.594 (p<0.001)). Histopathology validated the lung and ankle micro-CT findings.

CONCLUSIONS

Implementation of automated wheel running behavior metrics allows for evaluation of longitudinal activity modifications hands-off and in real-time to relate with biomarkers of disease severity. Through such analysis, we determined that wheel running activity increases aerated lung volumes, but exacerbates inflammatory-erosive arthritis in TNF-Tg mice. To the end of a clinically relevant model, additional functional assessment of these outcomes and studies of pain behavior are warranted.

Prevalence, mortality, and treatment of patients with rheumatoid arthritis: A cohort study of the French National Health Data System, 2010-2019

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic inflammatory disease mostly affecting the joints. Data on the prevalence of RA differ widely, depending on the study and country. Our objectives were to estimate the prevalence of RA in France and the mortality rate, characterise the causes of death, and identify prescribed treatments.

METHODS

This nationwide cohort study was based on data of the French National Health Data System (SNDS) which covers 99% of the French population. All patients identified with RA based on specific ICD-10 codes (M05 and M06, except M06.1) between 2010 and 2019 were included.

RESULTS

We identified 385,919 RA cases between 2010 and 2019, 318,243 of which were followed in 2019 (65.8±16.8 years, 72% women). The overall crude prevalence rate in 2019 was 0.47%: 0.66% for women and 0.28% for men. The crude annual mortality rate was 3.1%. The overall standardised mortality ratio (SMR) of RA patients relative to the French general population decreased over time, reaching 1.21 in 2019. Cause-specific mortality was increased in RA patients for cardiovascular (SMR 1.40, 95% confidence interval 1.36-1.43), respiratory system (1.80, 1.73-1.87), digestive system (1.73, 1.59-1.88), and urogenital system (1.73, 1.59-1.88) diseases and infections (1.91, 1.76-2.06). We found no excess mortality due to tumours. The prevalence of treatment with conventional synthetic and biological/targeted synthetic disease-modifying antirheumatic drugs for RA in 2019 was 41.9% (n=133,477) and 18.7% (n=59,409), respectively.

CONCLUSION

Our results may provide a better understanding of RA and its care in France.

Increased Risk of Common Orthopedic Surgeries for Patients with Rheumatic Diseases in Taiwan

Background and Objectives: Rheumatic diseases, including rheumatoid arthritis, ankylosing spondylitis, psoriasis, and systemic lupus erythematosus (SLE), are characterized by chronic arthritis or spondyloarthritis, which can lead to joint and spine destruction. Our previous studies showed that the risk of common orthopedic surgeries, including total knee replacement (TKR), total hip replacement (THR), or spine surgery, was increased in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. The aim of this review was to summarize the risk of TKR, THR, cervical spine, and lumbar spine surgery on the basis of studies conducted using data from Taiwan’s National Health Insurance Research Database (NHIRD). Materials and Methods: The risk of TKR, THR, cervical spine surgery, and lumbar spine surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE was summarized from the results of our previous studies and unpublished findings based on NHIRD data. Results: Patients with rheumatoid arthritis and psoriasis and men with ankylosing spondylitis showed an increased risk of TKR. Patients with rheumatoid arthritis, ankylosing spondylitis, and women with SLE showed an increased risk of receiving THR. Only patients with ankylosing spondylitis had an increased risk of cervical spine surgery, and patients with rheumatoid arthritis or ankylosing spondylitis showed an increased risk of lumbar spine surgery. Although the risk of THR, TKR, or spine surgery in these patients has declined in the era of biologics use, direct evidence for the effects of biologics agents is not yet available. Conclusions: There was an increased risk of common orthopedic surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. Clinicians should be vigilant to reduce the increased risk of TKR and THR in young and middle-aged patients with rheumatoid arthritis, THR in young patients with ankylosing spondylitis, and young female patients with SLE, as well as cervical spine surgery in young patients with ankylosing spondylitis.

Fetal-neonatal and maternal pregnancy outcomes in women with rheumatoid arthritis: a population-based cohort study

OBJECTIVES

Rheumatoid arthritis (RA) may adversely influence pregnancy and lead to adverse birth outcomes. This study estimated the risk of adverse fetal-neonatal and maternal pregnancy outcomes in women with RA.

DESIGN

This was a retrospective cohort study.

SETTING

We used both the National Health Insurance database and the Taiwan Birth Reporting System, between 2004 and 2014.

PARTICIPANTS

We identified 2 100 143 singleton pregnancies with 922 RA pregnancies, either live births or stillbirths, delivered by 1 468 318 women.

OUTCOME MEASURES

ORs with 95% CIs for fetal-neonatal and maternal outcomes were compared between pregnancies involving mothers with and without RA using an adjusted generalised estimating equation model.

RESULTS

Covariates including age, infant sex, Charlson Comorbidity Index, urbanisation, income, occupation, birth year and maternal nationality were adjusted. Compared with pregnancies in women without RA, pregnancies in women with RA showed that the fetuses/neonates had adjusted ORs (95% CI) of 2.03 (1.66 to 2.50) for low birth weight (n=123), 1.99 (1.64 to 2.40) for prematurity (n=141), 1.77 (1.46 to 2.15) for small for gestational age (n=144) and 1.35 (1.03 to 1.78) for fetal distress (n=60). Pregnancies in women with RA had adjusted ORs (95% CI) of 1.24 (1.00 to 1.52) for antepartum haemorrhage (n=106), 1.32 (1.15 to 1.51) for caesarean delivery (n=398), and 3.33 (1.07 to 10.34) for disseminated intravascular coagulation (n=3), compared with women without RA. Fetuses/neonates born to mothers with RA did not have a higher risk of being stillborn or having fetal abnormalities. Pregnant women with RA did not have increased risks of postpartum death, cardiovascular complications, surgical complications or systemic organ dysfunction.

CONCLUSIONS

Pregnancies in women with RA were associated with higher risks of multiple adverse fetal-neonatal and maternal outcomes; however, most pregnancies in these women were successful.

Autoantibodies to Oxidatively Modified Peptide: Potential Clinical Application in Coronary Artery Disease

Coronary artery disease (CAD) is a global health issue. Lipid peroxidation produces various by-products that associate with CAD, such as 4-hydroxynonenal (HNE) and malondialdehyde (MDA). The autoantibodies against HNE and MDA-modified peptides may be useful in the diagnosis of CAD. This study included 41 healthy controls (HCs) and 159 CAD patients with stenosis rates of <30%, 30−70%, and >70%. The plasma level of autoantibodies against four different unmodified and HNE-modified peptides were measured in this study, including CFAH1211−1230, HPT78−108, IGKC2−19, and THRB328−345. Furthermore, feature ranking, feature selection, and machine learning models have been utilized to exploit the diagnostic performance. Also, we combined autoantibodies against MDA and HNE-modified peptides to improve the models’ performance. The eXtreme Gradient Boosting (XGBoost) model received a sensitivity of 78.6% and a specificity of 90.4%. Our study demonstrated the combination of autoantibodies against oxidative modification may improve the model performance.

A Roadmap for Investigating Preclinical Autoimmunity Using Patient-Oriented and Epidemiologic Study Designs: Example of Rheumatoid Arthritis

Background & Aims

Rheumatoid arthritis (RA) is a prototypic autoimmune disease causing inflammatory polyarthritis that affects nearly 1% of the population. RA can lead to joint destruction and disability along with increased morbidity and mortality. Similar to other autoimmune diseases, RA has distinct preclinical phases corresponding to genetic risk, lifestyle risk factors, autoantibody development, and non-specific symptoms prior to clinical diagnosis. This narrative review will detail observational studies for RA risk and clinical trials for RA prevention as a roadmap to investigating preclinical autoimmunity that could be applied to other diseases.

Methods

In this narrative review, we summarized previous and ongoing research studies investigating RA risk and prevention, categorizing them related to their design and preclinical phases.

Results

We detailed the following types of studies investigating RA risk and prevention: retrospective population-based and administrative datasets; prospective studies (case-control and cohort; some enrolling based on genetics, first-degree relative status, elevated biomarkers, or early symptoms/arthritis); and randomized clinical trials. These correspond to all preclinical RA phases (genetic, lifestyle, autoimmunity, early signs/symptoms). Previous and ongoing randomized controlled trials have enrolled individuals at very elevated risk for RA based on biomarkers, symptoms, imaging abnormalities, or early signs/symptoms.

Conclusion

We detailed the rich variety of study designs that is necessary to investigate distinct preclinical phases of an autoimmune disease such as RA. However, further progress is needed to fully elucidate the pathogenesis of RA that may ultimately lead to prevention or delay of disease onset.

Risk of Spine Surgery in Patients with Rheumatoid Arthritis: A Secondary Cohort Analysis of a Nationwide, Population-Based Health Claim Database

Background and Objectives: To study the risk of spine surgery, including cervical and lumbar spine surgeries in patients with rheumatoid arthritis (RA) compared with those without a diagnosis of RA. Materials and Methods: This is a secondary data analysis using population-based health claim data. We identified newly diagnosed adult patients with RA between January 2000 and December 2012, according to the International Classification of Diseases, Ninth revision, clinical modification code 714.0 from Taiwan’s National Health Insurance Research Database. Using data frequency-matched by 10-year age intervals, sex and index year with the RA cohort at a ratio of 5:1, we assembled a comparison cohort. All patients were followed until the study outcomes occurred (overall spine surgery, cervical spine surgery, or lumbar spine surgery) or the end of follow-up. Adjusted incidence rate ratios (aIRR) were calculated using Poisson regression analysis with age group, socioeconomic status, geographical region, and osteoporosis included as potential confounders. Results: We identified 1287 patients with RA and 6435 patients without RA. The incidence of overall spine surgery (aIRR = 2.13, 95% confidence interval (CI) = 1.49–3.04) and lumbar spine surgery (aIRR = 2.14, 95% CI = 1.46–3.15) were all significantly higher in the RA cohort. Moreover, females over 45 years of age were particularly at risk for lumbar spine surgery. In RA patients, older age and the combination with the diagnosis of osteoporosis had an elevated risk for overall and lumbar spine surgery. Conclusion: Patients with RA had an increased risk of receiving spine surgery. Physicians should be vigilant for possible spinal problems in women and older patients with RA.

Non-fermented tea consumption protects against osteoporosis among Chinese male elders using the Taiwan biobank database

Few studies compared the effects of non-fermented and fermented tea among the general population. We aimed to compare the risk of incident osteoporosis (OP) between non-fermented tea and fermented tea drinkers by this retrospective nationwide population-based analysis from the Taiwan Biobank. Participants ≥ 40 years who drink fermented tea (n = 2205) were compared with those who drink non-fermented tea (n = 1034) from 2008 to 2015 with a mean follow-up period of 3.64 years. OP was defined by T-score ≤ − 2.5. Multivariate Cox proportional hazards regression models were performed to estimate the risk of developing OP between the two groups. Separate models were used to determine the relationship between tea consumption and OP stratified by sex and age. There was a significant interaction between sex, age, and type of tea consumed. In men aged ≥ 60 years, the risk of developing OP decreased by 79% for those who drank non-fermented tea (hazard ratio, 0.21; 95% confidence level, 0.05–0.94) than those who drank fermented tea. Additionally, those with a family history of OP had a higher risk of developing osteoporosis. This study suggests that male elderly who consume non-fermented tea have a lower risk of OP. Drinking non-fermented tea, such as green tea, could be suggested, especially for those with a family history of osteoporosis.

SLAMF6 is associated with the susceptibility and severity of rheumatoid arthritis in the Chinese population

OBJECTIVES

A recently published genome-wide association study identified six novel loci associated with rheumatoid arthritis (RA) in Korean population. We aimed to investigate whether these newly reported RA-risk loci are associated with RA in the Chinese population and to further characterize the functional role of the susceptible gene.

METHODS

The susceptible variants of RA were genotyped in 600 RA patients and 800 healthy controls, including rs148363003 of SLAMF6, rs117605225 of CXCL13, rs360136 of SWAP70, rs111597524 of NFKBIA, rs194757 of ZFP36L1 and rs1547233 of LINC00158. Synovial tissues were collected from the knee joint of 50 RA patients and 40 controls without osteoarthritis for the gene expression analysis. Inter-group comparisons were performed with the Chi-square test for genotyping data or with Student's t-test for gene expression analysis.

RESULT

For rs148363003 of SLAMF6, RA patients were observed to have a significantly lower frequency of genotype CC (4.5% vs. 0.9%, p = 0.004) as compared with the controls. The frequency of allele C was remarkably higher in the patients than in the controls (11.5% vs. 8.0%, p = 0.002), with an odds ratio of 1.49 (95% CI = 1.16-1.92). There was no significant difference between the patients and the controls regarding genotype or allele frequency of the other 5 variants. The mRNA expression of SLAMF6 was 1.6 folds higher in the RA patients than in the controls. Moreover, SLAMF6 expression was 1.5 folds higher in patients with genotype CC than in the patients with genotype TT.

CONCLUSIONS

SLAMF6 was associated with both the susceptibility and severity of RA in the Chinese population. Moreover, rs148363003 could be a functional variant regulating the tissue expression of SLAMF6 in RA patients. It is advisable to conduct further functional analysis for a comprehensive knowledge on the contribution of this variant to the development of RA.

Mortality in Inflammatory Rheumatic Diseases: Lithuanian National Registry Data and Systematic Review

Despite significant improvement in survival, rheumatic diseases (RD) are associated with premature mortality rates comparable to cardiovascular and neoplastic disorders. The aim of our study was to assess mortality, causes of death, and life expectancy in an inflammatory RD retrospective cohort and compare those with the general population as well as with the results of previously published studies in a systematic literature review. Patients with the first-time diagnosis of inflammatory RD during 2012-2019 were identified and cross-checked for their vital status and the date of death. Sex- and age-standardized mortality ratios (SMR) as well as life expectancy for patients with inflammatory RDs were calculated. The results of a systematic literature review were included in meta-standardized mortality ratio calculations. 11,636 patients with newly diagnosed RD were identified. During a total of 43,064.34 person-years of follow-up, 950 death cases occurred. The prevailing causes of death for the total cohort were cardiovascular diseases and neoplasms. The age- and sex-adjusted SMR for the total cohort was calculated to be 1.32 (1.23; 1.40). Patients with rheumatoid arthritis if diagnosed at age 18-19 tend to live for 1.63 years less than the general population, patients with spondyloarthritis-for 2.7 years less, patients with connective tissue diseases-for almost nine years less than the general population. The findings of our study support the hypothesis that patients with RD have a higher risk of mortality and lower life expectancy than the general population.

Acute surgical site infection after total knee arthroplasty in patients with rheumatoid arthritis versus osteoarthritis

Osteoarthritis is the main cause for total knee arthroplasty (TKA), followed by rheumatoid arthritis. Previous studies have reported conflicting results concerning the risk of surgical site infection after TKA for rheumatoid arthritis and osteoarthritis patients. Thus, this study aimed to examine whether rheumatoid arthritis patients had a higher risk of acute surgical site infection after TKA compared to osteoarthritis patients. We conducted a retrospective cohort study using Taiwan’s National Health Insurance Research Database of the whole population from 2012 to 2015, and collected the medical records of osteoarthritis patients or rheumatoid arthritis patients who underwent TKA. To evaluate the risk of acute surgical site infection in rheumatoid arthritis patients, propensity score matching was implemented for osteoarthritis patients. Acute surgical site infection was observed in 2.58% of TKA cases in rheumatoid arthritis patients and 2.66% of TKA cases in osteoarthritis patients. Rheumatoid arthritis and osteoarthritis patients had comparable risk for 90-day (odds ratio = 0.81, 95% confidence interval: 0.371–1.768) and 1-year (odds ratio = 0.463, 95% confidence interval: 0.121–1.766) surgical site infection. In conclusion, patients with rheumatoid arthritis were not at higher risk of acute surgical site infection after TKA compared to osteoarthritis patients. The current treatment strategy for patients with RA is safe and appropriate if they require TKA.

Expression and Correlation of IgG4 and IL-21 in Collagen-Induced Arthritis Rats

Purpose

We explored the expression levels of IgG4 and interleukin (IL)-21 in the serum and ankle joints of collagen-induced arthritis (CIA) rats at different disease stages.

Materials and Methods

Wistar rats were randomly divided into normal and model groups, and the latter group was administered bovine type II collagen to induce arthritis. Enzyme-linked immunosorbent assay was performed at 21, 28, 35, and 42 days to detect IgG4 and IL-21 in the serum, followed by histological and immunohistochemical analyses of IgG4 and IL-21r in the ankle joint of rats.

Results

The contents of IgG4 and IL-21 in the serum of the CIA model group were positively correlated and increased with disease progression. The expression of IgG4 and IL-21 receptors in the ankle joint of the CIA model group was significantly higher than that in the control group. These proteins were closely related to the pathological score. The serum IL-21 level in the model group was closely related to the level of IL-21 receptor in the ankle joint.

Conclusion

IL-21 may promote the occurrence and development of rheumatoid arthritis by combining with IL-21r to regulate the content of IgG4.

All-cause and cause-specific mortality of patients with rheumatoid arthritis in Korea: A nation-wide population-based study

OBJECTIVE

To compare all-cause and cause-specific mortality between rheumatoid arthritis (RA) patients versus the general population of Korea.

METHODS

A nationally representative RA population aged≥40 years was identified from Korea National Health Insurance Service (KNHIS) database. We estimated age- and sex-adjusted all-cause and cause-specific standardized mortality ratios (SMRs) with 95% confidence intervals (CIs), comparing RA patients to the general population. Subgroup analyses were done by sex, age group, calendar year, and biologics use.

RESULTS

We identified 79,352 RA patients with 6404 deaths during 2011-2016. The all-cause SMR [95% CI] of RA patients compared to the general population was 1.53 [1.49-1.56]. The top five causes of death were cancer (19.5%), respiratory disease (19.1%), cardiovascular disease (18.8%), systemic rheumatic diseases (9.5%, 9.1% due to RA), and infection (6.1%). Cause-specific SMRs [95% CI] were 0.95 [0.90-1.01] for cancer, 3.34 [3.15-3.52] for respiratory disease, 1.26 [1.18-1.33] for cardiovascular disease, 3.41 [3.08-3.75] for infection, and 4.88 [3.10-6.65] for non-RA systemic rheumatic disease. The SMR of RA population was slightly higher among men than women, and highest in their 60s and 70s. The yearly SMR increased from 1.10 [1.01-1.18] in 2011 to 1.85 [1.75-1.95] in 2016 due to population aging and comorbidity accumulation. Users of biologics showed a higher SMR than non-users (1.82 [1.69-1.96] vs. 1.50 [1.46-1.54]), due to higher RA activity, and more comorbidities despite a younger mean age.

CONCLUSION

RA patients in Korea experienced 1.5-fold increase in all-cause mortality compared to the general population. Except for cancer, the top five causes of death were associated with excess mortality among RA patients. RA-associated mortality was largely determined by age, RA activity, and comorbidity status.

Factors associated with risk of major adverse cardiovascular events in patients with rheumatoid arthritis: a nationwide, population-based, case-control study

Objectives

To investigate factors associated with major adverse cardiovascular events (MACEs) in patients with rheumatoid arthritis (RA).

Methods

We conducted a nationwide, population-based, case-control study using Taiwan's National Health Insurance Research Database for 2003-2013. From 2004 to 2012, we identified 108,319 newly diagnosed RA patients without previous MACEs, of whom 7,580 patients (7.0%) developed MACEs during follow-up. From these incident RA patients, we included 5,994 MACE cases and 1:4 matched 23,976 non-MACE controls for analysis. The associations of MACEs with comorbidities and use of anti-rheumatic medications within 1 year before the index date were examined using conditional logistic regression analyses.

Results

Using multivariable conditional logistic regression analysis, the risk of MACE in RA patients was associated with use of golimumab [odd's ratio (OR), 0.09; 95% confidence interval (CI), 0.01-0.67], abatacept (OR, 0.13; 95% CI, 0.02-0.93), hydroxychloroquine (OR, 0.90; 95% CI, 0.82-0.99), methotrexate (OR, 0.72; 95% CI, 0.64-0.81), cyclosporin (OR, 1.43; 95% CI, 1.07-1.91), nonsteroidal anti-inflammation drugs (NSAIDs) (OR, 1.36; 95% CI, 1.27-1.46), antiplatelet agent (OR, 2.47; 95% CI, 2.31-2.63), hypertension (without anti-hypertensive agents: OR, 1.04; 95% CI, 0.96-1.12; with anti-hypertensive agents: OR, 1.47; 95% CI, 1.36-1.59), diabetes (OR, 1.27; 95% CI, 1.18-1.37), hyperlipidemia without lipid-lowering agents (OR, 1.09; 95% CI, 1.01-1.17), ischemic heart disease (OR, 1.20; 95% CI, 1.10-1.31), and chronic obstructive pulmonary disease (COPD) (OR, 1.12; 95% CI, 1.03-1.23) in the parsimonious model. The risk of MACE in RA patients also increased markedly in participants younger than 65 years with some comorbidities.

Conclusions

This population-based case-control study revealed that the use of golimumab, abatacept, hydroxychloroquine, and methotrexate were associated with a decreased risk of MACE development in newly diagnosed RA patients, while the use of cyclosporin, NSAIDs, and antiplatelet agents, and comorbidities, including hypertension, diabetes, hyperlipidemia without lipid-lowering agent therapy, ischemic heart disease, and COPD, were associated with an increased risk of MACE development in RA patients.

Switching and Discontinuation Pattern of Biologic Disease-Modifying Antirheumatic Drugs and Tofacitinib for Patients With Rheumatoid Arthritis in Taiwan

Rheumatoid arthritis (RA) is a chronic inflammatory systemic disease characterized by persistent joint synovial inflammation and swelling, leading to cartilage damage and bone erosion. This retrospective, longitudinal study is to evaluate the treatment patterns of biologic-naïve RA patients receiving index biologic disease-modifying antirheumatic drug (bDMARD) and tofacitinib by the data of Taiwan National Healthcare Insurance Claims and the Death Registry between 2012 and 2017. Drug survival and treatment patterns were determined by investigating the occurrence of switching and discontinuation from index treatment. At baseline, 70.0% of patients used tumor necrosis factor inhibitors (TNFi) bDMARD with the majority taking etanercept (27.0%) or adalimumab (26.2%). During the follow-up period, 40.0% (n = 3,464) of index users switched (n = 1,479) or discontinued (n = 1,985) the treatment with an average incidence rate of 0.18 per patient-year. Among the six index treatment groups, drug survival was the lowest for adalimumab and highest for tocilizumab. When compared with etanercept, only adalimumab had a higher cumulative probability of switching/discontinuation (adjusted HR = 1.17, 95% CI: 1.08-1.28), whereas golimumab, non-TNFi bDMARDs and tofacitinib were significantly less probable to switch or discontinue. For patients switching the index treatment, tocilizumab (31.2%) and tofacitinib (23.4%) were the main regimens being switched to. In addition, 48.2% of patients who discontinued the index treatment received further retreatment, and 63.8-77.0% of them were retreated with same agent. In conclusion, this population-based study found that TNFi were the preferred agents as the index treatments during 2012-2017. Non-TNFi and tofacitinib were more common second-line agents being switched to. Nearly half of discontinued patients received retreatment, with a majority receiving the same agent.

Using Anti-Malondialdehyde Modified Peptide Autoantibodies to Import Machine Learning for Predicting Coronary Artery Stenosis in Taiwanese Patients with Coronary Artery Disease

Machine learning (ML) algorithms have been applied to predicting coronary artery disease (CAD). Our purpose was to utilize autoantibody isotypes against four different unmodified and malondialdehyde (MDA)-modified peptides among Taiwanese with CAD and healthy controls (HCs) for CAD prediction. In this study, levels of MDA, MDA-modified protein (MDA-protein) adducts, and autoantibody isotypes against unmodified peptides and MDA-modified peptides were measured with enzyme-linked immunosorbent assay (ELISA). To improve the performance of ML, we used decision tree (DT), random forest (RF), and support vector machine (SVM) coupled with five-fold cross validation and parameters optimization. Levels of plasma MDA and MDA-protein adducts were higher in CAD patients than in HCs. IgM anti-IGKC^76-99 MDA and IgM anti-A1AT^284-298 MDA decreased the most in patients with CAD compared to HCs. In the experimental results of CAD prediction, the decision tree classifier achieved an area under the curve (AUC) of 0.81; the random forest classifier achieved an AUC of 0.94; the support vector machine achieved an AUC of 0.65 for differentiating between CAD patients with stenosis rates of 70% and HCs. In this study, we demonstrated that autoantibody isotypes imported into machine learning algorithms can lead to accurate models for clinical use.

Opposing Trends in Total Knee and Hip Arthroplasties for Patients With Rheumatoid Arthritis vs. the General Population-A 14-Year Retrospective Study in Taiwan

Objective: To determine the trend of incidence rate of total knee arthroplasty (TKA), total hip arthroplasty (THA), and TKA or THA (major joint arthroplasty, MJA) among rheumatoid arthritis (RA) population and compared them with general population (GP) in Taiwan.

Methods: Incidence rates and trends of TKA, THA, and MJA were determined over a 14-year period (2000–2013) among RA patients and compared them with GP. RA of patients was diagnosed based on the ACR 1987 criteria and extracted from GP. Subanalyses of incidences of TKA, THA, and MJA by year, 10-year age group, and gender were further conducted for demographic analysis. Patient profiles were extracted from the National Health Insurance Research Database (NHIRD) for interrupted time-series analysis and cohort studies.

Results: Patients enrolled were 168,457 receiving TKA, 64,543 receiving THA, and 228,191 receiving MJA surgery. Incidences of TKA, THA, and MJA in RA patients were significantly lower by 49.0, 41.5, and 41.0% compared with concomitantly rises in GP by 131.0, 25.1, and 90.0% among the GP during the study period. The dominant age population for TKA, THA, and MJA were those aged 70–79 years in both GP and RA groups.

Conclusions: We found an opposing trend in incidence of TKA, THA, and MJA between RA patients and the GP. The possible influence of pharmacological treatment is implicated for the lower incidence rates of TKA, THA, and MJA surgeries among RA patients.

Epidemiology of Rheumatoid Arthritis in Korea

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterised by symmetrical involvement of the joints, associated extra-articular manifestations and functional disability. In Korea, several epidemiologic studies reporting prevalence and incidence rates of RA have been conducted using large databases such as claims databases, national surveys, prospective cohort databases or electronic health records; according to these data sources, the estimated prevalence ranged from 0.27% to 1.85%. The prevalence of extra-articular manifestations such as interstitial lung disease (ILD) and Sjögren's syndrome (SS) were also reported, but an issue of external validity of the study results persisted. In this review, we detail the epidemiology of Korean RA patients, focusing on the prevalence of RA and the frequency of systemic extra-articular manifestations including ILD and SS reported in previous studies. In addition, we discuss the current methodological issues which are inherent in Korean epidemiologic studies for patients with RA with understanding of the characteristics of each database.

Isotypes of autoantibodies against novel differential 4-hydroxy-2-nonenal-modified peptide adducts in serum is associated with rheumatoid arthritis in Taiwanese women

Background

Rheumatoid arthritis (RA) is an autoimmune disorder with systemic inflammation and may be induced by oxidative stress that affects an inflamed joint. Our objectives were to examine isotypes of autoantibodies against 4-hydroxy-2-nonenal (HNE) modifications in RA and associate them with increased levels of autoantibodies in RA patients.

Methods

Serum samples from 155 female patients [60 with RA, 35 with osteoarthritis (OA), and 60 healthy controls (HCs)] were obtained. Four novel differential HNE-modified peptide adducts, complement factor H (CFAH)^1211–1230, haptoglobin (HPT)^78–108, immunoglobulin (Ig) kappa chain C region (IGKC)^2–19, and prothrombin (THRB)^328–345, were re-analyzed using tandem mass spectrometric (MS/MS) spectra (ProteomeXchange: PXD004546) from RA patients vs. HCs. Further, we determined serum protein levels of CFAH, HPT, IGKC and THRB, HNE-protein adducts, and autoantibodies against unmodified and HNE-modified peptides. Significant correlations and odds ratios (ORs) were calculated.

Results

Levels of HPT in RA patients were greatly higher than the levels in HCs. Levels of HNE-protein adducts and autoantibodies in RA patients were significantly greater than those of HCs. IgM anti-HPT⁷⁸⁻¹⁰⁸ HNE, IgM anti-IGKC²⁻¹⁹, and IgM anti-IGKC²⁻¹⁹ HNE may be considered as diagnostic biomarkers for RA. Importantly, elevated levels of IgM anti-HPT⁷⁸⁻¹⁰⁸ HNE, IgM anti-IGKC²⁻¹⁹, and IgG anti-THRB^328−345 were positively correlated with the disease activity score in 28 joints for C-reactive protein (DAS28-CRP). Further, the ORs of RA development through IgM anti-HPT⁷⁸⁻¹⁰⁸ HNE (OR 5.235, p < 0.001), IgM anti-IGKC²⁻¹⁹ (OR 12.655, p < 0.001), and IgG anti-THRB^328−345 (OR 5.761, p < 0.001) showed an increased risk. Lastly, we incorporated three machine learning models to differentiate RA from HC and OA, and performed feature selection to determine discriminative features. Experimental results showed that our proposed method achieved an area under the receiver operating characteristic curve of 0.92, which demonstrated that our selected autoantibodies combined with machine learning can efficiently detect RA.

Conclusions

This study discovered that some IgG- and IgM-NAAs and anti-HNE M-NAAs may be correlated with inflammation and disease activity in RA. Moreover, our findings suggested that IgM anti-HPT⁷⁸⁻¹⁰⁸ HNE, IgM anti-IGKC²⁻¹⁹, and IgG anti-THRB^328−345 may play heavy roles in RA development.

The global prevalence of rheumatoid arthritis: a meta-analysis based on a systematic review

The objective is to determine the global population prevalence of rheumatoid arthritis (RA) based on population-based studies and assess factors that influence RA prevalence estimates. Four electronic databases were searched (ProQuest Central, MEDLINE, Web of Science, and EMBASE) for peer-reviewed English publications that report prevalence estimates of RA from 1980 and 2019. We included case-control studies, cross-sectional studies, and prospective or retrospective cohort studies in our search strategy. A random-effect meta-analysis model was used to produce the pooled prevalence estimates. The potential between-study heterogeneity was identified using sensitivity analysis, sub-group and meta-regression analyses. A total of 67 studies were included in the meta-analysis, containing 742,246 RA patients and 211,592,925 healthy controls in the study period. The global RA prevalence estimate was 0.46% (95% confidence interval [CI] 0.39-0.54; I² = 99.9%) with a 95% prediction interval (0.06-1.27). The RA point-prevalence was 0.45% (95% CI 0.38-0.53%) between 1986 and 2014, while the pooled period-prevalence was 0.46% (95% CI 0.36% and 0.57%) from 1955 to 2015. The highest RA pooled prevalence (0.69%; 95% CI 0.47-0.95) was derived from linked data source studies. Based on meta-regression, the factors that explain the studies' heterogeneity of RA prevalence, including geographical location, the risk bias assessment of studies and sample size. The global prevalence of RA between 1980 and 2019 was 460 per 100,000 population, with variations due to geographical location and study methodology. Linked data are the preferred method to estimate RA population prevalence as they provide the best case ascertainment.

Reinterpreting Evidence of Rheumatoid Arthritis-Associated Interstitial Lung Disease to Understand Etiology

Interstitial Lung Disease (ILD) is a well-known complication of rheumatoid arthritis (RA) which often results in significant morbidity and mortality. It is often diagnosed late in the disease process via descriptive criteria. Multiple subtypes of RA-ILD exist as defined by chest CT and histopathology. In the absence of formal natural history studies and definitive diagnostics, a conventional dogma has emerged that there are two major subtypes of RA-ILD (nonspecific interstitial pneumonia (NSIP) and Usual Interstitial Pneumonia (UIP)). These subtypes are based on clinical experience and correlation studies. However, recent animal model data are incongruous with established paradigms of RA-ILD and beg reassessment of the clinical evidence in order to better understand etiology, pathogenesis, prognosis, and response to therapy. To this end, here we: 1) review the literature on epidemiology, radiology, histopathology and clinical outcomes of the various RAILD subtypes, existing animal models, and current theories on RA-ILD pathogenesis; 2) highlight the major gaps in our knowledge; and 3) propose future research to test an emerging theory of RAILD that posits initial rheumatic lung inflammation in the form of NSIP-like pathology transforms mesenchymal cells to derive chimeric disease, and subsequently develops into frank UIP-like fibrosis in some RA patients. Elucidation of the pathogenesis of RA-ILD is critical for the development of effective interventions for RA-ILD.

The risk of coronary artery disease in patients with rheumatoid arthritis using Chinese herbal products and conventional medicine in parallel: a population-based cohort study

Background

Few studies have evaluated the association between the risk of coronary artery disease (CAD) and the use of Chinese herbal products (CHP) in patients with rheumatoid arthritis (RA). This study investigated the risk of CAD among patients with RA using CHP in combination with conventional medicine.

Methods

A retrospective cohort study was conducted using the Taiwan National Insurance Research Database to assess 22,353 patients who had been newly diagnosed with RA between 1997 and 2010. Patients were assigned to the CHP group or non-CHP group according to their use or nonuse of CHP after being diagnosed with RA. The Cox proportional hazards model was used to estimate the hazard ratio (HR) of CAD for a 1:1 matched sample.

Results

Both the CHP and non-CHP groups comprised 4889 patients after 1:1 matching. The risk of CAD was significantly reduced in the CHP group [adjusted HR (aHR): 0.59, 95% confidence interval (CI): 0.50–0.71] compard with the non-CHP group. Those who used CHP for > 180 days had an even lower risk of CAD than users with CHP usage less than 30 days (aHR: 0.64, 95% CI: 0.43–0.95). Additionally, frequently prescribed formulae, such as Kuei-Chih-Shao-Yao-Chih-Mu-Tang, Tang-Kuei-Nien-Tung-Tang, and Shu-Ching-Huo-Hsieh-Tang, were associated with a reduced risk of CAD.

Conclusion

The use of CHP was associated with a lower risk of CAD in patients with RA. Additional randomized controlled trials are required to assess any causal relationship between the effect of CHP usage and the risk of CAD.

The effectiveness of nurse-led case management for patients with rheumatoid arthritis in Taiwan

BACKGROUND

Case management is a patient-centred approach which has shown efficacy in managing patients with chronic and life-threatening disease. Presently, the effect of case management delivered by nurses for rheumatoid arthritis (RA) patients remains unclear, especially for those subjects who reside in Asia. This study aimed to examine the effectiveness of nurse-led case management (NLCM) among RA patients in Taiwan.

METHODS

A quasi-experimental research design was utilised to recruit RA patients from a hospital in Taiwan. All patients who were diagnosed as having RA from January 2017 to June 2018 were free to opt to participate in the intervention. The experiment group (n = 50) received six sessions of NLCM over six months, while the control group (n = 46) received only standard care during the same time period. Effectiveness data were collected through the review of medical records and a structured questionnaire that included the Taiwanese Depression Questionnaire (TDQ), the arthritis self-efficacy scale and a disease activity score by 28 joints (DAS28) at three time points (T1: before NLCM; T2: three days after NLCM completion; and T3: six months after NLCM completion). The effects of NLCM were determined using a generalised estimating equations model.

RESULTS

After adjusting for several potential confounders, we found that the NLCM implementation decreased the levels of DAS28 (T1 = -0.78; T2 = -0.85; all at P = .01) and TDQ (T1 = -3.86; T2 = -10.57; all at P < .05) and enhanced ASES level for RA patients (T1 = 132.03; T2 = 484.69; all at P < .05).

CONCLUSIONS

This study adopted a non-randomised, unblinded and uncontrolled intervention, and the findings supported the positive effects of NLCM following the use of a robust statistical method. The findings may serve as a reference for instituting more appropriate interventions for RA patients.

Risk of preventable hospitalization before and after diagnosis among rheumatoid arthritis patients compared to non-rheumatoid arthritis controls

OBJECTIVE

The purpose of the study is to investigate the risk of preventable hospitalization among patients with rheumatoid arthritis (RA).

METHODS

We identified 11,852 incident RA patients and 59,260 age-, sex-, and index year-matched controls from the Taiwan National Health Insurance Database. Index date was the RA diagnosis date for cases, which was assigned to their matched controls. The odds ratios (OR) of preventable hospitalizations between RA patients and controls were estimated using a mixed effect model adjusted for age, sex, patient characteristics, Elixhauser comorbidity index, medical utilization and regional medical resources.

RESULTS

The overall annualized incidence of preventable hospitalization in RA patients and controls was 38.7 vs. 20.9 events per 1,000 person-years (adjusted OR, 1.61; 95% confidence interval [CI], 1.51-1.71). The adjusted OR of preventable hospitalization in RA patients compared to matched controls was 1.17 (1.00-1.37) one year prior to RA diagnosis and remained elevated after RA diagnosis. Adjusted ORs (95% CI) for specific preventable hospitalization categories were 1.93 (1.58-2.36) for chronic obstructive pulmonary disease, 1.64 (1.21-2.21) for asthma, 1.95 (1.78-2.13) for bacterial pneumonia, and 1.59 (1.44-1.75) for urinary tract infection. When assessing the trend of individual preventable hospitalizations before and after diagnosis, bacterial pneumonia and urinary tract infection hospitalizations had a significantly higher OR in RA patients one year before diagnosis and five years afterward (adjusted OR ranges 2.75 to 4.48 and 1.83 to 3.07 respectively, all P-values<0.05) CONCLUSION: RA is independently associated with a higher risk of preventable hospitalization specifically for chronic lung diseases and infections.

The role of bone mineral density in therapeutic decision-making using the Fracture Risk Assessment Tool (FRAX): a sub-study of the Taiwan OsteoPorosis Survey (TOPS)

Fracture Risk Assessment Tool (FRAX)-based intervention threshold (IT) is widely applied for treatment decision-making; however, an IT based on FRAX without the measurement of bone mass density (BMD) has not been validated. The study demonstrated that estimates of fracture risk by FRAX without BMD were higher than those by FRAX with BMD in women with old age.

INTRODUCTION

BMD is an integral component for bone strength assessment, but age-specific impacts of BMD on fracture risk assessment and therapeutic decision-making remained unclear. We aimed to investigate whether using BMD measurement changed the interpretation of the FRAX-based fracture probability assessment and treatment decision.

METHODOLOGY

The database was provided by the Taiwanese Osteoporosis Association (TOA) which conducted a nationwide survey of BMD. We calculated the 10-year major and hip fracture probabilities using the FRAX for each participant, either with (FRAX + BMD) or without BMD (FRAX - BMD). Age-specific individual intervention thresholds (IITs) were established using the FRAX-based fracture risk, equivalent to a woman with a prior fracture. Participants whose FRAX scores of major fracture were greater than or equal to their IITs were deemed suitable for therapeutic intervention.

RESULTS

A total of 14,007 postmenopausal women were enrolled. Compared with FRAX + BMD, FRAX - BMD predicted lower FRAX scores in major and hip fractures in subjects aged 40-60 years; however, FRAX - BMD estimated higher risks for those aged 61-90 years. The therapeutic decision using FRAX - BMD was concordant to that using FRAX + BMD in 90.5% of the subjects, especially in the younger age group (40-70 years). FRAX - BMD identified more treatment candidates (7.7-16.4%) among those aged 71-90 years.

CONCLUSIONS

The FRAX scores are influenced by age, irrespective of the consideration of BMD. FRAX - BMD is able to identify more subjects for therapeutic intervention in the elderly population. We should reconsider the role of BMD at different ages for therapeutic decision-making.

Comparison of Healthcare Utilization and Costs Between RA Patients Receiving Biological and Conventional Synthetic DMARDs: A Nationwide Population-Based Cohort Study in Taiwan

Background: The therapy with biological disease-modifying anti-rheumatic drugs (bDMARDs) has proven to rapidly reduce articular symptoms/signs, decrease morbidities, and improve health outcome in patients with rheumatoid arthritis (RA) and be cost-effective in Western countries. However, the difference in healthcare utilization and costs between conventional synthetic DMARDs (csDMARDs) and bDMARDs in the treatment of RA patients in Taiwan remains largely unexplored.

Methods: Two cohorts of RA patients and their matched controls were identified from the National Health Insurance Research database (NHIRD). The csDMARD cohort comprised of patients who submitted claims during 1997–2003 for cyclosporine≥50 mg/day with concomitant use of ≥2 csDMARDs for ≥28 days (n=1,569), whilst the bDMARD cohort comprised of patients who had ≥1 claim during 2003–2011 for bDMARD (n = 1,530). The per-patient per-year healthcare utilization and costs were estimated by bootstrapping method, with a comparison being undertaken between csDMARD and bDMARD.

Results: The incremental number of hospitalization days was reduced from 2.3 days for csDMARD to 0.58 day for bDMARD. When compared to csDMARD-treated patients, the incremental total costs and RA-related medication costs were significantly higher in bDMARD-treated patients (US$9,081 vs. US$2,481; US$8,992 vs. US$1,883). However, the combined incremental healthcare utilization costs and non-RA medication costs were significantly lower in bDMARDs-treated patients compared to csDMARD-treated patients (US$374.7 vs. US$1,156.2).

Conclusion: Although total costs increased as a result of introducing biologics in RA treatment, biologics have undoubtedly given rise to the benefits of reduced healthcare utilization. The increase in medication costs from biologics was offset by the lower costs of healthcare utilization. Our findings suggest that the medication costs of biologics may be alleviated by an improvement in clinical outcomes.

Tofacitinib in the treatment of moderate-to-severe rheumatoid arthritis: a cost-effectiveness analysis compared with adalimumab in Taiwan

Aims: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). This analysis investigated the cost-effectiveness of the second-line treatment with tofacitinib, compared with adalimumab, both plus methotrexate (MTX), in patients with moderate-to-severe RA and an inadequate response to the first-line MTX, from a Taiwan National Health Insurance Administration perspective. Materials and methods: A patient-level simulation model was used to project lifetime costs and quality-adjusted life-years (QALYs). Base-case analysis compared second-line treatment with tofacitinib 5 mg twice daily plus MTX vs adalimumab 40 mg every 2 weeks plus MTX. Patients switched or discontinued treatment due to a lack or loss of effectiveness or a serious adverse event. Efficacy was measured by change in Health Assessment Questionnaire-Disability Index (HAQ-DI) score. HAQ-DI scores were used to predict mortality and resource utilization, and were mapped onto utility values to estimate QALYs. Efficacy and safety data were derived from clinical trials and other secondary sources. Uncertainty in model parameters was explored using one-way deterministic and probabilistic sensitivity analyses. Results: Patients gained 0.09 more QALYs with second-line tofacitinib plus MTX compared with adalimumab plus MTX (5.13 vs 5.04, respectively) at an additional cost of New Taiwan Dollars (NT$) 12,881. The incremental cost-effectiveness ratio was NT$143,122/QALY. One-way sensitivity analysis confirmed the base-case result was robust. Limitations: The lack of available clinical data, particularly for HAQ-DI scores, may introduce some bias in the analysis. No patients were in an early stage of RA, which may limit the generalizability of these results. Base-case results from our study are not necessarily generalizable to countries with healthcare systems that differ considerably from Taiwan. Conclusions: From a payer perspective, second-line treatment with tofacitinib plus MTX is a cost-effective treatment strategy, compared with adalimumab plus MTX, in patients with moderate-to-severe RA in Taiwan.

Fruits, vegetables, and health: A comprehensive narrative, umbrella review of the science and recommendations for enhanced public policy to improve intake

Fruit and vegetables (F&V) have been a cornerstone of healthy dietary recommendations; the 2015-2020 U.S. Dietary Guidelines for Americans recommend that F&V constitute one-half of the plate at each meal. F&V include a diverse collection of plant foods that vary in their energy, nutrient, and dietary bioactive contents. F&V have potential health-promoting effects beyond providing basic nutrition needs in humans, including their role in reducing inflammation and their potential preventive effects on various chronic disease states leading to decreases in years lost due to premature mortality and years lived with disability/morbidity. Current global intakes of F&V are well below recommendations. Given the importance of F&V for health, public policies that promote dietary interventions to help increase F&V intake are warranted. This externally commissioned expert comprehensive narrative, umbrella review summarizes up-to-date clinical and observational evidence on current intakes of F&V, discusses the available evidence on the potential health benefits of F&V, and offers implementation strategies to help ensure that public health messaging is reflective of current science. This review demonstrates that F&V provide benefits beyond helping to achieve basic nutrient requirements in humans. The scientific evidence for providing public health recommendations to increase F&V consumption for prevention of disease is strong. Current evidence suggests that F&V have the strongest effects in relation to prevention of CVDs, noting a nonlinear threshold effect of 800 g per day (i.e., about 5 servings a day). A growing body of clinical evidence (mostly small RCTs) demonstrates effects of specific F&V on certain chronic disease states; however, more research on the role of individual F&V for specific disease prevention strategies is still needed in many areas. Data from the systematic reviews and mostly observational studies cited in this report also support intake of certain types of F&V, particularly cruciferous vegetables, dark-green leafy vegetables, citrus fruits, and dark-colored berries, which have superior effects on biomarkers, surrogate endpoints, and outcomes of chronic disease.

Do rheumatoid arthritis patients have more major complications and length of stay after lower extremities fracture surgery?: A nationwide data with propensity score matching

Patients with rheumatoid arthritis (RA) have a high risk of cardiovascular diseases and fractures. This retrospective cohort study explored whether patients with RA face higher complication risks or longer hospital stays than other patients when they had a lower limb fracture that required the surgery. Patients aged >45 years who received lower limb fracture surgeries between 2005 and 2012 were selected from the National Health Insurance Research Database, and 10 related variables including sex and age were used in propensity score matching to pair RA patients with non-RA patients in a 1:4 ratio. The final study sample comprised 1109 patients with RA and 4436 non-RA patients. The results indicated that 5.57% of the study sample had postoperative complications, accounting for 5.05% of patients with RA and 5.70% of the control group. After conditional logistic regression analysis was performed, the risk of major complications has no significant differences between patients with RA and the control group (odds ratio [OR] = 0.87; 95% confidence interval [CI]: 0.61-1.24; P > .05). However, the comorbidity severity score exerted a significant effect on complications; patients with scores ≥3 were 2.78 times more likely to experience complications (OR = 2.78; 95% CI 1.52-5.07). When considering different types of complications, patients with RA were less likely to be exposed to the risk of stroke (OR = 0.48). After controlling all related factors, no significant differences were observed in the complication risks or deaths between the 2 groups (P > .05). Regarding hospitalization length, the average stay for all patients was 8.12 days; after controlling related factors, the hospitalization length for patients with RA was 0.97 times that of the control group, which was nonsignificant (P > .05). These results may provide some information to healthcare professionals when providing treatments.

Potential benefits of biologics on stroke and mortality in patients with rheumatoid arthritis: A nationwide population-based cohort study in Taiwan

AIM

To examine the changes in the risks of death and cardiovascular diseases (CVD) in rheumatoid arthritis (RA) patients treated with conventional synthetic or biologic disease-modifying antirheumatic drugs (csDMARD or bDMARD) during 1997-2013.

METHODS

Two cohorts of RA patients and their matched controls were identified from the National Health Insurance Research database. There were 1569 patients in the csDMARD cohort who received cyclosporine ≥50 mg/d with concomitant usage of ≥2 csDMARDs during 1997-2003. There were 1530 patients in the bDMARD cohort if patients had ≥1 claim for bDMARD during 2003-2011. Adjusted hazard ratios (aHRs) for the risk of death, myocardial infarction, and stroke, were assessed using the Kaplan-Meier survival curves and the Cox proportional hazards models.

RESULTS

Compared with matched cohorts, the incidence of death was higher with csDMARD with a more than 6-fold increase (csDMARD vs controls: 33% vs 5%); while it only increased with a much smaller magnitude with bDMARD (bDMARD vs controls: 15% vs 11%). In addition, an increase in the reduction of incidence rate of stroke with bDMARD (bDMARD vs controls: 2% vs 5%) than that with csDMARD (csDMARD vs controls: 3% vs 4%) was found. Results from multivariate analysis showed that RA patients receiving bDMARD had a significantly lower increase in the risk of deaths (aHR 1.05; 95% CI 0.84-1.33) compared with those receiving csDMARD (aHR 8.75; 95% CI 7.43-10.31). In addition, bDMARD was associated with a higher reduction in the risk of stroke compared with csDMARD (bDMARD: aHR 0.37; 95% CI 0.22-0.62; csDMARD: aHR 0.73; 95% CI 0.51-1.05).

CONCLUSION

Biologics used in RA patients have been shown to have a beneficial impact on improving clinical outcomes, including decreased risks of death and stroke. The economic burden from costs of biologics may be alleviated by improving outcomes.

Prevalence, clinical features and treatment pattern of patients with concurrent diagnoses of rheumatoid arthritis and psoriatic disease: results of a 14-year retrospective study in a tertiary referral center

Background:

Multiple comorbidities, including rheumatoid arthritis (RA), have been reported to be associated with psoriasis.

Objective:

This study aimed to determine the prevalence and the clinical features of RA among patients with psoriasis in a tertiary referral center.

Methods:

Between January 2000 and December 2013, all patients coded with psoriatic disease (ICD-9 CM 696.0 OR ICD-9 CM696.1) and RA (ICD-9 CM 714.0) in a tertiary medical center were enrolled.

Results:

There were 10,844 patients and 9073 patients with psoriatic disease and RA identified by diagnostic codes, respectively. Among patients with psoriasis, 111 patients had claim-based diagnosis of RA (1.02%). By reviewing medical records and telephone interview or clinic visits, 25 of the 111 patients (0.23%) was identified unequivocally as having concurrent RA. Among them, 17 (68%) were female and 16 (64%) patients developed arthritis prior to the onset of psoriasis with a mean lag of 6.3 years (1–19 years); 8 (32%) had psoriasis skin lesions prior to the onset of arthritis with a mean lag of 6.9 years (3–20 years); 1 (4%) had skin lesions and arthritis in the same time; 17 (68%) patients also fulfilled the CASPAR classification criteria for psoriatic arthritis. The mean age of onset for arthritis was 49.6 years old.

Conclusions:

The prevalence of RA in psoriasis might be overestimated in some previous studies using claimed database. Patients with concurrent RA and psoriasis showed a comparable age of onset and male to female ratio, but had more axial involvements compared to patients without psoriasis.

Autoimmune Disease in Women: Endocrine Transition and Risk Across the Lifespan

Women have a higher incidence and prevalence of autoimmune diseases than men, and 85% or more patients of multiple autoimmune diseases are female. Women undergo sweeping endocrinological changes at least twice during their lifetime, puberty and menopause, with many women undergoing an additional transition: pregnancy, which may or may not be accompanied by breastfeeding. These endocrinological transitions exert significant effects on the immune system due to interactions between the hormonal milieu, innate, and adaptive immune systems as well as pro- and anti-inflammatory cytokines, and thereby modulate the susceptibility of women to autoimmune diseases. Conversely, pre-existing autoimmune diseases themselves impact endocrine transitions. Concentration-dependent effects of estrogen on the immune system; the role of progesterone, androgens, leptin, oxytocin, and prolactin; and the interplay between Th1 and Th2 immune responses together maintain a delicate balance between host defense, immunological tolerance and autoimmunity. In this review, multiple autoimmune diseases have been analyzed in the context of each of the three endocrinological transitions in women. We provide evidence from human epidemiological data and animal studies that endocrine transitions exert profound impact on the development of autoimmune diseases in women through complex mechanisms. Greater understanding of endocrine transitions and their role in autoimmune diseases could aid in prediction, prevention, and cures of these debilitating diseases in women.

Current screening practice in patients under long-term hydroxychloroquine medication in Taiwan: A nationwide population-based cohort study

Hydroxychloroquine (HCQ), an analog of chloroquine, is widely used in various rheumatologic and dermatologic disorders. However, it may cause severe retinopathy with long-term use. The guidelines proposed by the American Academy of Ophthalmology suggested a baseline fundus examination and an annual screening after 5 years by using automated visual fields (VF) plus spectral-domain optical coherence tomography (SD-OCT). Both multifocal electroretinogram (mfERG) and fundus autofluorescence (FAF) can also be used to improve the accuracy of diagnosis. The purpose of this study was to examine if the current HCQ screening practice in Taiwan was sufficient according to the guidelines to prevent severe macular complications.This study could remind every doctor to explain visual side effects thoroughly to every patient using HCQ, and refer patients for the ophthalmologic survey to eliminate potential visual impairment caused by this medicine.This nationwide population-based cohort study included all patients who started taking HCQ (n = 5826) from January 1, 1997, to December 31, 2007, in the Longitudinal Health Insurance Database 2000. The ICD codes used for HCQ retinopathy were 362.10, 362.55, 362.89, and 362.9. Patients previously diagnosed these retinal disorders were excluded. Demographic data including sex, age, diagnostic tools used, and the date of the initial diagnosis of the subsequent HCQ-related retinal disorder were collected. Patients were divided into 2 groups. The patients taking HCQ <5 years were defined as group 1, and >5 years as group 2. The risk of developing retinal diseases between these 2 groups was compared with a 2-sample t-test for continuous variables, and Fisher's exact test for discrete variables. Multiple logistic regressions were used for odds ratio calculation.The baseline examination ratio of the automated VF, SD-OCT scans, and multifocal electroretinograms (mfERGs) in the first 3 months were only 0.2% in both groups. The screening ratio of the 3 examination tools after 5 years were 1.1% in group 1 and 1.2% in group 2. 2.5% and 3.9% of patients developed a retinal disorder after HCQ use in group 1 and 2, respectively. The risk of developing retinal disorder was significantly higher in group 2 (relative risk = 1.53, P = .006). The odds ratio (OR) was also significantly higher in group 2 (1.67 with 95% cumulative incidence 1.20-2.30)The examination ratio according to the guidelines was very low in Taiwan. Thus, it is very important for doctors who prescribe HCQ to schedule both baseline and annual ophthalmology screening tests and inform patients of possible severe ocular complications, even in the patient taking HCQ <5 years. It is also important for ophthalmologists to review medical history carefully to find out the causes of retinotoxicity. Medications should be stopped, if possible when toxicity is recognized or strongly suspected.

Assessing whether the association between rheumatoid arthritis and schizophrenia is bidirectional: A nationwide population-based cohort study

Since many studies have shown a reduction in the incidence of rheumatoid arthritis (RA) in patients with schizophrenia (SCZ), little effort has been devoted to studying this link in the Asian population. Moreover, the relationship between these two disorders could be bidirectional, but the influence of RA on the SCZ incidence is unclear. The study aims to determine whether there is a bidirectional association between RA and SCZ in an Asian population. We analyzed a 10-year population- based longitudinal cohort using the National Health Insurance Research Database of Taiwan. In the first analysis, we included a total of 58,847 SCZ patients and 235,382 non-SCZ controls, and in the second analysis, a total of 30,487 RA patients and 121,833 non-RA controls, both matched by gender, age, and index date. Cox regression analyses were performed to examine the risk of RA incidence in the first analysis and the risk of SCZ incidence in the second analysis. The main finding of this study was the discovery of a lower incidence of RA in patients with SCZ (hazard ratio (HR): 0.48, 95% confidence interval (95% CI): 0.31–0.77) after adjustment for baseline demographics and comorbidities. Additionally, the presence of RA predicted a reduced incidence rate for SCZ, but the estimate was not statistically significant (HR: 0.77, 95% CI: 0.44–1.37). The study found a unidirectional association between RA and SCZ. However, RA has an age of onset later than RA, and the protective effect of RA on SCZ incidence would be biased due to the limited number of cases.

Correlation between genetic polymorphism of angiopoietin-2 gene and clinical aspects of rheumatoid arthritis

The Angiopoietin-2 (Ang2) gene encodes angiogenic factor, and the polymorphisms of Ang2 gene predict risk of various human diseases. We want to investigate whether the single nucleotide polymorphisms (SNPs) of the Ang2 gene can predict the risk of rheumatoid arthritis (RA). Between 2016 and 2018, we recruited 335 RA patients and 700 control participants. Comparative genotyping for SNPs rs2442598, rs734701, rs1823375 and rs12674822 was performed. We found that when compared with the subjects with the A/A genotype of SNP rs2442598, the subjects with the T/T genotype were 1.78 times likely to develop RA. The subjects with C/C genotype of SNP rs734701 were 0.53 times likely to develop RA than the subjects with TT genotype, suggesting the protective effect. The subjects with G/G genotype of SNP rs1823375 were 1.77 times likely to develop RA than the subjects with C/C genotype. The subjects with A/C and C/C genotype of SNP rs11137037 were 1.65 and 2.04 times likely to develop RA than the subjects with A/A genotype. The subjects with G/T and T/T genotype of SNP rs12674822 were 2.42 and 2.25 times likely to develop RA than the subjects with G/G genotype. The T allele over rs734701 can lead to higher serum erythrocyte sedimentation rate level (p = 0.006). The A allele over rs11137037 was associated with longer duration between disease onset and blood sampling (p = 0.003). Our study suggested that Ang2 might be a diagnostic marker and therapeutic target for RA therapy. Therapeutic agents that directly or indirectly modulate the activity of Ang2 may be the promising modalities for RA treatment.

eDRAM: Effective early disease risk assessment with matrix factorization on a large-scale medical database: A case study on rheumatoid arthritis

Recently, a number of analytical approaches for probing medical databases have been developed to assist in disease risk assessment and to determine the association of a clinical condition with others, so that better and intelligent healthcare can be provided. The early assessment of disease risk is an emerging topic in medical informatics. If diseases are detected at an early stage, prognosis can be improved and medical resources can be used more efficiently. For example, if rheumatoid arthritis (RA) is detected at an early stage, appropriate medications can be used to prevent bone deterioration. In early disease risk assessment, finding important risk factors from large-scale medical databases and performing individual disease risk assessment have been challenging tasks. A number of recent studies have considered risk factor analysis approaches, such as association rule mining, sequential rule mining, regression, and expert advice. In this study, to improve disease risk assessment, machine learning and matrix factorization techniques were integrated to discover important and implicit risk factors. A novel framework is proposed that can effectively assess early disease risks, and RA is used as a case study. This framework comprises three main stages: data preprocessing, risk factor optimization, and early disease risk assessment. This is the first study integrating matrix factorization and machine learning for disease risk assessment that is applied to a nation-wide and longitudinal medical diagnostic database. In the experimental evaluations, a cohort established from a large-scale medical database was used that included 1007 RA-diagnosed patients and 921,192 control patients examined over a nine-year follow-up period (2000-2008). The evaluation results demonstrate that the proposed approach is more efficient and stable for disease risk assessment than state-of-the-art methods.

Healthcare resource utilization and costs among patients with rheumatoid arthritis on biologic therapies in Taiwan: A 1-year mirror-image study using a national claims database

Objectives

This nationwide population-based study aimed at evaluating healthcare resource utilization and direct medical costs among rheumatoid arthritis (RA) patients receiving biologic therapies in Taiwan.

Design and setting

A retrospective cohort of 2,425 RA patients who had received first-line tumor necrosis factor (TNF)-α antagonist treatment for at least 6 months (the baseline period) between 2007 and 2011 was identified from the National Health Insurance Research Database in Taiwan.

Outcome measures

Healthcare resource utilization and direct medical costs of those patients were analyzed and compared 1 year before the index date and during the 1-year follow-up.

Results

Analytical results demonstrated that 87.7% of RA patients received the same TNF-α antagonist during the 1-year follow-up, 2.4% of the patients switched to another TNF-α antagonist after the baseline period, 7.1% of the study cohort received a second-line biologic agent, while the remaining patients discontinued use of any TNF-α antagonist. Compared to 1 year before the index date, there were significant reductions in emergency room visits and hospitalization days for RA patients treated with the same TNF-α antagonist during the 1-year follow-up. However, there was an increase of outpatient visits among those patients. For those RA patients who switched to another TNF-α antagonist or received a second-line biologic agent, they consumed more healthcare resources. Furthermore, the corresponding medication costs went up markedly during the 1-year follow-up, but nearly all total direct medical costs (biologics excluded) were significantly reduced across the study cohort. Lastly, male patients incurred slightly higher medical costs than their counterparts, albeit in a statistically insignificant fashion.

Conclusions

This investigation revealed that RA patients treated with biologics utilized fewer emergency room visits and shorter hospitalization days, but incurred higher costs. In summary, this study provides meaningful information on healthcare resource utilization and medical costs of RA patients for healthcare providers and policymakers.

Dietary fruits and arthritis

Arthritis is a global health concern affecting a significant proportion of the population and associated with reduced quality of life. Among the different forms of arthritis, osteoarthritis (OA) and rheumatoid arthritis (RA) are the most common and lacking a definite cure in the affected individuals. Fruits, such as berries and pomegranates are rich sources of a variety of dietary bioactive compounds, especially the polyphenolic flavonoids that have been associated with antioxidant, anti-inflammatory and analgesic effects. Emerging research demonstrates a protective role of fruits and their polyphenols in pre-clinical, clinical and epidemiological studies of OA and RA. In this context, commonly available fruits, such as blueberries, raspberries and strawberries, and pomegranates have shown promising results in reducing pain and inflammation in experimental models and in human clinical studies of arthritis. There is also some evidence on the role of specific fruit polyphenols, such as quercetin and citrus flavonoids in alleviating RA symptoms. These emerging data deserve further investigation in rigorous scientific studies to determine the mechanisms, dosing and selection of fruits and fruit extracts in arthritis management.

Chemokine C-C Motif Ligand 4 Gene Polymorphisms Associated with Susceptibility to Rheumatoid Arthritis

Chemokine C-C motif ligand 4 (CCL4) gene is a chemokine-encoding gene, and the polymorphism of CCL4 gene has been shown to predict risk of various diseases. We want to investigate whether the single nucleotide polymorphisms (SNPs) of the CCL4 gene can predict the risk of rheumatoid arthritis (RA). Between 2007 and 2015, we recruited 217 patients diagnosed with RA and 371 control participants. Comparative genotyping of the rs1634507, rs10491121, and rs1719153 SNPs was performed. When compared with participants with the A/A genotype of rs1719153, those with the A/T genotype were less likely to develop RA, as were those with the A/T+T/T genotype. The protective effect of the T-containing genotype was even more prominent among females. Those with A/T in rs1719153 were 56% less likely to develop RA compared with females with A/A; a similar protective effect was seen for females with the A/T+T/T genotype compared with those with A/A. The GTEx database revealed that patients carrying the T/T genotype had lower levels of CCL4 gene expression than those carrying the A/A genotype. These results indicate that the nucleotide T over the rs1719153 is associated with decreased CCL4 gene expression and decreased risk for RA.