Metformin and its therapeutic applications in autoimmune inflammatory rheumatic disease

Metformin is a first-line therapeutic agent for type 2 diabetes. Apart from its glucose- lowering effect, metformin is attracting interest regarding possible therapeutic benefits in various other conditions. As metformin regulates cell metabolism, proliferation, growth, and autophagy, it may also modulate immune cell functions. Given that metformin acts on multiple intracellular signaling pathways, including adenosine monophosphate (AMP)-activated protein kinase (AMPK) activation, and that AMPK and its downstream intracellular signaling control the activation and differentiation of T and B cells and inflammatory responses, metformin may exert immunomodulatory and anti- inflammatory effects. The efficacy of metformin has been investigated in preclinical and clinical studies on rheumatoid arthritis, osteoarthritis, systemic lupus erythematosus, Sjögren’s syndrome, scleroderma, ankylosing spondylitis, and gout. In this review, we discuss the potential mechanisms through which metformin exerts its therapeutic effects in these diseases, focusing particularly on rheumatoid arthritis and osteoarthritis.

Baseline use of hydroxychloroquine or immunosuppressive drugs and the risk of coronavirus disease 2019

Background/Aims@#The preventive role of hydroxychloroquine (HCQ) on coronavirus disease 2019 (COVID-19) remains unclear. The aim of this study was to examine the effects of HCQ and other immunosuppressive drugs on the incidence of COVID-19. @*Methods@#The data were collected from the South Korea National Health Insurance Sharing-COVID-19 database. All individuals who underwent nasopharyngeal and oropharyngeal swab tests for COVID-19 from January 2020 to May 2020 are included. The association between COVID-19 risk and HCQ use was examined in a propensity score-matched population. Factors associated with COVID-19 were identified using multiple logistic regression analysis. @*Results@#Total 8,070 patients with COVID-19 and 121,050 negative controls were included from the database. Among all participants, 381 were HCQ users. In a propensity score-matched population, the incidence of COVID-19 was 7.1% in HCQ users and 6.8% in non-users. The odds ratio (OR) for HCQ use was 1.05 with a 95% confidence interval (CI) of 0.58 to 1.89. Among the subpopulation of patients with rheumatoid arthritis (RA), 33 were diagnosed with COVID-19 and 478 were not. Use of HCQ, glucocorticoids, or other immunosuppressive drugs was not associated with COVID-19 risk, whereas abatacept use was. Chronic lung disease was an independent risk factor for COVID-19 diagnosis in patients with RA (adjusted OR, 6.07; 95% CI, 1.10 to 33.59). @*Conclusions@#The risk of COVID-19 did not differ between HCQ users and non-users. Glucocorticoids, conventional disease-modifying antirheumatic drugs (DMARDs), and biological DMARDs other than abatacept did not increase the risk of COVID-19.

Activation of CpG-ODN-Induced TLR9 Signaling Inhibited by Interleukin-37 in U937 Human Macrophages

Purpose@#Interleukin-37 (IL-37) is an anti-inflammatory cytokine that inhibits a broad spectrum of inflammatory responses in various human cells, including neutrophils, macrophages, and endothelial cells. The aim of this study was to identify the role of IL-37 in toll-like receptor 9 (TLR9) signaling in human macrophages. @*Materials and Methods@#Human macrophage U937 cells treated with CpG-oligonucleotides (CpG-ODN), recombinant IL-37, or dexamethasone were used in an in vitro study. IL-37 small interfering RNA (siRNA) and TLR9 siRNA were used to silence endogenous IL-37 and TLR9, respectively. Expression levels of phosphorylated nuclear factor-κB (NF-κB), IκBα, IL-37, IL-1β, tumor necrosis factor-α (TNF-α), and IL-6 protein were assessed by real-time quantitative polymerase chain reaction and Western blotting. CpG-ODN-mediated IL-37 expression stimulated by dexamethasone was detected using immunofluorescent analysis. @*Results@#U937 cells treated with CpG-ODN induced activation of the NF-κB pathway and increased the expression of the pro-inflammatory cytokines IL-1β, TNF-α, and IL-6, but reduced that of IL-37. Recombinant IL-37 attenuated phosphorylation of NF-κB and IκBα and the expression of IL-1β, TNF-α, and IL-6 stimulated by CpG-ODN. Human macrophages transfected with IL-37 siRNA augmented the expression of IL-1β, TNF-α, and IL-6 mRNA and protein in cells treated with CpG-ODN. Dexamethasone markedly inhibited expression of pro-inflammatory cytokines in U937 cells, whereas IL-37 expression was increased with the addition of dexamethasone. Inflammatory responses elicited by CpG-ODN were dependent on an MyD88-TRAF6 pathway. IL-37 inhibited CpG-ODN-induced ubiquitination of TRAF6 in U937 macrophages. @*Conclusion@#IL-37 inhibits CpG-ODN-mediated inflammatory responses through regulation of a TRAF6- NF-κB pathway in human macrophages.

Clinical influences of anticentromere antibody on primary Sjögren’s syndrome in a prospective Korean cohort

This study was performed to clarify inf luences of anticentromere antibody (ACA) on clinical phenotypes of primary Sjögren’s syndrome (pSS) patients in Korea. Methods: We assessed 318 patients who met the 2016 American College of Rheumatology/ European League Against Rheumatism classification criteria for pSS. All patients were selected from the Korean Initiative of primary Sjögren’s Syndrome (KISS), a prospective cohort. Among them, 53 patients were positive for ACA, while another 265 patients were not. We compared various clinical data including demographic features, extra-glandular manifestations (EGMs), clinical indices, and laboratory values available from the KISS database between the two groups. Results: Patients in the ACA-positive pSS group were older (p = 0.042), and had higher xerostomia inventory scores (p = 0.040), whereas glandular dysfunction represented with Schirmer I test was more severe in the ACA-negative group. More frequent Raynaud’s phenomenon and liver involvement (both p < 0.001) and less articular involvement (p = 0.037) were observed among the EGMs in the ACA-positive group. Less frequency of leukopenia (p = 0.021), rheumatoid factor (p < 0.001), anti-Ro/SSA antibody positivity (p < 0.001), and hypergammaglobulinemia (p = 0.006), as well as higher positivity rates of anti-nuclear antibody and anti- topoisomerase antibody (p < 0.001 and p = 0.006, respectively) were found in the laboratory data in the ACA-positive pSS group. Conclusions: Considering distinct phenotypes in hematological and serological features and EGMs, we should monitor the occurrence of these clinical features among pSS patients with ACA in caution.

Lopinavir-ritonavir versus hydroxychloroquine for viral clearance and clinical improvement in patients with mild to moderate coronavirus disease 2019

Background/Aims@#The efficacies of lopinavir-ritonavir or hydroxychloroquine remain to be determined in patients with coronavirus disease 2019 (COVID-19). To compare the virological and clinical responses to lopinavir-ritonavir and hydroxychloroquine treatment in COVID-19 patients. @*Methods@#This retrospective cohort study included patients with COVID-19 treated with lopinavir-ritonavir or hydroxychloroquine at a single center in Korea from February 17 to March 31, 2020. Patients treated with lopinavir-ritonavir and hydroxychloroquine concurrently and those treated with lopinavir-ritonavir or hydroxychloroquine for less than 7 days were excluded. Time to negative conversion of viral RNA, time to clinical improvement, and safety outcomes were assessed after 6 weeks of follow-up. @*Results@#Of 65 patients (mean age, 64.3 years; 25 men [38.5%]), 31 were treated with lopinavir-ritonavir and 34 were treated with hydroxychloroquine. The median duration of symptoms before treatment was 7 days and 26 patients (40%) required oxygen support at baseline. Patients treated with lopinavir-ritonavir had a significantly shorter time to negative conversion of viral RNA than those treated with hydroxychloroquine (median, 21 days vs. 28 days). Treatment with lopinavir-ritonavir (adjusted hazard ratio [aHR], 2.28; 95% confidence interval [CI], 1.24 to 4.21) and younger age (aHR, 2.64; 95% CI 1.43 to 4.87) was associated with negative conversion of viral RNA. There was no significant difference in time to clinical improvement between lopinavir-ritonavir- and hydroxychloroquine-treated patients (median, 18 days vs. 21 days). Lymphopenia and hyperbilirubinemia were more frequent in lopinavir-ritonavir-treated patients compared with hydroxychloroquine-treated patients. @*Conclusions@#Lopinavir-ritonavir was associated with more rapid viral clearance than hydroxychloroquine in mild to moderate COVID-19, despite comparable clinical responses. These findings should be confirmed in randomized, controlled trials.

Ultrasound Findings were Associated With Radiographic Changes, But Not Clinical and Functional Outcomes in Hand Osteoarthritis

Objective@#. There is a debate over the relevance of ultrasound abnormalities to the pain, functional impairment, and radiologic severity in hand osteoarthritis (OA). This study aims to determine the association between ultrasound abnormalities and clinical, functional, and radiographic measures in hand OA. @*Methods@#. A total of 66 patients was consecutively enrolled. All patients with gray-scale synovitis, joint effusion, and osteophytes were examined by ultrasound for 20 hand joints. Radiographic changes in both hands were evaluated by the Kellgren-Lawrence (K-L) grading system and were described as total radiographic severity score and number of affected joints. Other measures were also assessed, including each patient’s visual analogue scale for pain, the Functional Index for Hand Osteoarthritis for functional disability, and grip and pinch strength for hand muscle strength. @*Results@#. In total, 10 patients with gray-scale synovitis, 35 with joint effusion, and 66 with osteophytes were detected in hand OA scans on ultrasound. Osteophytes on ultrasound were significantly associated with total radiographic severity score and number of affected joint (r=0.293, p=0.003 and r=0.336, p＜0.001, respectively). In addition, there were weak associations of synovitis and joint effusion with radiographic changes. Patients with higher total radiographic severity score showed larger number of ultrasound-detected abnormalities, such as synovitis, joint effusion, and osteophytes (p=0.011, p=0.002, and p＜0.001, respectively). @*Conclusion@#. This study shows that ultrasound findings, especially osteophytes, were associated with radiographic changes based on K-L grade, but not clinical and functional status in hand OA.

KOBIO, the First Web-based Korean Biologics Registry Operated With a Unified Platform Among Distinct Disease Entities

The KOrean College of Rheumatology BIOlogics and targeted therapy (KOBIO) registry is a nationwide observational cohort that captures detailed data on exposure of patients to biologic and targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs). This registry was launched in December 2012 with an aim to prospectively investigate clinical manifestations and outcomes of patients with rheumatoid arthritis (RA), ankylosing spondylitis, and psoriatic arthritis who initiated a biologic or targeted synthetic DMARD or switched to another. Demographic data, disease activity, current treatment, adverse events, terms based on Medical Dictionary for Regulatory Activities, and so on are registered for patients who are then followed up annually in a web-based unified platform. The KOBIO registry also recruits and collects data of patients with RA on conventional DMARDs for comparison. As of today, more than 5,500 patients were enrolled from 47 academic and community Rheumatology centers across Korea. The KOBIO registry has evolved to become a powerful database for clinical research to improve clinical outcomes and quality of treatment.

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

Objective@#The increase in mortality in rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) is well known. However, there are few studies on serum markers that can evaluate acute exacerbation or prognosis in RA-ILD patients. The purpose of this study was to identify the association between biomarkers and lung lesions in patients with RA-ILD. @*Methods@#We analyzed 153 patients with serum samples in a prospective, multicenter cohort of Korean RA-ILD patients. The serum levels of biomarkers, matrix metalloproteinase (MMP-7), surfactant protein-D (SP-D), and Krebs von den Lungen-6 (KL-6) were measured and correlated with forced vital capacity (FVC), diffusing capacity for carbon monoxide (DLCO) and the results of computed tomography (CT). CT results were interpreted semi-quantitatively according to the extent of lung lesions (grade 1, 0%∼ 25%; grade 2, 26%∼50%; grade 3, 51%∼75%; grade 4, 76%∼100%). @*Results@#MMP-7, SP-D, and KL-6 were negatively correlated with FVC (MMP-7, r=−0.267, p=0.001; SP-D, r=−0.250, p=0.002; KL-6, r=−0.223, p=0.006) and DLCO (MMP-7, r=−0.404, p＜0.001; SP-D, r=−0.286, p=0.001; KL-6, r=−0.226, p=0.007). In addition, MMP-7, SP-D, and KL-6 tended to increase with higher grades of lung lesions on CT (MMP-7, p=0.013; SP-D, p＜0.001; KL-6, p＜0.001). @*Conclusion@#MMP-7, SP-D, and KL-6 can be used to evaluate the functional and anatomical status of lung involvement in the RA-ILD patients.

Activation of CpG-ODN-Induced TLR9 Signaling Inhibited by Interleukin-37 in U937 Human Macrophages

Purpose@#Interleukin-37 (IL-37) is an anti-inflammatory cytokine that inhibits a broad spectrum of inflammatory responses in various human cells, including neutrophils, macrophages, and endothelial cells. The aim of this study was to identify the role of IL-37 in toll-like receptor 9 (TLR9) signaling in human macrophages. @*Materials and Methods@#Human macrophage U937 cells treated with CpG-oligonucleotides (CpG-ODN), recombinant IL-37, or dexamethasone were used in an in vitro study. IL-37 small interfering RNA (siRNA) and TLR9 siRNA were used to silence endogenous IL-37 and TLR9, respectively. Expression levels of phosphorylated nuclear factor-κB (NF-κB), IκBα, IL-37, IL-1β, tumor necrosis factor-α (TNF-α), and IL-6 protein were assessed by real-time quantitative polymerase chain reaction and Western blotting. CpG-ODN-mediated IL-37 expression stimulated by dexamethasone was detected using immunofluorescent analysis. @*Results@#U937 cells treated with CpG-ODN induced activation of the NF-κB pathway and increased the expression of the pro-inflammatory cytokines IL-1β, TNF-α, and IL-6, but reduced that of IL-37. Recombinant IL-37 attenuated phosphorylation of NF-κB and IκBα and the expression of IL-1β, TNF-α, and IL-6 stimulated by CpG-ODN. Human macrophages transfected with IL-37 siRNA augmented the expression of IL-1β, TNF-α, and IL-6 mRNA and protein in cells treated with CpG-ODN. Dexamethasone markedly inhibited expression of pro-inflammatory cytokines in U937 cells, whereas IL-37 expression was increased with the addition of dexamethasone. Inflammatory responses elicited by CpG-ODN were dependent on an MyD88-TRAF6 pathway. IL-37 inhibited CpG-ODN-induced ubiquitination of TRAF6 in U937 macrophages. @*Conclusion@#IL-37 inhibits CpG-ODN-mediated inflammatory responses through regulation of a TRAF6- NF-κB pathway in human macrophages.

KOBIO, the First Web-based Korean Biologics Registry Operated With a Unified Platform Among Distinct Disease Entities

The KOrean College of Rheumatology BIOlogics and targeted therapy (KOBIO) registry is a nationwide observational cohort that captures detailed data on exposure of patients to biologic and targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs). This registry was launched in December 2012 with an aim to prospectively investigate clinical manifestations and outcomes of patients with rheumatoid arthritis (RA), ankylosing spondylitis, and psoriatic arthritis who initiated a biologic or targeted synthetic DMARD or switched to another. Demographic data, disease activity, current treatment, adverse events, terms based on Medical Dictionary for Regulatory Activities, and so on are registered for patients who are then followed up annually in a web-based unified platform. The KOBIO registry also recruits and collects data of patients with RA on conventional DMARDs for comparison. As of today, more than 5,500 patients were enrolled from 47 academic and community Rheumatology centers across Korea. The KOBIO registry has evolved to become a powerful database for clinical research to improve clinical outcomes and quality of treatment.

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

Objective@#The increase in mortality in rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) is well known. However, there are few studies on serum markers that can evaluate acute exacerbation or prognosis in RA-ILD patients. The purpose of this study was to identify the association between biomarkers and lung lesions in patients with RA-ILD. @*Methods@#We analyzed 153 patients with serum samples in a prospective, multicenter cohort of Korean RA-ILD patients. The serum levels of biomarkers, matrix metalloproteinase (MMP-7), surfactant protein-D (SP-D), and Krebs von den Lungen-6 (KL-6) were measured and correlated with forced vital capacity (FVC), diffusing capacity for carbon monoxide (DLCO) and the results of computed tomography (CT). CT results were interpreted semi-quantitatively according to the extent of lung lesions (grade 1, 0%∼ 25%; grade 2, 26%∼50%; grade 3, 51%∼75%; grade 4, 76%∼100%). @*Results@#MMP-7, SP-D, and KL-6 were negatively correlated with FVC (MMP-7, r=−0.267, p=0.001; SP-D, r=−0.250, p=0.002; KL-6, r=−0.223, p=0.006) and DLCO (MMP-7, r=−0.404, p＜0.001; SP-D, r=−0.286, p=0.001; KL-6, r=−0.226, p=0.007). In addition, MMP-7, SP-D, and KL-6 tended to increase with higher grades of lung lesions on CT (MMP-7, p=0.013; SP-D, p＜0.001; KL-6, p＜0.001). @*Conclusion@#MMP-7, SP-D, and KL-6 can be used to evaluate the functional and anatomical status of lung involvement in the RA-ILD patients.

Clinical Usefulness of Uric Acid as a Biomarker for Knee Osteoarthritis: A Comparative Analysis With Plain Radiography and Musculoskeletal Ultrasound

OBJECTIVE: The aim of this study was to determine the relationships of serum and urine uric acid with severity or activity in knee osteoarthritis (OA).METHODS: A total of 42 patients with knee OA was enrolled, together with 58 healthy controls. Serum uric acid and spot urine uric acid levels were assessed for all patients. The severity and activity of knee OA were assessed by musculoskeletal ultrasound (MSUS) and plain radiography of the knee joint. Ultrasonographic abnormalities in knee OA includedsynovial hypertrophy, suprapatellar effusion, cartilage degradation, and osteophyte formation. Kellgren-Lawrence (K-L) grade was used to evaluate radiological progression of knee OA.RESULTS: Patients with K-L grade III had a higher urine uric acid/creatinine ratio compared to those with K-L grade I (p=0.043). Patients with synovial hypertrophy had higher serum uric acid level compared to those without synovial hypertrophy (p=0.016). The urine uric acid/creatinine ratio was higher in patients with cartilage degradation compared to those without cartilage degradation (p=0.022). Serum uric acid was significantly associated with synovial hypertrophy thickness (r=0.375, p=0.018) but not with cartilage thickness after adjusting for age and body mass index. Lower urine uric acid was related with knee OA compared to healthy controls (odds ratio=0.974, 95% confidence interval 0.954~0.994, p=0.013).CONCLUSION: The results of our study suggest that serum and urine uric acid reflects synovial inflammation based on MSUS and radiographic progression and then is associated with the pathogenesis of knee OA.

Ethanol Augments Monosodium Urate-Induced NLRP3 Inflammasome Activation via Regulation of AhR and TXNIP in Human Macrophages

Purpose@#Ethanol elicits several inflammatory responses and affects the innate immune response. The aim of this study was to identify the mechanism by which ethanol affects uric acid-induced NLR family pyrin domain-containing 3 (NLRP3) inflammasome activation by regulation of aryl hydrocarbon receptor (AhR) and thioredoxin-interacting protein (TXNIP). @*Materials and Methods@#Human myeloid leukemia cells (U937 cells) were used to assess the role of ethanol in NLRP3 inflammasome activation induced by monosodium urate (MSU) crystals. Expression of target molecules, such as NLRP3 inflammasome components, AhR, and TXNIP, were measured using quantitative real-time PCR and Western blot analyses. The effect of ethanolinduced TXNIP on the NLRP3 inflammasome was assessed in human macrophages transfected with TXNIP siRNA. @*Results@#U937 cells treated with 100 mM ethanol for 24 h induced NLRP3 and interleukin (IL)-1β expression. Ethanol increased reactive oxygen species generation in a time- and dose-dependent manner. AhR mRNA expression was downregulated in U937 cells treated with 100 mM ethanol, whereas CYP1A1 mRNA expression increased. Treatment with ethanol increased NLRP3 and IL-1β mRNA and protein expression in U937 cells exposed to 1.0 mg/mL of MSU crystals for 24 h. TXNIP expression in U937 cells incubated with both 100 mM ethanol and 1.0 mg/mL of MSU crystals was significantly higher than in cells incubated with MSU crystals alone. Treatment with 100mM ethanol for 24 h downregulated NLRP3 and IL-1β expression in MSU crystal-activated U937 cells transfected with TXNIP siRNA, compared to those with scramble siRNA. @*Conclusion@#Ethanol stimulates uric acid-induced NLRP3 inflammasome activation through regression of AhR and upregulation of TXNIP.

Simplified disease activity changes in real-world practice: a nationwide observational study of seropositive rheumatoid arthritis patients with moderate-to-high disease activity

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

Anti-Sm Antibody, Damage Index, and Corticosteroid Use Are Associated with Cardiac Involvement in Systemic Lupus Erythematosus: Data from a Prospective Registry Study

Background@#Disease-specific factors that predispose patients to diverse cardiac diseases in systemic lupus erythematosus (SLE) have been established. The aim of this study was to identify risk factors for cardiac involvement in patients with SLE drawn from the Korean Lupus Network (KORNET) registry. @*Methods@#A total of 437 patients with SLE recruited from the KORNET registry were included in the analysis. The Cox proportional hazard model was used to identify risk factors for the development of cardiac involvement during the follow-up period. The hazard ratios for risk factors of cardiac involvement were assessed using Kaplan-Meier curves and log-rank test. @*Results@#Of 437 patients with SLE, 12 patients (2.7%) developed new cardiac involvement during a median follow-up period of 47.6 months. Frequencies in men and in patients with anti-Sm antibody, anti-Ro antibody, and at least one Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI) score in patients with cardiac involvement were higher, compared to those without cardiac involvement (P < 0.001, P = 0.026, P = 0.015, and P < 0.001, respectively). Men gender, older age, anti-Sm antibody, SDI, and corticosteroid dosage were potent predictors for cardiac involvement in patients with SLE in the determination of risk factors for cardiac involvement. Men, anti-Sm antibody positivity, and SDI ≥ 1 increased incidence rates of cardiac involvement for (P < 0.001, P = 0.036, and P < 0.001, respectively). @*Conclusion@#The results of this study reveal that SLE-related factors such as anti-Sm antibody, SDI, and corticosteroid dosage at baseline are risk factors for cardiac involvement in SLE.

Erratum: Clinical Usefulness of Uric Acid as a Biomarker for Knee Osteoarthritis: A Comparative Analysis With Plain Radiography and Musculoskeletal Ultrasound

The original version of this article contained a typographical error in the Abstract, Main text, and Figure 1. These errors have now been corrected in the online version of the Article.

Korean rheumatology workforce from 1992 to 2015: current status and future demand

BACKGROUND/AIMS@#Rheumatology in Korea has rapidly advanced in the 24 years since the subspecialty board certification program was established in 1992. The objective of this investigation was to analyze the distribution of rheumatology practices in Korea in order to better understand the rheumatology workforce.@*METHODS@#Using a membership list from the Korean College of Rheumatology (KCR), we obtained information on practicing rheumatologists. We mapped the ratio of rheumatologists to the general population and to patients with rheumatologic disease using data from Statistics Korea and the 2015 Health Insurance Review & Assessment Service (HIRA).@*RESULTS@#In the 16 administrative districts of Korea in 2015, there were 311 practicing rheumatologists on the list of KCR members. There were 218 members practicing in metropolitan areas and 93 members in the provinces. The mean number of rheumatologists per 100,000 people was 0.60, with 0.33/100,000 in the provinces, but 0.92/100,000 in metropolitan areas, a 2.7-fold difference. The number of rheumatologists per 100,000 patients with chronic rheumatic disease was 17.21 in metropolitan areas but 6.57 in the provinces, according to 2015 HIRA data. This geographic maldistribution emerged as a problem; indeed, the regional disparity in the distribution of Korean rheumatologists was striking when compared to the published medical professional distribution in 2014.@*CONCLUSIONS@#Because of the uneven distribution of rheumatologists, it is likely that some patients with chronic rheumatic conditions have limited access to rheumatology care. Thus, a policy-based approach is needed to alleviate this disparity.

Factors associated with time to diagnosis from symptom onset in patients with early rheumatoid arthritis

BACKGROUND/AIMS@#To identify the factors associated with time to diagnosis after symptom onset in patients with early rheumatoid arthritis (RA).@*METHODS@#Early RA patients with ≤ 1 year of disease duration in the KORean Observational study Network for Arthritis (KORONA) database were included in this analysis. Patients were further divided into two groups according to the time to diagnosis from symptom onset: the early diagnosis group (time to diagnosis ≤ 1 year) and the late diagnosis group (time to diagnosis > 1 year). Using the multivariable regression model, we identified factors associated with early diagnosis.@*RESULTS@#Among 714 early RA patients, 401 patients (56.2%) and 313 patients (43.8%) were included in the early diagnosis and late diagnosis groups, respectively. The mean disease duration was 0.47 years in the early diagnosis group and 0.45 years in the late diagnosis group. In multivariable model analysis, greater age at onset (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.02 to 1.05), high school education or higher (OR, 1.68; 95% CI, 1.14 to 2.47), higher income (OR, 1.48; 95% CI, 1.05 to 2.08), and initial small joint involvement (OR, 1.42; 95% CI, 1.02 to 1.98) were factors associated with early diagnosis. At diagnosis, disease activity scores using 28 joints on diagnosis (3.81 ± 1.44 vs. 3.82 ± 1.42, p = 0.92) and functional disability (0.65 ± 0.61 vs. 0.57 ± 0.62, p = 0.07) did not different between the two groups. However, hand joint erosion on X-ray (37.8% vs. 25.6%, p < 0.01) was more common in the late diagnosis group than the early diagnosis group.@*CONCLUSIONS@#Older onset age, higher educational level and income, and initial small joint involvement were positive factors for early diagnosis of RA.

The Effect of Mycophenolate Mofetil on Non-Renal Manifestations in Systemic Lupus Erythematosus: Results from Korean Lupus Network Registry

BACKGROUND: The objective of this study was to identify the effects of mycophenolate mofetil (MMF) on non-renal manifestations in systemic lupus erythematosus (SLE). METHODS: The study population comprised 439 SLE patients from the Korean Lupus Network registry who were followed up annually and completed the baseline survey and two follow-up visits from 2014 to 2018. Disease activity, laboratory markers, and clinical manifestations including mucocutaneous lesions, arthritis, serositis, neurological disorders, and hematologic/immunologic abnormalities were assessed. All variables by group (MMF and non-MMF) effects with time (baseline, 1st follow-up, and 2nd follow-up) were analyzed by generalized estimation equation. RESULTS: Seventy-two patients were treated with MMF. There was significant difference in frequencies of malar rash, arthritis, renal disorder, and hematologic disorder between MMF and non-MMF groups in total SLE patients. In subgroup analysis of hematologic abnormalities in total patients, frequency of leukopenia was significantly different between the two groups during follow-up (P = 0.001), but frequencies of hemolytic anemia, lymphopenia, and thrombocytopenia were not. In addition, frequencies of leukopenia in patients without lupus nephritis were significantly decreased in MMF group compared to non-MMF group (P = 0.012). CONCLUSION: This study showed that MMF might be a beneficial treatment for hematologic abnormalities, especially leukopenia, in SLE.

Prevalence and Associated Factors for Non-adherence in Patients with Rheumatoid Arthritis

OBJECTIVE: To estimate the prevalence of non-adherence to rheumatoid arthritis (RA) medication and identify the associated factors for non-adherence in RA patients. METHODS: Among the KORean Observational study Network for Arthritis 3,523 patients who completed a questionnaire about the adherence to RA medication were analyzed. The patients were divided into two groups: 1) adherent group, patients who skipped medication ≤5 days within the past 2 months; and 2) non-adherent group, patients who skipped ≥6 days of medication. The baseline characteristics were compared, and multivariable regression analysis was performed to identify the associated factors for non-adherence. RESULTS: The non-adherent group had 339 patients (9.6%). The common causes of non-adherence were forgetfulness (45.8%), absence of RA symptoms (24.7%), and discomfort with RA medication (13.1%). Younger age (odds ratio [OR] 1.02, p < 0.01) and higher income (OR 1.70, p < 0.01) were associated with an increased risk of non-adherence. Whereas higher functional disability (OR 0.68, p < 0.01) and oral corticosteroid use (OR 0.73, p=0.02) were associated with a decreased risk of non-adherence. The associated factors differed according to cause of non-adherence. Having adverse events (OR 2.65, p=0.02) was associated with the risk of non-adherence due to discomfort with RA medication while a higher level of education (OR 2.37, p=0.03) was associated with the risk of non-adherence due to an absence of RA symptoms. CONCLUSION: The 9.6% of Korean RA patients were non-adherent to RA medication. The associated factors differed according to the cause of non-adherence. Therefore, an individualized approach will be needed to improve the adherence to RA medication.