Corrigendum: Treatment sequence after initiating biologic therapy for patients with rheumatoid arthritis in Korea: a nationwide retrospective cohort study.

[This corrects the article on p. 26 in vol. 30, PMID: 37476522.].

Association of methotrexate polyglutamates concentration with methotrexate efficacy and safety in patients with rheumatoid arthritis treated with predefined dose: results from the MIRACLE trial.

OBJECTIVES: The usefulness of methotrexate-polyglutamates (MTX-PGs) concentration for management of rheumatoid arthritis has been debated. We aimed to clarify the association of MTX-PGs concentration with efficacy and safety in MTX-naïve patients initiating MTX in a prospective interventional clinical trial. METHODS: The MIRACLE trial enrolled 300 MTX-naïve patients. Oral MTX was initiated and increased to the maximum tolerated dose by week 12. Patients who did not achieve remission according to the Simplified Disease Activity Index at week 24 were randomised to either the continued dose or reduced dose group and were started on subcutaneous adalimumab. We measured the concentrations of MTX-PGs in erythrocytes using liquid chromatography-tandem mass spectrometry and analysed the association of these concentrations with efficacy and safety. RESULTS: The mean concentration of total MTX-PGs increased with an increasing dose of MTX and continued to elevate for another 12 weeks after the dose was fixed. At week 24, the total MTX-PGs concentration was 110.5 (SD 43.8) nmol/L with MTX dose of 12.6 (3.0) mg/week (0.23 (0.07) mg/kg/week). During MTX monotherapy, the higher MTX-PGs concentration was an independent factor for lower disease activity; however, this association disappeared after adalimumab initiation in patients with continued MTX dose. Hepatotoxicity was related to the higher MTX-PGs concentration regardless of adalimumab use. The total MTX-PGs concentration was significantly elevated by lower estimated glomerular filtration rate, serum albumin and body mass index. CONCLUSIONS: The MIRACLE trial demonstrated that higher total MTX-PGs concentration in erythrocytes is related to the higher efficacy and lower safety of MTX. TRIAL REGISTRATION NUMBER: NCT03505008.

Impact of concomitant methotrexate on disease activity in patients with rheumatoid arthritis tapering abatacept: results from KOBIO registry.

Objectives: Tapering biologic agents can be considered for patients with stable disease activity in rheumatoid arthritis (RA). However, the specific strategy for abatacept is uncertain. This study aimed to examine the impact of tapering abatacept on disease activity in RA patients and assess the potential influence of concomitant methotrexate (MTX) treatment. Methods: Using data from the KOBIO registry, we included 505 1 year intervals from 176 patients with RA that initiated abatacept with concomitant MTX at baseline. The intervals were divided into two groups based on the dose quotient (DQ) of abatacept during each period (i.e., the tapering group (DQ < 1) and control group (DQ = 1)). The primary outcome was achieving DAS28-remission at 1 year intervals. Marginal structural models (MSM) were used to minimize confounding caused by an imbalance in time-varying variables. Results: Abatacept was tapered at 146 (28.9%) intervals, and the mean DQ was 0.68. DAS28-remission was achieved in 207 (41.8%) intervals. Tapering abatacept did not affect the odds of achieving DAS28-remission compared with the control group (OR 1.04 [0.67-1.62]). The odds remained unaffected in the subgroup that continued MTX (OR 1.42 [0.88-2.30]) but not in the subgroup that discontinued MTX (OR 0.26 [0.10-0.57]). The effects of interaction between tapering abatacept and concomitant MTX use on DAS28 and patient's functional status showed consistent results. The incidence of adverse events within a 1 year interval was comparable between the two groups. Conclusion: Withdrawal of MTX while tapering abatacept may compromise meeting the treatment goal for patients with RA.

Clinical characteristics and courses of Korean patients with giant cell arteritis: a multi-center retrospective study.

Objective: Giant cell arteritis (GCA) is a large-vessel vasculitis that primarily affects elderly individuals. However, data regarding Korean patients with GCA are scarce owing to its extremely low prevalence in East Asia. This study aimed to investigate the clinical characteristics of Korean patients with GCA and their outcomes, focusing on relapse. Methods: The medical records of 27 patients with GCA treated at three tertiary hospitals between 2007 and 2022 were retrospectively reviewed. Results: Seventeen (63.0%) patients were females, and the median age at diagnosis was 75 years. Large vessel involvement (LVI) was detected in 12 (44.4%) patients, and polymyalgia rheumatica (PMR) was present in 14 (51.9%) patients. Twelve (44.4%) patients had fever at onset. The presence of LVI or concurrent PMR at diagnosis was associated with a longer time to normalization of the C-reactive protein level (p=0.039) or erythrocyte sedimentation rate (p=0.034). During follow-up (median 33.8 months), four (14.8%) patients experienced relapse. Kaplan-Meier analyses showed that relapse was associated with visual loss (p=0.008) and the absence of fever (p=0.004) at onset, but not with LVI or concurrent PMR. Conclusion: Concurrent PMR and LVI were observed in approximately half of Korean patients with GCA, and the elapsed time to normalization of inflammatory markers in these patients was longer. The relapse rate in Korean GCA is lower than that in Western countries, and afebrile patients or patients with vision loss at onset have a higher risk of relapse, suggesting that physicians should carefully monitor patients with these characteristics.

High vegetable consumption and regular exercise are associated with better quality of life in patients with gout.

BACKGROUND/AIMS: The Gout Impact Scale (GIS), a part of the Gout Assessment Questionnaire 2.0, is used to measure gout-specific health-related quality of life (HRQOL). Although several studies have been conducted on the factors affecting the HRQOL of patients with gout, few have focused on lifestyle factors. This study aimed to investigate the correlation between lifestyle habits and HRQOL using the GIS in patients with gout. METHODS: We used data from the Urate-Lowering TheRApy in Gout (ULTRA) registry, a prospective cohort of Korean patients with gout treated at multiple centers nationwide. The patients were aged ≥18 years and met the 2015 American College of Rheumatology/European League Against Rheumatism gout classification criteria. They were asked to complete a GIS and questions regarding their lifestyle habits at enrollment. RESULTS: The study included 232 patients. 'Gout concern overall' scores in the GIS were significantly lower in patients who exercised more frequently and consumed soft drinks and meat less, and 'well-being during attack' scores were significantly lower in patients who consumed vegetables and exercised more frequently. The frequency of vegetable consumption had a negative linear relationship with the 'well-being during attack' and 'gout concern during attack' scores (p = 0.01, p = 0.001, respectively). The frequency of exercise had a negative linear relationship with the 'gout concern overall' and 'gout concern during attack' scores (p = 0.04 and p = 0.002, respectively). CONCLUSION: Patients with gout who frequently consumed vegetables and exercised regularly experienced less impact of gout, exhibiting a better GIS that represented HRQOL.

Uncovering risk factors for adverse events and infections in rheumatoid arthritis and rheumatoid arthritis with interstitial lung disease under treatment with biologics or targeted synthetic DMARDs: insights from the KOBIO Registry.

OBJECTIVES: This study aimed to identify the risk factors associated with overall adverse events (AEs) and infections in patients with rheumatoid arthritis (RA) and comorbid interstitial lung disease (ILD), receiving biologic or targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs), using data from the Korean College of Rheumatology Biologics registry. METHODS: We analysed data from a cohort of 2,266 adult patients with RA who received b/tsDMARDs, including 169 patients with comorbid ILD. We identified the risk factors for overall AEs and infections in both the all RA group and the subgroup of patients with RA-ILD and investigated the impact of infections on mortality in patients with RA-ILD. RESULTS: Among all patients with RA, 45.7% withdrew b/tsDMARDs, whereas among those with RA-ILD, a higher proportion of 57.4% withdrew their treatment regimen. The main reason for withdrawing b/tsDMARDs in the RA-ILD group was AEs, with infections accounting for the largest proportion of reported AEs. In multivariable analysis of the risk factors for overall AEs and infections in the RA-ILD group, older age was identified as a risk factor for overall AEs (odds ratio [OR], 3.01; p=0.014), and only a current smoking status was identified as a risk factor for infections (OR, 2.11; p=0.035). CONCLUSIONS: Patients with RA-ILD exhibited a higher rate of b/tsDMARDs withdrawal due to overall AEs and infections than those with RA without ILD. In the RA-ILD group, older age was identified as a risk factor for overall AEs, whereas a current smoking status was identified as a risk factor for infections.

Flare prediction after tapering the dose of tumour necrosis factor inhibitors in patients with axial spondyloarthritis: A nationwide cohort study.

OBJECTIVES: To develop a model for predicting flares after tapering the dose of tumour necrosis factor inhibitors (TNFi) in patients with axial spondyloarthritis (axSpA). METHODS: Data were obtained from the Korean College of Rheumatology Biologics and Targeted Therapy Registry. In total, 526 patients who received the standard-dose TNFi for at least 1 year and tapered their dose were included in the derivation cohort. The main outcome was a flare occurrence defined as an Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP) score of ≥ 2.1 after 1 year of TNFi tapering. The final prediction model was validated using an independent cohort. RESULTS: Among 526 patients, 127 (24.1%) experienced flares. The final prediction model included negative human leucocyte antigen B27 (ß = 1.088), inflammatory back pain (ß = 1.072), psoriasis (ß = 1.567), family history of SpA (ß = 0.623), diabetes mellitus (ß = 1.092), TNFi tapering by ≥ 50% of the standard-dose (ß = 0.435), ASDAS-CRP at tapering (ß = 1.029), and Bath Ankylosing Spondylitis Functional Index score at tapering (ß = 0.194) as covariates. It showed an excellent discrimination performance (AUC = 0.828). According to the predictive risk, patients were classified into three groups (low-, intermediate-, and high-risk). The probabilities of flares in these groups were 4.5%, 18.1%, and 61.8%, respectively. The performance of the model in the validation cohort was also comparable. CONCLUSION: The established prediction model accurately predicted the risk of flares after TNFi dose tapering in patients with axSpA using eight simple clinical parameters, which could be helpful to select appropriate patients for tapering their TNFi without flare in daily clinical practice.

The Risk of COVID-19 and Its Outcomes in Korean Patients With Gout: A Multicenter, Retrospective, Observational Study.

This retrospective cohort study aimed to compare coronavirus disease 2019 (COVID-19)-related clinical outcomes between patients with and without gout. Electronic health record-based data from two centers (Seoul National University Hospital [SNUH] and Boramae Medical Center [BMC]), from January 2021 to April 2022, were mapped to a common data model. Patients with and without gout were matched using a large-scale propensity-score algorithm based on population-level estimation methods. At the SNUH, the risk for COVID-19 diagnosis was not significantly different between patients with and without gout (hazard ratio [HR], 1.07; 95% confidence interval [CI], 0.59-1.84). Within 30 days after COVID-19 diagnosis, no significant difference was observed in terms of hospitalization (HR, 0.57; 95% CI, 0.03-3.90), severe outcomes (HR, 2.90; 95% CI, 0.54-13.71), or mortality (HR, 1.35; 95% CI, 0.06-16.24). Similar results were obtained from the BMC database, suggesting that gout does not increase the risk for COVID-19 diagnosis or severe outcomes.

Corrigendum: Korean treatment recommendations for patients with axial spondyloarthritis.

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

Knee osteoarthritis with a high grade of Kellgren-Lawrence score is associated with a worse frailty status, KNHANES 2010-2013.

Frailty as a syndrome of physical decline in late life is associated with adverse health outcomes. Knee osteoarthritis (KOA) could contribute to frailty conditions. The objective of this study was to evaluate the impact of KOA on frailty risk in a Korean National Health and Nutrition Examination Survey (KNHANES) cohort. In this study (N, total = 11,910, age; 64.10 years old [63.94-64.27; mean 95% CI], sex (female, %); 6,752 (56.69)), KOA patients were defined as those with knee joint pain and grade 2 Kellgren-Lawrence (K-L) or more on plain radiographic images who were 40 years old or older in Korean population data of KNHANES. The frailty index was calculated using 46 items related to co-morbidities and laboratory parameters. The impact of KOA on frailty risk was evaluated with logistic regression analyses. The prevalence of KOA patients was 35.6% [95% CI 34.7-36.46]. In polytomous logistic regression, the relative risk ratio (RRR) of KOA was significantly increased in the pre-frail group (2.76, 95% CI 2.30-3.31) and the frail group (7.28, 95% CI 5.90-8.98). RRR of frailty was significantly increased in patients with K-L grade 3 (1.36, 95% CI 1.13-1.63) and K-L grade 4 (2.19, 95% CI 1.72-2.79). Older age, higher BMI, smoking status, alcohol intake, low-income status, higher WBC count, higher platelet count, higher serum creatinine level and low estimated GFR were significantly associated with increased frailty risk. High hemoglobin and regular walking habits were associated with decreased frailty risk in KOA patients. In this large observation population- based survey cohort, KOA is linked to an increased risk of frailty syndrome. We found a significant connection between KOA and frailty syndrome. These results show that we need to think about the overall health of people with KOA and give them special care to prevent frailty syndrome.

Factors for achieving target serum uric acid levels after initiating urate-lowering therapy in patients with gout: results from the ULTRA registry.

Achieving target serum uric acid (SUA) levels is important in gout management. Guidelines recommend lowering SUA levels to < 6 mg/dL; however, many patients fail to reach this target, even with uric acid-lowering therapy (ULT). This study investigated clinical characteristics of target SUA achievers among Korean patients with gout. This study used data from the ULTRA registry, a nationwide inception cohort established in September 2021 that enrolls patients with gout who initiate ULT. Demographic, clinical, and laboratory data were collected at baseline; the 6-month follow-up. Patients were divided into two groups: target achievers (SUA level < 6 mg/dL at 6 months) and non-achievers. The mean participant (N = 117) age was 56.1 years, and 88.0% were male. At 6 months, 83 patients (70.9%) reached target SUA levels. Target achievers had better drug adherence (≥ 80%) to ULT (97.6% vs. 76.5%; p < 0.01) than non-achievers. Target non-achievers had a higher percentage of a family history of gout (32.4% vs. 10.8%; p < 0.01) and less antihypertensive agent use (38.2% vs. 59.0%; p = 0.03) than target achievers. Multivariate regression analysis revealed that good adherence to ULT, the absence of a family history of gout, and antihypertensive agent use were key factors associated with achieving target SUA levels at 6 months.

The predictability of ASDAS on drug survival in patients with ankylosing spondylitis on biologic therapy: data from the KOBIO registry.

Background: The Ankylosing Spondylitis (AS) Disease Activity Score (ASDAS) is largely used for assessing disease activity in patients with AS. Objectives: We aimed to investigate the predictability of ASDAS on drug survival in patients with low Bath AS Disease Activity Index (BASDAI) during biologic therapy. Design: Using data from multi-center, prospective, observational prospective cohort, Korean College of Rheumatology Biologics and Targeted Therapy (KOBIO) registry. Methods: The study population consisted of patients enrolled in the KOBIO registry from December 2012 to December 2018. The baseline demographic data and variables such as extra-articular manifestations, HLA-B27 positivity, family history of spondyloarthritis, ASDAS C-reactive protein (CRP), BASDAI, and Bath AS Functional Index scores were collected from the database. The disease activity indices were followed yearly after initiating a tumor necrosis factor (TNF) inhibitor (TNFi). Disease activities were defined as high (ASDAS-CRP ⩾ 2.1, BASDAI ⩾ 4) and low (ASDAS-CRP < 2.1, BASDAI < 4). Results: Data from 1773 patients were analyzed. Among 269 patients with low BASDAI at baseline, 151 (56.1%) patients had high ASDAS-CRP, yet in 142 patients with low ASDAS-CRP at baseline, only 24 (16.9%) patients had a high BASDAI. High ASDAS-CRP captured more patients who had initiated or switched to a TNFi than those with high BASDAI (92.5% versus 84.8%, respectively, p < 0.001). Moreover, among AS patients with low BASDAI after 1 year of therapy, drug persistence in the following year was significantly lower in patients with high ASDAS than in those with low ASDAS (68.7% versus 82.5%, p < 0.001). Conclusion: ASDAS-CRP not only has its advantages over BASDAI in assessing disease activity but also low ASDAS-CRP at 1 year can be a marker of long-term drug survival of TNFi therapy.

Unveiling difficult-to-treat rheumatoid arthritis: long-term impact of biologic or targeted synthetic DMARDs from the KOBIO registry.

BACKGROUND: While the availability of biological or targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) has improved outcomes for rheumatoid arthritis (RA) patients, there remains a subset of individuals who fail to achieve low disease activity or remission despite multiple cycles of b/tsDMARDs. This state is referred to as 'difficult-to-treat (D2T)' RA. METHODS: Data from the Korean College of Rheumatology Biologics registry were utilized to analyze patients with RA who were treated with b/tsDMARDs. RESULTS: Among 2,321 RA patients with RA treated with b/tsDMARDs, 271 (11.7%) were diagnosed with D2T RA. Lower age (OR = 0.98, p < 0.001), longer disease duration (OR = 1.06, p < 0.001), lower patient global assessment (OR = 0.89, p = 0.045), higher SDAI (OR = 1.06, p = 0.014) and RAPID3 (OR = 1.06, p = 0.002), lower RF positivity (OR = 0.65, p = 0.04), and lower prior use of methotrexate (OR = 0.44, p = 0.008), sulfasalazine (OR = 0.59, p = 0.003), and leflunomide (OR = 0.67, p = 0.013) were associated with D2T RA. The drug survival rate of b/tsDMARDs did not differ between patients with D2T RA and non-D2T RA (p = 0.35). However, the drug survival of individual b/tsDMARD differed between patients with D2T RA and non-D2T RA after eight years. Patients with D2T RA withdrew from b/tsDMARDs due to inefficacy more frequently than those without D2T RA (p < 0.001). CONCLUSIONS: D2T RA patients experienced higher disease activity despite maintaining b/tsDMARD therapy. Withdrawal rates due to inefficacy were higher in D2T RA. Effective therapeutic strategies are needed to improve disease control and treatment outcomes in this unique patient population.

Reliability and Validity of the Korean Version of the Gout Impact Scale.

BACKGROUND: The Gout Impact Scale (GIS), part of the Gout Assessment Questionnaire 2.0, measures gout-specific health-related quality of life (HRQOL). This study aimed to translate the GIS into Korean and validate the Korean version (K-GIS) using generic HRQOL measures. METHODS: The GIS was translated into Korean and back-translated into English. We asked patients aged 18 years or older who met the 2015 gout classification criteria to fill out the questionnaires (from January 2022 to June 2022); the K-GIS (5 scales [0-100 scores each]), along with the Korean version of Health Assessment Questionnaire (HAQ) and EuroQol-5 dimension (EQ-5D). We investigated the internal consistency, construct validity, and discriminative validity for gout characteristics of K-GIS. The K-GIS form was administrated to patients 4 weeks later to assess the test-retest reliability using the intraclass correlation coefficient (ICC). RESULTS: One hundred patients completed the questionnaire. The mean ± standard deviation age of the patients was 53.0 ± 15.1 years, and 99.0% of the patients were men. All scales had high degree of internal consistency (Cronbach's α = 0.59 to 0.96) and test-retest reliability (n = 18, ICC = 0.83 to 0.94, all P < 0.001), except for unmet gout treatment needs. Weak-to-moderate correlations were observed between the K-GIS scales and HAQ or EQ-5D (r = 0.21 to 0.46). The K-GIS scores were significantly higher in the presence of bone erosion, absence of urate-lowering therapy, serum urate levels > 6 mg/dL, frequent gout flares in the past year, and fewer comorbidities. In contrast, neither the HAQ nor the EQ-5D could discern these subsets of patients. CONCLUSION: The K-GIS is a reliable and valid HRQOL measure for patients with gout. Higher K-GIS scores were associated with clinical characteristics leading to unfavorable outcomes, which were not demonstrated by the HAQ and EQ-5D.

Treatment Sequence After Initiating Biologic Therapy for Patients With Rheumatoid Arthritis in Korea: A Nationwide Retrospective Cohort Study.

Objective: To evaluate treatment patterns and healthcare resource utilization (HCRU) after initiating biologic disease-modifying antirheumatic drugs (bDMARDs) in Korean patients with rheumatoid arthritis (RA). Methods: Patients newly diagnosed with RA in 2014 were identified and followed up on using the Korean National Health Insurance Database until 2018. The initial line of therapy (LOT) or LOT1 included patients treated with conventional DMARDs (cDMARD). Patients who started a bDMARD were assigned to LOT2 bDMARD. Those who moved from a bDMARD to a Janus kinase inhibitor were assigned to LOT3. Analyzed outcomes were treatment patterns and HCRU in LOT2 bDMARD. Results: The most prescribed initial bDMARD was a tumor necrosis factor inhibitor. Seventy-five percent of patients had changes in treatment after starting a bDMARD, such as addition/removal or switch of a DMARD, and transition to LOT3. For the first and second changes in LOT2 bDMARD, adding a cDMARD to a bDMARD was more common than switching to another bDMARD (7.98% vs. 2.93% for the first change, and 17.10% vs. 6.51% for the second change). Tocilizumab was the most common bDMARD that was switched to. Forty-eight percent of patients had at least one hospitalization after initiating bDMARDs. Of these patients, 64.3% were admitted due to RA-related reasons. Conclusion: This real-world study provides information on treatment characteristics of RA patients in Korea after starting a bDMARD. In contrary to guidelines, cDMARD addition was more often than bDMARD switches in daily clinical practice.

Korean treatment recommendations for patients with axial spondyloarthritis.

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

Korean treatment recommendations for patients with axial spondyloarthritis.

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