Association between Hyperuricemia and Hearing Impairment: Results from the Korean National Health and Nutrition Examination Survey.

Background and Objectives: Hyperuricemia is associated with a variety of comorbidities. The objective of this study was to investigate the association between hyperuricemia and hearing impairment in Korean adults. Materials and Methods: Audiometric and laboratory test data from the 2019 to 2020 Korean National Health and Nutrition Examination Survey (KNHANES) were used for analysis. Hearing impairment was defined as a pure-tone average (0.5, 1, 2, 4 kHz) threshold level ≥ 41 decibels. The definition of hyperuricemia was different for males and females: >7 mg/dL for males vs. >6 mg/dL for females. Results: A total of 4857 (weight n = 17,990,725) subjects were analyzed. The mean age was 56.8 years old. The weighted prevalence was 12.1% for hyperuricemia and 2.5% for gout. The prevalence of hearing impairment was 13.4%. In the univariable analysis, hyperuricemia was significantly associated with hearing impairment. However, the diagnosis of gout was not associated with hearing impairment. In the multivariable analysis, hyperuricemia (odds ratios (OR): 1.41, 95% confidence interval [CI]: 1.03-1.92, p = 0.030) was associated with hearing impairment along with age (OR: 1.12, 95% CI: 1.10-1.14, p < 0.001), female sex (OR: 0.43, 95% CI: 0.34-0.64, p < 0.001), education (OR: 0.43, 95% CI: 0.30-0.63, p = 0.001), and occupational noise exposure (OR: 1.67, 95% CI: 1.25-2.22, p = 0.001). In the subgroup analysis, hyperuricemia was associated with hearing impairment in females (OR: 1.59, 95% CI: 1.02-2.48, p = 0.041) and the elderly aged 60 years or more (OR: 1.45, 95% CI: 1.05-1.99, p = 0.023). Conclusions: Hyperuricemia was independently associated with hearing impairment, especially in females and the elderly aged 60 years or more.

Rheumatoid factor is associated with severe COVID-19.

AIM: Coronavirus disease 2019 (COVID-19) has been proposed as triggering autoimmunity. The aim of this study was to evaluate the presence and clinical significance of autoantibodies in patients with COVID-19. METHODS: We retrospectively collected data from 245 patients who were hospitalized for COVID-19. All patients were tested for the presence of antinuclear antibody (ANA), rheumatoid factor (RF), anti-citrullinated peptide antibody (ACPA), and anti-cytoplasmic neutrophil antibody (ANCA). Risk factors for death and critical COVID-19, defined as the need for invasive mechanical ventilation or extracorporeal membrane oxygenation, were analyzed. RESULTS: Ninety (36.7%) patients tested positive for ANA, and 51 (20.8%) patients tested positive for RF. Three patients each (1.2%) tested positive for ACPA and ANCA. RF-positive patients had higher rates of invasive mechanical ventilation and death than RF-negative patients (70.6% vs 28.4%, P < 0.001 and 45.1% vs 18.6%, P < 0.001, respectively). Underlying lung disease, kidney disease, heart disease, quick COVID severity index (qCSI), and lactate dehydrogenase (LDH) were associated with in-hospital death. RF (odds ratio [OR] 7.31, 95% CI 2.50-21.37, P < 0.001), qCSI (OR 1.42, 95% CI 1.19-1.69, P < 0.001), and LDH (OR 1.004, 95% CI 1.002-1.005, P < 0.001) were associated with critical COVID-19. Combination of RF, qCSI, and LDH showed good prognostic value (area under the curve = 0.903, P < 0.001) for critical COVID-19. CONCLUSIONS: ANA and RF were frequently detected in COVID-19 patients. RF could be a risk factor for critical COVID-19. The results of this study suggest immune dysfunction contributes to the complications of COVID-19.

Gender-Specific Association of Serum Uric Acid and Pulmonary Function: Data from the Korea National Health and Nutrition Examination Survey.

Background and Objectives: Hyperuricemia is associated with several comorbidities. The association between uric acid (UA) and pulmonary function is still a controversial issue. This study evaluated the gender-specific association of serum UA and pulmonary function. Materials and Methods: A total of 3177 (weighted n = 19,770,902) participants aged 40 years or older were selected from the 2016 Korean National Health and Nutrition Examination Survey and included. Results: Female participants with hyperuricemia were older than participants with normouricemia. Body mass index (BMI), mean arterial pressure (MAP), hemoglobin A1c (HbA1c), and estimated glomerular filtration rate (eGFR) were significantly associated with UA levels in both males and females. Hyperuricemia and increase in UA quartile were significantly associated with decreased forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) in females after adjustment for age, income, region, education, marital status, alcohol consumption, smoking, BMI, MAP, HbA1c, and eGFR. There was no significant association between UA levels and lung function in males. After additional adjustment for respiratory disease including pulmonary tuberculosis, asthma, and lung cancer, the association between hyperuricemia and decreased FEV1 and FVC in females was revealed. Conclusions: Hyperuricemia was associated with decreased FVE1 and FVC in the female general population.

Selective estrogen receptor modulator lasofoxifene suppresses spondyloarthritis manifestation and affects characteristics of gut microbiota in zymosan-induced SKG mice.

Ankylosing spondylitis is a male-predominant disease and previous study revealed that estrogens have an anti-inflammatory effect on the spondyloarthritis (SpA) manifestations in zymosan-induced SKG mice. This study aimed to evaluate the effect of selective estrogen receptor modulator (SERM) lasofoxifene (Laso) on disease activity of SpA. Mice were randomized into zymosan-treated, zymosan + 17ß-estradiol (E2)-treated, and zymosan + Laso-treated groups. Arthritis was assessed by 18F-fluorodeoxyglucose (18F-FDG) small-animal positron emission tomography/computed tomography and bone mineral density (BMD) was measured. Fecal samples were collected and 16S ribosomal RNA gene sequencing was used to determine gut microbiota differences. Both zymosan + E2-treated mice and zymosan + Laso-treated mice showed lower arthritis clinical scores and lower 18F-FDG uptake than zymosan-treated mice. BMD was significantly higher in zymosan + E2-treated mice and zymosan + Laso-treated mice than zymosan-treated mice, respectively. Fecal calprotectin levels were significantly elevated at 8 weeks after zymosan injection in zymosan-treated mice, but it was not significantly changed in zymosan + E2-treated mice and zymosan + Laso-treated mice. Gut microbiota diversity of zymosan-treated mice was significantly different from zymosan + E2-treated mice and zymosan + Laso-treated mice, respectively. There was no significant difference in gut microbiota diversity between zymosan + E2-treated mice and zymosan + Laso -treated mice. Laso inhibited joint inflammation and enhanced BMD in SKG mice, a model of SpA. Laso also affected the composition and biodiversity of gut microbiota. This study provides new knowledge regarding that selected SpA patients could benefit from SERM treatment.

The Effects of Sex and Estrogen on Radiographic Progression of Ankylosing Spondylitis in Korean Patients.

Objective: Ankylosing spondylitis (AS) is a chronic inflammatory disease with obvious male preponderance Males show more severe radiographic manifestations compared with females This study aimed to evaluate the effects of sex and estrogen on the radiographic progression of AS. Methods: A total of 101 patients with AS were included in this study All of the radiographs were scored using the modified Stoke AS Spine Score (mSASSS) Serum levels of 17ß-estradiol (E2), dickkopf-1 (Dkk1), and leptin were detected by enzyme-linked immunosorbent assay The generalized estimating equations model was used to evaluate factors associated with spinal radiographic progression. Results: The mean age at disease onset was 273±107 years, and 16 patients (158%) were female In the multivariable analysis, body mass index (ß-coefficient=012; p=0047) and levels of Dkk1 (ß-coefficient=-011; p<0001), and female (ß-coefficient=-140; p=0001) were associated with radiographic progression Among male patients with AS, baseline C-reactive protein (ß=011; p=0005) and mSASSS (ß=021; p=0030) were also associated with radiographic progression E2 and leptin levels were not significantly related to the radiographic progression. Conclusion: Although female patients were associated with less radiographic progression in AS, there was no significant relationship between serum estrogen level and radiographic progression Results of current study suggests that genetic factors or other environmental factors associated with female may influence radiographic progression in patients with AS.

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.

The Practice Guideline for Vaccinating Korean Patients with Autoimmune Inflammatory Rheumatic Disease.

To develop a clinical practice guideline for vaccination in patients with autoimmune inflammatory rheumatic disease (AIIRD), the Korean College of Rheumatology and the Korean Society of Infectious Diseases developed a clinical practice guideline according to the clinical practice guideline development manual. Since vaccination is unlikely to cause AIIRD or worsen disease activities, required vaccinations are recommended. Once patients are diagnosed with AIIRD, treatment strategies should be established and, at the same time, monitor their vaccination history. It is recommended to administer vaccines when the disease enters the stabilized stage. Administering live attenuated vaccines in patients with AIIRD who are taking immunosuppressants should be avoided. Vaccination should be considered in patients with AIIRD, prior to initiating immunosuppressants. It is recommended to administer influenza, Streptococcus pneumoniae, hepatitis A, hepatitis B, herpes zoster, measles-mumps-rubella virus, human papillomavirus, and tetanus-diphtheria-pertussis vaccines in patients with AIIRD; such patients who planned to travel are generally recommended to be vaccinated at the recommended vaccine level of healthy adults. Those who live in a household with patients with AIIRD and their caregivers should also be vaccinated at levels that are generally recommended for healthy adults.

C reactive protein level as a marker for dyslipidaemia, diabetes and metabolic syndrome: results from the Korea National Health and Nutrition Examination Survey.

OBJECTIVE: Plasma C reactive protein (CRP) is a marker of inflammation, and increased plasma CRP is reported in many diseases, including cardiovascular disease, diabetes, metabolic syndrome, arthritis and malignancies. The aim of the study was to evaluate the association between plasma CRP levels and cardiovascular disease, metabolic syndrome, malignancies and other comorbidities. DESIGN: A retrospective, cross-sectional survey study. SETTING: Large population survey in Korea. METHODS: A total of 5887 (weighted n=40 251 868) participants aged 19 years or older from the 2016 Korea National Health and Nutrition Examination Survey were included for analysis. Weighted prevalence and OR of comorbidities were analysed according to the continuous variable of log plasma high-sensitivity CRP levels. RESULTS: The mean age was 46.7±0.37 years and the median plasma CRP was 0.58 mg/L (IQR 0.36-1.09). The mean plasma CRP levels were higher in participants with cardiovascular diseases and cardiovascular risk factors, osteoarthritis, rheumatoid arthritis, pulmonary tuberculosis, and several cancers, including gastric, colon, breast and cervix, than in the general population. In the multivariable analysis, plasma CRP concentration was associated with increased prevalence of hypertriglyceridaemia (OR 1.157, 95% CI 1.040 to 1.287, p=0.007), diabetes (OR 1.204, 95% CI 1.058 to 1.371, p=0.005) and metabolic syndrome (OR 1.228, 95% CI 1.112 to 1.357, p<0.001) after adjustment for socioeconomic and lifestyle characteristics. There was no significant association between plasma CRP level and cancers. CONCLUSION: Plasma CRP was associated with an increased risk of dyslipidaemia, diabetes and metabolic syndrome in the general population.

Clinical characteristics and risk factors for gout flare during the postsurgical period.

OBJECTIVES: To evaluate the clinical features and risk factors for gout flare during postsurgical period in patients who were previously diagnosed with gout. METHODS: Seventy patients who had histories of gout and had been consulted in the rheumatologic clinic before surgery under general anesthesia were included. Clinical characteristics of patients who developed a postsurgical gout flare were compared with those of patients who did not develop gout flare. RESULTS: Among 70 patients, 31 (44.3%) developed gout flare during the postsurgical period. Mean intervals from surgery to gout flare was 3.7 days. Flares tended to involve monoarticular joints (61.3%) and affect lower extremity joints (83.9%). Knee joints (26%) and foot joints except the first metatarsophalangeal (MTP) joint (26%) were more frequently involved than the first MTP joint (13%). Presurgical uric acid level ≥ 9 mg/dL (OR 3.77, 95% CI 1.28-11.10, p = 0.016) and amount of uric acid changes between before and after surgery (OR 1.62, 95% CI 1.21-2.18, p = 0.001) were risk factors for postsurgical gout flare. Taking allopurinol reduced the risk of postsurgical gout flare (OR 0.15, 95% CI 0.05-0.45, p = 0.001). Operation time, amount of blood loss during surgery, and surgery site were not significantly associated with postsurgical gout flare. CONCLUSIONS: Adequate uric acid control before surgery could prevent the postsurgical gout flare.

Clinical characteristics and risk factors for gout flare during the postsurgical period

Abstract Objectives: To evaluate the clinical features and risk factors for gout flare during postsurgical period in patients who were previously diagnosed with gout. Methods: Seventy patients who had histories of gout and had been consulted in the rheumatologic clinic before surgery under general anesthesia were included. Clinical characteristics of patients who developed a postsurgical gout flare were compared with those of patients who did not develop gout flare. Results: Among 70 patients, 31 (44.3%) developed gout flare during the postsurgical period. Mean intervals from surgery to gout flare was 3.7 days. Flares tended to involve monoarticular joints (61.3%) and affect lower extremity joints (83.9%). Knee joints (26%) and foot joints except the first metatarsophalangeal (MTP) joint (26%) were more frequently involved than the first MTP joint (13%). Presurgical uric acid level ≥ 9 mg/dL (OR 3.77, 95% CI 1.28-11.10, p = 0.016) and amount of uric acid changes between before and after surgery (OR 1.62, 95% CI 1.21-2.18, p = 0.001) were risk factors for postsurgical gout flare. Taking allopurinol reduced the risk of postsurgical gout flare (OR 0.15, 95% CI 0.05-0.45, p = 0.001). Operation time, amount of blood loss during surgery, and surgery site were not significantly associated with postsurgical gout flare. Conclusions: Adequate uric acid control before surgery could prevent the postsurgical gout flare.

Korean Guideline for the Prevention and Treatment of Glucocorticoid-induced Osteoporosis.

BACKGROUND: To develop guidelines and recommendations to prevent and treat glucocorticoid (GC)-induced osteoporosis (GIOP) in Korea. METHODS: The Korean Society for Bone and Mineral Research and the Korean College of Rheumatology have developed this guideline based on Guidance for the Development of Clinical Practice Guidelines ver. 1.0 established by the National Evidence-Based Healthcare Collaborating Agency. This guideline was developed by adapting previously published guidelines, and a systematic review and quality assessment were performed. RESULTS: This guideline applies to adults aged ≥19 years who are using or plan to use GCs. It does not include children and adolescents. An initial assessment of fracture risk should be performed within 6 months of initial GC use. Fracture risk should be estimated using the fracture-risk assessment tool (FRAX) after adjustments for GC dose, history of osteoporotic fractures, and bone mineral density (BMD) results. All patients administered with prednisolone or an equivalent medication at a dose ≥2.5 mg/day for ≥3 months are recommended to use adequate calcium and vitamin D during treatment. Patients showing a moderate-to-high fracture risk should be treated with additional medication for osteoporosis. All patients continuing GC therapy should undergo annual BMD testing, vertebral X-ray, and fracture risk assessment using FRAX. When treatment failure is suspected, switching to another drug should be considered. CONCLUSIONS: This guideline is intended to guide clinicians in the prevention and treatment of GIOP.

Differences in quality of life determinants according to the presence of fibromyalgia in middle-aged female patients with systemic lupus erythematosus: a multicenter, cross-sectional, single-ethnicity cohort.

OBJECTIVE: The purpose of this study was to identify whether determinants of health-related quality of life (HRQoL) in middle-aged female patients with systemic lupus erythematosus (SLE) differed according to the presence or absence of fibromyalgia. METHODS: One hundred and fifty-two patients with SLE and 139 healthy controls (HCs) completed the Medical Outcomes Study 36-Item Short Form (SF-36) and EuroQol EQ-5D questionnaires about HRQoL. Disease activity and cumulative disease damage were assessed with standard indices. Sleep quality was assessed using the Korean version of the Pittsburgh Sleep Quality Index (K-PSQI). RESULT: The mean EQ-5D and physical and mental components of SF-36 were lower in SLE patients with fibromyalgia (n = 41) than in those without fibromyalgia (n = 111) and HCs. The scores in all eight domains of the SF-36 were lower in SLE patients with fibromyalgia than in patients without fibromyalgia and HCs. Poor sleep (defined as a K-PSQI > 5) was reported by 85% of SLE patients with fibromyalgia, by 51% of patients without fibromyalgia, and by 33% of HCs. Multivariate logistic regression analysis showed that lower educational level, cumulative organ damage severity and poor sleep quality were independent determinants of HRQoL in SLE patients with fibromyalgia, whereas disease activity, sleep quality and depressive mood were independent determinants of HRQoL in those without fibromyalgia. CONCLUSION: Poor sleep quality is the common independent risk factor for poor HRQoL in both middle-aged SLE patients with fibromyalgia and without fibromyalgia. Sleep quality improvement may improve HRQoL in female SLE patients, even in those without fibromyalgia.

Outcome in Patients with Fever of Unknown Origin whose ¹8Fluoro-Deoxyglucose Positron Emission Tomography/Computerized Tomography Finding is Non-Diagnostic.

Prognosis has not been known for patients with fever of unknown origin (FUO) whose ¹8fluoro-deoxyglucose (¹8F-FDG) positron emission tomography/computerized tomography (PET/CT) finding is non-diagnostic. A total of eight patients with FUO that underwent ¹8F-FDG PET/CT were retrospectively identified January 2016 - June 2017 in a tertiary hospital in Korea. Of these, two patients were diagnosed with microscopic polyangitis and Kikuchi's disease and one patient was transferred to another hospital. Of five patients whose diagnoses were not confirmed, four patients received non-steroidal anti-inflammatory drug and/or low dose steroid and symptoms disappeared. Our study suggests that outcome of patients with FUO whose ¹8F-FDG PET/CT finding is non-diagnostic would be favorable.

Effect of tumor necrosis factor α inhibitors on spinal radiographic progression in patients with ankylosing spondylitis.

AIM: To evaluate the effect of tumor necrosis factor α inhibitors (TNFi) on spinal radiographic progression in patients with ankylosing spondylitis (AS). METHODS: Subjects were selected from patients at a single tertiary hospital between 1995 and 2014. Patients who used TNFi with baseline and paired follow-up radiographic data with a minimum interval of 2 years were included. Time to start TNFi was defined as the time from symptom onset to the start of TNFi use. TNFi index was defined as the ratio of the period of TNFi use to the entire period of disease. Radiographic damage was assessed by the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Univariable and multivariable linear regression analyses were used to identify factors associated with radiographic progression. RESULTS: A total of 151 patients were included in the analysis. Seventeen (11.3%) patients were female and mean ΔmSASSS/year was 1.01 units/year. Mean X-ray follow-up duration was 102.9 ± 54.9 months. Mean time from symptom onset to start of TNFi use was 104.8 ± 83.6 months (median 84 months) and mean TNFi index was 42.9 ± 23.8% (median 40.9%). In multivariable analysis, initial mSASSS, initial C-reactive protein, body mass index, current smoker, and delayed start of TNFi use were associated with radiographic progression. Presence of peripheral arthritis and the TNFi index were negatively associated with radiographic progression. CONCLUSIONS: A delay in starting TNFi use and low TNFi index were associated with radiographic progression. Early and long-term use of TNFi appear to reduce spinal radiographic progression in patients with AS.

Spondyloarthritis features in zymosan-induced SKG mice.

OBJECTIVES: Spondyloarthritis (SpA) encompasses a group of disorders including ankylosing spondylitis, psoriatic arthritis, reactive arthritis, and enteropathic arthritis. SpA pathogenesis is still not well understood. Animal models are important for studying disease mechanisms and identifying new therapeutic agents. Recently, a ß-glucan-induced SKG mouse was used as an animal model for SpA. The aim of this study was to evaluate the clinical and molecular characteristics of a zymosan-induced SKG mouse. METHODS: Zymosan was injected intraperitoneally into SKG mice. Clinical arthritis scores were measured, and fluorine-18 fluorodeoxyglucose (18F-FDG) small-animal positron emission tomography/computed tomography (PET/CT) was performed to quantify joint inflammation. Histologic features of the joints, intestines, skin, and eyes were evaluated. Inflammatory cytokine and Wnt inhibitor expression was measured in mouse serum. RESULTS: Zymosan exposure triggered SpA-like diseases in SKG mice, including peripheral arthritis, spondylitis, dactylitis, enteritis, and psoriatic skin lesions. 18F-FDG uptake was significantly higher in the zymosan-treated mice compared with controls. The expression of tumor necrosis factor α, interleukin (IL)-6, and Dickkopf-1 increased significantly, while IL-4 and sclerostin expression decreased significantly in zymosan-induced mice compared with control mice. CONCLUSIONS: Zymosan-induced SKG mice developed articular and extra-articular features as well as molecular changes that resembled those of human SpA. These findings suggest that the zymosan-induced SKG mouse is a good animal model to reflect the complex features of human SpA.

Comorbidities and health-related quality of life in Koreans with knee osteoarthritis: Data from the Korean National Health and Nutrition Examination Survey (KNHANES).

OBJECTIVES: This study aimed to evaluate the association of knee osteoarthritis (OA) with comorbidities and health-related quality of life (HRQOL). METHODS: A total of 8,907 (weighted n = 13,687,058) participants aged ≥50 years who had undergone knee radiography were selected from the 2010-2012 Korea National Health and Nutrition Examination Survey. OA was classified into four subgroups based on the presence or absence of pain and radiographic OA (ROA): non-OA (Pain-/ROA-), pain only (Pain+/ROA-), ROA only (Pain-/ROA+), and painful ROA (Pain+/ROA+). ROA was defined as Kellgren-Lawrence grade ≥ 2. HRQOL measurements including EuroQOL visual analogue scale (EQ-VAS) scores and the five dimensions and summary index of the EuroQOL-5 dimension (EQ-5D index) were also analyzed. Multivariable logistic regression and linear regression analyses were performed. RESULTS: After adjustment for socioeconomic and lifestyle characteristics, cardiovascular disease, malignancy, and other comorbidities were not significantly associated with OA. Pain only and painful ROA were each significantly associated with limitations in physical activity (odds ratio (OR) 2.66, 95% CI 2.07-3.44, p < 0.001 and OR 2.83, 95% CI 2.25-3.58, p < 0.001, respectively), lower EQ-VAS (ß-coefficient = -10.95, p < 0.001 and ß-coefficient = -9.75, p < 0.001, respectively), and EQ-5D index (ß-coefficient = -0.10, p < 0.001 and ß-coefficient = -0.13, p < 0.001) compared with the non-OA group, whereas ROA only was not associated with limitations in physical activity or lower HRQOL score. CONCLUSIONS: Comorbidities were not significantly associated with knee OA after adjustment. Knee OA was associated with physical activity and HRQOL. Painful knee OA, with or without ROA, was more strongly associated with decreased physical activity and lower quality of life than ROA without pain.

Estrogen attenuates the spondyloarthritis manifestations of the SKG arthritis model.

BACKGROUND: Ankylosing spondylitis (AS) is a male-predominant disease, and radiographic evidence of damage is also more severe in males. Estrogen modulates immune-related processes such as T cell differentiation and cytokine production. This study aimed to evaluate the effect of estrogen on the disease activity of spondyloarthritis (SpA). METHODS: The effects of estrogen on the development of arthritis were evaluated by performing ovariectomy and 17ß-estradiol (E2) pellet implantation in zymosan-treated SKG mice. Clinical arthritis scores were measured, and 18F-fluorodeoxyglucose (18F-FDG) small-animal positron emission tomography/computed tomography performed to quantify joint inflammation. The expression of inflammatory cytokines in joint tissue was measured. RESULTS: E2-treated mice showed remarkable suppression of arthritis clinically and little infiltration of inflammatory cells in the Achilles tendon and intervertebral disc. 18F-FDG uptake was significantly lower in E2-treated mice than in sham-operated (sham) and ovariectomized mice. Expression of TNF, interferon-γ, and IL-17A was significantly reduced in E2-treated mice, whereas expression of sclerostin and Dickkopf-1 was increased in E2-treated mice compared with sham and ovariectomized mice. CONCLUSIONS: Estrogen suppressed arthritis development in SKG mice, a model of SpA. Results of this study suggest that estrogen has an anti-inflammatory effect on the spondyloarthritis manifestations of the SKG arthritis model.

Switching profiles in a population-based cohort of rheumatoid arthritis receiving biologic therapy: results from the KOBIO registry.

Despite improved quality of care for rheumatoid arthritis (RA) patients, many still experience treatment failure with a biologic agent and eventually switch to another biologic agent. We investigated patterns of biologic treatment and reasons for switching biologics in patients with RA. Patients with RA who had started on a biologic agent or had switched to another biologic agent were identified from the prospective observational Korean nationwide Biologics (KOBIO) registry. The KOBIO registry contained 1184 patients with RA at the time of initiation or switching of biologic agents. Patients were categorized according to the chronological order of the introduction of biologic agents, and reasons for switching biologics were also evaluated. Of the 1184 patients with RA, 801 started with their first biologic agent, 228 were first-time switchers, and 89 were second-time or more switchers. Second-time or more switchers had lower rheumatoid factor and anti-CCP positivity, and higher disease activity scores at the time of enrollment than the other groups. Among these patients, tocilizumab was the most commonly prescribed biologic agent, followed by adalimumab and etanercept. The most common reason for switching biologics was inefficacy, followed by adverse events, including infusion reactions, infections, and skin eruptions. Furthermore, the proportion of inefficacy, as a reason for switching, was significantly higher with respect to switching between biologics with different mechanisms of action than between biologics with similar mechanisms. In this registry, we showed diverse prescribing patterns and differing baseline profiles based on the chronological order of biologic agents.