Objective: This study aimed to elucidate the clinical and laboratory differences between chronic sclerosing sialadenitis (CSS) and primary Sjögren’s syndrome (pSS), highlighting CSS as a distinct pathological entity within the spectrum of salivary gland pathology. Methods: This retrospective, single-center study was conducted at Seoul St. Mary’s Hospital between January 2000 and December 2022. Patients diagnosed with CSS via salivary gland biopsy were included, and those with IgG4-related disease (IgG4-RD) or other confounding factors were excluded. Clinical and laboratory CSS profiles were compared with those of a control group of patients with typical pSS from the Korean Initiative of Primary Sjögren’s Syndrome (KISS) prospective cohort study. Twenty-one with CSS and 501 patients with pSS from Seoul St. Mary’s Hospital were retrospectively analyzed. Results: Patients with CSS were older at diagnosis, had a lower prevalence of ocular symptoms, and exhibited distinct immunological markers compared to those with pSS. Logistic regression analysis revealed that anti-Ro antibody positivity, elevated erythrocyte sedimentation rate levels, low serum complement 3 levels, and accompanying dry eye symptoms were factors distinguishing pSS from CSS. Conclusion Even after excluding IgG4-RD, CSS was significantly different from pSS in terms of clinical and laboratory findings.Recognition of these differences is crucial for the accurate diagnosis and management of CSS, underscoring its status as a distinct pathological entity among salivary gland pathologies.

Background/Aims: We aimed to clarify the clinical characteristics of psoriatic arthritis (PsA) in Korean patients focusing on PsA with axial involvement. Methods: A retrospective medical chart review was performed to identify PsA patients at a single tertiary center. Cases of AS patients with psoriasis were recruited from a prospective AS registry of the same center. Demographics, laboratory findings, and radiologic characteristics were assessed. Results: A total of 69 PsA patients were identified. In PsA patients, spondylitis (46.4%) was the most common form. Compared to AS patients with psoriasis, PsA patients with radiographic axial involvement were older (50.9 vs. 32.4 years; p < 0.001) and showed greater peripheral disease activity (peripheral arthritis 78.1 vs. 12.5%, p < 0.001; enthesitis 50.0 vs. 6.3%, p = 0.003). AS patients with psoriasis presented a higher rate of HLA-B*27 positivity (81.3 vs. 17.2%; p < 0.001) and a more frequent history of inflammatory back pain (100.0 vs. 75.0%; p = 0.039) than PsA patients with radiographic axial involvement. Significant proportions of PsA patients with radiographic axial involvement had cervical spine involvement (10/18, 55.6%) and spondylitis without sacroiliitis (10/23, 43.5%). Conclusions We demonstrate that axial involvement is common in Korean PsA patients, and its characteristics can be distinct from those of AS.

Background/Aims: Renal relapse has known to be a poor prognostic factor in patients with lupus nephritis (LN), but there were few studies that identified the risk factors of renal relapse in real world. We conducted this study based on 35-years of experience at a single center to find out predictors of renal relapse in Korean patients with LN after achieving complete response (CR). Methods: We retrospectively analyzed the clinical, laboratory, pathologic and therapeutic parameters in 296 patients of LN who reached CR. The cumulative risk and the independent risk factors for renal relapse were examined by Kaplan-Meier methods and Cox proportional hazards regression analyses, respectively. Results: The median follow-up period from CR was 123 months. Renal relapse had occurred in 157 patients. Renal relapse occurred in 38.2%, 57.6% and 67.9% of patients within 5-, 10-, and 20-year, respectively. The age at diagnosis of SLE and LN were significantly younger, and the proportions of severe proteinuria and serum hypoalbuminemia were higher in patients with renal relapse. Interestingly, the proportion of receiving cytotoxic maintenance treatment was higher in patients with renal relapse. In Cox proportional hazards regression analyses, only young-age onset of LN (by 10 years, HR = 0.779, p = 0.007) was identified to independent predictor of renal relapse. Conclusions Young-age onset of LN was only independent predictor and the patients with severe proteinuria and serum hypoalbuminemia also tended to relapse more, despite of sufficient maintenance treatment. Studies on more effective maintenance treatment regimens and duration are needed to reduce renal relapse.

Background/Aims: We aimed to compare the effectiveness and safety of Janus kinase inhibitors (JAKi) vs. biologic disease- modifying antirheumatic drugs (bDMARD) in Korean patients with rheumatoid arthritis (RA) who had an inadequate response to conventional synthetic DMARDs. Methods: A quasi-experimental, multi-center, prospective, non-randomized study was conducted to compare response rates between JAKi and bDMARDs in patients with RA naïve to targeted therapy. An interim analysis was performed to estimate the proportion of patients achieving low disease activity (LDA) based on disease activity score (DAS)–28– erythroid sedimentation rate (ESR) (DAS28-ESR) at 24 weeks after treatment initiation and to evaluate the development of adverse events (AEs). Results: Among 506 patients enrolled from 17 institutions between April 2020 and August 2022, 346 (196 JAKi group and 150 bDMARD group) were included in the analysis. After 24 weeks of treatment, 49.0% of JAKi users and 48.7% of bDMARD users achieved LDA (p = 0.954). DAS28-ESR remission rates were also comparable between JAKi and bDMARD users (30.1% and 31.3%, respectively; p = 0.806). The frequency of AEs reported in the JAKi group was numerically higher than that in the bDMARDs group, but the frequencies of serious and severe AEs were comparable between the groups. Conclusions Our interim findings reveal JAKi have comparable effectiveness and safety to bDMARDs at 24 weeks after treatment initiation.

Systemic autoimmune diseases arise from loss of self-tolerance and immune homeostasis between effector and regulator functions. There are many therapeutic modalities for autoimmune diseases ranging from conventional disease-modifying anti-rheumatic drugs and immunosuppressants exerting nonspecific immune suppression to targeted agents including biologic agents and small molecule inhibitors aiming at specific cytokines and intracellular signal pathways. However, such current therapeutic strategies can rarely induce recovery of immune tolerance in autoimmune disease patients. To overcome limitations of conventional treatment modalities, novel approaches using specific cell populations with immune-regulatory properties have been attempted to attenuate autoimmunity. Recently progressed biotechnologies enable sufficient in vitro expansion and proper manipulation of such ‘tolerogenic’ cell populations to be considered for clinical application. We introduce 3 representative cell types with immunosuppressive features, including mesenchymal stromal cells, Tregs, and myeloid-derived suppressor cells. Their cellular definitions, characteristics, mechanisms of immune regulation, and recent data about preclinical and clinical studies in systemic autoimmune diseases are reviewed here. Challenges and limitations of each cell therapy are also addressed.

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 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.

Group 3 innate lymphoid cells (ILC3), which express IL-22 and IL-17A, has been introduced as one of pathologic cells in axial spondyloarthritis (axSpA). Dyslipidaemia should be managed in axSpA patients to reduce cardiovascular disease, and dyslipidaemia promotes inflammation. This study aimed to reveal the role of circulating ILC3 in axSpA and the impact of dyslipidaemia on axSpA pathogenesis. AxSpA patients with or without dyslipidaemia and healthy control were recruited. Peripheral blood samples were collected, and flow cytometry analysis of circulating ILC3 and CD4+ T cells was performed. The correlation between Ankylosing Spondylitis Disease Activity Score (ASDAS)-C-reactive protein (CRP) and circulating immune cells was evaluated. The effect of oxidized low-density lipoprotein cholesterol (oxLDL-C) on immune cell differentiation was confirmed. AxSpA human monocytes were cultured with with oxLDL-C, IL-22, or oxLDL-C plus IL-22 to evaluate osteoclastogenesis using tartrate-resistant acid phosphatase (TRAP) staining and realtime quantitative PCR of osteoclast-related gene expression. Total of 34 axSpA patients (13 with dyslipidaemia and 21 without) were included in the analysis. Circulating IL-22+ ILC3 and Th17 were significantly elevated in axSpA patients with dyslipidaemia (p=0.001 and p=0.034, respectively), and circulating IL-22+ ILC3 significantly correlated with ASDAS-CRP (Rho=0.4198 and p=0.0367). Stimulation with oxLDL-C significantly increased IL-22+ ILC3, NKp44 − ILC3, and Th17 cells, and these were reversed by CD36 blocking agent. IL-22 and oxLDL-C increased TRAP + cells and osteoclast-related gene expression. This study suggested potential role of circulating IL-22+ ILC3 as biomarker in axSpA. Furthermore, dyslipidaemia augmented IL-22+ ILC3 differentiation, and oxLDL-C and IL-22 markedly increased osteoclastogenesis of axSpA.