Bone homeostasis, which involves formation and resorption, is an important process for maintaining adequate bone mass in humans. Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation and bone loss, leading to joint destruction and deformity, and is a representative disease of disrupted bone homeostasis. The bone loss and joint destruction are mediated by immunological insults by proinflammatory cytokines and various immune cells. The connection between bone and immunity has been intensely studied and comprises the emerging field of osteoimmunology. Osteoimmunology is an interdisciplinary science investigating the interplay between the skeletal and the immune systems. The main contributors in osteoimmunology are the bone effector cells, such as osteoclasts or osteoblasts, and the immune cells, particularly lymphocytes and monocytes. Physiologically, osteoclasts originate from immune cells, and immune cells regulate osteoblasts and vice versa. Pathological conditions such as RA might affect these interactions, thereby altering bone homeostasis, resulting in the unfavorable outcome of bone destruction. In this review, we describe the osteoclastogenic roles of the proinflammatory cytokines and immune cells that are important in the pathophysiology of RA.
The proportion of elderly patients with rheumatoid arthritis (RA) is continuously growing as a result of the increasing aging population. We compared disease activity between different age groups, and evaluated the clinical factors associated with high disease activity.This cross-sectional study analyzed the data of RA patients enrolled in the Korean College of Rheumatology Biologics registry (KOBIO-RA) between 2012 and 2014. Disease activity between elderly (age ≥ 65 years) and non-elderly patients (age < 65 years) was compared, and the association of clinical factors with high disease activity was assessed using a multivariate logistic regression model.Of 1,227 patients in KOBIO-RA, 244 patients with RA were aged 65 years or over. In elderly patients, the proportion of men was higher (P = 0.012), and the duration of disease was longer (P < 0.001) compared with non-elderly patients. The elderly group showed a higher incidence of comorbidity (P < 0.001), and less use of methotrexate (P = 0.004). Assessment of disease activity using various composite measures showed a higher proportion of high disease activity in elderly patients than non-elderly patients. Longer disease duration, presence of comorbidity, and non-use of methotrexate were independently associated with high disease activity (P = 0.002, P < 0.001, and P = 0.029, respectively).At enrollment of KOBIO-RA, elderly patients showed higher disease activity compared with non-elderly patients. Disease duration, use of methotrexate, and comorbidity are associated with disease activity control in Korean patients with RA.
Objective. To examine humoral and cellular immune responses induced by a live attenuated herpes zoster (HZ) vaccine in patients with rheumatoid arthritis (RA) compared with osteoarthritis (OA) patients. Methods. This was an observational study of a live attenuated HZ vaccine in 41 patients with RA receiving conventional disease-modifying antirheumatic drugs (cDMARD) and/or low-dose glucocorticoids (GC) and in 28 patients with OA. Blood samples were obtained before and at 12 weeks after HZ vaccination. Immunogenicity was assessed using varicella zoster virus (VZV)-specific interferon gamma ELISA and an in-house ELISA. Clinical outcomes, including adverse events, HZ occurrence, and RA flares, were analyzed. Results. No patients developed vaccination-induced HZ during the followup period (median = 1.6 yrs). The HZ vaccine induced a significant increase in the VZV-specific enzyme-linked immunospot spot-forming units and anti-VZV immunoglobulin G antibodies in patients with RA and OA. The number of spot-forming units was lower in patients with RA than in patients with OA both at baseline and at 12 weeks after vaccination. The disease activity index for patients with RA was similar at baseline and at 12 weeks after vaccination. However, 6 patients with RA (14.6%) experienced a flare during the 12 weeks. Overall, 17 (24.6%) participants reported a mild adverse event such as an injection site reaction (11.6%). Conclusion. The HZ vaccine induced VZV-specific cellular and humoral responses in patients with RA. Although patients with RA showed a weaker vaccine-induced VZV-specific cellular immune response than patients with OA, the vaccine may be considered in patients with RA receiving cDMARD and/or low dose GC.
ABSTRACT Objectives Few studies have examined factors affecting steroid-free remission (SFR) in patients with immunoglobulin G4–related disease (IgG4-RD). The aim of this study was to investigate clinical factors affecting SFR in IgG4-RD. Methods The medical records of 68 patients who met the 2020 revised comprehensive diagnostic criteria for IgG4-RD were reviewed retrospectively. SFR was defined as remission maintained for at least 6 months without corticosteroids. Cox regression analysis was performed to examine the associations between SFR and various clinical factors. The relapse rate after SFR was examined using the log-rank test. Results After a median follow-up of 36 months, 30.9% (21/68) of patients with IgG4-RD achieved SFR. Multivariate Cox regression analysis revealed that IgG4-RD diagnosed by complete resection rather than by common diagnostic procedures was the only factor positively associated with SFR (hazard ratio, 7.41; 95% confidence interval, 2.23–24.60; P = .001). Furthermore, relapse after attainment of SFR was significantly less common in the group that underwent complete resection than in the group that did not undergo complete resection (log-rank P = .006). Conclusions Patients with IgG4-RD diagnosed by complete resection had a higher likelihood of achieving SFR and a lower rate of relapse after attaining SFR.
Mature somatic cells can be reversed into a pluripotent stem cell-like state using a defined set of reprogramming factors. Numerous studies have generated induced-Pluripotent Stem Cells (iPSCs) from various somatic cell types by transducing four Yamanaka transcription factors: Oct4, Sox2, Klf4 and c-Myc. The study of iPSCs remains at the cutting edge of biological and clinical research. In particular, patient-specific iPSCs can be used as a pioneering tool for the study of disease pathobiology, since iPSCs can be induced from the tissue of any individual. Rheumatoid arthritis (RA) is a chronic inflammatory disease, classified by the destruction of cartilage and bone structure in the joint. Synovial hyperplasia is one of the major reasons or symptoms that lead to these results in RA. Fibroblast-like Synoviocytes (FLSs) are the main component cells in the hyperplastic synovium. FLSs in the joint limitlessly proliferate, eventually invading the adjacent cartilage and bone. Currently, the hyperplastic synovium can be removed only by a surgical procedure. The removed synovium is used for RA research as a material that reflects the inflammatory condition of the joint. As a major player in the pathogenesis of RA, FLSs can be used as a material to generate and investigate the iPSCs of RA patients. In this study, we used the FLSs of a RA patient to generate iPSCs. Using a lentiviral system, we discovered that FLSs can generate RA patient-specific iPSC. The iPSCs generated from FLSs can be further used as a tool to study the pathophysiology of RA in the future.
To assess the impact of a single intra-articular (IA) injection of bone marrow–derived mesenchymal stem cells (BM-MSCs) in patients with knee osteoarthritis (OA), a randomized, double-blind, placebo-controlled study was conducted. The study included 24 patients with knee OA who were randomly assigned to receive either a single IA injection of BM-MSCs or normal saline. Changes in the visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee Injury and Osteoarthritis Outcome Score (KOOS) after IA injection were assessed at 3, 6, 9, and 12 months. Magnetic resonance imaging (MRI) with T2 mapping sequences was conducted for knee cartilage assessment at baseline and at 3 and 12 months. The MSC group showed between-group improvement in WOMAC (–5.0 ± 3.6 vs. –0.1 ± 5.5, P = 0.02) and KOOS (23.9 ± 18.3 vs. 7.2 ± 15.9, P = 0.028) scores at 9 months compared with the control group. The MSC group exhibited a less sharp increase in the mean T2 value of the medial compartment than the control group at 12 months, with no serious adverse events observed during follow-up. A single IA injection of allogeneic BM-MSCs provided satisfactory pain relief for patients with knee OA compared with the control group at 9 months. Quantitative T2 MRI mapping of the cartilage showed that IA BM-MSCs could have a preventive effect on OA progression for 12 months. Our findings suggest the potential of allogeneic BM-MSCs IA injection as a pain-relieving and disease-modifying treatment for patients with knee OA in the outpatient setting.