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Objectives The variable region of most ACPA IgG molecules in the serum of RA patients carries N -glycan (N -glycanV). To analyse the pathogenicity of N -glycanV of ACPAs, we analysed the pathogenicity of a monoclonal ACPA, CCP-Ab1, with or without N -glycanV, which had been isolated from a patient with RA. Methods CCP-Ab1 with no N -glycosylation site in the variable region (CCP-Ab1 N-rev) was generated, and antigen binding, the effect on in vitro differentiation of osteoclasts from bone marrow mononuclear cells of autoimmune arthritis–prone SKG mice (the cell size of TRAP+ cells and bone resorption capacity) and the in vivo effect on the onset or exacerbation of autoimmune arthritis in SKG mice were evaluated in comparison with glycosylated CCP-Ab1. Results Amino acid residues in citrullinated peptide (cfc1), which are essential for binding to CCP-Ab1 N-rev and original CCP-Ab1, were almost identical. The size of TRAP+ cells was significantly larger and osteoclast bone resorption capacity was enhanced in the presence of CCP-Ab1, but not with CCP-Ab1 N-rev. This enhancing activity required the sialic acid of the N -glycan and Fc region of CCP-Ab1. CCP-Ab1, but not CCP-Ab1 N-rev, induced the exacerbation of experimental arthritis in the SKG mouse model. Conclusions These data showed that N -glycanV was required for promoting osteoclast differentiation and bone resorption activity in both in vitro and in vivo assays. The present study demonstrated the important role of N -glycanV in the exacerbation of experimental arthritis by ACPAs. [ABSTRACT FROM AUTHOR]

Objectives: To present safety and efficacy of the JAK1 preferential inhibitor filgotinib in Japanese patients with prior inadequate response (IR) to methotrexate (MTX) from a 52-week randomised controlled parent study (PS) and long-term extension (LTE) through June 2020. Methods: The PS (NCT02889796) randomised MTX-IR patients to filgotinib 200 (FIL200) or 100 mg (FIL100), adalimumab (ADA) 40 mg, or placebo; all took stable background MTX. At week (W) 24, placebo patients were rerandomised to FIL200 or FIL100. The primary endpoint was W12 American College of Rheumatology 20% improvement; safety was assessed by adverse event (AE) reporting. For the LTE (NCT03025308), eligible filgotinib patients continued FIL200/FIL100; ADA patients were rerandomised (blinded) to FIL200 or FIL100; all continued MTX. Results: In all, 114/147 Japanese patients completed the PS, 115 enrolled in LTE, and 103 remained on study in June 2020. In the PS, AEs were consistent with the overall population, and W24 efficacy was maintained or improved through W52, comparable with the overall population. LTE AE incidences were similar between doses; filgotinib efficacy was consistent from baseline to W48 and similar between PS ADA and filgotinib patients. Conclusions: Among MTX-IR Japanese patients, filgotinib maintained efficacy over 1 year; LTE safety was consistent with the PS. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the long-term safety and efficacy of filgotinib (FIL) for Japanese patients with rheumatoid arthritis (RA) and limited/no prior methotrexate (MTX) exposure. We present a Japanese population subanalysis of a global randomised-controlled trial at Week 52 and interim long-term extension (LTE) to Week 48 through June 2020. Methods: Patients were randomised to FIL 200 mg plus MTX, FIL 100 mg plus MTX, FIL 200 mg, or MTX for 52 weeks. At completion, eligible patients could enrol in the LTE. Those receiving FIL continued; those receiving MTX were rerandomised (blinded) to FIL 200 or 100 mg upon discontinuation of MTX. After a 4-week washout period, MTX could be re-added. Results: Adverse event rates at Week 52 and in the LTE to Week 48 were comparable across treatment groups. Week 52 American College of Rheumatology 20% improvement (ACR20) rates were 83% (19/23), 82% (9/11), 75% (9/12), and 76% (19/25) for FIL 200 mg plus MTX, FIL 100 mg plus MTX, FIL 200 mg, and MTX, respectively. Through LTE Week 48, ACR20 rates were maintained. Conclusions: In the 56 Japanese patients treated with FIL, efficacy was maintained through Week 52 and beyond, with no increases in the incidence of adverse events. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammatory bone destruction in which tumor necrosis factor alpha (TNF-α) plays a key role. Bovine lactoferrin (bLF) is a multifunctional protein with anti-inflammatory and immunomodulatory properties. This study aimed to clarify the inhibitory effects of bLF on the pathological progression of RA. The mannan-induced arthritis model in SKG mice (genetic RA model) was used. Orally applied liposomal bLF (LbLF) markedly reduced ankle joint swelling and bone destruction. Histologically, pannus formation and osteoclastic bone destruction were prevented in the LbLF-treated animals. Moreover, orally administered LbLF improved the balance between Th17 cells and regulatory T cells isolated from the spleen of mannan-treated SKG mice. In an in vitro study, the anti-inflammatory effects of bLF on TNF-α-induced TNF-α production and downstream signaling pathways were analyzed in human synovial fibroblasts from RA patients (RASFs). bLF suppressed TNF-α production from RASFs by inhibiting the nuclear factor kappa B and mitogen-activated protein kinase pathways. The intracellular accumulation of bLF in RASFs increased in an applied bLF dose-dependent manner. Knockdown of the lipoprotein receptor-related protein-1 (LRP1) siRNA gene reduced bLF expression in RASFs, indicating that exogenously applied bLF was mainly internalized through LRP-1. Immunoprecipitated proteins with anti-TNF receptor-associated factor 2 (TRAF2; an adapter protein/ubiquitin ligase) included bLF, indicating that bLF binds directly to the TRAF2-TRADD-RIP complex. This indicates that LbLF may effectively prevent the pathological progression of RA by suppressing TNF-α production by binding to the TRAF2-TRADD-RIP complex from the RASFs in the pannus. Therefore, supplemental administration of LbLF may have a beneficial effect on preventive/therapeutic reagents for RA. [ABSTRACT FROM AUTHOR]

Objective: To evaluate treatment satisfaction, disease outcomes, and perspectives of patients with poorly controlled rheumatoid arthritis (RA) treated with conventional synthetic, targeted synthetic, or biologic disease-modifying antirheumatic drugs (DMARDs), we conducted a subgroup (post hoc) analysis of Japanese patients participating in the SENSE study. Methods: Data for Japanese patients (n/N = 118/1629) from the global, multicenter, cross-sectional, observational SENSE study were analyzed. The primary endpoint was the global satisfaction subscore assessed using the Treatment Satisfaction Questionnaire for Medication (TSQM) version 1.4. Other patient-reported outcomes included self-reported RA medication adherence and Work Productivity and Activity Impairment-RA. Patient perspectives included patients' expectations and preference of pharmacologic treatment. Results: Median (range) age and RA disease duration were 67.0 (18.0–87.0) years and 8 (0.0-54) years, respectively; 81.4% of patients were female. Mean (SD) TSQM global satisfaction subscore was 56.8 (17.5), and only 5.9% of patients reported good satisfaction with treatment (TSQM global ≥80). Mean (SD) self-reported treatment adherence using VAS was high (93.5% [13.8%]). Mean (SD) total work productivity impairment was 45.6% (32.0%); presenteeism contributed toward more total work productivity impairment (43.9% [30.4%]) than absenteeism (8.3% [24.4%]). Patients expected improvement in all parameters from their treatment, especially improvement in joint symptoms. Most patients (80.7%) preferred oral medication and 18.7% preferred monotherapy. Patient acceptability of potentially manageable side effects was high (7.5%-34.0%). Although most patients (81.3%) found combination therapy acceptable, 43.2% were receiving DMARD monotherapy. Conclusion: Although most Japanese patients with RA with moderate-to-high disease activity were dissatisfied with their current DMARD treatment, high treatment adherence, high acceptability of combination therapy, high acceptability of manageable potential side effects, and preference for oral medication were reported. Data support the development of a more individualized and patient-centric approach for RA treatment. [ABSTRACT FROM AUTHOR]

A 77-year-old Japanese woman with a 21-year history of seropositive, erosive rheumatoid arthritis (RA) and a 10-year history of methotrexate (MTX) therapy was admitted with malaise and mild consciousness disturbance. Laboratory data showed hypercalcemia, acute kidney injury, normocytic anaemia, and thrombocytopenia. As we first assumed drug-induced toxicity by MTX and eldecalcitol, both were discontinued and leucovorin rescue therapy and calcitonin were administered. However, her condition continued to worsen. Serum protein electrophoresis showed only a small M-peak, immunoelectrophoresis of both the serum and urine demonstrated Bence-Jones kappa (κ) type monoclonal protein without immunoglobulin heavy chain, and bone marrow examination revealed proliferation of plasma cells. We diagnosed her with Bence-Jones κ type multiple myeloma (MM) and transferred her to the department of haematology of a higher order medical institution. Conclusively, the diagnosis of immunoglobulin (Ig) D-κ type MM, a rare variant of this disorder, was determined in accordance with serum immunofixation. Several previous studies have suggested that pre-existing RA is a risk factor for MM. Although IgD MM is characterised by its clinical severity and poor prognosis compared to other subtypes, it is often misdiagnosed or mistaken as light chain type MM, as in the present case, because of the low level of IgD M-protein, resulting in delayed diagnosis. Physicians must take MM into consideration as a differential diagnosis when inactive RA patients present with inexplicable elevated calcium, renal failure, anaemia, and bone lesion symptoms and should be aware of IgD MM to establish the correct diagnosis promptly. [ABSTRACT FROM AUTHOR]

Objective: In plasma from a patient with rheumatoid arthritis (RA), we previously isolated a human monoclonal anti–citrullinated protein antibody (ACPA), CCP‐Ab1, that recognizes various citrullinated antigens. In this study, we aimed to explore the physiologic target of CCP‐Ab1 and the role of molecular evolution, through affinity maturation, of this ACPA in the onset and the exacerbation of RA. Methods: The target protein of CCP‐Ab1 was identified in the plasma of a patient with RA and purified under native conditions. Germline‐reverted (GL‐rev) CCP‐Ab1 was generated, and its reactivity was compared to that of mature CCP‐Ab1. The functions of CCP‐Ab1 and GL‐rev CCP‐Ab1 in the onset or exacerbation of autoimmune arthritis were analyzed using autoimmune arthritis–prone SKG mice. Results: CCP‐Ab1 bound citrullinated fibrinogen under native conditions. In cultures with GL‐rev CCP‐Ab1, the binding affinity to citrullinated fibrinogen was drastically reduced (P < 0.05). The elements implicated in GL‐rev CCP‐Ab1 binding to a citrullinated peptide, cfc1‐cyc, were almost identical to those implicated in CCP‐Ab1 binding. In arthritis‐prone SKG mice, CCP‐Ab1, but not GL‐rev CCP‐Ab1, induced significant exacerbation of experimental arthritis (P < 0.05). Increased production of interleukin‐6, both in the joint tissue and in the serum, was observed in SKG mice treated with CCP‐Ab1 compared to those treated with GL‐rev CCP‐Ab1 (P < 0.05). Furthermore, the immune complex formed by CCP‐Ab1 and fibrinogen was detected at higher concentrations in the synovial tissue of SKG mice administered CCP‐Ab1 (P < 0.05 versus control treatment groups). Conclusion: These data show that germline‐encoded CCP‐Ab1, which binds weakly to citrullinated fibrinogen, undergoes hypermutation through the activation of naive B cells by citrullinated peptides/proteins, thereby stimulating high reactivity to citrullinated fibrinogen. These findings deepen our understanding of the role of molecular evolution of ACPAs in the onset and exacerbation of RA. [ABSTRACT FROM AUTHOR]

Objective To investigate the reactivity of monoclonal anti-citrullinated protein antibody (ACPA) obtained from peripheral blood B cells of rheumatoid arthritis (RA) patients with human autoantigens as well as environmental proteins by determining the essential epitope for the ACPA. Methods A human monoclonal ACPA (cyclic citrullinated peptide antibody 1 [CCP-Ab1]) was obtained by screening peripheral blood lymphocytes from 31 patients with RA using a novel monoclonal antibody-secreting cell (ASC) screening system, the immunospot-array assay on a chip. The essential epitope for CCP-Ab1 was determined using epitope mapping. Then, human, microbial, and plant proteins that share the essential epitope identified were searched using BLAST. Finally, representative proteins identified by the search were produced in vitro, and their reactivity with CCP-Ab1 was examined. Results CCP-Ab1 bound CCP in a citrulline-indispensable manner. In CCP, the 6 amino acid residues required for CCP-Ab1 binding were identified. In the BLAST search, 38 human, 56 viral, 1,383 fungal, 547 bacterial, and 1,072 plant proteins were found to share the essential epitope, and CCP-Ab1 reacted with all of the recombinant citrullinated proteins tested, which included the various environmental factors, such as various plant proteins that are part of the daily diet. Conclusion Our findings demonstrate, for the first time, that a monoclonal ACPA (CCP-Ab1) derived from RA patients cross-reacts not only with various autoantigens but also with numerous plant and microbial proteins. We propose that countless environmental factors, including microbes and diet, may trigger the generation of ACPAs that then cross-react with various citrullinated human autoantigens through molecular mimicry to induce RA. [ABSTRACT FROM AUTHOR]

Factor XIII is one of the twelve coagulation factors and also known as a fibrin-stabilizing factor. In 2012, we encountered a male RA patient with hemorrhagic factor XIII deficiency who had been treated with tocilizumab for two years. There are few reports regarding the relationship between tocilizumab (a humanized monoclonal antibody against the interleukin-6 receptor (IL-6R)) and factor XIII. We measured the factor XIII activity levels in the plasma of 40 RA patients (10 patients treated without biologics, 30 patients treated with biologics (15 patients treated with necrosis factor inhibitors and 15 patients treated with tocilizumab)) and 19 healthy controls. Consequently, the tocilizumab group exhibited lower levels than the other three groups according to the Steel-Dwass test (P<0.01). Furthermore, we compared the plasma factor XIII activity levels and the plasma factor XIII concentrations in the RA patients treated with biologics. Pearson's correlation test was used to assess the relationship between the factor XIII activity levels and the plasma factor XIII concentrations (r = 0.449, P = 0.019). According to the multiple regression analysis, the treatment with tocilizumab is an independent risk factor for plasma factor XIII reduction in RA patients. In conclusion, RA patients treated with tocilizumab, an IL-6R blocker, are at risk of developing acquired factor XIII deficiency. The mechanisms underlying the reduced factor XIII activity observed in RA patients treated with tocilizumab may result from the quantitative reduction in the plasma. These data imply that IL-6 plays an important role in maintaining the factor XIII activity level. [ABSTRACT FROM AUTHOR]

Osteoclasts are multinucleated giant cells responsible for bone resorption. Various mediators involved in osteoclast differentiation have been investigated as possible therapeutic targets for osteoporosis and rheumatoid arthritis (RA). Although transforming growth factor beta1 (TGFβ1) has been described as one such multifunctional cytokine essential for bone remodeling, its effect on osteoclastogenesis remains controversial. Therefore, we sought to examine the effect of TGFβ1 on osteoclast generation induced by receptor activator of nuclear factor (NF)-κB ligand (RANKL) in humans. Peripheral blood monocytes, isolated using magnetic bead sorting, were cultured with macrophage-colony stimulating factor (M-CSF) or RANKL with or without TGFβ1. Tartrate-resistant acid phosphatase (TRAP) staining, as well as bone resorption assays, revealed that TGFβ1 suppressed RANKL-mediated human osteoclast development. Real-time reverse transcription PCR and Western blotting revealed that TGFβ1 reduced the gene and protein expression of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), the master regulator of osteoclast differentiation, respectively. Luciferase assays indicated that TGFβ1 inhibited the NF-κB p65-stimulated promoter activity of NFATc1. Immunofluorescence analysis demonstrated that TGFβ1 abrogated RANKL-induced nuclear translocation of p65. Thus, TGFβ1 regulates human RANKL-induced osteoclastogenesis via downregulation of NFATc1 by blocking nuclear translocation of NF-κB, suggesting that TGFβ1 may be a potential therapeutic target for RA. [ABSTRACT FROM AUTHOR]

We report a 62-year-old man with rheumatoid arthritis (RA) who developed nodulosis after methotrexate (MTX) treatment. The epithelioid cells of nodules were positive for matrix metalloproteinases (MMP)-2, MMP-3, MMP-9, and Ki67. The synovial tissues obtained from the same patient were negative for MMP-3, MMP-9, and Ki67. This study demonstrated that MTX-induced nodules are different from synovial tissues in terms of MMP expression, suggesting the presence of different pathologic mechanisms and differential MTX susceptibility. [ABSTRACT FROM AUTHOR]

Survivin is an independent prognostic factor for joint destruction in rheumatoid arthritis (RA). However, the expression and function of survivin in RA synoviocytes remain unclear. We certified the expression of survivin in RA synovial tissues and performed the experiment using RA fibroblast-like synoviocytes (RA-FLS) treated with siRNA. As a result, the expression levels of wild type (WT) survivin and the 2B splice variants in RA synovial tissues were higher than those in osteoarthritis tissue samples, and, these variants were highly expressed in RA-FLS. The expression levels of survivin-WT and -2B in the RA-FLS were upregulated by PDGF. Treatment with siRNA against survivin-2B led to decreased viability of PDGF-treated RA-FLS due to cell cycle suppression and apoptosis promotion, while the siRNA against all survivin isoforms did not affect the viability. Moreover, an overexpression of survivin-2B in RA-FLS led to cell proliferation through cell cycle activation and by conferring resistance to apoptosis. In conclusion, survivin-2B has an important role in RA-FLS proliferation. These data suggest that survivin-2B might contribute to rheumatoid synovial hyperplasia, and have the potential as a novel therapeutic target for RA. [ABSTRACT FROM AUTHOR]