The double shared epitope: Its impact on clinical features and ultrasound findings in rheumatoid arthritis.

OBJECTIVES: The link between the HLA-DRB1 locus and the risk of rheumatoid arthritis (RA) shown in genome-wide association studies strengthens the shared epitope (SE) hypothesis. We aimed to assess the impact of the double dose of the SE (double SE) on RA and explore its clinical associations, including the response to abatacept. METHODS: We evaluated RA patients treated with csDMARDs or abatacept for HLA-DRB1 typing, clinical characteristics at baseline, and disease activity and ultrasound findings over 12 months. RESULTS: Patients with the double SE (n = 12) had significantly higher anti-citrullinated protein antibody (ACPA) titers, higher total grayscale (GS) score, and power Doppler (PD) score at baseline than patients without the double SE. Patients with the double SE exhibited reduced rates of SDAI remission and pronounced improvements in multiple disease activity between baseline and 12 months, including SDAI, CDAI, total GS score, and total PD score. When focusing on abatacept-treated patients, the decreases in SDAI, CDAI, and total PD score between baseline and 12 months were significantly larger in patients with the double SE. CONCLUSIONS: Patients with the double SE exhibited distinct characteristics, increased disease activity, and improved response to abatacept treatment.

Association of denosumab with serum cytokines, chemokines, and bone-related factors in patients with rheumatoid arthritis: A post hoc analysis of a multicentre, open-label, randomised, parallel-group study.

OBJECTIVES: To clarify changes in serum cytokines, chemokines, and bone-related factors during denosumab treatment in rheumatoid arthritis (RA) patients. METHODS: This was a post hoc analysis of a multicentre, open-label, randomised, parallel-group study. Patients were randomly assigned to continue treatment with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) plus receive treatment with denosumab (csDMARDs plus denosumab group) or to continue treatment with csDMARD therapy alone for 12 months. Serum biomarker levels were measured at baseline and 6 and 12 months. RESULTS: Baseline and 6-month data from the csDMARDs plus denosumab (n = 22) and csDMARD therapy alone (n = 22) groups were analysed. Statistically significant changes from baseline were seen: dickkopf-related protein 1 decreased at 6 and 12 months (both groups); osteopontin decreased at 6 months in the csDMARDs plus denosumab group; osteopontin and soluble CD40 ligand increased at 6 and 12 months in the csDMARD therapy alone group; osteocalcin decreased at 6 and 12 months, epidermal growth factor decreased at 12 months, and macrophage-derived chemokine decreased at 6 months in the csDMARDs plus denosumab group; and interferon gamma-induced protein-10 increased at 12 months in the csDMARD therapy alone group. CONCLUSIONS: Denosumab may inhibit bone destruction by suppressing bone-related factors/chemokines.

Efficacy and safety of 5-aminolevulinic acid in adult-onset Still's disease: A preclinical study in mice and a pilot study in humans.

The study aimed to investigate the therapeutic effects of 5-aminolevulinic acid/sodium ferrous citrate (5-ALA/SFC) on adult-onset Still's disease (AOSD), specifically focusing on arthritis and macrophage activation syndrome (MAS). We used mouse models to assess the impact of 5-ALA/SFC on collagen-induced arthritis (CIA) and MAS induced by synthetic oligonucleotides containing CpG motifs (CpG-S-ODN). Additionally, we conducted a pilot study with AOSD patients receiving prednisolone (PSL) treatment and 5-ALA/SFC administration to evaluate its efficacy and safety. The 5-ALA/SFC group exhibited significantly lower joint scores in CIA mice. In CpG-S-ODN-treated mice, 5-ALA/SFC administration led to reduced hemophagocytosis and splenomegaly. The anti-inflammatory properties of 5-ALA/SFC were attributed to the suppression of CCL4 and CXCL10 production in monocytes and the induction of M2 macrophages. AOSD patients treated with 5-ALA/SFC demonstrated successful PSL tapering without adverse events. Collectively, the administration of 5-ALA/SFC showed promising potential in ameliorating arthritis and MAS in AOSD patients.

Exploring the role of insulin-like growth factor binding protein-1 in identifying idiopathic multicentric Castleman's disease types: Implications for the mTOR signaling pathway.

OBJECTIVE: To determine the molecular differences between iMCD-thrombocytopenia, anasarca, fevers, reticulin myelofibrosis, organomegaly (TAFRO), and iMCD-not otherwise specified (NOS). METHODS: CD4-positive T cells were isolated from two iMCD-TAFRO and two iMCD-NOS patients for RNA sequencing comparison. Serum proteins of two iMCD-TAFRO and four iMCD-NOS patients were comprehensively analyzed to identify pathogenesis-associated proteins. IGFBP-1 protein, extracted from serum analysis, was compared to healthy controls, iMCD, systemic lupus erythematosus, and rheumatoid arthritis patients. RESULTS: RNA sequencing of CD4-positive T cells revealed enhanced mTOR-related signaling in iMCD-TAFRO compared to iMCD-NOS. Comprehensive serum analysis found IGFBP-1 linked to iMCD pathogenesis, significantly higher in iMCD-TAFRO. This protein may be elevated in patients with iMCD caused by an enhanced mTOR pathway. CONCLUSION: The mTOR pathway is suggested to be activated in iMCD-TAFRO compared to iMCD-NOS, which may elevate the protein IGFBP-1. This protein may be a biomarker to distinguish iMCD-TAFRO from iMCD-NOS.

The Toll-like Receptor 7-Mediated Ro52 Antigen-Presenting Pathway in the Salivary Gland Epithelial Cells of Sjögren's Syndrome.

OBJECTIVE: To investigate whether stimulation with toll-like receptor (TLR) 7 leads to pathways that proceed to tripartite motif-containing protein 21 (TRIM21) or Ro52/SS-A antigen presentation through major histocompatibility complex (MHC) class I in salivary gland epithelial cells (SGECs) from Sjögren's syndrome (SS) patients. DESIGN AND METHODS: Cultured SGECs from SS patients were stimulated with TLR7 agonist, loxoribine, and interferon-ß. Cell lysates immunoprecipitated by anti-MHC class I antibody were analyzed by Western blotting. The immunofluorescence of salivary gland tissue from SS and non-SS subjects and cultured TLR7-stimulated SGECs was examined. RESULTS: Significantly increased MHC class I expression was observed in SS patients' ducts versus non-SS ducts; no significant difference was detected for ubiquitin. Upregulated MHC class I in the cell membrane and cytoplasm and augmented Ro52 expression were observed in SGECs stimulated with TLR7. The formation of peptide-loading complex (PLC), including tapasin, calreticulin, transporter associated with antigen processing 1, and endoplasmic reticulum-resident protein 57 in labial salivary glands (LSGs) from SS patients, was dominantly observed and colocalized with MHC class I, which was confirmed in TLR7-stimulated SGEC samples. CONCLUSION: These findings suggest that the TLR7 stimulation of SS patients' SGECs advances the process toward the antigen presentation of TRIM21/Ro52-SS-A via MHC class I.

Inhibition of calcium/calmodulin-dependent protein kinase IV in arthritis: dual effect on Th17 cell activation and osteoclastogenesis.

OBJECTIVE: To investigate the role of calcium/calmodulin-dependent protein kinase IV (CaMK4) in the development of joint injury in a mouse model of arthritis and patients with RA. METHODS: Camk4-deficient, Camk4flox/floxLck-Cre, and mice treated with CaMK4 inhibitor KN-93 or KN-93 encapsulated in nanoparticles tagged with CD4 or CD8 antibodies were subjected to collagen-induced arthritis (CIA). Inflammatory cytokine levels, humoral immune response, synovitis, and T-cell activation were recorded. CAMK4 gene expression was measured in CD4+ T cells from healthy participants and patients with active RA. Micro-CT and histology were used to assess joint pathology. CD4+ and CD14+ cells in patients with RA were subjected to Th17 or osteoclast differentiation, respectively. RESULTS: CaMK4-deficient mice subjected to CIA displayed improved clinical scores and decreased numbers of Th17 cells. KN-93 treatment significantly reduced joint destruction by decreasing the production of inflammatory cytokines. Furthermore, Camk4flox/floxLck-Cre mice and mice treated with KN93-loaded CD4 antibody-tagged nanoparticles developed fewer Th17 cells and less severe arthritis. CaMK4 inhibition mitigated IL-17 production by CD4+ cells in patients with RA. The number of in vitro differentiated osteoclasts from CD14+ cells in patients with RA was significantly decreased with CaMK4 inhibitors. CONCLUSION: Using global and CD4-cell-targeted pharmacologic approaches and conditionally deficient mice, we demonstrate that CaMK4 is important in the development of arthritis. Using ex vivo cell cultures from patients with RA, CaMK4 is important for both Th17 generation and osteoclastogenesis. We propose that CaMK4 inhibition represents a new approach to control the development of arthritis.

Measurement of anti-suprabasin antibodies, multiple cytokines and chemokines as potential predictive biomarkers for neuropsychiatric systemic lupus erythematosus.

Neuropsychiatric systemic lupus erythematosus (NPSLE) varies in presentation and is one of the leading causes of morbidity and mortality among patients with SLE. This study determined the most critical serum biomarkers for the development of NPSLE as they may have clinical utility prior to the onset of neuropsychiatric symptoms. We retrospectively analyzed 35 NPSLE patients, 34 SLE patients, 20 viral meningitis (VM) patients, and 16 relapsing-remitting multiple sclerosis (MS) patients. We measured anti-suprabasin antibodies concentrations in serum by using Luciferase immunoprecipitation system (LIPS) assay. The serum concentrations of cytokines/chemokines were measured by using multiplex bead-based assay. We found serum FGF-2 level was significantly higher in the NPSLE group compared to the SLE group and the healthy control group. The anti-suprabasin antibody relative concentration (SRC) has high positive predictive values for the development of NPSLE. The most essential biomarkers are VEGF, anti-suprabasin antibodies, sCD40L, IL-10, GRO, MDC, IL-8, IL-9, TNF-α, MIP-1α.

A case of tocilizumab-refractory idiopathic multicentric Castleman's disease successfully treated with sirolimus.

mTOR signaling may be a new therapeutic target for IL-6 inhibitor refractory iMCD-NOS.

Methotrexate Alters the Expression of microRNA in Fibroblast-like Synovial Cells in Rheumatoid Arthritis.

We aimed to investigate the effect of methotrexate (MTX) on microRNA modulation in rheumatoid arthritis fibroblast-like synovial cells (RA-FLS). RA-FLS were treated with MTX for 48 h. We then performed miRNA array analysis to investigate differentially expressed miRNAs. Transfection with miR-877-3p precursor and inhibitor were used to investigate the functional role of miR-877-3p in RA-FLS. Gene ontology analysis was used to investigate the cellular processes involving miR-877-3p. The production of cytokines/chemokines was screened by multiplex cytokine/chemokine bead assay and confirmed by ELISA and quantitative real-time PCR. The migratory and proliferative activities of RA-FLS were analyzed by wound healing assay and MKI-67 expression. MTX treatment altered the expression of 13 miRNAs (seven were upregulated and six were downregulated). Among them, quantitative real-time PCR confirmed that miR-877-3p was upregulated in response to MTX (1.79 ± 0.46-fold, p < 0.05). The possible target genes of miR-877-3p in RA-FLS revealed by the microarray analysis were correlated with biological processes. The overexpression of miR-877-3p decreased the production of GM-CSF and CCL3, and the overexpression of miR-877-3p inhibited migratory and proliferative activity. MTX altered the miR-877-3p expression on RA-FLS, and this alteration of miR-877-3p attenuated the abundant production of cytokines/chemokines and proliferative property of RA-FLS.

Granulocyte-macrophage colony-stimulating factor and tumor necrosis factor-α in combination is a useful diagnostic biomarker to distinguish familial Mediterranean fever from sepsis.

OBJECTIVE: To identify potential biomarkers to distinguish familial Mediterranean fever (FMF) from sepsis. METHOD: We recruited 28 patients diagnosed with typical FMF (according to the Tel Hashomer criteria), 22 patients with sepsis, and 118 age-matched controls. Serum levels of 40 cytokines were analyzed using multi-suspension cytokine array. We performed a cluster analysis of each cytokine in the FMF and sepsis groups in order to identify specific molecular networks. Multivariate classification (random forest analysis) and logistic regression analysis were used to rank the cytokines by importance and determine specific biomarkers for distinguishing FMF from sepsis. RESULTS: Fifteen of the 40 cytokines were found to be suitable for further analysis. Levels of serum granulocyte-macrophage colony-stimulating factor (GM-CSF), fibroblast growth factor 2, vascular endothelial growth factor, macrophage inflammatory protein-1b, and interleukin-17 were significantly elevated, whereas tumor necrosis factor-α (TNF-α) was significantly lower in patients with FMF compared with those with sepsis. Cytokine clustering patterns differed between the two groups. Multivariate classification followed by logistic regression analysis revealed that measurement of both GM-CSF and TNF-α could distinguish FMF from sepsis with high accuracy (cut-off values for GM-CSF = 8.3 pg/mL; TNF-α = 16.3 pg/mL; sensitivity, 92.9%; specificity, 94.4%; accuracy, 93.4%). CONCLUSION: Determination of GM-CSF and TNF-α levels in combination may represent a biomarker for the differential diagnosis of FMF from sepsis, based on measurement of multiple cytokines.

Mediterranean fever gene variants modify clinical phenotypes of idiopathic multi-centric Castleman disease.

Four cases of idiopathic multi-centric Castleman disease (iMCD) reportedly have variants in hereditary autoinflammatory disease-related genes; however, the frequency and role of these variants in iMCD is still unknown. We therefore investigated such gene variants among patients with iMCD and aimed to reveal the relationship between iMCD and autoinflammatory disease-related genes. We reviewed 14 Japanese iMCD patients who were recruited between January 2015 and September 2019. All patients met both the Japanese tentative diagnostic criteria for Castleman disease and the international consensus diagnostic criteria for iMCD. We performed genetic analyses for 31 autoinflammatory disease-related genes by targeted next-generation sequencing. The MEFV gene variants were observed in 10 of 14 patients with iMCD. Although iMCD had a high percentage of exons 2 or 3 variants of MEFV, comparison of data from healthy Japanese subjects indicated that there was no significant difference in the percentage between healthy Japanese subjects and patients with iMCD. Variants of uncertain significance (VUS) in the TNFRSF1A and CECR1 genes were observed in two of the patients, respectively. We divided patients into two groups-those with MEFV variants (excluding E148Q variants) and those without MEFV variants-and compared the clinical characteristics between these two groups. Patients with MEFV variants, excluding E148Q variants, exhibited a significantly higher likelihood of fever and significantly lower levels of hemoglobin than those lacking MEFV variants. Our results indicated that patients with iMCD tended to have a high frequency of MEFV gene variants and the presence of such variants can affect iMCD clinical phenotypes.

Inhibitory effect of HTLV-1 infection on the production of B-cell activating factors in established follicular dendritic cell-like cells.

INTRODUCTION: The low frequency of ectopic germinal center in labial salivary glands of patients with human T-cell leukemia virus type 1 (HTLV-1) antibody-positive Sjögren's syndrome (SS) suggests that HTLV-1 has some effects on follicular dendritic cells (FDCs). METHODS: We used flow cytometry, immunofluorescence, and enzyme-linked immunosorbent assays (ELISAs) to investigate the direct effect of HTLV-1 on B-cell activating factors produced by established FDC like cells obtained from excised human tonsils. We then measured the serum B-cell activating factor (BAFF) and C-X-C motif ligand (CXCL) 13 concentrations of the HTLV-1-seropositive SS patients and the HTLV-1-seronegative SS patients by ELISA. RESULTS: Among the 31 isolated specimens, 22 showed morphological characteristics of FDCs. Day 2-cultured specimens showed expressions of CD14, CD23, CD40, intracellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1. After 2 weeks, 12 of these specimens expressed ICAM-1, FDC, and fibroblast cell marker. Intracellular BAFF and CXCL13 were constitutively expressed regardless of stimulation. After direct coculture with the HTLV-1-infected T-cell line HCT-5 or MT-2, the BAFF and CXCL13 expressions on the FDC-like cells were decreased in accord with the increased number of HCT-5 and MT-2 cells with styliform change and without HTLV-1 Gag protein expression. Interferons upregulated the concentration of BAFF (but not CXCL13) in the culture supernatant, which showed a declining trend under the presence of HCT-5 or MT-2. The serum concentrations of BAFF and CXCL13 in the HTLV-1-seropositive SS patients were lower than those of the HTLV-1 seronegative SS patients. CONCLUSIONS: HTLV-1 partially inhibited the BAFF and CXCL13 expressions of established FDC-like cells.

Systemic lupus erythematosus overlapping dermatomyositis owing to a heterozygous TREX1 Asp130Asn missense mutation.

The 3' repair exonuclease 1 (TREX1) gene encodes a nuclear protein with 3' exonuclease activity, and the mutations have been associated with autoimmune diseases. Herein, we performed genetic analysis for the TREX1 gene in 55 patients with systemic lupus erythematosus (SLE). We identified one SLE patient with overlapping dermatomyositis having a heterozygous p.Asp130Asn mutation in the TREX1 gene. The patient had a high level of serum interferon (IFN)-α compared with that in healthy controls and other patients with SLE. In addition, the patient expressed elevated IFN signature genes compared with healthy controls. Our molecular dynamics simulation of the TREX1 protein in a complex with double-stranded DNA revealed that the D130N mutant causes significant changes in the active site's interaction network. One of our cases exhibited a heterozygous TREX1 p.Asp130Asn mutation that contributed to the type I IFN pathway, which may lead to the development of a severe SLE phenotype.

Idiopathic multicentric Castleman disease with novel heterozygous Ile729Met mutation in exon 10 of familial Mediterranean fever gene.

OBJECTIVE: While the aetiology of idiopathic multicentric Castleman disease (iMCD) remains unclear, the involvement of autoinflammatory mechanisms has been suggested. Herein we report a Japanese patient with iMCD with a novel heterozygous Ile729Met mutation in exon 10 of the Mediterranean fever (MEFV) gene. METHODS: We performed genetic analysis via targeted next-generation sequencing analysis and Sanger sequencing and conducted molecular dynamics simulations to investigate the hydrophobic interactions around the 729th amino acid in human pyrin. RESULTS: In February 2011, a 59-year-old man was diagnosed with IgG4-related disease at our department based on the findings of cervical and hilar lymphadenopathies, typical lung lesions and cervical lymph node biopsy. The patient was followed up without treatment, as he was asymptomatic. However, he had been experiencing prolonged fatigue and fever with high levels of CRP since June 2017. Axillary lymph node biopsy findings led to the diagnosis of iMCD. He was successfully treated with an IL-6 inhibitor and has been in remission for 12 months. Genetic analyses for hereditary autoinflammatory disease-related genes were performed, revealing a novel heterozygous Ile729Met mutation in exon 10 of the MEFV gene. We identified that this novel mutation significantly altered the local interaction of the human pyrin B30.2 domain by molecular dynamics simulation analysis and experimentally had the potential for inflammasome activation with increased inflammatory cytokines. CONCLUSION: The abnormal function of pyrin due to a mutation in the MEFV gene in this patient may have contributed to the development of MCD by inducing IL-6 production via inflammasome signalling.

The possession of exon 2 or exon 3 variants in the MEFV gene promotes inflammasome activation in Japanese patients with familial Mediterranean fever with a heterozygous exon 10 mutation.

OBJECTIVES: The modification and pathogenesis of MEFV exon 2 or 3 variants in familial Mediterranean fever (FMF) remains unclear. We compared the clinical and laboratory characteristics between the coexistence and noncoexistence of MEFV exon 2 or 3 variants in patients with FMF that had a heterozygous MEFV exon 10 mutation. METHODS: We excluded patients with FMF that had two MEFV exon 10 mutations in one or more alleles and/or MEFV mutations in exons other than in exons 2, 3, or 10. Finally, we reviewed 131 Japanese patients with FMF that had a heterozygous MEFV exon 10 mutation, and they were divided into the groups with and without MEFV exon 2 or 3 variants of 97 and 34, respectively. RESULTS: All patients with MEFV exon 2 variants had either E148Q and/or L110P variants, none of patients had exon 3 variants. In the univariate analysis, the group with variants had significantly earlier onset, a higher percentage of thoracic pain with febrile attacks, a higher frequency of attack, and a higher IL-18 level at remission compared to the group without variants (all, p<0.05). Importantly, multivariate analyses showed that the coexistence of MEFV exon 2 variants was independently and significantly associated with earlier onset of FMF and thoracic pain (both, p<0.05). CONCLUSIONS: Our results suggested that coexistence of MEFV exon 2 variants have additional effects on manifestations of FMF with MEFV exon 10 mutations. Our findings highlighted the modifications and pathogenesis of such MEFV variants in FMF.