Absence of Glucocorticoids Concomitant With Avacopan and Subsequent Liver Injury in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

Avacopan, a C5a receptor (C5aR) inhibitor, has emerged as a novel treatment for antineutrophil cytoplasmic antibody-associated vasculitis (AAV), providing an alternative to glucocorticoids (GCs).1 Despite its promising potential, severe liver dysfunction associated with avacopan has been reported in Japan.2,3.

Influences of advanced age in rheumatoid arthritis: A multicentre ultrasonography cohort study.

OBJECTIVES: We aimed to evaluate the effects of age on clinical characteristics and outcomes in biologic or targeted synthetic disease-modifying antirheumatic drug (b/tsDMARD)-naïve patients with rheumatoid arthritis (RA). METHODS: We analysed the cases of 234 Japanese b/tsDMARD-naïve RA patients who underwent b/tsDMARD treatment in a multicentre ultrasound prospective observational cohort. We compared the clinical characteristics at baseline and outcomes at 12 months between those aged ≥60 years and those <60 years. RESULTS: Compared to the <60-year-old group (n = 78), the ≥60-year-old group (n = 156) had higher inflammatory marker values and ultrasound combined scores, especially wrist joints, at baseline. Age at baseline positively correlated significantly with the ultrasound scores at baseline; however, age was not a significant variable by the multiple regression analysis. The patients treated with different MOAs in the ≥60-year-old group had comparable outcomes and multiple regression analysis revealed that mechanism of action (MOA) was not a significant contributor to the Clinical Disease Activity Index at 12 months. CONCLUSIONS: RA patients with advanced age demonstrated distinctive clinical characteristics. The MOAs were not associated with clinical outcomes and ultrasound outcomes in RA patients with advanced age.

The impact of glucocorticoid use on the outcomes of rheumatoid arthritis in a multicenter ultrasound cohort study.

OBJECTIVE: Glucocorticoids are effective in treating rheumatoid arthritis (RA) when used appropriately considering the balance of the risks and benefits, especially at low doses. We aimed to evaluate the response of biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in patients having already been treated with glucocorticoids. METHODS: We reviewed RA patients treated with b/tsDMARDs in a prospective multicenter ultrasound cohort study. We compared the differences in the clinical characteristics at baseline and outcomes at 12 months between the two groups having been treated with and without glucocorticoids at baseline. The differences in the clinical characteristics and the treatments were balanced by the inverse probability weighting (IPW) with the propensity score. RESULTS: Of 307 patients with RA, 160 patients were treated with glucocorticoids at baseline. The median dose of glucocorticoids was equivalent to 5.0 mg/day of prednisolone. Significant differences were in age and concomitant methotrexate use, composite measures for the disease activity, and the ultrasound grayscale score at baseline. Patients treated with glucocorticoids had less frequent remissions defined by composite measures and ultrasound findings than those treated without glucocorticoids. These significant differences in the achievement of remissions remained robust even after adjusting differences in the clinical characteristics and the treatments between the two groups by IPW. CONCLUSION: RA patients treated with glucocorticoids had a higher disease activity at baseline and a poorer response to treatments with b/tsDMARDs than those without glucocorticoids. The states of patients requiring glucocorticoids might be associated with the poor response to the b/tsDMARDs.

Improved Hearing Impairment of Granulomatosis with Polyangiitis Treated with Rituximab and Avacopan without Glucocorticoids.

A 78-year-old woman with a history of intractable otitis media presented with a fever, hearing impairment, thigh pain, and a skin rash. She had renal dysfunction, positive myeloperoxidase-antineutrophil cytoplasmic autoantibody, otitis media, and multiple nodules in both lungs. She was diagnosed with granulomatosis with polyangiitis, crescentic glomerulonephritis, and interstitial nephritis, which was confirmed in a kidney biopsy specimen. Induction therapy with rituximab and avacopan without glucocorticoids promptly resolved her fever and thigh pain and improved her auditory acuity and nodule in the right lung. The patient experienced no adverse effects with rituximab or avacopan.

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.

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.

Association between anti-thyroid peroxidase antibody and thyroid stimulating hormone: a cross-sectional study.

To maintain normal level of thyroid hormone, especially for free thyroxine (FT4), individuals with latent thyroid gland damage might have required higher thyroid stimulating hormone (TSH) than those without latent thyroid gland damage. Anti-thyroid peroxidase antibody (TPO-Ab) is a main cause of auto-immune thyroiditis, and therefore euthyroid individuals positive for TPO-Ab might have latent damage to the thyroid gland. Therefore, the association between TSH values and TPO-Ab positivity may be useful to determine the influence of latent thyroid gland damage on requirement of TSH. Furthermore, because latent damage of thyroid might elevate TSH level but not FT4 level, those associations should be observed independent from FT4. This cross-sectional study analyzed 1431 Japanese with normal ranges of free triiodothyronine (FT3) and FT4. Since TPO-Ab is associated with atherosclerosis in euthyroid individuals, cardiovascular risk factors might underlie the association between TPO-Ab and TSH values. After adjusting for FT4 and known cardiovascular risk factors, the adjusted odds ratio (95% confidence interval) of TPO-Ab positivity for logarithmic value of TSH was 1.53 (1.20, 1.95). Essentially the same association was observed when the analysis was restricted to individuals without subclinical hypothyroidism (1.54 [1.15, 2.13]). Euthyroid individuals with latent thyroid gland damage might have increased the requirement of TSH.

Inhibition of protein arginine deiminase 4 prevents inflammation-mediated heart failure in arthritis.

Rheumatoid arthritis is a prototypic inflammatory condition with affected patients being at greater risk of incident heart failure (HF). Targeting innate immune cell function in the pathogenesis of HF bears the potential to guide the development of future therapies. A collagen-induced arthritis (CIA) model in DBA/1 J mice was used to generate arthritis. Mice with CIA developed concentric hypertrophic myocardial remodeling, left ventricular (LV) diastolic dysfunction, and HF with elevated plasma B-type natriuretic peptide levels but preserved LV ejection fraction. Key features of HF in CIA were increased infiltration of activated neutrophils, deposition of neutrophil extracellular traps in the myocardium, and increased tissue levels of the proinflammatory cytokine IL-1ß. Specific inhibition of protein arginine deiminase 4 (PAD4) by an orally available inhibitor (JBI-589), administered after the onset of clinical arthritis, prevented HF with reduced neutrophil infiltration. We identify PAD4-mediated neutrophil activation and recruitment as the key thromboinflammatory pathway driving HF development in arthritis. Targeting PAD4 may be a viable therapeutic approach for the prevention of HF secondary to chronic inflammation.

Comparison of risks of cancer, infection, and MACEs associated with JAK inhibitor and TNF inhibitor treatment: a multicentre cohort study.

OBJECTIVES: The objective of this study was to compare the incidence rates (IRs) of infectious diseases, major adverse cardiovascular events (MACEs), and malignancies in RA patients treated with tofacitinib, baricitinib or a TNF inhibitor. METHODS: We retrospectively analysed the cases of 499 RA patients treated with tofacitinib (n = 192), baricitinib (n = 104), or a TNF inhibitor (n = 203). We determined the IRs of infectious diseases and the standardized incidence ratio (SIR) of malignancies and investigated factors related to infectious diseases. After adjusting the clinical characteristic imbalance by propensity score weighting, we compared the incidence of adverse events between the Janus kinase (JAK)-inhibitor and TNF-inhibitor groups. RESULTS: The observational period was 959.7 patient-years (PY), and the median observational period was 1.3 years. The IRs within the JAK-inhibitor treatment group were: serious infectious diseases other than herpes zoster (HZ), 8.36/100 PY; HZ, 13.00/100 PY. Multivariable Cox regression analyses revealed independent risk factors: the glucocorticoid dose in serious infectious diseases other than HZ, and older age in HZ. Two MACEs and 11 malignancies were identified in JAK-inhibitor-treated patients. The overall malignancy SIR was (non-significantly) higher than that of the general population (1.61/100 PY, 95% CI: 0.80, 2.88). The IR of HZ in the JAK-inhibitor-treated group was significantly higher than the TNF-inhibitor-treated group, but there were no significant differences in the IRs of other adverse events between the JAK-inhibitor-treated group and the TNF-inhibitor-treated group, or between the treatment groups of the two JAK inhibitors. CONCLUSIONS: The infectious disease IR in RA was comparable between tofacitinib and baricitinib, but the IR for HZ in these treatment groups was high compared with that in the TNF inhibitor treatment group. The malignancy rate in the JAK-inhibitor-treated group was high but not significantly different from that of the general population or that of the TNF-inhibitor-treated group.

Alleviation of arthritis through prevention of neutrophil extracellular traps by an orally available inhibitor of protein arginine deiminase 4.

Protein arginine deiminases (PAD) 4 is an enzyme that catalyzes citrullination of protein and its role in autoimmune diseases has been established through clinical genetics and gene knock out studies in mice. Further, studies with PAD4 - deficient mice have shown that PAD4 deficiency does not lead to increased infection or immune suppression, which makes PAD4 an attractive therapeutic target for auto-immune and inflammatory diseases. PAD4 has critical enzymatic role of promoting chromatin decondensation and neutrophil extracellular traps (NETs) formation that is associated with a number of immune-mediated pathological conditions. Here, we present a non-covalent PAD4 inhibitor JBI-589 with high PAD4 isoform selectivity and delineated its binding mode at 2.88 Å resolution by X-ray crystallography. We confirmed its effectiveness in inhibiting NET formation in vitro. Additionally, by using two mouse arthritis models for human rheumatoid arthritis (RA), the well-known disease associated with PAD4 clinically, we established its efficacy in vivo. These results suggest that JBI-589 would be beneficial for both PAD4 and NET-associated pathological conditions.

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.

Prediction of radiographic progression during a treat-to-target strategy by the sequential application of MRI-proven bone marrow oedema and power-Doppler grade ≥2 articular synovitis in rheumatoid arthritis: Retrospective observational study.

OBJECTIVES: To investigate the appropriate timing, useful findings and combination of magnetic resonance imaging (MRI) and ultrasound (US) for predicting the radiographic progression in early rheumatoid arthritis (RA). METHODS: Forty-four active RA patients, who examined by both of MRI and US in the symptomatic wrist and finger joints, were recruited in Nagasaki University Hospital from 2010 to 2017 and treated by the treat-to-target therapeutic strategy for 1 year. MRI was evaluated by RA MRI scoring and US by Outcomes Measures in Rheumatology Clinical Trial, respectively. Plain radiographs were assessed by the Genant-modified Sharp score for the symptomatic side in the same manner as MRI and US. Radiographic progression was defined as an annual increase ≥0.75 at 1 year. Factors associated with radiographic progression were analysed. Also, the optimal combination of MRI and US at each timepoint was considered. RESULTS: Logistic regression model revealed that MRI-proven bone marrow oedema at baseline and 6 months and joint counts of power-Doppler grade ≥2 articular synovitis at 3 or 6 months were significantly associated with radiographic progression at 1 year. CONCLUSION: This study may suggest the favourable timing and combination of MRI and US at each point to predict radiographic progression in patients with early-stage RA.

NLRP3 inflammasome activation in neutrophils directs early inflammatory response in murine peritonitis.

NLR family pyrin domain containing 3 (NLRP3) inflammasome mediates caspase-1-dependent processing of inflammatory cytokines such as IL-1ß, an essential endothelial activator, and contributes to the pathology of inflammatory diseases. To evaluate the role of NLRP3 in neutrophils in endothelial activation, which is still elusive, we used the thioglycollate-induced peritonitis model characterized by an early neutrophil influx, on Nlrp3-/- and Nlrp3+/+ mice. Nlrp3-/- mice recruited fewer neutrophils than Nlrp3+/+ into the peritoneum and showed lower IL-1ß in peritoneal lavage fluid. The higher production of IL-1ß in Nlrp3+/+ was neutrophil-dependent as neutrophil depletion prevented the IL-1ß production. The Nlrp3+/+ neutrophils collected from the peritoneal fluid formed significantly more filaments (specks) than Nlrp3-/- neutrophils of ASC (apoptosis-associated speck-like protein containing a caspase activating and recruitment domain), a readout for inflammasome activation. Intravital microscopy revealed that leukocytes rolled significantly slower in Nlrp3+/+ venules than in Nlrp3-/-. Nlrp3-/- endothelial cells isolated from mesenteric vessels demonstrated a lower percentage of P-selectin-positive cells with lower intensity of surface P-selectin expression than the Nlrp3+/+ endothelial cells evaluated by flow cytometry. We conclude that neutrophils orchestrate acute thioglycollate-induced peritonitis by producing IL-1ß in an NLRP3-dependent manner. This increases endothelial P-selectin expression and leukocyte transmigration.

Anti-inflammatory protective effect of ADAMTS-13 in murine arthritis models.

BACKGROUND: Patients with rheumatoid arthritis (RA) have frequent thrombotic events with endothelial dysfunction. Von Willebrand factor (VWF) has been shown to bind neutrophil extracellular traps (NETs) and NETs are part of RA etiology. OBJECTIVES: This study aims to elucidate whether this prothrombotic status exacerbates inflammation in arthritis. Here we focus on the involvement of A Disintegrin And Metalloprotease with ThromboSpondin type 1 motif, member 13 (ADAMTS-13), an enzyme cleaving VWF and its effect on NET deposition and RA development. METHODS: We evaluated the influence of the Adamts13 gene and recombinant human ADAMTS-13 (rhADAMTS-13) on arthritis in the mouse models of collagen-induced arthritis (CIA). We also assessed VWF and NETs in synovial tissue. RESULTS: Several Adamts13-/- mice developed arthritis, while Adamts13+/+ siblings did not. Synovial tissue from Adamts13-/- showed accumulation of NETs. Treatment of DBA/1 J mice, an arthritis-susceptible strain, with well-tolerated doses of rhADAMT13 reduced arthritis incidence and alleviated the severity of arthritis. Mice treated with rhADAMT13 presented less serum interleukin 6 and less bone erosion determined by micro-computed tomography. The effects on arthritis severity were observed both when administering rhADAMTS-13 prophylactically and also when given after arthritis has developed. In both conditions, rhADAMTS-13 reduced VWF and NET deposition on proliferated synovial tissue evaluated by immunoblotting. CONCLUSIONS: Our results demonstrate the inhibitory role of Adamts13 in murine arthritis and the effectiveness of rhADAMTS-13 treatment. Additionally, this study suggests that deposition of VWF in the synovium and subsequent pathogenic NET retention promotes arthritis. Treatment with rhADAMTS-13 provides a potential therapeutic approach targeting inflammation and pro-thrombotic state in arthritis.

Corrigendum: The Contribution of Serum Complement Component 3 Levels to 90-Day Mortality in Living Donor Liver Transplantation.

[This corrects the article DOI: 10.3389/fimmu.2021.652677.].

Clinical Characteristics of Patients With IgG4-Related Disease Complicated by Hypocomplementemia.

Background: A proportion of patients with immunogloblin G (IgG) 4-related disease (IgG4-RD) have hypocomplementemia. We aimed to identify characteristics of such patients. Methods: We analyzed the demographic and clinical data and complement levels of 85 patients with IgG4-RD. We defined hypocomplementemia as serum C3 and/or C4 levels below the lower limit of normal at diagnosis. We also compared the characteristics of patients with and without IgG4-RD. Results: Thirty-two (38%) patients had hypocomplementemia at diagnosis. Patients with hypocomplementemia had more lymph node (p < 0.01), lung (p < 0.01), and kidney (p = 0.02) involvement and a higher IgG4-RD responder index than those without (p = 0.05). Additionally, patients with hypocomplementemia had significantly higher IgG (p < 0.01), IgG4 (p < 0.01), and soluble interleukin 2-receptor (sIL-2R) (p < 0.01) levels and total IgG minus IgG4 (p < 0.01). C3 and C4 levels negatively correlated with IgG, IgG4, and sIL-2R levels, total IgG minus IgG4, and number of IgG4-RD responder index: a measure of the disease activity in IgG4-RD. Patients with hypocomplementemia at diagnosis had a significantly higher frequency of relapse (p = 0.024), as determined using the log-rank test. A multivariate logistic regression analysis showed the presence of hypocomplementemia was independently associated with relapse (OR, 6.842; 95% confidence interval [95%CI], 1.684-27.79; p = 0.007). Conclusions: Patients with IgG4-RD with hypocomplementemia have a more active clinical phenotype, suggesting contributions of the complement system in the pathophysiology of IgG4-RD.

The Prominent Role of Hematopoietic Peptidyl Arginine Deiminase 4 in Arthritis: Collagen- and Granulocyte Colony-Stimulating Factor-Induced Arthritis Model in C57BL/6 Mice.

OBJECTIVE: Genome-wide association studies have connected PADI4, encoding peptidylarginine deiminase 4 (PAD4), with rheumatoid arthritis (RA). PAD4 promotes neutrophil extracellular trap (NET) formation. This study was undertaken to investigate the origin of PAD4 and the importance of NET formation in a C57BL/6 mouse model of arthritis. METHODS: To permit the effective use of C57BL/6 mice in the collagen-induced arthritis (CIA) model, we introduced the administration of granulocyte colony-stimulating factor (G-CSF) for 4 consecutive days in conjunction with the booster immunization on day 21. Mice with global Padi4 deficiency (Padi4-/- ) and mice with hematopoietic lineage-specific Padi4 deficiency (Padi4Vav1Cre/+ ) were evaluated in the model. RESULTS: G-CSF significantly increased the incidence and severity of CIA. G-CSF-treated mice showed elevated citrullinated histone H3 (Cit-H3) levels in plasma, while vehicle-treated mice did not. Immunofluorescence microscopy revealed deposition of Cit-H3 in synovial tissue in G-CSF-treated mice. Padi4-/- mice developed less severe arthritis and had lower levels of serum interleukin-6 and plasma Cit-H3, lower levels of Cit-H4 in synovial tissue, and less bone erosion on micro-computed tomography than Padi4+/+ mice in the G-CSF-modified CIA model. Similarly, Padi4Vav1Cre/+ mice developed less severe arthritis, compared with Padi4fl/fl mice, and presented the same phenotype as Padi4-/- mice. CONCLUSION: We succeeded in developing an arthritis model suitable for use in C57BL/6 mice that is fully compliant with high animal welfare standards. We observed a >90% incidence of arthritis in male mice and detectable NET markers. This model, with some features consistent with human RA, demonstrates that hematopoietic PAD4 is an important contributor to arthritis development and may prove useful in future RA research.