GM-CSF Promotes the Survival of Peripheral-Derived Myeloid Cells in the Central Nervous System for Pain-Induced Relapse of Neuroinflammation.

We recently discovered a (to our knowledge) new neuroimmune interaction named the gateway reflex, in which the activation of specific neural circuits establishes immune cell gateways at specific vessel sites in organs, leading to the development of tissue-specific autoimmune diseases, including a multiple sclerosis (MS) mouse model, experimental autoimmune encephalomyelitis (EAE). We have reported that peripheral-derived myeloid cells, which are CD11b+MHC class II+ and accumulate in the fifth lumbar (L5) cord during the onset of a transfer model of EAE (tEAE), play a role in the pain-mediated relapse via the pain-gateway reflex. In this study, we investigated how these cells survive during the remission phase to cause the relapse. We show that peripheral-derived myeloid cells accumulated in the L5 cord after tEAE induction and survive more than other immune cells. These myeloid cells, which highly expressed GM-CSFRα with common ß chain molecules, grew in number and expressed more Bcl-xL after GM-CSF treatment but decreased in number by blockade of the GM-CSF pathway, which suppressed pain-mediated relapse of neuroinflammation. Therefore, GM-CSF is a survival factor for these cells. Moreover, these cells were colocalized with blood endothelial cells (BECs) around the L5 cord, and BECs expressed a high level of GM-CSF. Thus, GM-CSF from BECs may have an important role in the pain-mediated tEAE relapse caused by peripheral-derived myeloid cells in the CNS. Finally, we found that blockade of the GM-CSF pathway after pain induction suppressed EAE development. Therefore, GM-CSF suppression is a possible therapeutic approach in inflammatory CNS diseases with relapse, such as MS.

Dynamics of corticocortical brain functional connectivity relevant to therapeutic response to biologics in inflammatory arthritis.

Aberrant functional connectivity (FC) of the brain regions, evaluated by functional magnetic resonance imaging (fMRI), affects clinical courses in inflammatory arthritis (IA). The static analysis methods would be simplistic to estimate the whole picture of resting-state brain function because blood oxygen level-dependent (BOLD) signals fluctuate over time. The effects of FC dynamics on clinical course are unknown in IA. Therefore, we aimed to evaluate dynamic FC for therapeutic responsiveness to biologics in IA patients. We analyzed resting-state fMRI data of 64 IA patients in 2 cohorts. Dynamic FC was derived as a correlation coefficient of the windowed BOLD signal time series. We determined representative whole-brain dynamic FC patterns by k-means++ cluster analysis, leading to 4 distinct clusters. In the first cohort, occurrence probability of the distinct cluster was associated with favorable therapeutic response in disease activity and patients' global assessment, which was validated by the second cohort. The whole-brain FC of the distinct cluster indicated significantly increased corticocortical connectivity, and probabilistically decreased after therapy in treatment-effective patients compared with -ineffective patients. Taken together, frequent emergence of corticocortical connections was associated with clinical outcomes in IA. The coherence of corticocortical interactions might affect pain modulation, possibly relevant to therapeutic satisfaction.

Anti-ganglionic nicotinic acetylcholine receptor α3 subunit antibody as a potential biomarker associated with lupus enteritis.

OBJECTIVES: We aimed to identify the clinical significance of anti-ganglionic nicotinic acetylcholine receptor α3 subunit (gAChRα3) antibodies (Abs) in patients with systemic lupus erythematosus (SLE). METHODS: This retrospective study comprised adult patients with SLE who visited our hospital from 2006 through 2019. Anti-gAChRα3 Abs were measured in the sera of patients with SLE using a luciferase immunoprecipitation system assay. The clinical features of the patients with or without anti-gAChRα3 Abs were compared. We evaluated whether the Abs predict a specific manifestation and affect its development or relapse rate. RESULTS: Among 144 patients, anti-gAChRα3 Abs were detected in 29 patients. Lupus enteritis (LE) was more frequently seen in anti-gAChRα3 Ab-positive patients than negative patients. The levels of anti-gAChRα3 Abs were significantly higher in patients with LE than those with other lupus manifestations. Logistic regression analysis revealed the anti-gAChRα3 Abs were independent predictors for LE (odds ratio 6.2, 95% confidence interval 1.9-20.3, p = .002). Kaplan-Meier analysis showed the rate of LE development or relapse from the time of sera collection was higher in anti-gAChRα3 Ab-positive patients than in negative patients (p < .001). CONCLUSION: Anti-gAChRα3 Abs could be a predictive biomarker for the development or relapse of LE.

Glycogen synthase kinase 3ß/CCR6-positive bone marrow cells correlate with disease activity in multicentric Castleman disease-TAFRO.

Multicentric Castleman disease-thrombocytopenia, anasarca, reticulin fibrosis of bone marrow, renal dysfunction and organomegaly (MCD-TAFRO)-is an emergent phenotype characterized by lymphoproliferation, fluid collection, hemocytopenia and multiple organopathy. Although studies have demonstrated an aberrant blood cytokine/chemokine profile referred to as "chemokine storm", the pathogenesis remains unclear. We aimed to identify pathogenic key molecules, potential diagnostic targets and therapeutic markers in MCD-TAFRO using serum cytokine/chemokine profiles. We performed the targeted cytokine/chemokine multiplex analysis in six cases of MCD-TAFRO with remission or non-remission status. We observed significant changes in serum concentrations of CCL2, CCL5, and Chitinase-3-like-1 in the MCD-TAFRO patients with active state compared to inactive state. Ingenuity pathway analysis revealed that glycogen synthase kinase 3 (GSK3) and CCR6, which is expressed in megakaryocytes, were detected as upstream positive regulators for activating MCD-TAFRO status. More GSK3ß+ CCR6+ cells like megakaryocytes were detected in the bone marrow of patients with MCD-TAFRO than in those with systemic lupus erythematosus, MCD-not otherwise specified or autoimmune haemophagocytic lymphohistiocytosis. The cellularity of GSK3ß+ CCR6+ cells was correlated with disease activity, including thrombocytopenia and anaemia. In conclusion, GSK3ß and CCR6 of bone marrow cells were potentially involved in the pathogenesis of MCD-TAFRO and may act as diagnostic targets and therapeutic markers.

Pathogenic neuropsychiatric effect of stress-induced microglial interleukin 12/23 axis in systemic lupus erythematosus.

OBJECTIVES: The central nervous system disorder in systemic lupus erythematosus (SLE), called neuropsychiatric lupus (NPSLE), is one of the most severe phenotypes with various clinical symptoms, including mood disorder, psychosis and delirium as diffuse neuropsychological manifestations (dNPSLE). Although stress is one of the aggravating factors for neuropsychiatric symptoms, its role in the pathogenesis of dNPSLE remains to be elucidated. We aimed to investigate stress effects on the neuropsychiatric pathophysiology in SLE using lupus-prone mice and patients' data. METHODS: Sleep disturbance stress (SDS) for 2 weeks was placed on 6-8-week-old female MRL/lpr and control mice. Behavioural phenotyping, histopathological analyses and gene and protein expression analyses were performed to assess SDS-induced neuroimmunological alterations. We also evaluated cytokines of the cerebrospinal fluid and brain regional volumes in patients with dNPSLE and patients with non-dNPSLE. RESULTS: SDS-subjected MRL/lpr mice exhibited less anxiety-like behaviour, whereas stressed control mice showed increased anxiety. Furthermore, stress strongly activated the medial prefrontal cortex (mPFC) in SDS-subjected MRL/lpr. A transcriptome analysis of the PFC revealed the upregulation of microglial activation-related genes, including Il12b. We confirmed that stress-induced microglial activation and the upregulation of interleukin (IL) 12/23p40 proteins and increased dendritic spines in the mPFC of stressed MRL/lpr mice. IL-12/23p40 neutralisation and tyrosine kinase 2 inhibition mitigated the stress-induced neuropsychiatric phenotypes of MRL/lpr mice. We also found a higher level of cerebrospinal fluid IL-12/23p40 and more atrophy in the mPFC of patients with dNPSLE than those with non-dNPSLE. CONCLUSIONS: The microglial IL-12/23 axis in the mPFC might be associated with the pathogenesis and a promising therapeutic target for dNPSLE.

Prediction of the intolerance or non-responder to Janus kinase inhibitors in patients with rheumatoid arthritis: a preliminary retrospective study with integrative cluster analysis.

OBJECTIVES: To identify the subpopulation of rheumatoid arthritis (RA) non-responders to Janus kinase inhibitors (JAKis) using cluster analysis. METHODS: This retrospective study enrolled RA patients who had been treated with JAKis (tofacitinib or baricitinib) between July 2013 and September 2019 in six centres. The endpoint was set as inadequate response to JAKis (JAKis-IR), defined as either non-response to JAKis or their intolerance. Non-response to JAKis was defined as achieving neither American College of Rheumatology 20% response nor Disease Activity Score (ΔDAS28-CRP) >1.2 at 12 weeks. Withdrawal time point included earlier than after 12 weeks from baseline. A hierarchical cluster analysis was performed with variables related with clinical and serological parameters at baseline. RESULTS: The 132 RA patients enrolled were classified into four groups (Group A-D). Groups consisted of three components defined at baseline, as seropositivity, advanced joint destruction, interstitial lung disease presumably associated with RA (RA-ILD). Group A (n=32): seronegative, presence of advanced joint destruction, absence of RA-ILD. Group B (n=35): seropositive, absence of advanced joint destruction and RA-ILD. Group C (n=20): seropositive, absence of advanced joint destruction, presence of RA-ILD. Group D (n=45): seropositive, presence of advanced joint destruction and RA-ILD. The rate of JAKis-IR in four groups was as follows: A, 34.3%; B, 17.1%; C, 20.0%; and D, 8.9%. The difference in JAKis-IR rate between group A and D was statistically significant. CONCLUSIONS: A subpopulation of RA patients with a combination of the following three components, seronegativity, advanced joint destruction and absence of RA-ILD, was identified as being prone to JAKis-IR.

Dramatic improvement with colchicine in antihistamine- and omalizumab-resistant chronic spontaneous urticaria.

Chronic spontaneous urticaria (CSU) is defined as the presence of recurrent urticaria, angioedema or both without any specific triggers, which persists for ≥ 6 weeks. Refractory cases to standard therapeutic regimens including antihistamines, immunosuppressants and biologics have been reported. Therefore, it is crucial to evolve novel therapeutic strategies through accumulating refractory CSU cases, which are successfully treated. We here report a refractory case of CSU to antihistamines and omalizumab, which was dramatically improved with colchicine.

Right ventricular dimension index by cardiac magnetic resonance for prognostication in connective tissue diseases and pulmonary hypertension.

OBJECTIVES: Pulmonary hypertension (PH) in patients with CTD is a heterogeneous condition affected by left heart disease, chronic lung disease and thromboembolism as well as pulmonary vascular disease. Recent studies using cardiac magnetic resonance (CMR) have shown that right ventricular dysfunction is predictive for mortality in patients with PH, but limited to pulmonary arterial hypertension. This study aimed to analyse prognostic factors in PH-CTD. METHODS: This retrospective analysis comprised 84 CTD patients, including SSc, who underwent both CMR and right heart catheterization from 2008 to 2018. Demographics, laboratory findings, and haemodynamic and morphological parameters were extracted. The prognostic value of each parameter was evaluated by multivariate analysis using covariables derived from propensity score to control confounding factors. RESULTS: Of 84 patients, 65 had right heart catheterization-confirmed PH (54 pulmonary arterial hypertension, 11 non-pulmonary arterial hypertension). Nine out of these PH patients died during a median follow-up period of 25 months. In 65 patients with PH, right ventricular end-diastolic dimension index (RVEDDI) evaluated by CMR was independently associated with mortality (hazard ratio 1.24; 95% CI: 1.08-1.46; P = 0.003). In a receiver operating characteristic analysis, RVEDDI highly predicted mortality, with area under the curve of 0.87. The 0.5-2-year follow-up data revealed that RVEDDI in both survivors and non-survivors did not significantly change over the clinical course, leading to the possibility that an early determination of RVEDDI could predict the prognosis. CONCLUSION: RVEDDI simply evaluated by CMR could serve as a significant predictor of mortality in PH-CTD. A further validation cohort study is needed to confirm its usability.

Potential therapeutics for antiphospholipid antibody associated thrombocytopenia: A systematic review and meta-analysis.

Objectives: Thrombocytopenia is frequently observed in antiphospholipid antibody (aPL) carriers. Due to the paradoxical risks of thrombosis and hemorrhage, the management of aPL-associated thrombocytopenia (APAT) is often deductive. We aimed to investigate the efficacy and safety of therapeutic approaches for APAT through a systematic review.Methods: Four therapeutic approaches for APAT, including antiplatelet agents, glucocorticoids, splenectomy and thrombopoietin receptor agonists, were selected. Clinical trials evaluating therapeutic outcomes including the remission, complications, mortality and relapse, were searched in MEDLINE, EMBASE and CENTRAL from the inception dates to 28 November 2016. A meta-analysis was performed to calculate risk ratios (RRs) and 95% confidence intervals (CIs) using random-effects models.Results: Out of 1407 papers, eight controlled clinical trials were included. In patients with APAT, the remission rates were higher in patients on glucocorticoids (RR 8.33 [95% CI 3.07-22.6]) or splenectomy (RR 8.37 [95% CI 1.61-43.7]) than in patients without those treatments. There was no significant association between glucocorticoids and thrombosis (RR 1.57 [95% CI, 0.17-14.9]) or between splenectomy and hemorrhage (RR 0.17 [95% CI 0.02-1.28]). The extracted data of mortality and relapse rate were not available for synthesis.Conclusion: Glucocorticoids or splenectomy seemed suitable therapeutic approaches for APAT.

Reduced diffusing capacity for carbon monoxide predicts borderline pulmonary arterial pressure in patients with systemic sclerosis.

Early intervention in pulmonary arterial hypertension associated with systemic sclerosis (SSc) may improve its prognosis. We aimed to establish an algorithm to detect mean pulmonary artery pressure (mPAP) > 20 mmHg using non-invasive examinations in SSc patients by modifying the DETECT algorithm. This study included SSc patients who underwent right heart catheterization (RHC) in our hospital during 2010-2018. Following variables were assessed for performance to predict mPAP ≥ 25 mmHg or > 20 mmHg; anti-centromere or U1-RNP antibody, plasma BNP level, serum urate level, right axis deviation, forced vital capacity (FVC)/diffusing capacity for carbon monoxide (DLCO) ratio, and tricuspid regurgitation velocity. Of 58 patients enrolled in this study, 24 had mPAP of ≥ 25 mmHg and 9 had mPAP of 21-24 mmHg. Among variables tested, only FVC/DLCO elevated similarly in patients with mPAP of ≥ 25 mmHg (median 2.5) and those with mPAP of 21-24 mmHg (median 2.5) compared to those with mPAP of ≤ 20 mmHg (median 1.5). Given the particularly good correlation between DLCO and mPAP of > 20 mmHg, each variable was weighted according to its odds ratio and the total weighted score was calculated. The total weighted score exhibited a good predictive performance for mPAP of > 20 mmHg with its sensitivity of 87.5% and specificity of 92%. Among conventional risk factors for PAH, decreased DLCO may predict mPAP > 20 mmHg with priority in SSc patients. Weighting DLCO may improve the performance of screening algorithm for early SSc-PAH.

Inhibitor of NF-κB Kinase Subunit ε Contributes to Neuropsychiatric Manifestations in Lupus-Prone Mice Through Microglial Activation.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by multiorgan dysfunction. Neuropsychiatric SLE (NPSLE) occurs in 30-40% of lupus patients and is the most severe presentation of SLE, frequently resulting in limitation of daily life. Recent studies have shown that microglia, tissue-resident macrophages in the central nervous system, are involved in the pathogenesis of NPSLE. This study was undertaken to explore new therapeutic targets for NPSLE focusing on microglia. METHODS: RNA sequencing of microglia in MRL/lpr, lupus-prone mice, as well as that of microglia cultured in vitro with cytokines were performed. A candidate gene, which could be a therapeutic target for NPSLE, was identified, and its role in microglial activation and phagocytosis was investigated using specific inhibitors and small interfering RNA. The effect of intracerebroventricular administration of the inhibitor on the behavioral abnormalities of MRL/lpr was also evaluated. RESULTS: Transcriptome analysis revealed the up-regulation of Ikbke, which encodes the inhibitor of NF-κB kinase subunit ɛ (IKBKε) in both microglia from MRL/lpr mice and cytokine-stimulated microglia in vitro. Intracerebroventricular administration of an IKBKε inhibitor ameliorated cognitive function and suppressed microglial activation in MRL/lpr mice. Mechanistically, IKBKε inhibition reduced glycolysis, which dampened microglial activation and phagocytosis. CONCLUSION: These findings suggest that IKBKε plays a vital role in the pathogenesis of NPSLE via microglial activation, and it could serve as a therapeutic target for NPSLE.

Regulation of NETosis and Inflammation by Cyclophilin D in Myeloperoxidase-Positive Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

OBJECTIVE: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is pathologically characterized by focal fibrinoid necrosis, in which ANCA-mediated neutrophil extracellular trap (NET) formation and subsequent endothelial cell necrosis occur. Cyclophilin D (CypD) plays an important role in mediation of cell necrosis and inflammation via the opening of mitochondrial permeability transition pores. This study was undertaken to examine the role of CypD in AAV pathogenesis. METHODS: We assessed the role and mechanism of CypD in ANCA-stimulated neutrophils in vitro by immunostaining and electron microscopy observation. We performed a comprehensive RNA-sequencing analysis on ANCA-treated murine neutrophils. To investigate the role of CypD in vivo, we assessed disease features in CypD-knockout mice and wild-type mice using 2 different murine AAV models: anti-myeloperoxidase IgG transfer-induced AAV and spontaneous AAV. RESULTS: In vitro experiments showed that pharmacologic and genetic inhibition of CypD suppressed ANCA-induced NET formation via the suppression of reactive oxygen species and cytochrome c release from the mitochondria. RNA-sequencing analyses in ANCA-treated murine neutrophils revealed the involvement of inflammatory responses, with CypD deficiency reducing ANCA-induced alterations in gene expression. Furthermore, analyses of upstream regulators revealed the relevance of intracellular calcium (CypD activator) and cyclosporin (CypD inhibitor) in ANCA stimulation, indicating that the CypD-dependent opening of mitochondrial permeability transition pores is associated with ANCA-induced neutrophil activation and NETosis. In both AAV mouse models, the genetic deletion of CypD ameliorated crescentic glomerulonephritis via the inhibition of CypD-dependent neutrophil and endothelial necrosis. CONCLUSION: CypD targeting is a novel and specific therapeutic strategy for AAV via the resolution of necrotizing vasculitis.