Risk factors for serious infections and infection-related mortality in patients with microscopic polyangiitis: Multicentre REVEAL cohort study.

OBJECTIVE: Infections are a critical concern for patients with microscopic polyangiitis (MPA). This study aimed to identify the risk factors associated with serious infections (SIs) and infection-related mortality in patients with MPA, as well as the effect of glucocorticoid (GC) dose tapering on these outcomes. METHODS: This multicentre, retrospective, and observational study utilised data from a cohort of patients with MPA in Japan [Registry of Vasculitis Patients to Establish REAL World Evidence (REVEAL) cohort]. Patients were categorised based on the occurrence of SIs or infection-related deaths, and various characteristics were compared among the groups. RESULTS: Among 182 patients, 66 (36.2%) experienced 129 SIs and 27 (14.8%) developed infection-related deaths. Advanced age, elevated C-reactive protein (CRP) levels, and higher ratio of the GC dose at 3 months to the initial dose were identified as independent risk factors for SIs. Older age was also associated with infection-related deaths. Furthermore, the cumulative incidence of infection-related deaths was significantly higher in patients with a higher ratio of the GC dose at 24 months to the initial dose. CONCLUSION: Older age, elevated CRP levels, and slower GC dose tapering predispose patients to SIs and infection-related deaths. Strategies, such as rapid GC dose tapering, are anticipated to mitigate the risk of infections.

Factors associated with drug retention of mepolizumab in patients with eosinophilic granulomatosis with polyangiitis: A multicentre REVEAL cohort study.

OBJECTIVES: To determine the current retention rate of mepolizumab (MPZ) and identify factors associated with drug retention in patients with eosinophilic granulomatosis with polyangiitis (EGPA) in the Kansai multicentre cohort (REVEAL cohort). METHODS: Sixty patients diagnosed with EGPA and treated with MPZ between December 2016 and June 2023 were enrolled. The clinical characteristics, including laboratory data, treatments administered, and disease course outcomes were collected retrospectively. The patients were stratified into MPZ continuation (n=53) and discontinuation (n=7) groups, and drug retention was statistically compared using the log-rank test. RESULTS: The median age of patients was 54.5 years, with 55% females, and 33% antineutrophil cytoplasmic antibody-positive at disease onset. MPZ exhibited a retention rate of 78.7% after five years. The reasons for discontinuation included treatment of coexisting diseases, inadequate response, and remission. Patient characteristics at disease onset were comparable between the groups. Patients receiving immunosuppressants (IS) before MPZ introduction demonstrated significantly higher retention rates (P = 0.038). During the final observation, the MPZ continuation group had a lower vasculitis damage index score (P = 0.027). CONCLUSIONS: MPZ exhibited a high 5-year retention rate, particularly in patients requiring IS. This study implies that long-term use of MPZ may mitigate irreversible organ damage.

Examination of nailfold videocapillaroscopy findings in ANCA-associated vasculitis.

OBJECTIVE: The objective of this study was to evaluate nailfold videocapillaroscopy (NVC) as a useful tool for assessing the disease activity of ANCA-associated vasculitis (AAV). METHODS: This study enrolled 51 patients with AAV and 21 healthy controls. We scored NVC findings semiquantitatively, and compared them between AAV patients and controls. We examined the association of NVC findings with disease activity indicators, histopathological findings of skin biopsies, and high-resolution CT (HRCT) scores in AAV. Additionally, we repeatedly rated the NVC findings 3 months after immunosuppressive therapy. RESULTS: Of the 51 enrolled patients, 36 (70.6%) showed a microangiopathy pattern and 4 (7.8%) showed a scleroderma pattern in AAV. The scores for microhaemorrhage, capillary loss, neoangiogenesis, and tortuosity were significantly higher in the AAV group than in the control group. NVC abnormalities correlated with the severity of skin, lung and kidney involvement. The scores of giant capillaries significantly correlated with the total BVAS and the chest BVAS; the scores of capillary loss correlated with the chest BVAS and the renal BVAS. The scores of microhaemorrhage significantly correlated with perivascular inflammatory cell infiltrations in the upper dermis of the purpura and tended to correlate with the total ground-glass opacity and consolidation scores on HRCT. In addition, capillary loss scores had a significant positive correlation with serum creatinine levels. Additionally, the microhaemorrhage scores were significantly reduced after 3 months of immunosuppressive therapy. CONCLUSION: In AAV patients, NVC abnormalities are significantly associated with disease severity. This result suggests that NVC is a useful tool for assessing the disease activity and treatment response in AAV.

Prediction model for respiratory-related mortality in microscopic polyangiitis with interstitial lung disease: multicenter REVEAL cohort study.

OBJECTIVE: This study aimed to establish prediction models for respiratory-related mortality in microscopic polyangiitis (MPA) complicated by interstitial lung disease (ILD) using clinical characteristics. METHODS: We enrolled patients with MPA with ILD between May 2005 and June 2021 in a multicentre cohort of Japanese patients with MPA (REVEAL cohort). We evaluated the demographic, clinical, laboratory, radiological findings, treatments, and the presence of honeycombing 1 cm above the diaphragm using chest high-resolution computed tomography (HRCT) on admission. We explored the risk factors predictive of respiratory-related mortality. RESULTS: Of 115 patients, 26 cases died of respiratory-related diseases during a median follow-up of 3.8 years. Eighteen patients (69%) died due to respiratory infection, three (12%) had diffuse alveolar hemorrhage (DAH), and five (19%) had exacerbation of ILD. In univariate analysis, older age, lower percent forced vital capacity (%FVC), lower percent diffusing capacity of carbon monoxide (%DLco), and the presence of honeycombing in the right lower lobe were identified as risk factors. Additionally, in multivariate analysis adjusted for age and treatment, %FVC, %DLco, and the presence of honeycombing in the right lower lobe were independently associated with respiratory-related mortality. We created prediction models based on the values of %FVC, %DLco, and presence of honeycombing on chest HRCT (MPF model). The 5-year respiratory-related death-free rate was significantly different between patients with MPA with ILD stratified by the number of risk factors based on the MPF model. CONCLUSIONS: Our study indicates that the MPF model may help predict respiratory-related death in patients with MPA with ILD.

Serum Complement C4 Levels Are a Useful Biomarker for Predicting End-Stage Renal Disease in Microscopic Polyangiitis.

This study aimed to evaluate the risk factors for end-stage renal disease (ESRD) in microscopic polyangiitis (MPA). In total, 74 patients with MPA were enrolled, and we compared the baseline clinical characteristics and disease activity between MPA patients who have progressed to ESRD and those without ESRD to select predictive factors for ESRD. Out of 74 patients, 12 patients (16.2%) had ESRD during follow-up. Serum C4 levels were significantly higher in MPA patients who have progressed to ESRD than in those without ESRD (p = 0.009). Multivariate analyses revealed that high serum creatinine levels (odds ratio (OR) 4.4, 95% confidence interval (CI) 1.25-15.5) and high serum C4 levels (OR 1.24, 95% CI 1.03-1.49) were risk factors for ESRD. Using receiver operating characteristic analysis, the cut-off value for initial serum C4 levels and serum creatinine levels were 29.6 mg/dL and 3.54 mg/dL, respectively. Patients with MPA with a greater number of risk factors (serum C4 levels > 29.6 mg/dL and serum creatinine levels > 3.54 mg/dL) had a higher ESRD progression rate. Serum C4 levels were significantly positively correlated with serum creatinine levels and kidney Birmingham vasculitis activity score (p = 0.02 and 0.04, respectively). These results suggest that serum C4 levels are useful tools for assessing renal disease activity and prognosis in MPA.

Adipose-derived stem/stromal cells with heparin-enhanced anti-inflammatory and antifibrotic effects mitigate induced pulmonary fibrosis in mice.

Interstitial lung disease (ILD) is a life-threatening pathological condition that causes respiratory failure and often presents as pulmonary fibrosis. Although it is treated using immunosuppressive and antifibrotic agents, the beneficial effects of these agents remain limited. Thus, the development of new therapeutic strategies for lung fibrosis is crucial. Mesenchymal stem/stromal cells (MSCs) have multilineage differentiation potential; additionally, they have anti-inflammatory and antifibrotic effects as well as the ability to modulate the immune response and modify the microenvironment at the site of engraftment. Numerous adipose-derived MSCs (ASCs) are present in the adipose tissue. Heparin and low-molecular-weight heparin (LMWH) mediate the secretion of several cytokines and growth factors with cell migratory and antifibrotic effects. This study aimed to confirm the therapeutic effect of LMWH-activated ASCs on ILD. Mouse ASCs (mASCs) were cultured in an LMWH-supplemented medium. LMWH significantly increased the number of mASC and enhanced their migratory, anti-inflammatory, and antifibrotic effects. Furthermore, mice with bleomycin-induced pulmonary fibrosis were intravenously administered LMWH-activated mASCs. The relative mRNA expression of inflammation-related genes in ILD lungs was significantly lower in the treatment group than in the pathological model group. Our findings suggest that LMWH-activated mASC administration reduces lung fibrosis.

Human MIKO-1, a Hybrid Protein That Regulates Macrophage Function, Suppresses Lung Fibrosis in a Mouse Model of Bleomycin-Induced Interstitial Lung Disease.

Although interstitial lung disease (ILD) is a life-threatening pathological condition that causes respiratory failure, the efficiency of current therapies is limited. This study aimed to investigate the effects of human MIKO-1 (hMIKO-1), a hybrid protein that suppresses the abnormal activation of macrophages, on murine macrophage function and its therapeutic effect in a mouse model of bleomycin-induced ILD (BLM-ILD). To this end, the phenotype of thioglycolate-induced murine peritoneal macrophages co-cultured with hMIKO-1 was examined. The mice were assigned to normal, BLM-alone, or BLM + hMIKO-1 groups, and hMIKO-1 (0.1 mg/mouse) was administered intraperitoneally from day 0 to 14. The mice were sacrificed on day 28, and their lungs were evaluated by histological examination, collagen content, and gene expression levels. hMIKO-1 suppressed the polarization of murine macrophages to M2 predominance in vitro. The fibrosis score of lung pathology and lung collagen content of the BLM + hMIKO-1 group were significantly lower than those in the BLM-alone group. The expression levels of TNF-α, IL-6, IL-1ß, F4/80, and TIMP-1 in the lungs of the BLM + hMIKO-1 group were significantly lower than those in the BLM-alone group. These findings indicate that hMIKO-1 reduces lung fibrosis and may be a future therapeutic candidate for ILD treatment.

Association between Serum Biomarkers and Peripheral Neuropathy in Microscopic Polyangiitis.

This study aimed to elucidate the pathomechanism of peripheral neuropathy (PN) in microscopic polyangiitis (MPA) and to identify biomarkers useful for diagnosis and severity assessment. Patients with MPA (n = 37) and other non-inflammatory neurological diseases (ONDs; n = 12) were enrolled, and the peripheral nerves of all patients were evaluated using nerve conduction studies. We compared the clinical characteristics and 14 serum biomarker profiles among patients with MPA and PN, MPA without PN, and ONDs. Patients with MPA had a higher prevalence of motor neuropathy than patients with ONDs. Among the patients with MPA, those with motor neuropathy had significantly higher total Birmingham Vasculitis Activity Scores and serum levels of C-reactive protein (CRP), tissue inhibitor of metalloproteinase-1 (TIMP-1), and interleukin-6 than patients without motor neuropathy. Multivariable analyses adjusted for age, serum CRP level, and diabetes mellitus showed that high serum levels of TIMP-1 were independently related to a diagnosis of motor neuropathy in MPA. Additionally, there were significant negative correlations between the serum levels of TIMP-1 and compound muscle action potential amplitudes. Serum levels of TIMP-1 may be associated with the pathomechanism of motor neuropathy in MPA and could be a useful biomarker for diagnosing and evaluating the severity of motor neuropathy in MPA.

The addition of iguratimod can reduce methotrexate dose in rheumatoid arthritis with clinical remission.

OBJECTIVES: We prospectively evaluated whether the addition of iguratimod (IGU) could sustain clinical remission in rheumatoid arthritis (RA) patients after tapering of methotrexate (MTX). METHODS: The study included 47 patients; 25 patients in the MTX maintenance group, and 22 patients in the IGU addition group who were treated with additional IGU and tapering of MTX dose. Clinical efficacy and safety were evaluated at 12, 24, and 36 weeks. RESULTS: In the IGU addition group, the dose of MTX could be reduced from 8.6 ± 2.4 mg/week at baseline to 4.7 ± 2.2 mg/week at 36 weeks (p < .001). Clinical remission was maintained (disease activity score [DAS]28-ESR 1.48 ± 0.63 at baseline and 1.69 ± 0.76 at 36 weeks, p = .911), and disease activity remained low (clinical disease activity index [CDAI] 2.4 ± 1.5 at baseline and 3.1 ± 3.4 at 36 weeks, p = .825). The US-GLOSS score significantly decreased from 9.2 ± 5.3 at baseline to 6.4 ± 4.3 at 36 weeks (p = .034). In the IGU addition group, two patients discontinued IGU because of stomatitis and three patients relapsed during the follow-up period (flare rate: 15.0%). There was no significant difference in RA disease activity at 36 weeks between the two groups. CONCLUSION: Additional use of IGU can effectively reduce the MTX dose required by patients during clinical remission without inducing a flare.

Comparison of therapeutic effects of combination therapy with prednisolone and tacrolimus or azathioprine on progressive interstitial pneumonia with systemic sclerosis.

OBJECTIVES: We retrospectively compared the therapeutic effects of combination therapy with prednisolone (PSL) and oral tacrolimus (TAC) or azathioprine (AZA) on progressive interstitial pneumonia with systemic sclerosis (SSc-PIP). METHODS: The effects of PSL (0.2-0.5 mg/kg/day) and TAC (3 mg/day) or AZA (1-2 mg/kg/day) therapies (n = 18) were evaluated for short (12 months) and long (36 months or more) periods. RESULTS: In the short period, IP improved in 6 and 5 patients and was stable in 12 and 13 patients in the TAC and AZA groups, respectively. In the long period, 11 patients were followed up in the TAC group and 12 in the AZA group. IP improved in 4 and 2 patients and was stable in seven and nine in the TAC and AZA groups, respectively. The rates of evolution of total fibrosis score, and those corrected by disease duration for the long period, in the TAC group were significantly lower than those in the AZA group (p = .017 and .025, respectively). CONCLUSION: The inhibitory effect of PSL and TAC combination therapy on the progression of fibrosis in SSc-PIP may be superior to that of PSL and AZA in the long period.

CCL2 produced by CD68+/CD163+ macrophages as a promising clinical biomarker of microscopic polyangiitis-interstitial lung disease.

OBJECTIVES: Microscopic polyangiitis (MPA) is often complicated by interstitial lung disease (ILD); however, biomarkers that can be used to diagnose and predict the progression of MPA-ILD have not been identified. In this study, we evaluated various serum biomarkers in MPA-ILD to assess their diagnostic and predictive performance. METHODS: We enrolled 49 patients with anti-neutrophil cytoplasmic antibody (ANCA)+ MPA and 10 healthy controls, with 32 of the MPA patients also presenting ILD. The presence of ILD was assessed by high-resolution CT and evaluated by ground-glass opacity and fibrosis score. We compared 16 biomarker profiles among MPA-ILD patients, those without ILD, and healthy controls and extracted biomarkers with higher levels in MPA-ILD groups to determine correlations with disease activity and other biomarkers. Three lung biopsies were examined by haematoxylin-eosin staining and immunostaining. RESULTS: Initial serum C-C motif chemokine ligand 2 (CCL2) levels were significantly higher in the MPA-ILD group than those of the MPA group, and were significantly higher in MPA-ILD patients 1 year after immunosuppressive therapy than those before treatment. Initial serum CCL2 levels positively correlated with an increased fibrosis score during the year after treatment and with initial serum platelet-derived growth factor levels. Immunohistochemical staining showed intense CCL2 signals in CD68+/CD163+ macrophages and metaplastic epithelial cells in MPA-ILD lungs. CONCLUSION: CCL2 is associated with MPA-ILD pathogenesis and suggested its potential efficacy as a useful marker for diagnosing and predicting MPA-ILD progression. Therefore, targeting CCL2 in alveolar CD68+/CD163+ macrophages might represent a therapeutic intervention in ANCA+ MPA-ILD.

Sexually Dimorphic Regulation of Behavioral States by Dopamine in Caenorhabditis elegans.

Sex differences in behavior allow animals to effectively mate and reproduce. However, the mechanism by which biological sex regulates behavioral states, which underlie the regulation of sex-shared behaviors, such as locomotion, is largely unknown. In this study, we studied sex differences in the behavioral states of Caenorhabditis elegans and found that males spend less time in a low locomotor activity state than hermaphrodites and that dopamine generates this sex difference. In males, dopamine reduces the low activity state by acting in the same pathway as polycystic kidney disease-related genes that function in male-specific neurons. In hermaphrodites, dopamine increases the low activity state by suppression of octopamine signaling in the sex-shared SIA neurons, which have reduced responsiveness to octopamine in males. Furthermore, dopamine promotes exploration both inside and outside of bacterial lawn (the food source) in males and suppresses it in hermaphrodites. These results demonstrate that sexually dimorphic signaling allows the same neuromodulator to promote adaptive behavior for each sex.SIGNIFICANCE STATEMENT The mechanisms that generate sex differences in sex-shared behaviors, including locomotion, are not well understood. We show that there are sex differences in the regulation of behavioral states in the model animal Caenorhabditis elegans Dopamine promotes the high locomotor activity state in males, which must search for mates to reproduce, and suppresses it in self-fertilizing hermaphrodites through distinct molecular mechanisms. This study demonstrates that sex-specific signaling generates sex differences in the regulation of behavioral states, which in turn modulates the locomotor activity to suit reproduction for each sex.

Exploration of pathomechanism using comprehensive analysis of serum cytokines in polymyositis/dermatomyositis-interstitial lung disease.

OBJECTIVES: To elucidate the serum cytokine profile and address the pathomechanism of interstitial lung disease (ILD) complicated with PM/DM. METHODS: Forty patients with PM/DM-ILD were enrolled, and principal components analysis and cluster analysis were performed to classify patients into subgroups. Additionally, we compared cytokine profiles between the survivors and dead patients and between anti-melanoma differentiation-associated gene 5 antibody- and anti-aminoacyl tRNA synthetase antibody-positive ILD patients. We also examined the association of various cytokines with disease activity indicators and prognosis of ILD. RESULTS: The principal components analysis data allowed classification of the cytokine profile into three groups: group 1, neutrophilic and M1-macrophage-driven cytokines; group 2, type 1 Th cell-driven and M2-macrophage-induced cytokines; and group 3, M2-macrophage-driven cytokines. Cluster analysis showed the presence of PM/DM-ILD patient groups with high or low levels of total cytokines. Ninety percent of patients who died of ILD were included in clusters with high cytokine levels. Serum cytokine levels of all groups were significantly higher in the anti-melanoma differentiation-associated gene 5 antibody-positive patients than in the anti-aminoacyl tRNA synthetase antibody-positive patients. Groups 1 and 2 significantly correlated with known factors for poor prognosis, such as serum ferritin levels and alveolar-arterial oxygen difference. Serum cytokine levels of patients in group 1 were significantly higher initially and at 2 and 4 weeks in those who died. CONCLUSION: These findings suggested that the activation of monocytes, macrophages and type 1 Th cells, and neutrophils play roles in the pathomechanism of PM/DM-ILD, and group 1 cytokines could be useful biomarkers for predicting prognosis of PM/DM-ILD.

Asymptomatic rheumatoid meningitis revealed by magnetic resonance imaging, followed by systemic rheumatic vasculitis: A case report and a review of the literature.

We report the case of a 66-year-old man with seropositive rheumatoid arthritis who developed neurologically asymptomatic rheumatoid meningitis (RM) revealed by MRI. RM worsened and chest CT showed pericardial effusion, pleural effusion, and bilateral consolidation, and his serum C3 level was decreased. We diagnosed systemic rheumatic vasculitis based on these findings. After a review of more than 20 previously reported cases of RM, this is the first case of RM without central nerve system symptoms.

Eosinophilic granulomatosis with polyangiitis complicated by subarachnoid hemorrhage and coronary vasculitis: a case report and review of the literature.

Eosinophilic granulomatosis with polyangiitis (EGPA) is characterized by necrotizing vasculitis of small-sized vessels with extravascular granulomas and eosinophilic infiltration. The case of a 48-year-old Japanese woman with EGPA, who presented concurrently with subarachnoid hemorrhage (SAH) and coronary vasculitis, is reported. She initially presented with bronchial asthma, and then 8 months later she developed various symptoms caused by systemic eosinophilic vasculitis and was admitted to our hospital. Three days after admission, she started oral corticosteroid therapy, and her 2009 Five-Factor Score (FFS) was 0. However, she developed an SAH, followed by coronary vasculitis 1 day later. With extensive treatment with a combination of betamethasone, cyclophosphamide, intravenous immunoglobulin, and rituximab, her systemic vasculitis improved dramatically. This seems to be the first case of EGPA with SAH and coronary vasculitis. In previous reports of EGPA with SAH, 4 of 11 cases developed SAH as an exacerbation of systemic vasculitis during remission induction therapy. The present patient also had SAH during remission induction therapy. However, the period between bronchial asthma and SAH was only 8 months. This is the shortest among case reports of EGPA with SAH. In addition, the present patient rapidly developed coronary vasculitis. These findings suggest that EGPA causes SAH and coronary vasculitis as early complications of systemic vasculitis. In EGPA, it is necessary to pay careful attention to rapid changes of disease activity, even when the FFS indicates a good prognosis.

RGB-Color Intensiometric Indicators to Visualize Spatiotemporal Dynamics of ATP in Single Cells.

Adenosine triphosphate (ATP) provides energy for the regulation of multiple cellular processes in living organisms. Capturing the spatiotemporal dynamics of ATP in single cells is fundamental to our understanding of the mechanisms underlying cellular energy metabolism. However, it has remained challenging to visualize the dynamics of ATP in and between distinct intracellular organelles and its interplay with other signaling molecules. Using single fluorescent proteins, multicolor ATP indicators were developed, enabling the simultaneous visualization of subcellular ATP dynamics in the cytoplasm and mitochondria of cells derived from mammals, plants, and worms. Furthermore, in combination with additional fluorescent indicators, the dynamic interplay of ATP, cAMP, and Ca2+ could be visualized in activated brown adipocyte. This set of indicator tools will facilitate future research into energy metabolism.