Epoxy fatty acids (EpFA), cytochrome P450(CYP)-mediated metabolites of polyunsaturated fatty acids (PUFA), have anti-inflammatory effects[1]. However, EpFA is quickly converted to an inactive form by the soluble epoxide hydrolase(sEH). In recent years, the efficacy of sEH inhibitors (sEHi) has been reported in a variety of diseases[2-4]. However, compared to ω-6 epoxides, such as epoxyeicosatirienioic acids (EET) derived from arachidonic acid (AA), there are few reports on ω-3 epoxides, epoxyeicosapentaenoic acid (EEQ) from eicosapentaenoic acid (EPA) and epoxydocosapentaenoic acids (EDP) from docosapentaenoic acid (DHA)5), and their effects on arthritis are not well understood.
Objectives
To investigate and compare the effects of ω-6 and ω-3 epoxides on inflammatory arthritis.
Methods
Collagen induced arthritis (CIA) were treated with three different diets (ω-6 PUFA rich, ω-3 PUFA rich, and Control) and two types of drinking solution, one containing sEHi and the other containing only polyethylene glycol as solvent control (total 6 groups, 8 mice each). Arthritis and pathological scores were evaluated, and feces were collected before the onset of arthritis (day 25) for intergroup comparative analysis of bacterial flora.
Results
In all the dietary groups, there was a tendency for arthritis scores to decrease with sEHi administration, but the incidence of arthritis, arthritis scores, and pathological scores decreased dramatically in the group fed with the ω-3 rich diet and sEHi combination. The groups fed the ω-6 rich diet and Control diet showed almost similar results. In the ω-3 rich diet and sEHi combination group, showed an increase in a certain specific bacterial strain.
Conclusion
ω-3 epoxides were found to be more effective in reducing arthritis, and changes in intestinal bacteria may have influenced this pathological change.
References
[1]Shi, Z. et al. CYP450 Epoxygenase Metabolites, Epoxyeicosatrienoic Acids, as Novel Anti-Inflammatory Mediators. Molecules 2022,27,3873 [2]Sandra, C. et al. Discovery and In Vivo Proof of Concept of a Highly Potent Dual Inhibitor of Soluble Epoxide Hydrolase and Acetylcholinesterase for the Treatment of Alzheimer's Disease. J.Med.Chem,2022,65,4909-4925 [3]Merce, P.et al. Soluble Epoxide Hydrolase Inhibition to Face Neuroinflammation in Parkinson's Disease: A New Therapeutic Strategy.Biomolecules 2020, 10, 703; doi:10.3390/biom10050703 [4]Rebecca, L.et al. Protection from hypertension in mice by the Mediterranean diet is mediated by nitro fatty acid inhibition of soluble epoxide hydrolase. PNAS,2014,22,111,8167-8172 [5]Yang, Y. et al. Differential Effects of 17,18-EEQ and 19,20-EDP Combined with Soluble Epoxide Hydrolase Inhibitor t-TUCB on Diet-Induced Obesity in Mice. Int. J. Mol. Sci. 2021,22,8267 g. Characters from table content including title and footnotes.
Lung involvement is a prevalent extraarticular manifestation of rheumatoid arthritis (RA) that remains a significant clinical challenge. Few studies have comprehensively quantified lung abnormalities of RA patients using artificial intelligence-based (AI) technology.
Objectives
The aim of this study was to quantify lung lesions in RA patients and classify them based on their lung parameters.
Methods
An AI-based quantitative computed tomography (CT) image analysis software (AIQCT) was applied to high-resolution CT scans of RA patients in a cross-sectional manner. AIQCT automatically classified and quantified 10 types of parenchymal image patterns, expressing the volumes as percentages of total lung volume [1]. Hierarchical Ward's linkage clustering based on these patterns identified five clusters. Visual assessments (ILD, and airway lesions) of HRCT and clinical phenotypes were assessed.
Results
A total of 408 RA patients were included in the study. The lung profiles of the five clusters were as follows: Cluster I (68.6%), characterized by nearly normal lungs; Cluster II (23.5%), characterized by slight lung lesions with honeycombs or ground-glass opacities (GGOs); Cluster III (5.6%), characterized by the predominance of GGOs; Cluster IV (1.0%), characterized by a predominant hyperlucent area; and Cluster V (1.2%), characterized by extensive lung abnormalities (Figure 1, Table 1). The number of patients in each cluster with ILD and airway lesions, based on visual assessments, were as follows: [ILD] Cluster I, 11/280 (3.9%), Cluster II, 19/96 (19.8%), Cluster III, 5/23 (21.7%), Cluster IV, 0/4 (0%), and Cluster V, 5/5 (100%) (p < 0.001): [airway lesions] Cluster I, 31/280 (11.1%), Cluster II, 29/96 (30.2%), Cluster III, 6/23 (26.1%), Cluster IV, 0/4 (0%), and Cluster V, 1/5 (20%) (p < 0.001). Clinical characteristics of each cluster were described in Table 1. The disease activity of RA in each cluster were as follows: [DAS28ESR, mean (SD)] Cluster I, 2.4 (1.0), Cluster II, 3.0 (1.2), Cluster III, 2.8 (1.0), Cluster IV, 2.2 (0.7), and Cluster V, 3.0 (0.8) (p < 0.001); [HAQ, mean (SD)] Cluster I, 0.4 (0.6), Cluster II, 0.9 (0.9), Cluster III, 1.1 (0.9), Cluster IV, 0.3 (0.3), and Cluster V, 0.8 (0.9) (p < 0.001).
Conclusion
This study is the first to classify lung lesions in comprehensive RA patients using quantitative data derived from novel AI technology. The AIQCT-derived clustering of RA patients appears to be associated with their clinical backgrounds and characteristics.
Growing evidence reveals a pathological role of somatic mutations in various autoimmune diseases, such as the mutation in UBA1 in VEXAS syndrome, CARD11 and KLHL6 in cryoglobulinemic vasculitis, or STAT3 in Felty's syndrome[1]. Somatic mutations might also be involved in the pathogenesis of ANCA-associated vasculitis (AAV), which typically manifests in middle-aged and elderly individuals.
Objectives
We aimed to identify somatic mutations in patients with AAV.
Methods
We collected whole blood and obtained peripheral blood mononuclear cells (PBMCs) and neutrophils from patients with AAV in active-disease status (n=16), as well as from patients with other autoimmune diseases (n=8) as disease controls, and healthy subjects (n=10). In addition, we collected these specimens from 12 out of the 16 patients with AAV after remission induction. We performed RNA sequencing (RNA-seq) on the obtained cells and whole genome sequencing (WGS) on DNA extracted from the whole blood. Somatic mutations were detected by comparing the RNA and DNA sequences[2].
Results
After stringent quality control, we identified 108 somatic mutations across 16 patients in active-disease status. The mean coverage of RNA-Seq at the mutation site was 100.9 ± 367.8 ×, and that of WGS was 14.4 ± 4.3 ×, while the mean allele fraction was 22.9 ± 20.5%. One or more mutations were detected in each of the 15 (93.8%) patients. The median mutation count of each patient was 4.0, which was not significantly different from disease controls or samples after remission induction. We mapped one gene to each of the 108 mutations, resulting in 95 genes in total. Mutations for six of the 95 genes were observed in two or more patients, and two of them were related to the ubiquitin system. Of the 108 mutations, 37 were missense, and 20 were predicted to be deleterious (combined annotation-dependent depletion Phred score > 20). Among the 20 mutations, the HIST2H2AC mutation (NM_003517: p.L86P) in neutrophils was observed in two patients. To evaluate the functional outcome of the 20 mutations, we analysed the data on knocking out the corresponding genes using CRISPR in K562 cells[3]. The results showed that the expression of genes related to antigen presentation was increased in HEATR1 and RPL18 knockouts. When we followed up with 12 of the 16 patients after remission induction, 81.4% of the somatic mutations were no longer detected. Additionally, 91.7% of the deleterious mutations disappeared.
Conclusion
We found somatic mutations with potential pathological effects in some patients with AAV exhibiting active-disease status. Notably, the majority of these mutations were not detected after remission induction.
References
[1]Mustjoki, S. & Young, N. S. Somatic Mutations in 'Benign' Disease. N. Engl. J. Med. 384, 2039–2052 (2021). [2]Yizhak, K. et al. RNA sequence analysis reveals macroscopic somatic clonal expansion across normal tissues. Science 364, (2019). [3]Replogle, J. M. et al. Mapping information-rich genotype-phenotype landscapes with genome-scale Perturb-seq. Cell 185, 2559-2575.e28 (2022).
Acknowledgements
The present study was supported in part by JSPS KAKENHI. (Grant No. 19H03209).
Although the survival rates of patients with relapsing polychondritis (RP) have increased remarkably, the high recurrence rate remains a significant concern for physicians and patients. This retrospective study aimed to investigate the risk factors for RP recurrence.Patients with RP who presented to Kyoto University Hospital from January 2000 to March 2020 and fulfilled Damiani's classification criteria were included. Patients were classified into recurrence and non-recurrence groups. Risk factors for RP recurrence were analysed using a Cox proportional hazards model, and Kaplan-Meier survival curves were drawn.Thirty-four patients were included. Twenty-five patients (74%) experienced 64 recurrences (mean: 2.56 recurrences per patient). The median duration before the first recurrence was 202 [55-382] days. The median prednisolone dose at the initial recurrence was 10 [5-12.75] mg/day. Tracheal involvement was significantly more frequent in the recurrence group at the initial presentation (44.0% vs. 0.0%, p=0.0172) than in the non-recurrence group, and pre-treatment C-reactive protein levels were significantly higher in the recurrence group than in the non-recurrence group (4.7 vs 1.15 mg/dL, p=0.0024). The Cox proportional hazards model analysis revealed that tracheal involvement (hazard ratio [HR] 4.266 [1.535-13.838], p=0.0048), pre-treatment C-reactive protein level (HR 1.166 [1.040-1.308], p=0.0085), and initial prednisolone monotherapy (HR 4.443 [1.515-16.267], p=0.0056) may be associated with recurrence. The median time before the initial recurrence was significantly longer in patients who received combination therapy with prednisolone and immunosuppressants or biologics (400 vs. 70 days, p=0.0015).Tracheal involvement, pre-treatment C-reactive protein level, and initial prednisolone monotherapy were risk factors for recurrence in patients with RP. Initial combination therapy with prednisolone and immunosuppressants may delay recurrence.
Finding the ideal balance between efficacy and safety of immunosuppression is challenging, particularly in cases of severe TAFRO syndrome. We herein report a 60-year-old man diagnosed with grade 5 TAFRO syndrome mimicking hepatorenal syndrome that was successfully treated by glucocorticoid, tocilizumab, and cyclosporin despite virus infection. Furthermore, by examining 14 peer-reviewed remission cases, we revealed that the recovery periods among inflammation, renal dysfunction, and thrombocytopenia were quite different, with recovery from thrombocytopenia notably slow. All patients requiring dialysis were successfully withdrawn from dialysis, and the reversibility from kidney injury was good. This clinical information will help clinicians plan treatments and tailor the intensity of immunosuppression.
The present study aimed to clarify comprehensive relationships among the clinical variables of systemic lupus erythematosus (SLE).We retrospectively surveyed 32 clinical variables in 581 patients and conducted comprehensive association studies among SLE clinical phenotypes. A univariate analysis of all possible combinations was performed, and the results of phenotypic correlations were reduced into two dimensions. We also created a regression formula using L1 regularisation (LASSO) to calculate the probability of exhibiting each phenotype.The univariate analysis identified 26 correlations, including multiple phenotypes with low complement. Some unpredicted correlations were identified, including fever and the anti-Sm antibody (odds ratio; OR = 2.3, p = 1.6 × 10-5) or thrombocytopenia and psychosis (OR = 3.7, p = 3.2 × 10-5). The multivariate analysis accurately estimated the probability of exhibiting each phenotype (area under the curve > 0.7) in 10 out of 20 phenotypes.The present results show the phenotypic architecture of SLE and represent a model for estimating the probability of exhibiting each phenotype. They also offer insights into the pathology of SLE and estimating the probability of the onset of new phenotypes in clinical practice.
Suppressor of TCR signaling-2 (STS-2) is one of the RA susceptibility genes identified in genome-wide association studies (GWAS). We tried to verify the involvement of STS-2 on the development of autoimmune arthritis in a mouse model.STS-2 knock-out (KO) and wild type (WT) mice were immunized with chicken type II collagen (CII). For CD4+ helper T cell (Th) subset analysis, intracellular cytokines in splenocytes and lymph node cells were stained and analyzed by flow cytometry. Regulatory T cell (Treg) function was analyzed by co-culturing effector CD4+T cells and Tregs collected from non-immunized mice.CII-immunized STS-2 KO mice developed arthritis more frequently than WT mice. Although the T cell activation profile and Th subset in spleen and LNs were similar between STS-2 KO and WT mice, STS-2 KO mice showed increased IL-2-producing CD4+T cells in spleen when compared with WT mice. Accordingly, STS-2 KO CD4+T cells promoted IL-2 production by TCR stimulation. However, STS-2 KO Tregs normally suppressed T cell proliferation.We proved that STS-2 is involved in the arthritis development by collagen-induced arthritis. Higher IL-2 production from STS-2 KO T cells is suggested to have a main pathogenic role in arthritis development.
The associations of myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs) with clinical features and remission in idiopathic inflammatory myopathy (IIM) are different between those of juvenile-onset (JIIM) and adult-onset.
Objectives
Since the associations in JIIM had not been fully elucidated, we analyzed them comparing that in adults using clinical information and autoantibodies.
Methods
A total of 320 cases of IIMs (juvenile-onset, 2004-2021, n=34; adult-onset, 2018-2021, n=286) with a history of attendance at our hospital were retrospectively analyzed using medical records. Remission without glucocorticoids and immunosuppressive drugs for 30 years was also examined. MSAs were identified by assays of RNA immunoprecipitation (IP), protein IP, protein IP-blot, and ELISA. Logistic regression analysis, Mann-Whitney U test, Fisher's exact test, and log-rank test were performed.
Results
In JIIM, anti-MDA5 (15%) and anti-TIF1-γ (15%) were the most frequent MSAs, followed by anti-ARS (9%) and anti-NXP2 (6%) (Table 1). In particular, the frequency of anti-ARS was significantly lower in juveniles whereas it was the highest in adults (9% vs. 32%, respectively, p=0.01). Anti-SRP and anti-Mi-2 were not identified in juveniles, although they were identified with low frequencies in adults. In MAAs (juvenile-onset vs. adult-onset), anti-Ku (9% vs. 2%, p=0.03) and anti-U1-RNP (18% vs. 4%, p=0.02) were more common in juveniles while anti-SS-A (15% vs. 16%, p=1) was not significantly different between juveniles and adults. Dermatomyositis tended to be more dominant than polymyositis in juveniles than in adults (76% vs. 59%, p=0.06) (Table 1). Fever was more frequently observed in juveniles (74% vs. 12%, p<0.0001) and interstitial lung disease (ILD) was less frequently observed in juveniles than adults (29% vs. 66%, p<0.0001). Malignancy was observed in 2 juvenile-onset patients (6%) during 14.7±12.3 years while in 32 adult-onset patients (12%) during 6.8±7.5 years (p=0.56). Anti-NXP2 (n=1) and anti-PL12 (n=1) were observed in juveniles. In contrast, anti-TIF1-γ (n=11/32, 34%) was mainly observed in adults. Anti-MDA5 (OR [95%CI]: 14.0 [1.31, 150]) in juveniles and anti-ARS (23.2 [7.07, 76.1]) and anti-MDA5 (13.3 [4.03, 43.8]) in adults were associated with ILD. Anti-MDA5 was poorly associated with muscle symptoms in both juveniles (0.06 [0.004, 0.88]) and adults (0.43 [0.22, 0.85]). The rate of drug-free remission for 30 years in juveniles is higher than that in adults (32% vs 7%, respectively, p<0.0001, Figure 1). The drug-free remission in juveniles was observed in the order of anti-TIF1-γ, anti-NXP2, anti-MDA5, and anti-ARS, reaching a plateau at 5.7 years. In contrast, the remission in adults was observed in the order of anti-MDA5, anti-TIF1-γ, anti-SRP, and anti-ARS. The use of glucocorticoid (88% vs. 91%, p=0.76) was similar in juveniles and adults, while methotrexate (32% vs. 8%, p=0.0002) was used more frequently in juveniles.
Conclusion
There were differences in the clinical characteristics of IIM and autoantibodies between juvenile-onset and adult-onset. Further analysis is needed in a larger sample size.
ABSTRACT 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.
