Dataset Information

Serum 20S proteasome levels are associated with disease activity in MPO-ANCA-associated microscopic polyangiitis.

ABSTRACT: Background:Proteasomes are found in both the cell nucleus and cytoplasm and play a major role in the ubiquitin-dependent and -independent non-lysosomal pathways of intracellular protein degradation. Proteasomes are also involved in the turnover of various regulatory proteins, antigen processing, cell differentiation, and apoptosis. To determine the diagnostic value of serum proteasome in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), we investigated patients with AAV at various stages of the disease. Methods:Serum 20S-proteasome was measured by ELISA in 44 patients with MPO-ANCA-associated microscopic polyangiitis (MPA) and renal involvement. Thirty of the patients provided serum samples before the initial treatment, and 30 provided samples during remission; 16 provided samples at both time points. Results:The mean serum 20S-proteasome level was significantly higher in the active-vasculitis patients (3414.6?±?2738.9?ng/mL; n?=?30) compared to the inactive-vasculitis patients (366.4?±?128.4?ng/mL; n?=?30; p?

SUBMITTER: Maruyama H

PROVIDER: S-EPMC7447580 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Serum 20S proteasome levels are associated with disease activity in MPO-ANCA-associated microscopic polyangiitis.

Maruyama Hiroshi H Hirayama Kouichi K Yamashita Marina M Ohgi Kentaro K Tsujimoto Ryuji R Takayasu Mamiko M Shimohata Homare H Kobayashi Masaki M

BMC rheumatology 20200825

<h4>Background</h4>Proteasomes are found in both the cell nucleus and cytoplasm and play a major role in the ubiquitin-dependent and -independent non-lysosomal pathways of intracellular protein degradation. Proteasomes are also involved in the turnover of various regulatory proteins, antigen processing, cell differentiation, and apoptosis. To determine the diagnostic value of serum proteasome in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), we investigated patients with ...[more]

PMID: 32864569

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Project description:Among antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV), granulomatosis with polyangiitis (GPA) and proteinase 3-ANCA-positive AAV (PR3-AAV) are prevalent in European populations, while microscopic polyangiitis (MPA) and myeloperoxidase-ANCA-positive AAV (MPO-AAV) are predominant in the Japanese. We previously demonstrated association of DRB1*09:01-DQB1*03:03 haplotype, a haplotype common in East Asians but rare in the European populations, with MPA/MPO-AAV, suggesting that a population difference in HLA-class II plays a role in the epidemiology of this disease. To gain further insights, we increased the sample size and performed an extended association study of DRB1 and DPB1 with AAV subsets in 468 Japanese patients with AAV classified according to the European Medicines Agency algorithm (MPA: 285, GPA: 92, eosinophilic GPA [EGPA]: 56, unclassifiable: 35) and 596 healthy controls. Among these patients, 377 were positive for MPO-ANCA and 62 for PR3-ANCA. The significance level was set at ? = 3.3x10-4 by applying Bonferroni correction. The association of DRB1*09:01 with MPO-AAV was confirmed (allele model, P = 2.1x10-4, odds ratio [OR] = 1.57). Protective association of DRB1*13:02 was detected against MPO-AAV (allele model, P = 2.3x10-5, OR = 0.42) and MPA (dominant model, P = 2.7x10-4, OR = 0.43). A trend toward increased frequency of DPB1*04:01, the risk allele for GPA in European populations, was observed among Japanese patients with PR3-AAV when conditioned on DRB1*13:02 (Padjusted = 0.0021, ORadjusted = 3.48). In contrast, the frequency of DPB1*04:01 was decreased among Japanese patients with MPO-AAV, and this effect lost significance when conditioned on DRB1*13:02 (Padjusted = 0.16), suggesting that DRB1*13:02 or other allele(s) in linkage disequilibrium may be responsible for the protection. The differential association of DPB1*04:01 with PR3-AAV and MPO-AAV and difference in DPB1*04:01 allele frequencies between populations supported the hypothesis that the HLA-class II population difference may account in part for these epidemiologic characteristics. Furthermore, taken together with our previous observations, the haplotype carrying DRB1*13:02 was suggested to be a shared protective factor against multiple autoimmune diseases.

Project description:ObjectivesThe aim of this study is to investigate the clinical significance of myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) on eosinophilic granulomatosis with polyangiitis (EGPA) from a longitudinal Chinese cohort.MethodsA total of 120 patients with EGPA were consecutively enrolled and followed up. Two patients with PR3 ANCA was excluded and our analysis focused on the 118 patients with EGPA. On the basis of MPO-ANCA status, baseline clinical manifestations, treatment, and outcomes were analyzed. Logistic regression analysis was performed to analyze the independently associated factors for renal involvement.ResultsANCA positivity was observed in 24.2% of patients with EGPA. Patients with MPO-ANCA accounted for 20.8%. Patients with positive MPO-ANCA had higher levels of erythrocyte sedimentation rate (ESR), C-reactive protein, Birmingham Vasculitis Activity Score (BVAS), higher ratios of fever, myalgia, renal involvement, and biopsy-proven vasculitis. Heart manifestations and asthma were more common in patients with negative ANCA. Baseline MPO-ANCA titers positively correlated with ESR, eosinophil count, and BVAS and were higher in patients with methylprednisolone pulse. Among patients with renal involvement, patients with positive MPO-ANCA had higher proportions of female, fever, biopsy-proven vasculitis, and faster ESR; patients with negative ANCA developed more skin and cardiac involvement. MPO-ANCA positivity, male, and ear involvement were the independent factors associated with renal involvement. Intravenous cyclophosphamide and immunoglobulins were prescribed more frequently in patients with positive MPO-ANCA.ConclusionIn this cohort, patients with positive MPO-ANCA and negative ANCA displayed distinct clinical features, suggesting that MPO-ANCA might be a valuable biomarker for EGPA stratification. Baseline MPO-ANCA level correlated positively with disease activity of EGPA. MPO-ANCA was a significant independent factor associated with renal involvement.

Project description:Our understanding of immune recognition and response to infection and non-infectious forms of cell damage and death is rapidly increasing. The major focus is on host immunity and microbiological invasion. However, it is also clear that these same pathways are important in the initiation and maintenance of autoimmunity and the damage caused to targeted organs. Understanding the involvement of cell death in autoimmune disease is likely to help define critical pathways in the immunopathogenesis of autoimmune disease and new therapeutic targets. An important immune responder cell population in host defense and autoimmunity is the neutrophil. One autoimmune disease where neutrophils play important roles is MPO-ANCA Microscopic Vasculitis. This a severe disease that results from inflammation to small blood vessels in the kidney, the glomeruli (high blood flow and pressure filters). One of the best studied ways in which neutrophils participate in this disease is by cell death through NETosis resulting in the discharge of proinflammatory enzymes and nuclear fragments. In host defense against infection this process helps neutralize pathogens however in auto immunity NETosis results in injury and death to the surrounding healthy tissues. The major autoimmune target in this disease is myeloperoxidase (MPO) which is found uniquely in the cytoplasm of neutrophils. Although the kidney is the major organ targeted in this disease MPO is not expressed in the kidney. Autoantibodies target surface MPO on activated circulating neutrophils resulting in their lodgment in glomerular capillaries where they NETose releasing extracellularly MPO and nuclear fragments initiating injury and planting the key autoantigen MPO. It is the cell death of neutrophils that changes the kidney from innocent bystander to major autoimmune target. Defining the immunopathogenesis of this autoimmune disease and recognizing critical injurious pathways will allow therapeutic intervention to block these pathways and attenuate autoimmune injury. The insights (regarding mechanisms of injury and potential therapeutic targets) are likely to be highly relevant to many other autoimmune diseases.

Project description:BackgroundRapidly progressive glomerulonephritis caused by antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is typically characterized as pauci-immune glomerulonephritis. However, immune complex (IC) deposition in the glomerulus has been reported in a growing number of studies. Here, we assess the presence of glomerular immune deposits alongside renal outcome in myeloperoxidase (MPO)-ANCA associated glomerulonephritis (MPO-ANCA GN).MethodsClinical and histopathologic characteristics of 97 patients with MPO-ANCA GN classified by renal biopsy from January 2008 to December 2019 were extracted retrospectively from electronic medical records. The extent of immune deposits in the kidney (C3, C4, C1q, IgA, IgG, IgM) at diagnosis were analyzed by immunofluorescence (IF). Patients were followed up for a median period of 15 months. The response to treatment and outcomes of renal and histological lesion changes were also assessed.ResultsIn our study, 41% (40/97) of patients showed positive IF (≥2+) for at least one of the six immunoglobulin or complement components tested. Patients with IC deposits showed higher levels of serum creatinine (p=0.025), lower platelet counts (p=0.009), lower serum complement C3 (sC3) (≤790 ml/L) (p=0.013) and serum IgG (p=0.018) than patients with pauci-immune (PI) deposition at diagnosis. End-stage renal disease was negatively associated with eGFR (HR 0.885, 95% CI 0.837 to 0.935, p<0.0001), platelet count (HR 0.996, 95% CI 0.992 to 1.000, p=0.046) and serum globulin (HR 0.905, 95% CI 0.854 to 0.959, p=0.001). Patients with lower sC3 levels showed a worse renal outcome than the patients with normal sC3 at diagnosis (p=0.003). Analysis of the components of the renal deposits found that patients with IgG deposits exhibited a poorer renal outcome compared to patients that were IgG negative (p=0.028). Moreover, Bowman's capsule rupture occurred less frequently in patients with IgM deposition compared with IgM negative counterparts (p=0.028). Vascular lesions and granuloma-like lesions had been seen more frequently in cases with IgA deposition than those without IgA deposition (p=0.03 and 0.015, respectively).ConclusionIn conclusion, patients with immune complex deposits in the kidney showed less platelet count, lower sC3 and sIgG levels, and higher serum creatinine levels. Patients with low sC3 at initial and with continued low sC3 during the treatment displayed a trend toward poorer kidney survival. Moreover, the IC group showed a worse renal outcome than the PI group, further enforcing the present strategy of introducing complement targeted therapies in AAV.

Project description:BackgroundInterstitial lung disease (ILD) is a severe complication with poor prognosis in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Prevalence of AAV-associated ILD (AAV-ILD) in Japan is considerably higher than that in Europe. Recently, we reported that a MUC5B variant rs35705950, the strongest susceptibility variant to idiopathic pulmonary fibrosis (IPF), was strikingly increased in AAV-ILD patients but not in AAV patients without ILD; however, due to the low allele frequency in the Japanese population, the MUC5B variant alone cannot account for the high prevalence of AAV-ILD in Japan. In this study, we examined whether other IPF susceptibility alleles in TERT and DSP genes are associated with susceptibility to AAV subsets and AAV-ILD.MethodsFive hundred and forty-four Japanese patients with AAV and 5558 controls were analyzed. Among the AAV patients, 432 were positive for myeloperoxidase (MPO)-ANCA (MPO-AAV). A total of 176 MPO-AAV patients were positive and 216 were negative for ILD based on CT or high-resolution CT. Genotypes of TERT and DSP variants were determined by TaqMan SNP Genotyping Assay, and their association was tested by chi-square test.ResultsWhen the frequencies of the IPF risk alleles TERT rs2736100A and DSP rs2076295G were compared between AAV subsets and healthy controls, both alleles were significantly increased in microscopic polyangiitis (MPA) (TERT P = 2.3 × 10-4, Pc = 0.0023, odds ratio [OR] 1.38; DSP P = 6.9 × 10-4, Pc = 0.0069, OR 1.32) and MPO-AAV (TERT P = 1.5 × 10-4, Pc = 0.0015, OR 1.33; DSP P = 0.0011, Pc = 0.011, OR 1.26). On the other hand, no significant association was detected when the allele frequencies were compared between MPO-AAV patients with and without ILD.ConclusionsUnexpectedly, TERT and DSP IPF risk alleles were found to be associated with MPA and MPO-AAV, regardless of the presence of ILD. These findings suggest that TERT and DSP may be novel susceptibility genes to MPA/MPO-AAV and also that some susceptibility genes may be shared between IPF and MPA/MPO-AAV.

Dataset Information

Serum 20S proteasome levels are associated with disease activity in MPO-ANCA-associated microscopic polyangiitis.

Publications

Serum 20S proteasome levels are associated with disease activity in MPO-ANCA-associated microscopic polyangiitis.

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