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Increasing evidence suggested that gut microbiota played critical roles in developing autoimmune diseases. This study investigated the correlation between gut microbiota and antineutrophil cytoplasmic antibody-associated vasculitis (AAV) with kidney injury. We analyzed the fecal samples of 23 AAV patients with kidney injury using a 16s RNA microbial profiling approach. The alpha-diversity indexes were significantly lower in AAV patients with kidney injury than healthy controls (Sobs P < 0.001, Shannon P < 0.001, Chao P < 0.001). The beta-diversity difference demonstrated a significant difference among AAV patients with kidney injury, patients with lupus nephritis (LN), and health controls (ANOSIM, p = 0.001). Among these AAV patients, the Deltaproteobacteria, unclassified_o_Bacteroidales, Prevotellaceae , Desulfovibrionaceae Paraprevotella , and Lachnospiraceae _NK4A136_group were correlated negatively with serum creatinine, and the proportion of Deltaproteobacteria, unclassified_o_Bacteroidales, Desulfovibrionaceae , Paraprevotella, and Lachnospiraceae _NK4A136_group had a positive correlation with eGFR. In conclusion, the richness and diversity of gut microbiota were reduced in AAV patients with kidney injury, and the alteration of gut microbiota might be related with the severity of kidney injury of AAV patients. Targeted regulation of gut microbiota disorder might be a potential treatment for AAV patients with kidney injury. [ABSTRACT FROM AUTHOR]

Background: Therapeutic plasma exchange (TPE) has been recommended by guidelines for the treatment of anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) with severe kidney dysfunction. In recent years, some researchers have proposed that double-filtration plasmapheresis (DFPP) can also be used effectively in the treatment of these patients, but the difference between the 2 modalities of plasmapheresis is not clear. Methods: In this retrospective cohort study of AAV patients with serum creatinine ≥500 μmol/L from March 2013 to July 2018 who received TPE or DFPP treatment, we compared TPE and DFPP in terms of the changes of clinical parameters before and after plasmapheresis, the rates of adverse events during plasmapheresis, and kidney and patient survival during follow-up. Results: Forty-two AAV patients with kidney injury were included in this study. Twenty patients were treated with TPE and 22 patients were treated with DFPP. All patients were followed up for a median of 22 months. In each group, there were 10 deaths, and 6 patients developed end-stage kidney disease (ESKD). There were no significant differences between TPE and DFPP in terms of the changes of renal function or other laboratory results after treatment. During the plasmapheresis treatment, there was no significant difference in the rate of adverse events (p = 0.67). During the follow-up, there was no difference between the groups regarding the level of serum creatinine for patients with kidney recovery. The hazard ratio (HR) for TPE compared to DFPP for the outcome of ESKD was 0.92 (95% CI 0.45–1.9; p = 0.79) and the HR for death was 1.11 (95% CI 0.45–2.76; p = 0.82). Conclusion: There were no differences in short-term effectiveness, safety, or long-term outcomes between the 2 modalities of plasmapheresis. Our study suggests that DFPP may be a choice of plasmapheresis for AAV patients with severe kidney injury especially in countries and regions with limited blood resources. [ABSTRACT FROM AUTHOR]

Objective. Previous studies have shown that in patients with ANCA-associated vasculitis (AAV), anti-plasminogen antibodies were associated with reduced renal function and the presence of fibrinoid necrosis and cellular crescents in renal histology. The purpose of the current study was to investigate whether anti-plasminogen antibodies are associated with the systemic disease activity of AAV.Methods. One hundred and four Chinese patients with AAV were recruited. Anti-plasminogen antibodies were detected in sequential serum samples at initial onset and remission of the disease. Associations of anti-plasminogen antibodies with clinicopathological parameters were analysed.Results. The prevalence of anti-plasminogen antibodies was significantly higher in AAV patients than in healthy controls (19/104 vs 0/50, χ2 = 8.8, P = 0.003). The prevalence of anti-plasminogen antibodies was significantly higher in the active stage of AAV than in remission (19/104 vs 1/48, χ2 = 7.5, P = 0.013). The level of anti-plasminogen antibodies (expressed as a percentage of the positive controls) correlated with the ESR (r = 0.207, P = 0.042), serum creatinine (r = 0.302, P = 0.002), d-dimer (r = 0.273, P = 0.009) and the percentage of glomeruli with crescents in renal specimens (r = 0.393, P = 0.004). The level of Birmingham vasculitis activity scores and the prevalence of arthralgia and gastrointestinal involvement in patients with anti-plasminogen antibodies were significantly higher than in patients without anti-plasminogen antibodies [22.5 (s.d. 5.63) vs. 19.4 (s.d. 4.66), P = 0.015; 63.2% vs. 25.8%, P = 0.002; 57.9% vs. 21.1%, P = 0.001, respectively].Conclusion. Circulating anti-plasminogen antibodies were associated with systemic disease activity and renal disease activity of AAV. [ABSTRACT FROM PUBLISHER]

Objective: Increasing evidences have suggested the pathogenic role of anti-neutrophil cytoplasmic antibodies (ANCA) directing myeloperoxidase (MPO) in ANCA-associated vasculitis (AAV). The current study aimed to analyze the association between the linear epitopes of MPO-ANCA and clinicopathological features of patients with AAV. Methods: Six recombinant linear fragments, covering the whole length amino acid sequence of a single chain of MPO, were produced from E.coli. Sera from 77 patients with AAV were collected at presentation. 13 out of the 77 patients had co-existence of serum anti-GBM antibodies. Ten patients also had sequential sera during follow up. The epitope specificities were detected by enzyme-linked immunosorbent assay using the recombinant fragments as solid phase ligands. Results: Sera from 45 of the 77 (58.4%) patients with AAV showed a positive reaction to one or more linear fragments of the MPO chain. The Birmingham Vasculitis Activity Scores and the sera creatinine were significantly higher in patients with positive binding to the light chain fragment than that in patients without the binding. The epitopes recognized by MPO-ANCA from patients with co-existence of serum anti-GBM antibodies were mainly located in the N-terminus of the heavy chain. In 5 out of the 6 patients, whose sera in relapse recognize linear fragments, the reactivity to linear fragments in relapse was similar to that of initial onset. Conclusion: The epitope specificities of MPO-ANCA were associated with disease activity and some clinicopathological features in patients with ANCA-associated vasculitis. [ABSTRACT FROM AUTHOR]

Studies in animal models suggest that complement activation is crucial in the pathogenesis of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). Here we investigate the circulating complement activation profile of 66 patients with active stage AAV compared to that of 54 patients with AAV in remission. Plasma levels of C3a, C5a, soluble C5b-9, and Bb, all determined by enzyme-linked immunosorbent assay, were significantly higher in active stage than in remission of AAV, while plasma levels of properdin were significantly lower in the former than the latter disease stage. There was no significant difference in the plasma levels of C4d between active stage and remission. The plasma level of Bb in patients with active AAV significantly correlated with the proportion of total and cellular crescents in the renal biopsy, the erythrocyte sedimentation rate, and the Birmingham Vasculitis Activity Scores. Thus, systemic activation of complement by the alternative pathway takes place in human AAV. Circulating Bb might be a useful biomarker in assessing disease activity of AAV. [ABSTRACT FROM AUTHOR]