SummaryIncreasing evidence indicates that aberrant neutrophil extracellular trap (NET) formation could contribute to the pathogenesis of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Recent research has provided evidence that a novel type of ANCA autoantibody, anti-lysosomal membrane protein-2 (LAMP-2) antibody, may have a pathogenic role in AAV. We have shown previously that anti-LAMP-2 antibody-stimulated NET formation contains autoantigens and antimicrobial peptides. The current study sought to determine whether LAMP-2, as a novel antigen of ANCA, was present on NETs in AAV patients, the influence of the anti-LAMP-2 antibody on the neutrophil apoptosis rate and the role of autophagy in anti-LAMP-2 antibodyinduced NET formation. NET formation was assessed using immunofluorescence microscopy, scanning electron microscopy or live cell imaging. The neutrophil apoptosis rate was analysed using fluorescence activated cell sorting (FACS). Autophagy was detected using LC3B accumulation and transmission electron microscopy. The results showed that enhanced NET formation, which contains LAMP-2, was observed in kidney biopsies and neutrophils from AAV patients. The apoptosis rate decreased significantly in human neutrophils stimulated with anti-LAMP-2 antibody, and this effect was attenuated by the inhibitors of autophagy 3-methyladenine (3MA) and 2-morpholin-4-yl-8-phenylchromen-4-one (LY294002). The anti-LAMP-2 antibody-stimulated NET formation was unaffected by benzyloxycarbonyl-Val-Ala-Asp (OMe)-fluoromethylketone (zVAD-fmk) and necrostatin-1 (Nec-1), which are inhibitors of apoptosis and necrosis, respectively, but was inhibited by 3MA and LY294002. Moreover, the proportion of LC3BI that was converted to LC3BII increased significantly (P 5 0Á0057), and massive vacuolizations that exhibited characteristics typical of autophagy were detected in neutrophils stimulated with anti-LAMP-2 antibody. Our results provide further evidence that autophagy is involved in ANCAinduced NET formation in human neutrophils.
Few studies have analyzed the clinicopathologic characteristics and outcomes of lupus nephritis (LN) patients with antineutrophil cytoplasmic antibody (ANCA).The clinical and renal histopathologic data of 154 patients with biopsy-proven LN from 2011 to 2013 were analyzed retrospectively. The patients were followed up for a median period of 16.8 ± 9.4 months, and their outcomes were analyzed. Multivariate Cox analysis was used to evaluate the independent factors for poor outcomes.Among the 154 LN patients, 26 (16.88%) were seropositive for ANCA. The incidences of alopecia, oral ulcer, photosensitivity and skin lesion, and psychosomatic manifestations in the ANCA-positive group were significantly higher than in the ANCA-negative group (P = 0.007, 0.02, 0.02, and 0.03, respectively). Compared with the ANCA-negative group, the ANCA-positive group had significantly lower levels of complement C3 (P = 0.03). Additionally, the positive rate of antinucleosome antibodies, antihistone antibodies, antimitochondrial antibody M2, and anticardiolipin antibodies were higher significantly in the ANCA-positive patients than in the ANCA-negative patients (P = 0.001, 0.001, 0.03, 0.005, respectively). The ANCA-positive group had a notably higher chronic index than the ANCA-negative group (P = 0.01). During the follow-up, the complete remission rate in the ANCA-negative group was higher than that in the ANCA-positive group (P = 0.01). The cumulative renal survival rate in the ANCA-positive group was significantly lower than in the ANCA-negative group (log-rank = 6.59, P = 0.01). Multivariate Cox analysis revealed that the reduced estimated glomerular filtration rate (HR, 1.02; 95% confidence interval, 1.01 to 1.03; P = 0.005), NLR (HR, 1.20; 95% confidence interval, 1.02 to 1.40; P = 0.03), and ANCA (HR, 3.37; 95% confidence interval, 1.12 to 10.09; P = 0.03) were independent risk factors for patients’ renal survival after adjusting for age, sex, crescent formation, and glomerulosclerosis.The study found ANCA in LN patients is not rare, and patients with ANCA present with more severe clinicopathologic injuries. Thus, ANCA is an independent risk factor for poor renal outcomes in LN patients.
IntroductionAntineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is characterised by the autoinflammation and necrosis of blood vessel walls. The renal involvement is commonly characterised by a pauci-immune crescentic glomerulonephritis (PiCGN) with a very rapid decline in renal function. Cathelicidin LL37, an endogenous antimicrobial peptide, has recently been implicated in the pathogenesis of autoimmune diseases. To assess whether serum LL37 reflects renal crescentic formation, we measured the serum levels of LL37 in AAV patients with and without crescentic glomerulonephritis (crescentic GN) as compared to healthy controls (HCs). We also analysed the correlation of the serum levels of LL37 and interferon-α (IFN-α) with the clinical characteristics of the patients.MethodsThe study population consisted of 85 AAV patients and 51 HCs. In 40 ANCA-positive patients, a parallel analysis was performed, including the assessment of LL37 and IFN-α levels in the serum and renal biopsies. Of those studied, 15 AAV patients had biopsy-proven crescentic GN, and 25 AAV patients lacked crescent formation. The serum levels of cathelicidin LL37 and IFN-α were both measured by ELISA, and the clinical and serological parameters were assessed according to routine procedures. Immunofluorescence staining was performed on frozen sections of kidney needle biopsies from AAV patients with crescentic GN.ResultsThe serum levels of LL37 and IFN-α were significantly increased in AAV patients with crescentic GN compared to AAV patients without crescentic formation and HCs, and patients with high LL37 and IFN-α levels were more likely to be in the crescentic GN group. The LL37 levels were positively correlated with the IFN-α levels, and both LL37 and IFN-α levels showed a positive correlation with serum creatinine and no correlation with complement C3. The renal tissue of crescentic GN patients showed expression of LL37 and IFN-α at the Bowman’s capsule and extracellular sites, suggesting the active release of LL37 and IFN-α.ConclusionsSignificantly higher levels of LL-37 and IFN-α were observed in AAV patients, particularly those with crescentic formation, and LL37 and IFN-α were expressed in the renal tissue of patients with crescentic GN. These data suggest that serum levels of LL37 and IFN-α may reflect both local renal inflammation and systemic inflammation.
Purpose Which kind of elements could be determined by the portable X-ray Fluorescence (PXRF) analyzer in field conditions? How about the accuracy of the results? It is necessary to conduct some researches in order to well understand the application of PXRF which is regarded as a new kind of in-situ measurement method. Methods A set of 221 farmland soil samples were collected within a basin once it has been a lead-zinc smelting base. PXRF was used for field detection at all sample sites, then the soil samples were brought back to the laboratory to be analyzed again by atomic absorption spectrometry (AAS), paired T test and linear regression were conducted to analyze the difference and correlation between the result of PXRF and AAS methods. Results There was little difference and high correlation between PXRF and AAS methods, indicating that in field conditions PXRF can effectively predict the concentrations of Pb and Zn in soil. Although there were some differences in the determinationresults of Cu, the pollution level of Cu in this study area still could be predicted. Unfortunately, PXRF method had large errors in the determination of Cd and Cr, so it was not suitable for the in-situ determination of Cd and Cr in this study area. Conclusion The concentrations of Pb and Zn in the soil of lead-zinc smelting area can be accurately monitored by PXRF, while concentrations of Cu in soil can also be predicted by PXRF in the less accuracy level, Cd and Cr should not be monitored by PXRF.
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