scholarly journals Neutrophil Extracellular Traps Profiles in Patients with Incident Systemic Lupus Erythematosus and Lupus Nephritis

2019 ◽  
Vol 47 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Maurizio Bruschi ◽  
Alice Bonanni ◽  
Andrea Petretto ◽  
Augusto Vaglio ◽  
Federico Pratesi ◽  
...  

Objective.Neutrophil extracellular traps (NET) expose modified antigens for autoantibodies in vasculitis. Little is known about levels and removal pathways of NET in systemic lupus erythematosus (SLE), especially in lupus nephritis (LN). We determined circulating levels and defined NET removal in large subsets of patients with incident SLE (iSLE), some of whom had new-onset nephritis.Methods.Serum levels of NET (ELISA), DNase1/DNase1L3 (ELISA), and DNase activity (functional assay) were determined in 216 patients with iSLE [103 had incident LN (iLN)], in 50 patients with other primary glomerulonephritis, and in healthy controls. Ex vivo NET production by neutrophils purified from a random selection of patients was quantified as elastase/DNA release and by immunofluorescence techniques.Results.Serum NET levels were very high in iSLE/iLN compared to all groups of controls and correlated with anti-dsDNA, C3–C4, and proteinuria; iLN had the highest levels. DNase activity was decreased in iLN compared to SLE (20% had one-half DNase activity) despite similar serum levels of DNase1/DNase1L3. In these cases, pretreatment of serum with protein A restored DNase efficiency; 1 patient was homozygous for a c.289_290delAC variant of DNASE1L3. Ex vivo NET production by neutrophils purified from LN, SLE, and normal controls was similar in all cases.Conclusion.Patients with iLN have increased circulating NET and reduced DNase activity, the latter being explained by the presence of inhibitory substances in circulation and/or by rare DNase1L3 mutations. Accumulation of NET derives from a multifactorial mechanism, and is associated and may contribute to disease severity in SLE, in particular to renal lesions. (Clinical trial registration: The Zeus study was registered at ClinicalTrials.gov, study number NCT02403115).

2021 ◽  
Vol 8 ◽  
Author(s):  
Roberta Bertelli ◽  
Francesca Schena ◽  
Francesca Antonini ◽  
Daniele Reverberi ◽  
Sara Signa ◽  
...  

Circulating autoantibodies of IgG2 isotype predominate in Systemic Lupus Erythematosus (SLE) and concur to the development of the renal lesions characteristic of Lupus Nephritis (LN). Anti-dsDNA and anti-histones IgG2, together with anti-podocyte proteins (i.e., α-enolase) are the major autoantibodies in serum and renal glomeruli of LN patients. The mechanisms underlying autoantibody formation and isotype switching in SLE and LN are unknown. A major issue is how DNA/histones are externalized from cell nucleus, driving the autoimmune response. Neutrophil Extracellular Traps (NETs) have been recently identified as crucial players in this context, representing the main source of DNA and nucleosome proteins. A second key point is what regulates IgG2 isotype switching: in mouse models, T-bet transcription factor has been described as essential for IgG2a class switch. We hypothesized that, in SLE, NET formation is the key mechanism responsible for externalization of autoantigens (i.e., dsDNA, histones 2,3, and α-enolase) and that T-bet is upregulated by NETs, driving, in this way, immunoglobulin class switch recombination (CSR), with production of IgG2 autoantibodies. The data here presented show that NETs, purified from SLE patients, stimulate ex vivo IgG2 isotype class switch possibly through the induction of T-bet. Of note, we observed a prominent effect of NETs on the release of soluble IgG2 in SLE patients', but not in healthy donors' B cells. Our results add important knowledge on the mechanisms of IgG2 class switch in SLE and contribute to further elucidate the role of NETs in LN pathogenesis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meng Jiang ◽  
Nan Shen ◽  
Haibo Zhou ◽  
You Wang ◽  
Sihan Lin ◽  
...  

AbstractDespite the advances made in the management of pregnancies in women with systemic lupus erythematosus (SLE), the rate of adverse pregnancy outcomes is still higher than that in the general population. In the last few years, neutrophil extracellular traps (NETs) were proven to be detrimental in both autoimmune diseases and placental injury. We investigated whether NETs could be detected in the placentas of pregnant individuals with SLE and explored the relationship between NETs and decidual natural killer cells (dNKs), which comprise the majority of immune cells at the maternal–fetal interface, using clinical samples and animal models. In this study, we found that the infiltration of NETs and dNKs, especially CD56+CD16+ NK cells, was significantly increased in pregnant individuals with SLE with placental insufficiency. In the murine models of SLE, the number of dNKs was significantly decreased due to the decreased formation of NETs affected by Ly6G. Moreover, the histopathological placental injury was reduced, with a remarkable increase in fetal birth weight. This study shows that NETs may contribute to immunological disorder in the placenta and the pathological changes in pregnancies with SLE, which provides a research basis for further explorations of the mechanism of SLE in placental impairment.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Qingjun Pan ◽  
Linjie Guo ◽  
Jing Wu ◽  
Jun Cai ◽  
Huanjin Liao ◽  
...  

In order to investigate the association between IgG4 autoantibody and complement abnormalities in systemic lupus erythematosus (SLE), 72 newly diagnosed SLE patients, 67 rheumatoid arthritis (RA) patients, and 41 healthy normals were employed. Serum levels of antinuclear IgG4 and IgG4-specific IgM-rheumatoid factor (RF) were measured, and the correlations between serum levels of antinuclear IgG4 and several clinical parameters were analyzed. Also, the levels of IgG subclasses, C1q, and C3 deposition in lupus nephritis (LN) were detected. The results showed that serum levels of antinuclear IgG4 were higher in SLE patients relative to healthy normals (P<0.01). Serum levels of antinuclear IgG4 in SLE patients were positively correlated with serum levels of total IgG4, albumin, and C3 (r=0.61,P<0.05;r=0.40,P<0.05; andr=0.54,P<0.05, resp.) and negatively correlated with 24-hour urinary protein (r=0.49,P<0.05). Serum levels of IgG4-specific IgM-RF were higher in RA patients than in SLE patients (P<0.001). Also, the ratio of the deposition score for IgG4/(IgG1 + IgG2 + IgG3 + IgG4) was negatively correlated with the score for C1q and C3 deposition in LN (r=0.34,P<0.05;r=0.51,P<0.01, resp.). In summary, the IgG4 autoantibody may dampen the inflammatory response in SLE, thus maybe providing a novel therapeutic target for SLE.


2019 ◽  
Vol 39 (11) ◽  
pp. 1849-1857 ◽  
Author(s):  
Ivica Jeremic ◽  
Olivera Djuric ◽  
Milos Nikolic ◽  
Marina Vlajnic ◽  
Aleksandra Nikolic ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document