Soluble fibrin formation in the mesangial area of IgA nephropathy

SummarySoluble fibrin (SF) is regarded as an indicator of acute fibrin formation and a precursor of fibrin thrombi. Using a set of clinical plasma samples, and fibrin derivatives, five assays for measurement of SF, including two chromogenic assays, two ELISA systems, and one latex-enhanced photometric immunoassay were compared. Correlation between SF assays was moderate (Spearman’s rho values between 0.344 and 0.805). Re-calibration with serial dilutions of desAABBfibrin monomer resulted in adjustment of the numerical scale of the assays without improving correlation.All SF assays reacted with purified crosslinked fibrin derivatives. Using clinical plasma samples, Spearman’s rho of SF assays with D-dimer consensus values based upon results of 23 quantitative D-dimer assays were between 0.491 and 0.911.Although all SF assays react with desAABB-fibrin monomer complexes, SF assays are heterogeneous concerning reactivity with fibrin compounds observed in clinical plasma samples. The prospect of a common calibrator for SF assays therefore seems to be remote.Since SF assays react with crosslinked fibrin derivatives, it is not possible to clearly distinguish between acute fibrin formation, and fibrin dissolution on the basis of the results of current SF assays.

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microRNA-630 Regulates Underglycosylated IgA1 Production in the Tonsils by Targeting TLR4 in IgA Nephropathy

Frontiers in Immunology ◽

10.3389/fimmu.2020.563699 ◽

2020 ◽

Vol 11 ◽

Author(s):

Chan Liu ◽

Mu-Yao Ye ◽

Wen-Zhe Yan ◽

Xiao-Fei Peng ◽

Li-Yu He ◽

...

Keyword(s):

Iga Nephropathy ◽

Molecular Mechanisms ◽

Mononuclear Cells ◽

Immunohistochemical Analysis ◽

Bioinformatic Analysis ◽

Cell Culture Supernatant ◽

Mechanism Study ◽

Complement Components ◽

Mesangial Area ◽

Primary Glomerular Disease

IgA nephropathy (IgAN) is the most common primary glomerular disease. The characteristic pathology involves immune complexes formed by the deposition of IgA1 and underglycosylated IgA1 aggregates in the mesangial area, which may be accompanied by the deposition of IgG and/or IgM and complement components. However, the molecular mechanisms of IgAN remain unclear. In the present study, microarray analysis showed that the expression of microRNA-630 (miR-630) was significantly reduced in palatal tonsils from IgAN patients compared with chronic tonsillitis. Additionally, bioinformatic analysis showed that Toll-like receptor 4 (TLR4) was the predicted target gene of miR-630 and was regulated by miR-630. When miR-630 was overexpressed in palatal tonsil mononuclear cells from IgAN patients, the expression of TLR4 was reduced and the content of IgA1 in the cell culture supernatant was decreased, and the level of galactosylation in the IgA1 hinge region was increased. Moreover, immunohistochemical analysis showed that the expression of TLR4 in IgAN patients was significantly increased. After knocking down the expression of TLR4, both the concentration of IgA1 and the binding force of IgA1 with broad bean lectin were significantly reduced in IgAN. Furthermore, the mechanism study demonstrated that TLR4 might regulate the expression of IL-1β and IL-8 through NF-κB signaling pathway to modulate the concentration of IgA1 and the glycosylation level of IgA1. This interesting finding may offer new insight into the molecular mechanism of IgAN.

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A New Enzyme Immunoassay for Soluble Fibrin in Plasma, with a High Discriminating Power for Thrombotic Disorders

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614418 ◽

1999 ◽

Vol 81 (01) ◽

pp. 54-59 ◽

Cited By ~ 8

Author(s):

G. H. Laterveer-Vreeswijk ◽

D. Lockwood ◽

K. Szewczyk ◽

W. Nieuwenhuizen ◽

R. Bos

Keyword(s):

Enzyme Immunoassay ◽

Solid Phase ◽

Gamma Chain ◽

Soluble Fibrin ◽

Fibrin Formation ◽

Discriminating Power ◽

Multistep Process ◽

Intravascular Coagulopathy ◽

Buffer Composition

SummaryFibrin formation is a multistep process initiated by thrombin. At first thrombin converts fibrinogen to fibrin molecules which in vivo form soluble complexes with fibrinogen. Soluble fibrin is considered to be an early biochemical marker for intravascular fibrin formation and impending thrombotic events, such as deep venous thrombosis (DVT), pulmonary embolism (PE) and disseminated intravascular coagulopathy (DIC).A new enzyme immunoassay (EIA) was developed on the basis of a monoclonal antibody directed against a fibrin specific neo-epitope located on the gamma-chain of fibrinogen; γ-(312-324). In addition, it was possible to prepare a lyophilized reference material of thrombin-generated soluble fibrin, that allowed for full antigen recovery after reconstitution with buffer. Assay conditions, e.g. solid phase-Ig concentration and buffer composition, sample and conjugate dilution, and incubation times were optimised.The present assay was found to be specific (no interference of homologous antigens) and reproducible (intra-assay CV 4-8%, inter-assay CV 4-9%), and therefore highly suited for measuring soluble fibrin levels in a plasma milieu. The median normal value for soluble fibrin was determined in plasma samples obtained from apparently healthy volunteers (n = 81) and found to be 0.040 μg/ml, with a range (10-90 percentiles) of 0.026-0.059 μg/ml.A retrospective study showed that soluble fibrin levels were highly significantly increased in patients with a confirmed diagnosis of DIC (median 1.042 μg FEU/ml, range 0.160-2.319 μg/ml, n = 21, P <0.0001 vs normal), PE (median 0.527 μg FEU/ml, range 0.084-1.234 μg/ml, n = 29, P <0.0001 vs normal) and DVT (median 0.126 μg FEU/ml, range 0.059-0.878 μg/ml, n = 36, P <0.0001 vs normal), as determined by the Mann-Whitney U-Test.

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The TLR4-MyD88-NF-κB pathway is involved in sIgA-mediated IgA nephropathy

Journal of Nephrology ◽

10.1007/s40620-020-00722-3 ◽

2020 ◽

Vol 33 (6) ◽

pp. 1251-1261 ◽

Cited By ~ 2

Author(s):

Junjun Zhang ◽

Yiming Mi ◽

Ruwen Zhou ◽

Zhangsuo Liu ◽

Bo Huang ◽

...

Keyword(s):

Iga Nephropathy ◽

Mesangial Cells ◽

Immunofluorescence Assay ◽

Kidney Damage ◽

Secretory Iga ◽

Tnf Α ◽

Mesangial Area ◽

Enhanced Expression ◽

Better Than

AbstractPrevious studies have shown that secretory IgA (sIgA) was critically involved in IgA nephropathy (IgAN) immune responses. Toll-like receptors (TLRs), especially TLR4 which participates in mucosal immunity, may be involved in the pathogenesis of IgAN. The purpose of this study was to investigate whether sIgA and TLR4 interact to mediate kidney damage in IgAN patients. IgAN patients with positive sIgA deposition in renal tissues were screened by immunofluorescence assay. Patient salivary sIgA (P-sIgA) was collected and purified by jacalin affinity chromatography. Salivary sIgA from healthy volunteers was used as a control (N-sIgA). Expression of TLR4, MyD88, NF-κB, TNF-α, IL-6, and MCP-1 were detected in the mesangial area of IgAN patients by immunohistochemistry, the expression levels in patients with positive sIgA deposition were higher than that with negative sIgA deposition. Human renal mesangial cells (HRMCs) were cultured in vitro, flow cytometry showed that P-sIgA bound HRMCs significantly better than N-sIgA. HRMCs were cultured in the presence of sIgA (400 μg/mL) for 24 h, compared with cells cultured with N-sIgA, HRMCs cultured in vitro with P-sIgA showed enhanced expression of TLR4, increased secretion of TNF-α, IL-6, and MCP-1, and increased expression of MyD88/NF-κB. TLR4 shRNA silencing and NF-κB inhibition both reduced the ability of HRMCs to synthesize TNF-α, IL-6, and MCP-1. Our results indicate that sIgA may induce high expression of TLR4 in HRMCs and further activate downstream signalling pathways, prompting HRMCs to secrete multiple cytokines and thereby mediating kidney damage in IgAN patients.

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Distribution pattern of mesangial C4d deposits as predictor of kidney failure in IgA nephropathy

PLoS ONE ◽

10.1371/journal.pone.0252638 ◽

2021 ◽

Vol 16 (6) ◽

pp. e0252638

Author(s):

Suchin Worawichawong ◽

Sirithep Plumworasawat ◽

Wisit Liwlompaisan ◽

Vasant Sumethkul ◽

Bunyong Phakdeekitcharoen ◽

...

Keyword(s):

Iga Nephropathy ◽

Kidney Failure ◽

Interstitial Fibrosis ◽

Univariate Analysis ◽

Clinicopathological Parameters ◽

Positive Staining ◽

Global Pattern ◽

Mesangial Area ◽

Lower Egfr ◽

C4d Staining

Mesangial C4d deposits have been associated with worse outcomes in Western patients with IgA nephropathy (IgAN), but there is limited data in Asians. Previously, a high proportion of stained glomeruli was often required for the classification of C4d positive (C4d+ve). Positive staining in lower proportion of staining would be classified as C4d-ve. This retrospective study evaluated the prognostic value of C4d+ve using a less stringent definition (one C4d+ve glomerulus) in Thai patients with IgAN (n = 120). Baseline findings and outcomes were compared between those with more extensive C4d staining patterns and those with more restricted staining. Clinico-pathologic parameters and risk for kidney outcomes (kidney failure or decline GFR50%) were compared between C4d+ve versus C4d-ve, and between different patterns: Focal (< 50%) versus Diffuse (≥ 50% of glomeruli); or Global (≥ 50) versus Segmental (< 50% of mesangial area). The hazard ratios were estimated using Cox proportional hazard models for Model 1 (Oxford score+ C4d) and Model 2 (Model 1+ clinical factors). C4d+ve (n = 81) had lower eGFR, more global sclerosis, and interstitial fibrosis than C4d-ve at baseline. The 5-year kidney survival for C4d+ve was lower (53.7%) than C4d-ve (89.7%); P = 0.0255. By univariate analysis, T1, T2, C4d+ve, eGFR<60, proteinuria were predictors of kidney outcome. By multivariate analysis, proteinuria, T1, T2 and C4d+ve were independent predictors (Model 2 HR (95% CI) C4d+ve: 3.24 (1.09–9.58), p = 0.034). Segmental had lower eGFR, higher tubulointerstitial fibrosis, and segmental sclerosis compared to Global pattern. Clinicopathological parameters were not different between Focal and Diffuse patterns. Outcomes were similar between staining patterns. In conclusion, C4d staining may be a valuable marker of poor prognosis in Asian patients with IgAN. Less stringent criteria for C4d+ve should be considered as no differences in outcomes were observed between more extensive staining with less extensive patterns. More studies are needed to identify the optimum criteria for C4d+ve.

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Use of soluble fibrin antigen instead of D-dimer as fibrin-related marker may enhance the prognostic power of the ISTH overt DIC score

Thrombosis and Haemostasis ◽

10.1160/th03-09-0577 ◽

2004 ◽

Vol 91 (04) ◽

pp. 812-818 ◽

Cited By ~ 68

Author(s):

Michael Wurst ◽

Mathias Smolinski ◽

Stephan Lorenz ◽

Alexandra Osika ◽

Daniela Olenik ◽

...

Keyword(s):

Clinical Outcome ◽

Degradation Products ◽

Surgical Intensive Care ◽

Soluble Fibrin ◽

Fibrin Formation ◽

Fibrin Degradation Products ◽

Distribution Of Values ◽

Prognostic Power ◽

D Dimer ◽

Selection Of

SummaryThe overt DIC score of the DIC subcommittee of the ISTH includes a fibrin-related marker (FRM) as indicator of intravascular fibrin formation. The type of marker to be used has not been specified, but D-dimer antigen, or fibrin degradation products are used by most investigators. Soluble fibrin complexes have been suggested as more specific indicators of acute intravascular fibrin formation. The aim of the present study was to compare the predictive value of the overt DIC score concerning clinical outcome in a surgical intensive care cohort, using either D-dimer antigen, or soluble fibrin antigen as FRM. The cutoff values for 2 and 3 score points for the FRM were assigned on the basis of the 25% and 75% quartiles of 1870 plasma samples obtained from 359 ICU patients during a period of 6 months. For 331 patients with complete diagnostic workup and day 1 blood samples, the Iatro SF as FRM component of the overt DIC score displayed the highest prognostic power concerning clinical outcome. The 28-day mortality of patients with overt DIC at day 1, using Iatro SF as FRM assay was 50.0%, whereas 28-day mortality of patients without overt DIC was 14.0% (p <0.0001). Using MDA D-dimer, and TINAquant D-dimer, 28-day mortality was between 35.5% and 39.3% in patients with overt DIC, and 15.5% to 15.6% in patients without overt DIC. Selection of the FRM as component of the DIC score has a small, but relevant impact on the prognostic performance of the overt DIC score. The present data on the distribution of values may provide a basis for the selection of appropriate cutoff points for assigning 2, and 3 points in the score.

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Markers of fibrin formation in colorectal surgery: Fibrinopeptide A and soluble fibrin

Thrombosis Research ◽

10.1016/0049-3848(96)00031-x ◽

1996 ◽

Vol 81 (5) ◽

pp. 569-576 ◽

Cited By ~ 1

Author(s):

Lene H. Iversen ◽

Ole Thorlacius-Ussing

Keyword(s):

Colorectal Surgery ◽

Fibrinopeptide A ◽

Soluble Fibrin ◽

Fibrin Formation

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Intravenous administration of Streptococcus mutans induces IgA nephropathy-like lesions

Clinical and Experimental Nephrology ◽

10.1007/s10157-020-01961-1 ◽

2020 ◽

Vol 24 (12) ◽

pp. 1122-1131

Author(s):

Shuhei Naka ◽

Kaoruko Wato ◽

Taro Misaki ◽

Seigo Ito ◽

Yasuyuki Nagasawa ◽

...

Keyword(s):

Iga Nephropathy ◽

Streptococcus Mutans ◽

Intravenous Administration ◽

Mesangial Cells ◽

Late Phase ◽

Control Group ◽

Chronic Glomerulonephritis ◽

Sprague Dawley ◽

Mesangial Area ◽

Specific Pathogen

Abstract Background IgA nephropathy (IgAN) is one of the most frequently occurring types of chronic glomerulonephritis. Previous analyses have revealed that a major pathogen of dental caries, Streptococcus mutans [which expresses collagen-binding protein (Cnm) on its surface], is involved in the pathogenesis of IgAN. Methods Cnm-positive S. mutans isolated from a patient with IgAN was intravenously administered to specific pathogen-free Sprague–Dawley rats to evaluate their kidney conditions. Results The urinary protein level of the S. mutans group reached a plateau at 30 days, with increased numbers of mesangial cells and an increased mesangial matrix. The numbers of rats with IgA-positive and/or C3-positive glomeruli were significantly greater in the S. mutans group than in the control group at 45 days (P < 0.05). Electron microscopy analyses revealed electron-dense depositions in the mesangial area among rats in the S. mutans group. There were significantly more CD68-positive cells (macrophages) in the glomeruli of the S. mutans group than in the glomeruli of the control group during the late phase (P < 0.05), similar to the findings in patients with IgAN. Conclusion Our results suggested that intravenous administration of Cnm-positive S. mutans caused transient induction of IgAN-like lesions in rats.

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