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Search results for: Anti human Apolipoprotein H (β2 Glycoprotein I )

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#33444093   2021/01/14 To Up

β2 glycoprotein I participates in phagocytosis of apoptotic neurons and in vascular injury in experimental brain stroke.

Beta-2 Glycoprotein I (β2-GPI) is the main target of anti-phospholipid antibodies (aPL) in the autoimmune anti-phospholipid syndrome, characterized by increased risk of stroke. We here investigated the antibody independent role of β2-GPI after ischemia/reperfusion, modeled by transient middle cerebral artery occlusion (tMCAo) in male C57Bl/6J mice; by subjecting immortalized human brain microvascular endothelial cells (ihBMEC) to 16 h hypoxia and 4 h re-oxygenation. (coding for β2-GPI) was upregulated selectively in the liver at 48 h after tMCAo. At the same time β2-GPI circulating levels increased. β2-GPI was detectable in brain parenchyma and endothelium at all time points after tMCAo. Parenchymal β2-GPI recognized apoptotic neurons (positive for annexin V, C3 and TUNEL) cleared by CD68+ brain macrophages. Hypoxic ihBMEC showed increased release of IL-6, over-expression of and after re-oxygenation with β2-GPI alone. β2-GPI interacted with mannose-binding lectin in mouse plasma and ihBMEC medium, potentially involved in formation of thrombi. We show for the first time that brain ischemia triggers the hepatic production of β2-GPI. β2-GPI is present in the ischemic endothelium, enhancing vascular inflammation, and extravasates binding stressed neurons before their clearance by phagocytosis. Thus β2-GPI may be a new mediator of brain injury following ischemic stroke.
Claudia Grossi, Carolina Artusi, PierLuigi Meroni, Maria Orietta Borghi, Laura Neglia, Paola Adele Lonati, Marco Oggioni, Francesco Tedesco, Maria-Grazia De Simoni, Stefano Fumagalli

2320 related Products with: β2 glycoprotein I participates in phagocytosis of apoptotic neurons and in vascular injury in experimental brain stroke.

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#33295416   // To Up

Non-criteria Antiphospholipid Antibodies: a narrative review.

The 2006 Revised Sapporo Classification Criteria for Definite Antiphospholipid Syndrome included as laboratory criteria the tests for antiphospholipid antibodies whose accuracy was regarded as satisfactory according to the evidence available at that time. In practice, however, the sensitivity and specificity of these "criteria" of antiphospholipid antibodies are sometimes insufficient for identifying or ruling out antiphospholipid syndrome. It has been studied whether the accuracy of the laboratory diagnosis of the syndrome could be improved by testing for non-criteria antiphospholipid antibodies. In this work, we review evidence on the clinical associations and diagnostic value of the most commonly studied non-criteria antibodies, namely: antiphosphatidylethanolamine, anti-annexin A5, anti-prothrombin, anti-phosphatidylserine/prothrombin complex, IgA anticardiolipin, and IgG anti-domain I of the β2 glycoprotein antibodies.
Andreas Funke, Henrique Luiz Staub, Odirlei Andre Monticielo, Gustavo Guimarães Moreira Balbi, Adriana Danowski, Mittermayer Barreto Santiago, Danieli Castro Oliveira de Andrade, Jozelia Rêgo

2449 related Products with: Non-criteria Antiphospholipid Antibodies: a narrative review.

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#33255963   2020/11/26 To Up

The Weight of IgA Anti-β2glycoprotein I in the Antiphospholipid Syndrome Pathogenesis: Closing the Gap of Seronegative Antiphospholipid Syndrome.

The specific value of IgA Anti-β2glycoprotein I antibodies (aB2GP1) in the diagnosis and management of antiphospholipid syndrome (APS) is still controversial and a matter of active debate. The relevance of the IgA aB2GP1 isotype in the pathophysiology of APS has been increasingly studied in the last years. There is well know that subjects with multiple positive APS tests are at increased risk of thrombosis and/or miscarriage. However, these antibodies are not included in the 2006 APS classification criteria. Since 2010 the task force of the Galveston International Congress on APS recommends testing IgA aB2GP1 isotype in patients with APS clinical criteria in the absence of criteria antibodies. In this review, we summarize the molecular and clinical "state of the art" of the IgA aB2GP in the context of APS. We also discuss some of the characteristics that may help to evaluate the real value of the IgA aB2GP1 determination in basic research and clinical practice. The scientific community should be aware of the importance of clarifying the role of IgA aB2GP1 in the APS diagnosis.
Oscar Cabrera-Marante, Edgard Rodríguez de Frías, Manuel Serrano, Fernando Lozano Morillo, Laura Naranjo, Francisco J Gil-Etayo, Estela Paz-Artal, Daniel E Pleguezuelo, Antonio Serrano

1966 related Products with: The Weight of IgA Anti-β2glycoprotein I in the Antiphospholipid Syndrome Pathogenesis: Closing the Gap of Seronegative Antiphospholipid Syndrome.

100 μg10.1 mg

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#33178218   2020/10/15 To Up

Anti-Phospholipid Antibodies in COVID-19 Are Different From Those Detectable in the Anti-Phospholipid Syndrome.

Critically ill patients with coronavirus disease 2019 (COVID-19) have a profound hypercoagulable state and often develop coagulopathy which leads to organ failure and death. Because of a prolonged activated partial-thromboplastin time (aPTT), a relationship with anti-phospholipid antibodies (aPLs) has been proposed, but results are controversial. Functional assays for aPL (i.e., lupus anticoagulant) can be influenced by concomitant anticoagulation and/or high levels of C reactive protein. The presence of anti-cardiolipin (aCL), anti-beta2-glycoprotein I (anti-βGPI), and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies was not investigated systematically. Epitope specificity of anti-βGPI antibodies was not reported.
Maria Orietta Borghi, Asmaa Beltagy, Emirena Garrafa, Daniele Curreli, Germana Cecchini, Caterina Bodio, Claudia Grossi, Simonetta Blengino, Angela Tincani, Franco Franceschini, Laura Andreoli, Maria Grazia Lazzaroni, Silvia Piantoni, Stefania Masneri, Francesca Crisafulli, Duilio Brugnoni, Maria Lorenza Muiesan, Massimo Salvetti, Gianfranco Parati, Erminio Torresani, Michael Mahler, Francesca Heilbron, Francesca Pregnolato, Martino Pengo, Francesco Tedesco, Nicola Pozzi, Pier Luigi Meroni

1332 related Products with: Anti-Phospholipid Antibodies in COVID-19 Are Different From Those Detectable in the Anti-Phospholipid Syndrome.

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#33031793   2020/10/06 To Up

Distinct and overlapping effects of β-glycoprotein I conformational variants in ligand interactions and functional assays.

One of the most abundant coagulation proteins is β-glycoprotein I (βGPI) that is present in humans at a concentration of around 200 mg/L. Its physiological role is only partially understood, but it adopts several different structural forms the majority of which are the open and closed forms. We isolated native (circular) βGPI and converted it into an open conformation. The effectiveness of these procedures was assessed by Western blot and negative-staining electron microscopy. We found that in coagulation assays the open form of βGPI had a significant prolonging effect on fibrin formation in a dilute prothrombin time test (p < 0.001). In the dilute activated partial thromboplastin time test, both conformations had a significant prolonging effect (p < 0.001) but the open conformation was more effective. In a fluorescent thrombin generation assay both conformations slightly delayed thrombin generation with no significant effect on the quantity of formed thrombin. By using surface plasmon resonance assays, the equilibrium dissociation constants of both the open and closed conformations of βGPI showed a similar and strong affinity to isolated anti-βGPI autoantibodies (K closed βGPI = 5.17 × 10 M, K open βGPI = 5.56 × 10 M) and the open form had one order of magnitude stronger affinity to heparin (K = 0.30 × 10 M) compared to the closed conformation (K = 3.50 × 10 M). The two different forms of βGPI have distinct effects in functional tests and in ligand binding, which may considerably affect the intravascular events related to this abundant plasma protein in health and disease.
Gábor Szabó, Krisztina Pénzes, Bernadett Torner, Miklós Fagyas, Tünde Tarr, Pál Soltész, Gréta Kis, Miklós Antal, János Kappelmayer

1429 related Products with: Distinct and overlapping effects of β-glycoprotein I conformational variants in ligand interactions and functional assays.

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#32759297   2020/08/05 To Up

Complement Activation and Thrombin Generation by MBL Bound to β2-Glycoprotein I.

β2-Glycoprotein I (β2-GPI) is an abundant plasma glycoprotein with unknown physiological function and is currently recognized as the main target of antiphospholipid Abs responsible for complement activation and vascular thrombosis in patients with antiphospholipid syndrome (APS). In this study, we provide evidence that mannose-binding lectin (MBL) binds to β2-GPI in Ca and a dose-dependent manner and that this interaction activates complement and promotes complement-dependent thrombin generation. Surprisingly, a significant binding was observed between MBL and isolated domains II and IV of β2-GPI, whereas the carbohydrate chains, domain I and domain V, were not involved in the interaction, documenting a noncanonical binding mode between MBL and β2-GPI. Importantly, this interaction may occur on endothelial cells because binding of MBL to β2-GPI was detected on the surface of HUVECs, and colocalization of MBL with β2-GPI was observed on the endothelium of a biopsy specimen of a femoral artery from an APS patient. Because β2-GPI-mediated MBL-dependent thrombin generation was increased after priming the endothelium with TNF-α, our data suggests that this mechanism could play an important yet unrecognized role under physiological conditions and may be upregulated in pathological situations. Moreover, the complement activation and the procoagulant effects of the β2-GPI/MBL complex may contribute to amplify similar activities of anti-β2-GPI Abs in APS and possibly act independently of Abs, raising the issue of developing appropriate therapies to avoid recurrences and disability in patients at risk for these clinical conditions.
Paolo Durigutto, Paolo Macor, Nicola Pozzi, Chiara Agostinis, Fleur Bossi, Pier Luigi Meroni, Claudia Grossi, Maria O Borghi, William Planer, Peter Garred, Francesco Tedesco

2178 related Products with: Complement Activation and Thrombin Generation by MBL Bound to β2-Glycoprotein I.

961 mg10ml1 g430 tests100ug Lyophilized0.025 mg1 module100ug100ug100 ul

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#32723434   2020/07/28 To Up

Frequency and clinical correlates of antiphospholipid antibodies arising in patients with SARS-CoV-2 infection: findings from a multicentre study on 122 cases.

COVID-19 features include disseminated intravascular coagulation and thrombotic microangiopathy indicating a hypercoagulable state. We aimed to investigate antiphospholipid antibodies (aPL) prevalence and clinical relationships in a large cohort of COVID-19 patients.
Mariele Gatto, Carlo Perricone, Marta Tonello, Onelia Bistoni, Anna Maria Cattelan, Roberto Bursi, Giacomo Cafaro, Edoardo De Robertis, Antonella Mencacci, Silvia Bozza, Andrea Vianello, Luca Iaccarino, Roberto Gerli, Andrea Doria, Elena Bartoloni

1320 related Products with: Frequency and clinical correlates of antiphospholipid antibodies arising in patients with SARS-CoV-2 infection: findings from a multicentre study on 122 cases.



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#32702934   // To Up

Infective endocarditis mimicking ANCA-associated vasculitis: does it require immunosuppressive therapy?: A case report and literature review.

In the course of endocarditis, the development of antineutrophil cytoplasmic antibody (ANCA)-mediated disease introduces the dilemma of determining the best treatment approach for immune conditions, whether immunosuppressant therapy should be added to antibiotic treatment has remained controversial.
Xiao-Dong Shi, Wan-Yu Li, Xue Shao, Li-Mei Qu, Zhen-Yu Jiang

1076 related Products with: Infective endocarditis mimicking ANCA-associated vasculitis: does it require immunosuppressive therapy?: A case report and literature review.

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#32619328   2020/07/23 To Up

Antiphospholipid antibodies in patients with COVID-19: A relevant observation?

High incidence of thrombosis in COVID-19 patients indicates a hypercoagulable state. Hence, exploring the involvement of antiphospholipid antibodies (aPL) in these patients is of interest.
Katrien M J Devreese, Eleni A Linskens, Dominique Benoit, Harlinde Peperstraete

1252 related Products with: Antiphospholipid antibodies in patients with COVID-19: A relevant observation?

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#32583563   2020/09/30 To Up

The β -Glycoprotein I/HLA-DR Complex As a Major Autoantibody Target in Obstetric Antiphospholipid Syndrome.

The clinical manifestations of antiphospholipid syndrome (APS) include vascular thrombosis and pregnancy morbidity as well as recurrent pregnancy loss (RPL). However, in more than half of patients with RPL, the cause is never determined. Recently, β -glycoprotein I (β GPI) complexed with HLA class II molecules (β GPI/HLA-DR) was found to be a major autoantibody target in APS. The present study was undertaken to assess the serum levels of autoantibodies against the β GPI/HLA II complex as a potential risk factor for RPL in women.
Kenji Tanimura, Shigeru Saito, Mikiya Nakatsuka, Takeshi Nagamatsu, Tomoyuki Fujii, Atsushi Fukui, Masashi Deguchi, Yuki Sasagawa, Noriko Arase, Hisashi Arase, Hideto Yamada

1688 related Products with: The β -Glycoprotein I/HLA-DR Complex As a Major Autoantibody Target in Obstetric Antiphospholipid Syndrome.

0.1ml (1mg/ml)100 assays100 assays100 assays100 assays100 assays100 assays100 assays100 assays100 assays100 assays100 assays

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