Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The causes of thrombosis and pregnancy loss in antiphospholipid syndrome (APS) are still unknown, although several hypotheses have been proposed and hypofibrinolysis has been implicated. Anti-tissue-type plasminogen activator (tPA) antibodies may induce fibrinolytic defects and preliminary data indicate an association with thrombosis in APS. We measured plasma anti-tPA antibody levels in 91 consecutive patients with APS, 91 healthy controls, 40 patients with antiphospholipid antibodies without APS symptoms, and 23 patients with systemic lupus erythematosus (SLE) without antiphospholipid antibodies and APS symptoms. Patients with APS had anti-tPA antibody levels higher than controls (P = .0001), patients with SLE (P = .0001), and asymptomatic antiphospholipid patients (P = .05). A subgroup of 53 patients had plasma levels of tPA antigen higher (P = .0001) and tPA activity lower (P = .05) than controls, with an inverse correlation (r = -0.454; P = .003) between anti-tPA antibody levels and tPA activity and no correlation with tPA antigen. The 2 patients with the highest antibody levels had tPA activity below the normal range. Their antibodies were, respectively, IgG1 and IgG3; both recognized human tPA, recombinant tPA, and the catalytic domain of tPA, but not beta 2-glycoprotein I, prothrombin, or plasminogen. Our data indicate that anti-tPA antibodies specifically interacting with the catalytic domain of tPA can be found in patients with APS, representing a possible cause of hypofibrinolysis.
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PMID:Antibodies to tissue-type plasminogen activator (tPA) in patients with antiphospholipid syndrome: evidence of interaction between the antibodies and the catalytic domain of tPA in 2 patients. 1463 Jul 88

Antiphospholipid-mediated endothelium perturbation plays a role in antiphospholipid syndrome (APS)-associated vasculopathy. Antiphospholipid antibodies activate endothelium both in vitro and in vivo experimental models by inducing a pro-inflammatory/-coagulant phenotype; the antibodies recognize beta2 glycoprotein I (beta2GPI) on human endothelial cells (EC) from different parts of the vasculature. In spite of such large in vitro evidence, few studies have addressed the issue whether or not a comparable endothelial perturbation might be detectable in vivo. We investigated several indirect ex vivo parameters of endothelial dysfunction: plasma levels of soluble adhesion molecules (sADM), soluble thrombomodulin (sTM), von Willebrand factor (vWF) and tissue plasminogen activator (t-PA) by solid-phase assays. The study included: patients with primary antiphospholipid syndrome (n=32), with the syndrome secondary to non-active systemic lupus erythematosus (SLE, n=10), six patients with persistent antiphospholipid positivity at medium/high titre without any clinical manifestation of the syndrome. Fifty-two age and sex matched healthy subjects have been enrolled as controls. In addition, circulating endothelial cells identified by flow cytometry and the brachial artery flow-mediated vasodilation (FMV) were evaluated in 26 patients (20 primary and 6 lupus syndromes) and 30 healthy controls. Plasma levels of soluble adhesion molecules did not differ from controls, while a significant increase in von Willebrand factor titres (P<0.05) was found. No significant difference was found regarding the number of circulating endothelial cells and flow-mediated vasodilation. As a whole, these findings do suggest that antiphospholipid antibodies per se are not able to support a full-blown endothelial perturbation in vivo. As shown in antiphospholipid syndrome experimental animal models, a two-hit hypothesis is suggested.
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PMID:Inflammatory response and the endothelium. 1550 62

Because both immunoglobulin G (IgG) and phospholipids interfere with fibrinolysis, their combined modulating effects were investigated in experimental models of three consecutive steps of the fibrinolytic process [diffusion of tissue-type plasminogen activator (tPA) into the clot, plasminogen activation on fibrin surface and fibrin dissolution by plasmin] using IgGs isolated from healthy subjects and from patients with antiphospholipid syndrome in combination with mixtures of synthetic dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylserine. In fibrin clots containing phospholipids the normal IgG enhanced the barrier function of the phospholipids with respect to the diffusion of tPA and plasminogen activation, but did not modify the lysis by plasmin. One of the examined antiphospholipid syndrome-IgGs also restricted the diffusion of tPA, but it accelerated the plasminogen activation on the fibrin surface and slowed down the lysis of fibrin by plasmin. Another antiphospholipid syndrome IgG, which did not affect significantly the tPA penetration into the fibrin gel, did not modify the plasminogen activation on its own, but it partially opposed the inhibiting effect of phospholipids on plasmin formation and accelerated the end-stage lysis of fibrin containing phospholipids. The IgGs from the two examined antiphospholipid syndrome patients did not show consistent deviation from the pattern of normal IgG effects on fibrinolysis in phospholipid environment. Thus, a high degree of heterogeneity with respect to the profibrinolytic or antifibrinolytic effects of the pathological IgGs can be expected in the antiphospholipid syndrome patient population, which may contribute to the variable thrombotic symptoms in this clinical syndrome.
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PMID:Modulation of fibrinolysis by the combined action of phospholipids and immunoglobulins. 1818 Jun 21

Antiphospholipid syndrome (APS) is a multisystemic disorder of coagulation-causing thrombosis in the arterial and venous system as well as pregnancy-related complications such as miscarriage, stillbirth, preterm delivery and pre-eclampsia. The disease is characterized by the autoimmune production of antibodies against phospholipid, a substance found in the cell membrane. We here report the case of a patient with four second trimester miscarriages, who apart from a heterozygous plasminogen activator-inhibitor-1 mutation, had no risk factors explaining her condition. In the subsequent pregnancy she was therefore put on low-molecular-weight heparin, aspirin and granulocyte colony-stimulating factor. Antiphospholipid antibodies (APL), which had been negative before gestation, increased and remained high throughout pregnancy, thus suggesting a pregnancy-induced or -aggravated APS. The patient was kept on the above-mentioned medication and delivered a healthy male baby by Caesarean section after an otherwise uneventful pregnancy. Thus, in order to diagnose and treat pregnancy-triggered APS in patients with unexplained recurrent miscarriage, screening for APL should also be performed at several time points after conception.
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PMID:Pregnancy-triggered antiphospholipid syndrome in a patient with multiple late miscarriages. 2082 15

This article presents a case of a 17-year-old girl with primary antiphospholipid syndrome developing subacute signs of hand and leg ischaemia caused by radiologically verified radial and popliteal artery occlusion. She is successfully treated with a thrombolytic agent (alteplase) and recovers completely. Her laboratory results came positive for all three subtypes of antiphospholipid antibodies. This kind of antiphospholipid syndrome presentation is a very rare entity in itself. Shortly afterwards her mother is diagnosed with primary antiphospholipid syndrome as well. A familial form of antiphospholipid syndrome is suspected. Combination of a familial antiphospholipid syndrome presenting as bivessel arterial thrombosis is a unique case, to the best of our knowledge, never described in the literature before.
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PMID:Familial antiphospholipid syndrome presenting as bivessel arterial occlusion in a 17-year-old girl. 2219 Feb 75

The frequency of venous and arterial thromboses and plasminogen level were investigated in 78 patients with antiphospholipid syndrome (APS), 35 of whom with systemic lupus erythematosus (SLE+APS) and 43 - with primary APS (PAPS). The levels and genotype of plasminogen activator inhibitor type 1 (PAI-1) were determined in 45 patients with APS, of whom 21 patients with SLE + APS and 24 patients with PAPS. A control group included 10 healthy individuals without autoimmune disease signs and thromboses on period of investigation and in past history. It was shown for the first time that for one third of 67 patients with APS and thromboses high positive levels of antiphospholipid antibodies (aPL) are associated with low plasminogen levels. The levels of PAI-1 antigen measured by ELIZA method, which detects active, latent and bound with plasminogen activator PAI-1, were opposed with frequency of thromboses in APS patients. Correlation between the high and increased levels of PAI-1 and high positive aPL levels was found for one third of 43 patients with APS and thrombosis. One of the possible mechanisms of this interconnection was considered. It was shown that arterial and, to a more extent, venous thromboses are associated with the 4G/5G polymorphism of PAI-1 gene and high plasma level of the inhibitor in 79% of APS patients. At the presence of the 4G allele patients with SLE+APS had higher PAI-1 levels than patients with PAPS. The obtained results show that measuring the levels of plasminogen and PAI-1 as well as the 4G/5G polymorphism of PAI-1 gene which is associated with thromboses may have the practical significance for identification of high risk of thrombosis in APS patients.
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PMID:[Polymorphism of the plasminogen activator inhibitor type 1 gene, plasminogen level and thrombosis in patients with antiphospholipid syndrome]. 2474 49

Alteplase is the only approved drug for the treatment of acute ischemic stroke, but it is offered to a minority of patients, not only because of the short therapeutic window but also because of the numerous contraindications associated with thrombolysis, such as thrombocytopenia. There is some controversy on the true risk associated with thrombolysis in patients with thrombocytopenia. Here we report the case of a young patient, who developed an in-hospital acute ischemic stroke involving a large territory of the right middle cerebral artery, who was successfully treated with intravenous alteplase, despite having thrombocytopenia and prolonged prothrombin times due to systemic lupus erythematosus and antiphospholipid syndrome. This case exemplifies the need to reassess contraindications for thrombolysis, many based on expert opinion and not clinical evidence, especially in complex clinical situations.
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PMID:Successful intravenous thrombolysis in a patient with antiphospholipid syndrome, acute ischemic stroke and severe thrombocytopenia. 2657 92


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