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Hematology/oncology Clinics of North... Dec 2021Fibrinogen plays a fundamental role in coagulation through its support for platelet aggregation and its conversion to fibrin. Fibrin stabilizes clots and serves as a... (Review)
Review
Fibrinogen plays a fundamental role in coagulation through its support for platelet aggregation and its conversion to fibrin. Fibrin stabilizes clots and serves as a scaffold and immune effector before being broken down by the fibrinolytic system. Given its importance, abnormalities in fibrin(ogen) and fibrinolysis result in a variety of disorders with hemorrhagic and thrombotic manifestations. This review summarizes (i) the basic elements of fibrin(ogen) and its role in coagulation and the fibrinolytic system; (ii) the laboratory evaluation for fibrin(ogen) disorders, including the use of global fibrinolysis assays; and (iii) the management of congenital and acquired disorders of fibrinogen and fibrinolysis.
Topics: Blood Coagulation; Fibrin; Fibrinogen; Fibrinolysis; Hemostatics; Humans; Thrombosis
PubMed: 34404562
DOI: 10.1016/j.hoc.2021.07.011 -
Research and Practice in Thrombosis and... Aug 2021Hypodysfibrinogenemia (HD) is a heterogeneous disorder in which plasma fibrinogen antigen and function are both reduced but discordant. This report addresses the key...
Hypodysfibrinogenemia (HD) is a heterogeneous disorder in which plasma fibrinogen antigen and function are both reduced but discordant. This report addresses the key clinical question of whether genetic analysis enables clinically useful subclassification of patients with HD. We report a new case and identify a further eight previously documented cases that have the laboratory features of HD but biallelic inheritance of quantitative and qualitative fibrinogen gene variants. The cases displayed both bleeding and thrombosis and sometimes had undetectable fibrinogen activity. In all cases, the predicted effect of the coinherited variants is reduced levels of circulating fibrinogen that is all dysfunctional. We propose the term for this subtype of recessively inherited HD that is distinct from the more commonly recognized monoallelic HD caused by a single fibrinogen gene variant.
PubMed: 34458664
DOI: 10.1002/rth2.12568 -
Hamostaseologie Dec 2022Thrombophilia leads to an increased risk of venous thromboembolism. Widely accepted risk factors for thrombophilia comprise deficiencies of protein C, protein S, and... (Review)
Review
Thrombophilia leads to an increased risk of venous thromboembolism. Widely accepted risk factors for thrombophilia comprise deficiencies of protein C, protein S, and antithrombin, as well as the factor V "Leiden" mutation, the prothrombin G20210A mutation, dysfibrinogenemia, and, albeit less conclusive, increased levels of factor VIII. Besides these established markers of thrombophilia, risk factors of unclear significance have been described in the literature. These inherited risk factors include deficiencies or loss-of-activity of the activity of ADAMTS13, heparin cofactor II, plasminogen, tissue factor pathway inhibitor (TFPI), thrombomodulin, protein Z (PZ), as well as PZ-dependent protease inhibitor. On the other hand, thrombophilia has been linked to the gain-of-activity, or elevated levels, of α2-antiplasmin, angiotensin-converting enzyme, coagulation factors IX (FIX) and XI (FXI), fibrinogen, homocysteine, lipoprotein(a), plasminogen activator inhibitor-1 (PAI-1), and thrombin-activatable fibrinolysis inhibitor (TAFI). With respect to the molecular interactions that may influence the thrombotic risk, more complex mechanisms have been described for endothelial protein C receptor (EPCR) and factor XIII (FXIII) Val34Leu. With focus on the risk for venous thrombosis, the present review aims to give an overview on the current knowledge on the significance of the aforementioned markers for thrombophilia screening. According to the current knowledge, there appears to be weak evidence for a potential impact of EPCR, FIX, FXI, FXIII Val34Leu, fibrinogen, homocysteine, PAI-1, PZ, TAFI, and TFPI on the thrombotic risk.
Topics: Humans; Plasminogen Activator Inhibitor 1; Endothelial Protein C Receptor; Thrombophilia; Thrombosis; Factor IX; Fibrinogen
PubMed: 36549289
DOI: 10.1055/s-0042-1757562 -
Annales de Biologie Clinique Aug 2016Congenital fibrinogen disorders comprise quantitative disorders defined by a complete absence (afibrinogenemia) or by a decreased level (hypofibrinogenemia) of... (Review)
Review
Congenital fibrinogen disorders comprise quantitative disorders defined by a complete absence (afibrinogenemia) or by a decreased level (hypofibrinogenemia) of circulating fibrinogen and qualitative disorders characterized by a discrepancy between the activity and the antigenic levels of fibrinogen (dysfibrinogenemia and hypodysfibrinogenemia). The biological diagnosis is based on a standard haemostasis assessment. All the coagulation tests that depend on the formation of fibrin as the end point are affected; although in dysfibrinogenemia the specificity and sensitivity of routine test depend on reagent and techniques. A genetic exploration permits to confirm the diagnosis and may enhance the prediction of the patient's phenotype. Homozygous or composite heterozygous null mutations are most often responsible for afibrinogenemia while hypofibrinogenemic patients are mainly heterozygous carrier of an afibrinogenemic allele. Heterozygous missense mutations are prevalent in dysfibrinogenemia, with two hot spot localized in exon 2 of the FGA and in the exon 8 of the FGG. The correlation between phenotype and genotype has been identified in some fibrinogen variants, including six mutations clustered in exons 8 and 9 of the FGG leading to hypofibrinogenemia with hepatic inclusions of abnormal fibrinogen aggregates as well as a few mutations associated with an increase risk of thrombotic events. A familial screening and additional functional assays should be carried out when possible.
Topics: Afibrinogenemia; Blood Coagulation; Blood Coagulation Disorders, Inherited; Clinical Laboratory Techniques; Diagnosis, Differential; Fibrinogen; Fibrinogens, Abnormal; Humans; Molecular Diagnostic Techniques
PubMed: 27492693
DOI: 10.1684/abc.2016.1167 -
Annals of Translational Medicine Sep 2018Thrombophilia, either acquired or inherited, can be defined as a predisposition to developing thromboembolic complications. Since the discovery of antithrombin... (Review)
Review
Thrombophilia, either acquired or inherited, can be defined as a predisposition to developing thromboembolic complications. Since the discovery of antithrombin deficiency in the 1965, many other conditions have been described so far, which have then allowed to currently detect an inherited or acquired predisposition in approximately 60-70% of patients with thromboembolic disorders. These prothrombotic risk factors mainly include qualitative or quantitative defects of endogenous coagulation factor inhibitors, increased concentration or function of clotting proteins, defects in the fibrinolytic system, impaired platelet function, and hyperhomocysteinemia. In this review article, we aim to provide an overview on epidemiologic, clinic and laboratory aspects of both acquired and inherited rare thrombophilic risk factors, especially including dysfibrinogenemia, heparin cofactor II, thrombomodulin, lipoprotein(a), sticky platelet syndrome, plasminogen activator inhibitor-1 apolipoprotein E, tissue factor pathway inhibitor, paroxysmal nocturnal haemoglobinuria and heparin-induced thrombocytopenia.
PubMed: 30306081
DOI: 10.21037/atm.2018.08.12 -
Journal of Blood Medicine 2016Acquired hypofibrinogenemia is most frequently caused by hemodilution and consumption of clotting factors. The aggressive replacement of fibrinogen has become one of the... (Review)
Review
Acquired hypofibrinogenemia is most frequently caused by hemodilution and consumption of clotting factors. The aggressive replacement of fibrinogen has become one of the core principles of modern management of massive hemorrhage. The best method for determining the patient's fibrinogen level remains controversial, and particularly in acquired dysfibrinogenemia, could have major therapeutic implications depending on which quantification method is chosen. This review introduces the available laboratory and point-of-care methods and discusses the relative advantages and limitations. It also discusses current strategies for the correction of hypofibrinogenemia.
PubMed: 27713652
DOI: 10.2147/JBM.S90693 -
Archives of Pathology & Laboratory... Nov 2002To review the state of the art relating to congenital dysfibrinogenemia as a potential risk factor for thrombosis, as reflected by the medical literature and the... (Review)
Review
OBJECTIVES
To review the state of the art relating to congenital dysfibrinogenemia as a potential risk factor for thrombosis, as reflected by the medical literature and the consensus opinion of recognized experts in the field, and to make recommendations for the use of laboratory assays for assessing this thrombotic risk in individual patients.
DATA SOURCES
Review of the medical literature, primarily from the last 10 years.
DATA EXTRACTION AND SYNTHESIS
After an initial assessment of the literature, key points were identified. Experts were assigned to do an in-depth review of the literature and to prepare a summary of their findings and recommendations. A draft manuscript was prepared and circulated to every participant in the College of American Pathologists Conference on Diagnostic Issues in Thrombophilia. Each of the key points and associated recommendations were then presented for discussion at the conference. Recommendations were accepted if a consensus of experts attending the conference was reached. The results of the discussion were used to revise the manuscript into its final form.
CONCLUSIONS
Consensus was reached on 5 conclusions and 2 recommendations concerning the use of testing for dysfibrinogens in the assessment of thrombotic risk in individual patients. Detailed discussion of the rationale for each of these recommendations is found in the text of this article. Compared with the other, more common hereditary thrombophilias, dysfibrinogenemia encompasses a diverse group of defects with varied clinical expressions. Congenital dysfibrinogenemia is a relatively rare cause of thrombophilia. Therefore, routine testing for this disorder is not recommended as part of the laboratory evaluation of a thrombophilic patient. This is an evolving area of research, and further clinical studies may change these recommendations in the future.
Topics: Afibrinogenemia; Blood Coagulation Tests; Evidence-Based Medicine; Fibrinogens, Abnormal; Humans; Practice Guidelines as Topic; Risk Assessment; Risk Factors; Thrombophilia; Thrombosis
PubMed: 12421146
DOI: 10.5858/2002-126-1387-DAT -
Ugeskrift For Laeger Jan 2024Congenital fibrinogen disorders are rare pathologies of the haemostasis, comprising afibrinogenaemia, hypofibrinogenaemia, dysfibrinogenaemia and hypodysfibrinogenaemia.... (Review)
Review
Congenital fibrinogen disorders are rare pathologies of the haemostasis, comprising afibrinogenaemia, hypofibrinogenaemia, dysfibrinogenaemia and hypodysfibrinogenaemia. Phenotypic manifestations are variable, patients may be asymptomatic or suffer from bleeding or thrombosis. Most of congenital fibrinogen disorders are coincidentally discovered. Fibrinogen concentrate is used to treat bleeding, whereas low-molecular weight heparin is most often administered for the treatment of thrombotic complications. The aim of this review is to provide an update of the knowledge of congenital fibrinogen disorders for Danish physicians.
Topics: Humans; Fibrinogen; Afibrinogenemia; Hemorrhage; Hemostasis; Hemostatics; Thrombosis
PubMed: 38235772
DOI: 10.61409/V04230274 -
Archives of Pathology & Laboratory... Apr 2002Dysfibrinogenemia is a coagulation disorder caused by a variety of structural abnormalities in the fibrinogen molecule that result in abnormal fibrinogen function. It... (Review)
Review
Dysfibrinogenemia is a coagulation disorder caused by a variety of structural abnormalities in the fibrinogen molecule that result in abnormal fibrinogen function. It can be inherited or acquired. The inherited form is associated with increased risk of bleeding, thrombosis, or both in the same patient or family. Traditionally, dysfibrinogenemia is diagnosed by abnormal tests of fibrin clot formation; the thrombin time and reptilase time are the screening tests, and the fibrinogen clotting activity-antigen ratio is the confirmatory test. The inherited form is diagnosed by demonstrating similar laboratory test abnormalities in family members, and if necessary by analysis of the fibrinogen protein or fibrinogen genes in the patient. The acquired form is diagnosed by demonstrating abnormal liver function tests and by ruling out dysfibrinogenemia in family members. This article reviews the laboratory testing of dysfibrinogenemia and presents an algorithm for sequential test selection that can be used for diagnosis.
Topics: Algorithms; Blood Coagulation Disorders, Inherited; Fibrinogen; Humans; Mutation; Thrombin Time; Thrombophilia
PubMed: 11900586
DOI: 10.5858/2002-126-0499-LDOD -
Blood Nov 2021Congenital dysfibrinogenemia (CD) is caused by structural changes in fibrinogen that modify its function. Diagnosis is based on discrepancy between decreased fibrinogen...
Congenital dysfibrinogenemia (CD) is caused by structural changes in fibrinogen that modify its function. Diagnosis is based on discrepancy between decreased fibrinogen activity and normal fibrinogen antigen levels and is confirmed by genetic testing. CD is caused by monoallelic mutations in fibrinogen genes that lead to clinically heterogenous disorders. Most patients with CD are asymptomatic at the time of diagnosis, but the clinical course may be complicated by a tendency toward bleeding and/or thrombosis. Patients with a thrombosis-related fibrinogen variant are particularly at risk, and, in such patients, long-term anticoagulation should be considered. Management of surgery and pregnancy raise important and difficult issues. The mainstay of CD treatment remains fibrinogen supplementation. Antifibrinolytic agents are part of the treatment in some specific clinical settings. In this article, we discuss 5 clinical scenarios to highlight common clinical challenges. We detail our approach to establishing a diagnosis of CD and discuss strategies for the management of bleeding, thrombosis, surgery, and pregnancy.
Topics: Afibrinogenemia; Disease Management; Female; Hemorrhage; Humans; Pregnancy; Pregnancy Complications, Hematologic; Thrombosis
PubMed: 33895794
DOI: 10.1182/blood.2020010116