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Individuals experiencing episodic bleeding as a result of congenital dysfibrinogenemia should be treated at a center specialized in treating hemophilia. They should avoid all medications that interfere with normal platelet function. During bleeding episodes, treatment with fibrinogen concentrates or in emergencies or when these concentrates are unavailable, infusions of fresh frozen plasma and/or cryoprecipitate (a fibrinogen-rich plasma fraction) to maintain fibrinogen activity levels >1 gram/liter. Tranexamic acid or fibrinogen concentrates are recommended for prophylactic treatment prior to minor surgery while fibrinogen concentrates are recommended prior to major surgery with fibrinogen concentrates usage seeking to maintain fibrinogen activity levels at >1 gram/liter. Women undergoing vaginal or Cesarean child birth should be treated at a hemophilia center with fibrinogen concentrates to maintain fibrinogen activity levels at 1.5 gram/liter. The latter individuals require careful observation for bleeding during their post-partum periods.
Individuals experiencing episodic thrombosis as a result of congenital dysfibrinogenemia should also be treated at a center specialized in treating hemophilia using antithrombotic agents. They should be instructed on antithrombotic behavioral methods fur use in high risk situations such as long car rides and air flights. Venous thrombosis should be treated with low molecular weight heparin for a period that depends on personal and family history of thrombosis events. Prophylactic treatment prior to minor surgery should avoid fibrinogen supplementation and use prophylactic anticoagulation measures; prior to major surgery, fibrinogen supplementation should be used only if serious bleeding occurs; otherwise, prophylactic anticoagulation measures are recommended.
Treatment of asymptomatic congenital dysfibrinogenemia depends in part on the expectations of developing bleeding and/or thrombotic complications as estimated based on the history of family members with the disorder and, where available, determination of the exact mutation causing the disorder plus the propensity of the particular mutation type to develop these complications. In general, individuals with this disorder require regular follow-up and multidiscipline management prior to surgery, pregnancy, and giving childbirth. Women with the disorder appear to have an increased rate of miscarriages and all individuals with fibrinogen activity in clotting tests below 0.5 grams/liter are prone to bleeding and spontaneous abortions. Women with multiple miscarriages and individuals with excessively low fibrinogen activity levels should be considered for prophylaxis therapy with fibrinogen replacement during pregnancy, delivery, and/or surgery.
Studies have found that about 5 percent of Caucasians in North America have factor V Leiden. The condition is less common in Latin Americans and African-Americans and is extremely rare in people of Asian descent.
Up to 30 percent of patients who present with deep vein thrombosis (DVT) or pulmonary embolism have this condition. The risk of developing a clot in a blood vessel depends on whether a person inherits one or two copies of the factor V Leiden mutation. Inheriting one copy of the mutation from a parent (heterozygous) increases by fourfold to eightfold the chance of developing a clot. People who inherit two copies of the mutation (homozygous), one from each parent, may have up to 80 times the usual risk of developing this type of blood clot. Considering that the risk of developing an abnormal blood clot averages about 1 in 1,000 per year in the general population, the presence of one copy of the factor V Leiden mutation increases that risk to between 4 in 1,000 to 8 in 1,000. Having two copies of the mutation may raise the risk as high as 80 in 1,000. It is unclear whether these individuals are at increased risk for "recurrent" venous thrombosis. While only 1 percent of people with factor V Leiden have two copies of the defective gene, these homozygous individuals have a more severe clinical condition. The presence of acquired risk factors for venous thrombosis—including smoking, use of estrogen-containing (combined) forms of hormonal contraception, and recent surgery—further increase the chance that an individual with the factor V Leiden mutation will develop DVT.
Women with factor V Leiden have a substantially increased risk of clotting in pregnancy (and on estrogen-containing birth control pills or hormone replacement) in the form of deep vein thrombosis and pulmonary embolism. They also may have a small increased risk of preeclampsia, may have a small increased risk of low birth weight babies, may have a small increased risk of miscarriage and stillbirth due to either clotting in the placenta, umbilical cord, or the fetus (fetal clotting may depend on whether the baby has inherited the gene) or influences the clotting system may have on placental development. Note that many of these women go through one or more pregnancies with no difficulties, while others may repeatedly have pregnancy complications, and still others may develop clots within weeks of becoming pregnant.
Fibrinogen disorders are set of hereditary or acquired abnormalities in the quantity and/or quality of circulating fibrinogens. The disorders may lead to pathological bleeding and/or blood clotting or the deposition of fibrinogen in the liver, kidneys, or other organs and tissues. These disorders include:
- Congenital afibrinogenemia, an inherited blood disorder in which blood does not clot normally due to the lack of fibrinogen; the disorder causes abnormal bleeding and thrombosis.
- Congenital hypofibrinogenemia, an inherited disorder in which blood may not clot normally due to reduced levels of fibrinogen; the disorder may cause abnormal bleeding and thrombosis.
- Fibringogen storage disease, a form of congenital hypofibrinogenemia in which specific hereditary mutations in fibrinogen cause it to accumulate in, and damage, liver cells. The disorder may lead to abnormal bleeding and thrombosis but also to cirrhosis.
- Congenital dysfibrinogenemia, an inherited disorder in which normal levels of fibrinogen composed at least in part of a dysfunctional fibrinogen may cause abnormal bleeding and thrombosis.
- Hereditary fibrinogen Aα-Chain amyloidosis, a form of dysfibrinogenemia in which certain fibrinogen mutations cause blood fibrinogen to accumulate in the kidney and cause one type of familial renal amyloidosis; the disorder is not associated with abnormal bleeding or thrombosis.
- Acquired dysfibrinogenemia, a disorder in which normal levels of fibrinogen are composed at least in part of a dysfunctional fibrinogen due to an acquired disorder (e.g. liver disease) that leads to the synthesis of an incorrectly glycosylated (i.e. wrong amount of sugar residues) added to an otherwise normal fibrinogen. The incorrectly glycosalated fibrinogen is dysfunctional and may cause pathological episodes of bleeding and/or blood clotting.
- Congenital hypodysfibrinogenemia, an inherited disorder in which low levels of fibrinogen composed at least in part of a dysfunctional fibrinogen may cause pathological episodes of bleeding or blood clotting.
- Cryofibrinogenemia, an acquired disorder in which fibrinogen precipitates at cold temperatures and may lead to the intravascular precipitation of fibrinogen, fibrin, and other circulating proteins thereby causing the infarction of various tissues and bodily extremities.
All individuals with mutations causing fibrinogen storage disease have low blood fibrinogen levels but usually lack severe bleeding episodes, thrombotic episodes or liver disease. Individuals that do have fibrinogen storage disease often come to attention either because they have close relatives with the disease, are found to be hypofibrinogenmic during routing testing, or exhibit clinical (e.g. jaundice) or laboratory (e.g. elevated blood levels of liver enzymes) evidence of liver disease. Unlike other forms of congenital hypofibrinogenemia, a relatively high percentage of individuals with fibrinogen storage disease have been diagnosed in children of very young age.
Congenital hypofibrinogenemia is a rare disorder in which one of the two genes responsible for producing fibrinogen, a critical blood clotting factor, is unable to make a functional fibrinogen glycoprotein because of an inherited mutation. In consequence, liver cells, the normal site of fibrinogen production, make small amounts of this critical coagulation protein, blood levels of fibrinogen are low, and individuals with the disorder may suffer a coagulopathy, i.e. a diathesis or propensity to experience episodes of abnormal bleeding. However, individuals with congenital hypofibringenemia may also suffer episodes of abnormal blood clot formation, i.e. thrombosis. This seemingly paradoxical propensity to develop thrombosis in a disorder causing a decrease in a critical protein for blood clotting may be due to the function of fibrin (the split product of fibrinogen that is the basis for forming blood clots) to promote the lysis or desolution of blood clots. Lower levels of fibrin may reduce the lysis of early fibrin strand depositions and thereby allow these depositions to develop into clots.
Congenital hypofibrinogenemia must be distinguished from: a) congenital afibrinogenemia, a rare disorder in which blood fibrinogen levels are either exceedingly low or undetectable due to mutations in both fibrinogen genes; b) congenital hypodysfibrinogenemia, a rare disorder in which one or more genetic mutations cause low levels of blood fibrinogen, at least some of which is dysfunctional and thereby contributes to excessive bleeding; and c) acquired hypofibrinogenemia, a non-hereditary disorder in which blood fibrinogen levels are low because of e.g. severe liver disease or because of excessive fibrinogen consumption resulting from, e.g. disseminated intravascular coagulation.
Certain gene mutations causing congenital hypfibrinogenemia disrupt the ability of liver cells to secrete fibrinogen. In these instances, the un-mutated gene maintains blood fibrinogen at reduce levels but the mutated gene produces a fibrinogen that accumulates in liver cells sometimes to such extents that it becomes toxic. In the latter cases, liver disease may ensue in a syndrome termed fibrinogen storage disease.
In people without a detectable thrombophilia, the cumulative risk of developing thrombosis by the age of 60 is about 12%. About 60% of people who are deficient in antithrombin will have experienced thrombosis at least once by age 60, as will about 50% of people with protein C deficiency and about a third of those with protein S deficiency. People with activated protein C resistance (usually resulting from factor V Leiden), in contrast, have a slightly raised absolute risk of thrombosis, with 15% having had at least one thrombotic event by the age of sixty. In general, men are more likely than women to experience repeated episodes of venous thrombosis.
People with factor V Leiden are at a relatively low risk of thrombosis, but may develop thrombosis in the presence of an additional risk factor, such as immobilization. Most people with the prothrombin mutation (G20210A) never develop thrombosis.
Glanzmann's thrombasthenia can be inherited in an autosomal recessive manner or acquired as an autoimmune disorder.
The bleeding tendency in Glanzmann's thrombasthenia is variable, some individuals having minimal bruising, while others have frequent, severe, potentially fatal hemorrhages. Moreover, platelet αβ levels correlate poorly with hemorrhagic severity, as virtually undetectable αβ levels can correlate with negligible bleeding symptoms, and 10%–15% levels can correlate with severe hemorrhage. Unidentified factors other than the platelet defect itself may have important roles.
Therapy involves both preventive measures and treatment of specific bleeding episodes.
- Dental hygiene lessens gingival bleeding
- Avoidance of antiplatelet agents such as aspirin and other anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen, and anticoagulants
- Iron or folate supplementation may be necessary if excessive or prolonged bleeding has caused anemia
- Hepatitis B vaccine
- Antifibrinolytic drugs such as tranexamic acid or ε-aminocaproic acid (Amicar)
- Desmopressin (DDAVP) does not normalize the bleeding time in Glanzmann's thrombasthenia but anecdotally improves hemostasis
- Hormonal contraceptives to control excessive menstrual bleeding
- Topical agents such as gelfoam, fibrin sealants, polyethylene glycol polymers, custom dental splints
- Platelet transfusions (only if bleeding is severe; risk of platelet alloimmunization)
- Recombinant factor VIIa, AryoSeven or NovoSeven FDA approved this drug for the treatment of the disease on July 2014.
- Hematopoietic stem cell transplantation (HSCT) for severe recurrent hemorrhages
Blood relatives of the proband case should be evaluated for the presence of hypodysfibrinogenemia. Individuals with the disorder need to be advised on its inheritance, complications, and preventative measures that can be taken to avoid bleeding and/or thrombosis. Since >80% of individuals may develop bleeding or thrombosis complications of the disorder, asymptomatic individuals diagnosed with hydposyfibrinogenemia are best handled at a specialized center in order to benefit from multidisciplinary management.
Measures to prevent and/or treat complications of hypodysfibrinogenemia should be tailored to the personal and family history of the individual by a specialized center. Individuals with a personal or family history of bleeding are considered to be of low risk of bleeding when their functional fibrinogen levels are >1 gram/liter for major surgery, >0.5 gram/liter for minor surgery, >0.5 to 1-2 gram/liter for spontaneous bleeding (depending on its severity), >0.5 to > 1 gram/liter for the first two trimesters of pregnancy, and >1 to <2 gram/liter for the last trimester of pregnancy and postpartum period. Functional fibrinogen below these levels should be treated preferably with fibrinogen concentrate or if not available, fibrinogen-rich cryoprecipitate or plasma to attain low risk levels of functional fibrinogen. Antifibrinolytic drugs such as tranexamic acid or (ε-aminocaproic acid) may be considered as an alternative preventative or therapeutic treatments in cases of minor surgery, dental extractions, mucosal bleeding, or other episodes of mild bleeding. In individuals with a personal or family history of thrombosis, should be considered for long-term anticoagulation drugs such as low molecular weight heparin, coumadin, or rivaroxaban.
Purpura fulminans is rare and most commonly occurs in babies and small children but can also be a rare manifestation in adults when it is associated with severe infections. For example, Meningococcal septicaemia is complicated by purpura fulminans in 10–20% of cases among children. Purpura fulminans associated with congenital (inherited) protein C deficiency occurs in 1:500,000–1,000,000 live births.
Quebec Platelet Disorder (QPD) is a rare, autosomal dominant bleeding disorder described in a family from the province of Quebec in Canada.
It was first described in 1920 by German doctors, Fritz Rabe and Eugene Salomon, studying a bleeding disorder presenting itself in a child from birth. This disorder may also be simply called afibrinogenemia or familial afibrinogenemia. About 1 in 1 million individuals are diagnosed with the disease; typically at birth. Both males and females seem to be affected equally, but it has a higher occurrence in regions where consanguinity is prevalent.
Individuals with QPD are at risk for experiencing a number of bleeding symptoms, including joint bleeds, hematuria, and large bruising. In 2010, the genetic cause of QPD has been determined as a mutation involving an extra copy of the uPA (urokinase plasminogen activator) gene http://bloodjournal.hematologylibrary.org/content/115/6/1264.long. The mutation causes overproduction of an enzyme that accelerates blood clot breakdown.
Circulating fibrinogen is a glycoprotein made of two trimers each of which is composed of three polypeptide chains, Aα (also termed α) encoded by the "FGA" gene, Bβ (also termed β) encoded by the "FGB" gene, and γ encoded by the "FGG" gene. All three genes are located on the long or "p" arm of human chromosome 4 (at positions 4q31.3, 4q31.3, and 4q32.1, respectively) and are the sites where mutations occur that code for a dysfunctional fibrinogen and/or reduced fibrinogen levels which are the cause of congenital hypodysfibrinogenemia.
The normal clotting process depends on the interplay of various proteins in the blood. Coagulopathy may be caused by reduced levels or absence of blood-clotting proteins, known as clotting factors or coagulation factors. Genetic disorders, such as hemophilia and Von Willebrand's disease, can cause a reduction in clotting factors.
Anticoagulants such as warfarin will also prevent clots from forming properly. Coagulopathy may also occur as a result of dysfunction or reduced levels of platelets (small disk-shaped bodies in the bloodstream that aid in the clotting process).
The most important differential diagnosis is disseminated intravascular coagulation, which is characterized with similar features but presence of a low platelet count and microcirculatory thrombosis. Antifibrinolytic treatments are contraindicated in patients with disseminated intravascular coagulation while they are useful in the treatment of primary fibrinogenolysis.
The amount of fresh frozen plasma required to reverse disseminated intravascular coagulation associated with purpura fulminans may lead to complications of fluid overload and death, especially in neonates, such as transfusion-related acute lung injury. Exposure to multiple plasma donors over time increases the cumulative risk for transfusion-associated viral infection and allergic reaction to donor proteins found in fresh frozen plasma.
Allergic reactions and alloantibody formation are also potential complications, as with any protein replacement therapy.
Concomitant warfarin therapy in subjects with congenital protein C deficiency is associated with an increased risk of warfarin skin necrosis.
A missense or nonsense mutation to the genes that code for the fibrinogen protein are affected. Usually the mutation leads to an early stop in the production of the protein. Due to the problem being genetically based, there is no way to prevent the disease. Individuals can get genetic testing done to see if they are a carrier of the trait, and if so may choose to complete genetic counseling to better understand the disorder and help manage family planning. Parents can choose to do prenatal genetic testing for the disorder to determine if their child will have the disease. The only risk factor is if both parents of a child carry the recessive allele linked to the disorder.
The major ("type 1") thrombophilias are rare. Antithrombin deficiency is present in 0.2% of the general population and 0.5–7.5% of people with venous thrombosis. Protein C deficiency, too, is present in 0.2% of the population, and can be found in 2.5–6% of people with thrombosis. The exact prevalence of protein S deficiency in the population is unknown; it is found 1.3–5% of people with thrombosis.
The minor ("type 2") thrombophilias are much more common. Factor V Leiden is present in 5% of the population of Northern European descent, but much rarer in those of Asian or African extraction. In people with thrombosis, 10% have factor V Leiden. In those who are referred for thrombophilia testing, 30–50% have the defect. The prothrombin mutation occurs at rates of 1–4% in the general population, 5–10% of people with thrombosis, and 15% of people referred for thrombophilia testing. Like factor V Leiden, this abnormality is uncommon in Africans and Asians.
The exact prevalence of antiphospholipid syndrome is not well known, as different studies employ different definitions of the condition. Antiphospholipid antibodies are detected in 24% of those referred to thrombophilia testing.
The occurrence of cryofibrinogenemia as defined by a 4 °C-induced formation of fibrinogen-based precipitation in plasma occurs in 2% to 9% of asymptomatic individuals and 8% to 13% of hospitalized patients without symptoms attributable to this precipitation. Most of these cases have relatively low levels of cold temperature-induced fibrinogen precipitate levels (<50 milligram/liter of fibrinogen) and do not have a disorder associated with the development of cryofibrinogenmia.
DIC is observed in approximately 1% of academic hospital admissions. DIC occurs at higher rates in people with bacterial sepsis (83%), severe trauma (31%), and cancer (6.8%).
Prognosis varies depending on the underlying disorder, and the extent of the intravascular thrombosis (clotting). The prognosis for those with DIC, regardless of cause, is often grim: Between 20% and 50% of patients will die. DIC with sepsis (infection) has a significantly higher rate of death than DIC associated with trauma.
Cryoglobulonemia may occur without evidence of an underlying associated disorders, i.e. primary cryoglobulinemia (also termed essential cryoglobulinemia) or, far more commonly, with evidence of an underlying disease, i.e. secondary cryoglobulonemia. Secondary cryofibrinoenemia can develop in individuals suffering infection (~12% of cases), malignant or premalignant disorders (21%), vasculitis (25%), and autoimmune diseases (42%). In these cases of the secondary disorder, cryofibinogenema may or may not cause tissue injury and/or other symptoms and the actual cause-effect relationship between these diseases and the development of cryofibrinogenmia is unclear. Cryofibrinogenemia can also occur in association with the intake of certain drugs.
Primary fibrinogenolysis is the pathological lysis of fibrinogen characterized with a low fibrinogen, high fibrin degradation products, prolonged prothrombin time and activated partial thromboplastin time, a normal platelet count and absence of microcirculatory thrombosis.