Willebrand factor. Functions. What is von Willebrand's disease and its factor, how it is treated and how much it costs, prognosis for life Symptoms of a mild stage of the disease

Russian name

Willebrand factor

Latin name for the substance von Willebrand factor

(genus.)

Pharmacological group of the substance von Willebrand factor

Nosological classification (ICD-10)

Substance characteristic Willebrand factor

von Willebrand factor human with an activity of 1000 IU is a hemostatic agent. The activity of von Willebrand factor is determined by the method of dosing ristocetin cofactor VWF:Rko relative to the international standard for von Willebrand factor concentrate (WHO).

Pharmacology

pharmachologic effect- hemostatic.

Pharmacodynamics

Corrects hemostatic abnormalities in patients with von Willebrand factor deficiency (Willebrand disease) at two levels:

Restores adhesion of platelets to the vascular subendothelium at the site of injury (due to binding to the subendothelium and platelet membrane), providing primary hemostasis, which is manifested in a decrease in bleeding time. The effect is immediate and largely dependent on the level of multimerization;

Delayedly corrects the concomitant deficiency of endogenous factor VIII and stabilizes its content, preventing rapid degradation.

Replacement therapy with von Willebrand factor normalizes the blood coagulation factor VIII after the first injection. This effect is long lasting and persists during subsequent injections of von Willebrand factor.

Pharmacokinetics

A study of the pharmacokinetics of von Willebrand factor was conducted in 8 patients with von Willebrand disease type 3 by dosing ristocetin cofactor (WF:RCo). C max was observed 30-60 minutes after administration.

With a single administration of von Willebrand factor at a dose of 100 IU / kg, AUC o-∞ is 3444 IU h / dl, the average clearance is 3.0 ml / h / kg. T 1/2 is within 8-14 hours (average 12 hours).

With the introduction of the von Willebrand factor, the increase in the content of factor VIII: C occurs gradually and reaches normal values ​​​​after 6-12 hours. The content of factor VIII: C increases by an average of 6% (6 IU / dl) per hour. Therefore, even in patients with baseline factor VIII:C levels below 5% (5 IU/dl), starting at 6 hours, factor VIII:C levels reached approximately 40% (40 IU/dl) and persisted for 24 hours.

Application of the substance Willebrand factor

Prevention and treatment of bleeding in patients with von Willebrand's disease (including use before planned and emergency surgical or invasive interventions to reduce blood loss).

Contraindications

Hypersensitivity to the components of the von Willebrand factor preparation, hemophilia A (due to the low content of factor VIII), age up to 6 years (the use of von Willebrand factor in children under 6 years of age has not been studied in clinical studies).

Use during pregnancy and lactation

Controlled studies of von Willebrand factor in pregnant women have not been conducted. Data on the reproductive toxicity of von Willebrand factor and its entry into animal milk are not available. The safety of von Willebrand factor in pregnant women has not been established, therefore it is not recommended to use it during pregnancy and during breastfeeding, unless the potential benefit to the mother significantly outweighs the possible risk to the fetus and infant.

Side effects of the substance von Willebrand factor

Side effects of the von Willebrand factor are classified according to WHO recommendations according to the frequency of occurrence: very often (≥10%); often (>1, but<10%); нечасто (≥0,1, но <1%); редко (≥0,01, но <0,1%); очень редко (<0,01%); частота не известна (не может быть установлена на основании доступных данных). Нежелательные лекарственные реакции на фактор Виллебранда, согласно классификации MedDRA, приведены ниже.

From the immune system: infrequently - hypersensitivity reactions or allergic reactions; very rarely - severe anaphylactic reactions (angioedema or anaphylactic shock).

Mental disorders: infrequently - anxiety.

From the side of the central nervous system: infrequently - headache, drowsiness.

From the CCC: infrequently - tachycardia, hypotension, hot flashes.

From the respiratory system, chest organs and mediastinal organs: infrequently - shortness of breath.

From the gastrointestinal tract: infrequently - nausea, vomiting.

From the skin and subcutaneous tissues: infrequently - rash, generalized urticaria, pruritus, a feeling of crawling.

General disorders and reactions at the injection site: infrequently - burning or tingling at the injection site, chills, a feeling of shortness of breath; rarely - fever.

Others: very rarely - the formation of neutralizing antibodies (inhibitors) to the von Willebrand factor, especially in patients with type 3 von Willebrand disease. In a clinical study of von Willebrand factor in 62 patients, of whom 23 were type 3 von Willebrand disease, no formation of inhibitors was observed after administration of von Willebrand factor. The presence of inhibitors manifests itself as an inadequate clinical response (the expected level of VWF:PKo in blood plasma is not achieved or bleeding is difficult to control with an adequate dose of the drug) and may be associated with an increased risk of anaphylactic reactions.

Interaction

Do not mix with other drugs.

Only polypropylene injection/infusion products should be used, as adsorption of human plasma proteins on the internal surface of the injection/infusion products may result in treatment failure.

Clinically significant interactions of von Willebrand factor with other drugs are not known.

Overdose

There are no reports of cases of overdose of von Willebrand factor.

In case of a significant overdose, thromboembolic complications may develop.

Routes of administration

Precautions for substance von Willebrand factor

In cases of bleeding in patients at the initial stage of treatment, it is recommended to administer factor VIII simultaneously with von Willebrand factor.

Patients should be monitored throughout the entire period of von Willebrand factor administration for early signs of allergic or anaphylactic reactions. Patients should be informed of the early manifestations of hypersensitivity reactions, including pruritus, urticaria, chest tightness, dyspnea, hypotension, and anaphylactic reactions. If such symptoms appear, the administration of von Willebrand factor should be stopped immediately. In anaphylactic shock, treatment is carried out in accordance with current recommendations.

There is a risk of thromboembolic complications, especially in patients with risk factors. Therefore, patients at risk should be monitored for early signs of thrombosis. Prevention of venous thromboembolism should be carried out in accordance with current recommendations.

After correction of von Willebrand factor deficiency, due to the possible risk of thrombosis, early signs of thrombosis or disseminated intravascular coagulation should be detected and thromboembolic complications should be prevented in accordance with current recommendations.

Patients with von Willebrand disease, especially type 3, may develop neutralizing antibodies (inhibitors) to von Willebrand factor. The presence of inhibitors manifests itself in the form of an inadequate clinical response (the expected level of VW:PKo in blood plasma is not achieved or bleeding is difficult to control with an adequate dose of the drug). If the expected plasma EF:PKo is not achieved, or if bleeding is difficult to control with an adequate dose, then laboratory tests should be performed to determine the presence of von Willebrand factor inhibitors. In patients with high levels of inhibitors, the use of von Willebrand factor may not be effective enough and other treatment options should be considered. These patients should be treated by a physician experienced in the treatment of bleeding disorders.

The presence of antibodies to von Willebrand factor may be associated with an increased risk of anaphylactic reactions. Therefore, in all patients with anaphylactic reactions or in case of treatment failure, appropriate biological studies should be performed to determine the presence of inhibitors.

Standard measures to prevent the risk of transmission of infectious agents through drugs prepared from human blood or plasma include: clinical selection of donors, screening of individual blood samples and plasma lots for specific markers of infections. Virus inactivation and removal procedures are included in the manufacturing process. However, when using preparations made from human blood or plasma, the risk of transmission of infectious agents cannot be completely excluded. This also applies to unknown or emerging viruses or other types of infectious agents.

The drug is effectively protected against enveloped viruses: HIV, hepatitis B and C, but there is no full guarantee of protection against non-enveloped hepatitis A and parvovirus B19 viruses. Parvovirus B19 is most dangerous for pregnant women (infection of the fetus), for people with immunodeficiency and for patients with hemolytic anemia.

Patients systematically receiving therapy with blood clotting factors are recommended to receive the necessary vaccination against hepatitis A and B.

Influence on the ability to drive vehicles and engage in other potentially hazardous activities. The von Willebrand factor does not affect the ability to drive vehicles and engage in other potentially hazardous activities that require increased concentration and psychomotor speed.

Willebrand's disease (angiohemophilia) is a genetic pathology of the blood, caused by reduced activity or deficiency of von Willebrand factor (VWF). The disease occurs with a frequency of 1-2 cases per 10,000 people. Moreover, among hereditary hemorrhagic diathesis, it is in third place.

von Willebrand disease can be combined with hypermobility of the joints and weakness of the ligaments, increased extensibility of the skin, connective tissue dysplasia, prolapse of the heart valves (Ehlers-Danlos syndrome).

What it is?

von Willebrand disease is an inherited blood disorder characterized by the occurrence of episodic spontaneous bleeding, which is similar to bleeding in hemophilia. The cause of bleeding is a violation of blood clotting due to insufficient activity of von Willebrand factor, which is involved in platelet adhesion to collagen and protects factor VIII from proteolysis.

The reasons

One of the parts of the hemostatic system of the human body is the von Willebrand factor (VWF), which performs two main functions:

• triggers the mechanism of adhesion (sticking) of platelets to the site of damage to the blood vessel;
• stabilizes coagulation factor VIII circulating in the blood.

Various genetic disorders cause a defect in the synthesis of von Willebrand factor, as a result of which it is produced in insufficient quantities (in some cases, its synthesis is generally impossible). A variant of the disease is also possible, in which the amount of VWF is optimal, but the protein itself is defective and cannot perform its functions. As a result, according to various sources, from 0.1 to 1% of the population suffers from a deficiency of VWF. However, often this disease is mild and may not be diagnosed at all.

Classification

There are several clinical types of von Willebrand's disease - classic (type I); variant forms (type II); severe form (type III) and platelet type.

1. In the most common (70-80% of cases) type I disease, there is a slight or moderate decrease in the level of von Willebrand factor in plasma (sometimes slightly below the lower limit of normal). The spectrum of oligomers is not changed, but with the Winches form, the constant presence of superheavy VWF multimers is noted.
2. In type II (20-30% of cases), there are qualitative defects and a decrease in the activity of the von Willebrand factor, the level of which is within the normal range. The reason for this may be the absence or deficiency of high and medium molecular weight oligomers; excessive affinity (affinity) for platelet receptors, decreased ristomycin-cofactor activity, impaired binding and inactivation of factor VIII.
3. In type III, the von Willebrand factor in plasma is almost completely absent, the activity of factor VIII is low.

There is also a platelet type of this disease, which is characterized by an increase in the sensitivity of platelet receptors to high molecular weight multimers of von Willebrand factor.

Symptoms

The symptoms of von Willebrand disease are extremely diverse: from minor episodic bleeding to massive, debilitating, leading to severe blood loss.

Symptoms characteristic of von Willebrand disease:

• severe, prolonged or spontaneously recurring bleeding after minor surgical interventions, extraction of teeth;
• subcutaneous hematomas that appear after minor traumatic effects or spontaneously
• bleeding for more than 15 minutes after minor injuries or spontaneously recurrent bleeding 7 days or more after injury;
• hemorrhagic rash on the skin;
• severe anemia;
• intense, prolonged menstruation;
• spontaneous nosebleeds lasting more than 10 minutes or requiring due to the intensity of medical intervention;
• blood in the stool in the absence of gastrointestinal pathology that can provoke the development of gastrointestinal bleeding.

More often, increased bleeding is noted in childhood, decreasing as they grow older, and subsequently there is an alternation of exacerbations and remissions.

Diagnostics

Diagnosis of von Willebrand disease requires the indispensable participation of hematologists. It is impossible to make a diagnosis at the level of a polyclinic or children's consultation due to the lack of capabilities of the laboratories of these institutions in conducting specific diagnostic tests, enzyme immunoassay technologies. The doctor assumes the disease when interviewing relatives, examining the patient and taking into account information from the anamnesis.

Moreover, the available tests vary in sensitivity and diagnostic value. Therefore, an algorithm for examining the alleged patient has been developed.

1. First, a coagulogram is studied with all clotting indicators, including bleeding time. The analysis can be carried out in your clinic. If pathological abnormalities are detected, the patient is sent to the hematology center.
2. To identify a specific type of disease, the qualitative side of the defect, a comparison of impaired aggregation ability under the influence of ristocetin with normal - under the influence of collagen, thrombin, ADP, adrenaline is used.
3. The main method for detecting a decrease in the amount of factor VIII in the blood is to determine the activity of the patient's platelets treated with formalin in reaction with a solution of ristocetin.
4. Using the collagen-binding technique, the impaired functional ability of factor VIII, a specific type of disease, is detected.

In the diagnosis of concomitant lesions of the mucous membranes, it is necessary:

• examination by an otolaryngologist;
• esophagogastroduodenoscopy study;
• colonoscopy (examination of the intestines).

For treatment, it is important to identify vascular formations in the form of tortuosity, angiomas, extensions up to 2 mm, which contribute to bleeding.

How to treat von Willebrand disease

The basis of the treatment of von Willebrand's disease is substitution transfusion therapy. It is aimed at normalizing all links of hemostasis. Patients are administered blood preparations containing von Willebrand factor - antihemophilic plasma and cryoprecipitate. Substitution therapy increases the biosynthesis of the deficient factor in the body.

1. A pressure bandage, a hemostatic sponge, and thrombin wound treatment will help stop minor bleeding.
2. Drugs have a hemostatic effect: Desmopressin, antifibrinolytics, hormonal oral contraceptives for uterine bleeding.
3. Fibrin gel is applied to the bleeding wound.
4. With hemarthrosis, a plaster splint is applied to the leg, cold is applied and the limb is elevated. In the future, patients are prescribed UHF and limiting the load on the joint. In severe cases, the joint is punctured under local anesthesia.

For the treatment of blood diseases of types 1 and 2, Desmopressin is used - a drug that stimulates the release of VW into the systemic circulation. It is available as a nasal spray and injection. When this drug is ineffective, replacement therapy with plasma concentrate of VWF is carried out.

Antifibrinolytics include aminocaproic and tranexamic acids. They are administered intravenously by drip or taken orally. Preparations based on these acids are most effective in uterine, gastrointestinal and nasal bleeding. "Tranexam" is the main tool in the treatment of mild BV. In severe cases, the drug is used in combination with specific hemostatics - Etamzilat or Dicinon.

Prevention

Prevention of this pathology consists in observing caution (from getting injured), refusing to take drugs that violate blood clotting properties, as well as timely contacting a doctor and starting treatment.

Willebrand factor synthesize endothelial cells and megakaryocytes. It is essential for normal platelet adhesion and has the ability to prolong the half-life of factor VIII. Plasma coagulation factor VIII - antihemophilic globulin A - circulates in the blood as a complex of three subunits, designated VIII-k (coagulating unit), VIII-Ag (the main antigenic marker) and VIII-vB (von Willebrand factor associated with VIII-Ag ). It is believed that the von Willebrand factor regulates the synthesis of the coagulation part of antihemophilic globulin A (VIII-k) and is involved in vascular-platelet hemostasis.

Indications for the purpose of the analysis:
The study can be used in the differential diagnosis between congenital hemophilia A (factor VIII deficiency) and von Willebrand disease. In hemophilia, the content of VIII-k is sharply reduced, and the content of VIII-vB is within the normal range. This difference leads to a difference in the clinical forms of hemorrhagic diathesis: the hematoma form occurs with hemophilia, and the petechial-hematoma form occurs with von Willebrand's disease.

Special instructions: Do not conduct a study during acute periods of illness and while taking anticoagulant drugs (at least 30 days must pass after cancellation). Biomaterial for research must be taken on an empty stomach. At least 8 hours should elapse between the last meal and blood sampling.

GENERAL RULES OF PREPARATION FOR RESEARCH:

1. For most studies, it is recommended to donate blood in the morning, between 8 a.m. and 11 a.m., on an empty stomach (at least 8 hours should elapse between the last meal and blood sampling, you can drink water as usual), on the eve of the study, a light dinner with a restriction eating fatty foods. For infection tests and emergency investigations, it is acceptable to donate blood 4-6 hours after the last meal.

2. ATTENTION! Special rules for preparing for a number of tests: strictly on an empty stomach, after 12-14 hours of fasting, you should donate blood for gastrin-17, lipid profile (total cholesterol, HDL cholesterol, LDL cholesterol, VLDL cholesterol, triglycerides, lipoprotein (a), apolipo-proten A1, apolipoprotein B); a glucose tolerance test is performed in the morning on an empty stomach after 12-16 hours of fasting.

3. On the eve of the study (within 24 hours), exclude alcohol, intense physical activity, medication (as agreed with the doctor).

4. 1-2 hours before donating blood, refrain from smoking, do not drink juice, tea, coffee, you can drink non-carbonated water. Eliminate physical stress (running, fast climbing stairs), emotional arousal. It is recommended to rest and calm down 15 minutes before donating blood.

5. You should not donate blood for laboratory testing immediately after physiotherapy procedures, instrumental examinations, X-ray and ultrasound examinations, massage and other medical procedures.

6. When monitoring laboratory parameters in dynamics, it is recommended to conduct repeated studies under the same conditions - in the same laboratory, donate blood at the same time of day, etc.

7. Blood for research should be donated before the start of taking medications or no earlier than 10-14 days after they are discontinued. To evaluate the control of the effectiveness of treatment with any drugs, it is necessary to conduct a study 7-14 days after the last dose of the drug.

If you are taking medication, be sure to tell your doctor about it.

Von Willebrand factor is a membrane protein, one of the three protein objects of β-globulin of the eighth coagulation factor. Produced:

• endothelial cells of the inner surface of blood vessels;
• giant cells in the bone marrow;
• intracellular granules in which platelets retain growth factors;
• a single layer of flat cells of mesenchymal origin, located inside the blood and lymphatic vessels.

The factor monomers form a small protein fragment with two D fragments joining. Dimers are transformed into large complexes with high molecular weight. In the monomer, specific zones are born that are responsible for:

• adhesion to the platelet membrane and heparin,
• adhesion to vascular collagen,
• activation of spherical colorless cells.

The monomeric molecule has a site that connects to the eighth factor.

von Willebrand disease

The hematological syndrome is transmitted by genes, manifested by abruptly emerging blood outflows beyond the vascular bed. Deficiency of von Willebrand fibrinogen causes dysfunction of the coagulation system. Fibrinogen VIII is catalyzed by peptide hydrolase enzymes, blood channels expand. The anomaly manifests itself in the form of frequent outpourings of blood of varying intensity.

The hereditary form of hemorrhagic diathesis is caused by a lack or reduced activity of the vascular component of fibrinogen VIII (VWF). The disease is quite common, occurs in two people out of nine to ten thousand. It is diagnosed in both men and women. However, the weak half of humanity is detected more often. The anomaly may be associated with:

• impaired development of organ tissue;
• weakness of muscles and tendons;
• excessive joint mobility;
• skin hyperelasticity;
• sagging of one or both leaflets of the mitral valve during contraction of the left cavity of the heart.

The complex of reactions of the body that maintains the liquid state of the blood is normal, consists of a coagulation and anticoagulant system. If the integrity of the endothelium and connective tissue of the vessels is violated, bleeding occurs. The outpouring of blood will continue until anticoagulants come into play. When the components are activated, blood clots are formed that block the lumen, preventing the cessation of the outpouring. If there is not enough fibrinogen in the plasma, the clot formation process is disrupted.

On a note!

When the von Willebrand factor is slightly elevated, the tendency to effusion of blood appears only with cuts. A strong decrease in fibrinogen contributes to the occurrence of sudden bleeding from the ears, nose, and urinary organs.

Von Willebrand factor norms in the blood

The standard fibrinogen level is 59-165%. However, the parameter of high molecular weight organic matter often deviates from the norm. If the indicators are violated, in patients:

• bleeding gums;
• there are abundant long periods;
• bruising of soft tissues is observed;
• release of fluid connective tissue into the joints.

Permissible fibrinogen levels differ depending on the blood type. Therefore, the norm must be determined according to the certificate issued by the laboratory. In the line "Average reference parameters" find the items "vWF:Ag" and "FVIIIR:Rco". Normal Functional Scores After Laboratory Analysis – from 0.5 to 1.5.

Indications and contraindications

Laboratory examination for the determination of fibrinogen is prescribed for hemorrhages. Also, the basis for passing the analysis may be deviations in the results of the hemostasiogram. Initial examination of asymptomatic patients is performed when an abnormality occurs in a close relative. In such cases, due to the deviation from the norm of the von Willebrand factor, only 10-12% of patients need treatment, since the manifestations of the disease are not severe.

Indications for testing may be the presence of diseases:

• hepatonephrotic syndrome;
• systemic damage to the arteries of large and medium caliber;
• pulmonary hypertension;
• myocarditis;
• pericarditis;
• endocarditis;
• heart defects;
• tumor lesions of the hematopoietic system;
• swollen lymph nodes;
• plasmacytoma;
• agammaglobulinemia;
• Addison's disease;
• Behçet's disease;
• chronic inflammatory demyelinating polyneuropathy;
• discoid lupus;
• hemorrhagic vasculitis;
• low concentration of thyroid hormones;
• nephroblastoma.

Fibrinogen is an acute phase protein involved in the body's response to injury or inflammation. Therefore, the analysis of the content of the level is contraindicated in severe inflammation and aggressive neoplasms. Non-informative results after sampling will be with extensive vascular deformity and diabetes mellitus.

On a note!

If a patient with a diagnosis of arterial hypotension and anemia has poor clotting, testing for the von Willebrand factor is decided individually with the doctor.

Classification

According to sanitary statistics, in 75% of patients with pathology of the blood coagulation system, the anomaly passes in a mild form. In 20% of patients, the disease is moderate to severe. 5% of patients have the most severe stage.

The anomaly is classified into four types:

• The first type is the most common. A mild form of anomaly, in which there is a slight decrease in fibrinogen levels in the blood;
• the second type, in which the level of fibrinogen decreases, but does not go beyond the normal range. The anomaly is observed in 25%-32% of all patients;
• the third type, which is a severe degree of anomaly. There is no fibrinogen in the patient's blood. The manifestation of symptoms is regular profuse hemorrhages. Patients who have a third type of anomaly become disabled;
• the fourth pseudohemophilic type, characterized by a normal value of von Willebrand fibrinogen. With an anomaly, the thrombin receptor of the platelet membrane is deformed and begins to interact more actively with the protein.

On a note!

I call the first Rh factor “royal”, since its red blood cells are clean. However, patients with the first blood group have 22-26% less fibrinogen than those with other Rh factors.

Reasons for deviations

Regular hemorrhages are due to reduced activity or protein deficiency. Fibrinogen is involved in the adhesion of platelet collagen, maintains the biostructure of the blood. Protects vascular-platelet and coagulation hemostasis from hydrolysis.

The concentration of the factor may increase during childbearing, infections, taking steroid drugs, in people with the first blood group. The type of flow is determined by a gene anomaly in the twelfth chromosome. The genes in this threadlike structure of the cell nucleus are unevenly distributed, with which hematologists associate the development of many diseases.

The disease has a type of inheritance according to Mendel's law. The patient is a carrier of the abnormal gene in a heterozygous state. Each offspring has a one in two chance of inheriting a pathological factor from an affected blood relative. In some cases, there is an inheritance of an abnormal protein in a diploid organism that has received one recessive gene from each parent. If the mother and father suffer from an anomaly of the first or second type, the child will be born with a severe degree of the disease.

In some cases, pathology develops under the influence of inflammatory processes. The development of the disease is due to the formation of antibodies to fibrinogen. Immunoglobulins are formed due to:

• frequent blood transfusions;
• diffuse connective tissue disease;
• inflammatory diseases characterized by symmetrical damage to the joints and internal organs;
• narrowing of the mouth of the aortic valve;
• the development of a highly malignant embryonic tumor originating from developing kidney tissues;
• the occurrence of malignant monoclonal gammopathy, accompanied by the secretion of malignant plasma cells.

Preparation for analysis and collection of material

Usually an anomaly is suspected in patients who are prone to bleeding under the skin and bleeding of the mucous membranes. An internist or hematologist prescribes examinations to diagnose von Willebrand anomaly.

The study of the biological system of the blood will find out:

• increased bleeding time;
• the content of plasma formed elements responsible for stopping blood outpourings;
• activated partial thromboplastin time.

Plasma is taken for analysis before ten o'clock in the morning on an empty stomach. The day before the procedure, limit physical and emotional stress that affects the formation of the vWF protein. Blood is collected in a container with sodium salt of citric acid. The white crystalline powder is an anticoagulant, preventing plasma from clotting during storage and delivery to the laboratory. The analysis is carried out by immunoelectrophoresis using antigen.

On a note!

Analysis of fibrinogen activity is carried out only in highly specialized laboratories in which they study violations of the hemostasis system. In such institutions, they do not only draw and analyze blood. But also coagulograms, dimer tests and activated partial thromboplastin time.

Decryption

Additional values ​​that are needed to establish an accurate diagnosis: ristocetin-cofactor analysis (FFV: RCo), the level of the eighth factor. The severity of the course of the pathology depends on the degree of decrease in values.

Reference transcript after analysis:

Level up

Fibrinogen is an acute phase protein of inflammation. Therefore, the cause of an increase in protein levels can be autoimmune and infectious diseases. An increase in glycoprotein occurs when epithelial cells are disturbed due to: vascular inflammation, hypertension, diabetes mellitus, and the development of neoplasms.

In addition, the cause of an increase in glycoprotein may be:

• myocardial infarction;
• low cardiac output;
• sinus tachycardia;
• sinus bradycardia;
• atrial extrasystole;
• ischemia.

A temporary deviation of the protein value from the norm is possible when carrying a child, taking hormones and adrenergic drugs.

Level reduction

The reason for the decrease in glycoprotein is congenital or acquired deficiency of vWF, congenital thrombocytosis. As well as Gasser's disease, which is accompanied by an abnormal growth of protein molecules.

Pathologies are characterized by a lack of attraction of molecules and the process of gluing cells, prolonged and frequent hemorrhages. When making a differential diagnosis of vWF deficiency and coagulation disorder (A), third coagulation factors are compared. If VIII-vB is lower than VIII-vB, von Willebrand disease is confirmed.

Treatment

Checking plasma for the amount and activity of fibrinogen is a discriminant test. Allows you to evaluate the ability of platelets to aggregate and adhere when creating a clot. For a competent interpretation of the analysis and the appointment of treatment, you need to contact only a hematologist.

Treatment of the anomaly involves the introduction of plasma from freshly citrated blood containing antihemophilic globulin, the use of hemostatic drugs.

For blood flow, you will need:

• autogenous platelet gel;
• hemostatic plates to stop bleeding of various origins;
• applying a bandage from a bandage or gauze;
• use of hemostatic tablets.

On a note!

In mild forms of fibrinogen deficiency, treatment with folk remedies is allowed. To stop internal and external bleeding, apply: nettle, yarrow, comfrey.

Prevention

Due to the fact that the anomaly occurs with a genetic disorder, it is impossible to completely cure it. However, to reduce the risk of developing pathology, it is necessary to observe preventive measures:

• avoid injury and cuts;
• do not take antiplatelet agents and anticoagulants;
• timely undergo dispensary examination;
• to refuse from bad habits;
• stick to a healthy diet.

To prevent an attack of hemorrhage in the joints or muscles, hematologists recommend leading an active lifestyle, avoiding obesity. It is not recommended to engage in sports in which there is a high risk of injury.

Despite the fact that vWF gene deficiency is a rare anomaly, pathology can lead to death. The disease is insidious in that its symptoms may not appear for a long time. Often it develops over the years, starts, turns into complex forms. If at the initial stage of development, fibrinogen deficiency can be partially compensated, in the later stages disability or death occurs.

The von Willebrand factor is an element of blood plasma that plays a huge role in the blood coagulation system. It is thanks to him that platelets rush to the site of damage to the vessels and “seal” them.

According to the analysis, which is called vWF, the specialists of our laboratory diagnose diseases associated with increased bleeding: hemophilia A, von Willebrand disease, Bernard-Soulier syndrome and others.

Cost of testing for von Willebrand's disease*

• 1 800 R Willebrand factor activity
• 3 500 R Initial consultation with a hemostasiologist
• 2 500 R Repeated consultation with a hemostasiologist
• 1 000 R 1 300 R Hemostasiogram (coagulogram)
• 2 500 R ADAMTS-13 Activity
• 2 500 R ADAMTS-13INH
• 2 500 R ADAMTS-13 concentration
• 300 R Blood sampling

Why do we need an analysis for the activity of the von Willebrand factor

Diagnosis of von Willebrand factor deficiency helps to prevent the development of bleeding during childbirth, surgical interventions. The analysis is of great importance for people with I (0) blood group, who are prone to severe von Willebrand disease.

Women with vWF deficiency usually suffer from intense and prolonged periods - a similar problem is solved with the help of hormonal contraceptives. Determining the risk of bleeding before surgery allows the surgeon to correctly prescribe prophylactic treatment and administer to the patient a concentrate of "missing" factors.

Specialists

Preparation and conduct of the study

The study is prescribed for changes in the standard coagulogram, indicating a deficiency of vWF or the 8th coagulation factor. Such a marker is an increase in blood clotting time and aPTT at normal values ​​of prothrombin time and platelet count.

Blood for analysis is taken in the morning, on an empty stomach. The day before, you should limit physical activity and exclude emotional overstrain that affects the level of vWF. During pregnancy, stress and infectious diseases, when the activity of the von Willebrand factor increases sharply, its diagnosis is not carried out.

The analysis is performed by rocket electrophoresis or ELISA using a chromogen. The results of the study in the ILC are issued the very next day after donating blood.

Norm and decoding

Normally, the activity of the von Willebrand factor is 50-160%. A slight decrease in the marker is considered the norm for people with I (O) blood group, and an increase - with IV (AB).

If vWF is raised

A sign of diseases of the cardiovascular system, rheumatism or diabetes. At high titers of von Willebrand factor, additional tests for activity and an ADAMTS-13 inhibitor are performed. This eliminates the risk of developing thrombotic thrombocytopenic purpura and DIC.

If vWF is down

The activity of the factor decreases due to:

• one of the 4 types of von Willebrand disease;
• hemophilia;
• hereditary platelet defect (Bernard-Soulier syndrome);
• or Heide's syndrome - at risk of gastrointestinal bleeding.

Where to take an analysis for the von Willebrand factor in Moscow

The study of the activity of the von Willebrand factor is carried out only in highly specialized laboratories that study blood clotting disorders - for example, in the Women's Medical Center.

Other types of analyzes are also available in our Hemostasis Pathology Laboratory - extended hemostasiogram (coagulogram), D-dimer and APTT tests. And for deciphering the results, you can contact the hemostasiologists of the center.

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