Factor VII Deficiency

What is Factor VII Deficiency

The disease was first described in 1951 by Alexander and co-authors.

This is the only hemorrhagic diathesis with isolated prolongation of the prothrombin time (reduction of the prothrombin index) with absolutely normal indicators of all other coagulation tests (blood clotting time, activated partial thromboplastin time, autocoagulation test, thrombin time).

Factor VII belongs to K-vitamin-dependent factors synthesized in hepatocytes. Its function is that when interacting with tissue thromboplastin, it forms a fast-acting “external” activator of factor X.

In clinical reports, taking into account the most pronounced forms of hypoproconvertinemia, the deficit of factor VII accounts for from 0.2 to 1% of all hereditary coagulopathy. In most cases, the deficiency of factor VII is inherited autosomally by an incomplete recessive type.

A clinically expressed form of the disease with a level of factor VII in plasma below 5% is observed in all homozygotes, they have a severe form with a level of factor VII below 1-2%. In heterozygotes, the manifestations of this pathology vary from latent forms to forms with moderate or mild hemorrhagic syndrome (the level of factor VII in plasma is 3–15%).

Symptoms of Deficit Factor VII

A severe form of the disease is characterized by microcirculatory hematoma hemorrhage, and bleeding is often detected already at birth (hematomas, hemorrhages, umbilical and gastrointestinal bleeding) or during the first 2 years of life.

Later, hemorrhages are added to these phenomena in the muscles and muscles, in the brain, gastrointestinal bleeding, and also abundant menorrhagia lasting for 1020 days. Long-lasting and heavy bleeding with injuries and operations are also typical. Acute hemorrhages in the joints resemble those in hemophilia, but are much less common and rarely lead to osteoarthritis.

When hypoproconvertinemia of moderate severity level of factor VII does not exceed 5%, hematomas and hemorrhages in the joints are extremely rare, bleeding of the bruise type prevails, bleeding with injuries. The threat of life-threatening hemorrhages in the brain remains.

In milder forms of the disease, the level of factor VII is 15%, a typical type of bleeding is bleeding of the bruise type, however, hemorrhagic phenomena are less pronounced and diverse, often monosymptomatic forms. Much less often, the inferiority of hemostasis is detected only with injuries and operations.

In the latent forms of the disease, there is no bleeding and the level of factor VII in plasma ranges from 15 to 50%.

The prothrombin time is slightly extended or within normal limits. Occasionally, with a latent form, bleeding occurs after major injuries and operations. Among the descendants of individuals with a hidden carrier of the hypoproconvertinemia gene there are patients with clinically severe forms of the disease, which indicates an incomplete recession (intermediary) of this gene.

Diagnosis of Deficit Factor VII

This disease is characterized by isolated lengthening of the prothrombin time with normal indicators of general coagulation tests, normalization of the prothrombin time.

The correct diagnosis is easy enough to make using prothrombin test (without the use of complex two-step methods).

Defecit Factor VII Treatment

Stopping bleeding is provided by increasing the level of factor VII in the patient’s plasma to 15% or more with a jet transfusion of plasma at a dose of 15 ml / kg or a concentrate of factors of the prothrombin complex (PPSB).

During surgery, the doctor prescribes concentrates of factors of the prothrombin complex.

Nonspecific therapy includes a number of general and local effects: ingestion and irrigation of the bleeding surfaces with a solution of aminocaproic acid, local use of thrombin, hemostatic sponge, lebetox.

When uterine bleeding prescribe synthetic hormonal contraceptive drugs in decreasing doses, starting with 3-4 tablets per day. The simultaneous use of PPSB and aminocaproic acid should be avoided, as this is fraught with thrombohemorrhagic syndrome.