Hemophilia is a congenital bleeding disorder that results in the blood failing to clot normally. It is caused by a deficiency of a protein in the blood called a clotting factor. People with hemophilia bleed easily and often excessively. Untreated, hemophilia can be life-threatening. There are two types of hemophilia: “Hemophilia A” is the most common type and is caused by the deficiency of what is known as Clotting Factor VIII; “hemophilia B” is caused by deficiency of Clotting Factor IX.
Hemophilia occurs in about 1 in 10,000 births and it is much more common in males because it is an “X-linked” disorder. The number of affected persons worldwide is estimated to be about 400,000. Hemophilia A is more common than hemophilia B, representing 80-85% of all cases.
Hemophilia should be suspected in patients presenting with a history of:
- Easy bruising in early childhood.
- Spontaneous bleeding (bleeding for no apparent/known reason), especially into the joints, muscles, and soft tissues.
- Excessive bleeding following trauma or surgery.
A definitive diagnosis depends on a blood analysis to determine deficiency of Clotting Factor VIII or IX.
Because each type of hemophilia requires a different therapy, accurate diagnosis is essential.
Hemophilia can be very successfully managed by simply replacing the deficient clotting factor. Therapy can be either “on demand” - the treatment of active bleeding, or “prophylactic” - regular maintenance of clotting factor levels to prevent bleeding. In developed countries where these factors are readily available, the life expectancy of males suffering from hemophilia is essentially the same as for males in the general population.
Both clotting factors can be isolated from donated human plasma and they can also be engineered by means of recombinant DNA technology. There are many commercial brands from which to choose and that choice is generally made based on price and on the risk of developing antibodies that render the factor ineffective.
1.Srivastava a. et al. Guidelines for the management of Hemophilia. Haemophilia (2012), 1–47.
2. Mannucci PM et al. How we choose factor VIII to treat Hemophilia. Blood (2012) volume 119, number 18, 4108-4114.
Von Willebrand disease
The most common bleeding disorder is von Willebrand disease (VWD). It is congenital and caused by deficiency or abnormality in a plasma protein central to blood clotting known as the von Willebrand Factor (named after the Finnish physician who first identified the disorder).
Von Willebrand Factor (VWF) is the “glue” that helps platelets in the blood stick together to form a clot where a blood vessel has been ruptured. It also binds and stabilizes the clotting factor Factor VIII, so in patients with VWD, the lack of VWF activity results in premature elimination of Factor VIII in the circulation, thereby resulting in a dual defect in the body’s ability to stop bleeding. People with VWD produce normal amounts of Factor VIII, but with deficient VWF the clotting factor does not stay in the system long enough to adequately carry out its function.
There are three generally recognized forms of the disease:
- Type I: The most common and mildest form of von Willebrand disease. Levels of von Willebrand Factor are lower than normal, and levels of Factor VIII may also be reduced.
- Type II: In this form of von Willebrand disease, there is normal and sufficient von Willebrand Factor but it is deficient and does not work properly. The abnormality in the factor can vary and accordingly there are several subtypes of Type II von Willebrand disease – important to determine because treatment for each is specific.
- Type III: The most severe form of von Willebrand disease in which VWF is nearly or completely absent along with very low levels of Factor VIII.
People with von Willebrand disease can bruise easily; suffer frequent nosebleeds that can be difficult to stop; have heavy menstrual bleeding; and experience heavier and longer than normal bleeding after injury, surgery, childbirth, or dental work. In its most severe form, it can lead to spontaneous joint and organ bleeding and can be life-threatening.
Some patients respond favorably to injection of desmopressin acetate (DDAVP) but the most effective treatment and prophylaxis for VWD – especially in its more severe forms - is therapy with plasma-derived von Willebrand Factor products.
1. Federici AB. Classification and clinical aspects of von Willebrand disease. In: Textbook of Haemophilia 2nd Edition, Lee CA, Berntorp E, Hoots K (eds). Oxford: Wiley-Blackwell 2010. 302–308.