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Hemophilia

Hemophilia is an inherited (genetically passed to the child through the parent’s DNA) bleeding disorder in which the blood does not clot properly. The overwhelming majority of people with hemophilia are males. Blood contains many proteins (called clotting factors) that help stop bleeding. These clotting factors are numbered from 1 through 13, using roman numerals (such as I or X). People with hemophilia have either a low level of these clotting factors in their blood or none at all. The lower the level—the more serious the hemophilia. The result: problems, such as bleeding without an obvious cause and prolonged bleeding after an injury or surgery, are more likely.

There are 3 different types of hemophilia:

  • Hemophilia A (called classic hemophilia): this type is caused by a lack or decrease of clotting factor VIII (8)
  • Hemophilia B (called Christmas disease): this type is caused by a lack or decrease of clotting factor IX (9)
  • Hemophilia C (called Factor XI [11] deficiency)

Watch the video below to learn how blood clots form.

Diagnosis

Many people who have or have had family members with hemophilia will ask that their male infants be tested soon after birth. It is important to remember, however, that about one-third of people who are diagnosed with hemophilia have no family members with the disorder. In these cases, hemophilia is caused by a spontaneous genetic mutation. A health care provider might check for hemophilia if a newborn shows certain signs; for example, a baby might bleed more than normal after being circumcised. Screening tests and clotting factor tests, both of which are blood tests, are used to diagnose hemophilia. Screening tests show if the blood is clotting properly. Clotting factor tests (called factor assays) are used to confirm a diagnosis of a bleeding disorder. Factor assays are used to pinpoint the type of hemophilia and its severity. With this information, a health care provider can create the best treatment plan.

The table below shows the various levels of severity in hemophilia:

Severity Level of Factor VIII (8) or IX (9) in the Blood
Normal (person who does not have hemophilia) 50%-100%
Mild hemophilia Greater than 5% but less than 50%
Moderate hemophilia 1%-5%
Severe hemophilia Less than 1%

Treatments

Hemophilia is a complex disorder and, therefore, requires a multifaceted approach. The goal of treatment is to prevent bleeds and the damage associated with bleeding. Quality medical care from health care providers with expertise in this bleeding disorder can help prevent many serious problems. Often the best choice for care is a comprehensive Hemophilia Treatment Center (HTC).

A Hemophilia Treatment Center provides care to address all issues related to the bleeding disorder, as well as offers patient and caregiver education.

The HTC team consists of physicians (hematologists), nurses, social workers, physical therapists, and other health care professionals who specialize in the care of people with bleeding disorders.

The best way to treat hemophilia is to replace the missing clotting factor.

Replacing the missing blood clotting factor is done by injecting commercially prepared clotting factor concentrates into a person’s vein. The 2 main types of clotting factor concentrates available are:

  • Plasma-derived factor concentrates: plasma is the liquid part of blood. It is pale yellow or straw colored and contains proteins such as antibodies, albumin, and clotting factors. Several factor concentrates made from human plasma proteins are available. The clotting proteins are separated from other parts of the plasma, purified, and made into a freeze-dried product. This product is tested and treated to kill any potential viruses before it is packaged for use
  • Recombinant factor concentrates: before 1992, all factor replacement products were made from human plasma. In that year, the US Food and Drug Administration approved recombinant factor VIII (8) concentrate, which differs from plasma-derived products in 2 ways: they are either completely free of human plasma or use tiny amounts of pasteurized human serum albumin for cell culture or as a stabilizer. Pasteurized human serum albumin has a 50-year safety record. Recombinant factors VIII (8) and IX (9) are available and do not contain any plasma or albumin and, therefore, cannot transmit any viruses that are known to be transmitted in blood

Creating Recombinant Factor Concentrates

Here is a quick description of the process used to create recombinant factor concentrates:

  • The human factor VIII (8) (or IX [9]) gene is isolated through genetic engineering. The gene contains the code that instructs the cell on how to make human factor VIII (8) or IX (9)
  • The gene is inserted into nonhuman cells, such as baby hamster kidney cells or Chinese hamster ovary cells
  • These cells are grown in a cell culture, where they produce factor VIII (8) or IX (9)
  • The factor VIII (8) or IX (9) is separated from the cell culture and purified
  • A sugar is then added to some products to stabilize the final factor VIII (8) or IX (9) product

The products can be used as needed when a person is bleeding or they can be used routinely to help prevent bleeds. Today, people with hemophilia and their families can learn how to give clotting factors at home (called home therapy). Giving factor at home means that bleeds can be treated quicker, resulting in less serious bleeding, as well as fewer long-term problems.

Watch the video below to see how factor replacement therapy works.

Other treatment products include:

  • Desmopressin acetate (DDAVP): a synthetic form of the naturally occurring hormone that helps to release factor VIII (8) from where it is stored in the body’s tissues. For people with mild, and some cases of moderate, hemophilia, it can help increase their own factor VIII (8) levels enough so that they do not have to use a clotting factor. This medicine can be given through a vein or by nasal spray
  • Epsilon amino caproic acid and tranexamic acid: chemicals that prevent clots from breaking down, resulting in a firmer clot. This medicine is often used to prevent bleeding in the mouth or after a tooth has been removed because it blocks an enzyme in the saliva that causes clots to come apart. Amino caproic acid can be given in a vein or taken by mouth (as a pill or a liquid). Tranexamic acid can be given as an injection or by mouth (as a pill)