Haemophilia, Hemophilia

Hemophilia is a bleeding disorder that occurs almost exclusively among boys and men. Currently hemophilia is not curable, but most cases of it can now be treated effectively. Although it is an inherited condition that can be detected before a child is born, hemophilia is usually discovered when a small child who is beginning to crawl suffers exaggerated bruising from what ordinarily would be minor injuries. While most people think of bleeding from open wounds when they think of hemophilia, external injuries do not usually present the most serious problem. Uncontrolled internal bleeding is much more dangerous. Internal bleeding close to the skin surface causes bruises; bleeding into deeper tissues may result in a hematoma, which is a pocket of blood inside a muscle or organ. Individuals with hemophilia not only tend to have more bruises than other individuals, their bruises are usually more severe. Something as simple as a shot that is injected into muscle tissue may cause a large bruise that lasts for several weeks.

In the late 1800s and early 1900s, hemophilia was sometimes called "The Royal Disease", because many members of the English, German, Russian and Spanish royal families either had it or carried it. Until the 1960's, when clotting factors were identified, the only treatment for hemophilia was blood transfusions. Unfortunately, not enough of the needed clotting factors are present in whole blood or blood plasma to stop serious internal bleeding, so most individuals with severe hemophilia died before reaching adulthood. Others suffered painful and disabling joint damage. Today, because hemophilia can be controlled with clotting factor products, most individuals who have it lead nearly normal lives. Excellent resources, including support groups, are available for individuals with hemophilia and their families. Research, especially in the field of gene therapy, offers hope for better treatment and even a cure in the not-too-distant future.

What is it?

Hemophilia is a disorder of the blood clotting system. Normally, an injury to a blood vessel activates certain blood components known as “clotting factors”. A series of 12 natural clotting factors helps to change ordinary blood components into sticky clumps. Platelets, tiny cell particles that circulate in blood, begin attaching to each other and to protein fibers that are also in the blood. Ordinarily, a soft mass of platelets and fibers (a blood clot) forms quickly, bleeding stops, and the wound begins to heal. This process is known as coagulation. Hemophilia results when one or more clotting factors are absent or insufficient. As a result, either blood clots break apart because they are too fragile to withstand blood flow or clots do not form, at all.

Although a deficiency of any of the 12 clotting factors is possible, the two that appear to be most essential to forming blood clots are factor 8 (designated by the Roman numeral VIII) and factor 9 (IX). A deficiency of factor VIII is also called hemophilia A or classic hemophilia. Approximately 80% of individuals with hemophilia have hemophilia A. Abnormal production of factor IX is called hemophilia B or Christmas Disease (because the first person diagnosed with it was named Stephen Christmas). About 10% to 15% of individuals with hemophilia have hemophilia B. Other inherited bleeding disorders, including deficiencies of other clotting factors and von Willebrand's disease, are very rare.

Both hemophilia A and hemophilia B are classified by the estimated percentage of natural clotting factor that is produced by the individual.

Mild hemophilia is considered to be 5% of normal production

Moderate hemophilia is 1% to 5% of normal production

Severe hemophilia is 1% or less

About two-thirds of individuals with hemophilia A and about half with hemophilia B have severe cases. The severity of an individual’s condition often corresponds to the likelihood of physical problems. It may also predict how serious those problems might be and suggest which treatments may be most effective.

Although most bleeding episodes in mild to moderate hemophilia usually result from an injury, individuals with severe hemophilia may experience bleeding with no apparent cause. In severe hemophilia, most bleeding is internal. Bleeding may occur inside joints and muscles, or more seriously, in organs such as the stomach or brain. However, if the appropriate clotting factor is given as quickly as possible following injury, individuals with hemophilia may not have either visible evidence of bleeding or interference with everyday life.

The physical damage that can result from untreated serious bleeding depends on where the bleeding occurs.

• Serious bleeding into muscle tissue: Areas of muscle cells around the bleeding may die. The resulting scar tissue contracts as it is formed, potentially leading to decreased ability to bend joints. The scar tissue may also squeeze nerves, causing numbness and tingling.
• Serious bleeding into joints: Knees, elbows, ankles, shoulders, hips, and wrists, are usually affected in that order. Joint bleeding may cause multilayered damage that may result in severe, painful arthritis. Commonly, damage progresses as follows:
  • Blood flows into the joint until pressure in the joint space increases significantly, shutting off the flow of blood.
  • Bone ends in the joint are forced apart by the extra blood, causing pain and swelling,
  • Red blood cells release iron and other compounds as they break down within the joint space. Both the resulting debris and the scavenger cells that enter the joint to remove it, attack the smooth cartilage at the ends of the bones.
  • Eventually, patches of cartilage erode away, softened areas of bone splay out, and small areas of dead bone form cysts. Ligaments stretch and slacken, allowing bones to shift into unnatural positions. Chronic handicaps may develop. Hemophilic arthritis can lead to muscle wasting. Weakened bones also increase the risk of fractures.
• Bleeding into the skull or brain: Because bleeding can press on the brain, drowsiness, extreme headaches, nausea, vomiting, and sensitivity to light may result. Scar tissue, which can also be caused by bleeding into the brain, occasionally leads to epilepsy.