Hemophilia
Basic Information
Hemophilia is a bleeding disorder in which the affected person lacks or has a low supply of the plasma proteins necessary for normal blood clotting. The most common type of hemophilia is hemophilia A, with an incidence of one in 7500 males. The second most common type is hemophilia B, which accounts for only about 15-20% of all cases. The difference between the two conditions is a matter of degree, with hemophilia B being the more severe type. The number of individuals with hemophilia in the United States is approximately 25,000. It affects all races and socio-economic groups equally.
With both conditions, the affected person experiences episodes of prolonged bleeding, particularly into muscles, joints, and internal organs. These episodes happen because the blood is unable to clot properly. People with a deficiency of plasma proteins can suffer from sustained blood oozing even after a minor injury. At the same time, not all bleeding episodes happen as a result of injury. More than half of those people affected by either hemophilia A or B are classified as severe cases, and they can undergo internal bleeding with no trauma or injury and without apparent cause. The remaining hemophiliacs suffer from a moderate type, and they rarely have spontaneous bleeds. Both of these groups are at risk for bleeding after dental work, surgery, and trauma. There is a third type, even more mild, in which the disease can be so negligible that it may go unnoticed until bleeding happens after intense trauma. In all cases, recurring joint bleeds can turn into other health complications, including chronic joint damage and loss of range of motion. Another concern is that if hemorrhaging were to affect vital organs (especially the brain), continual bleeding could be fatal.
Medical professionals consider hemophilia an X-linked genetic condition. Typically people are born with hemophilia. Among the genes and chromosomes we acquire from our parents are two sex chromosomes, named X and Y. While a woman inherits two X chromosomes, a man inherits one X chromosome from his mother and one Y chromosome from his father. The hemophilia gene is carried by females on one of their X chromosomes. In most instances, females can only be carriers because even when they have a defective X chromosome they always have another X chromosome with a working gene. If a woman carries hemophilia, there is a 50% chance that her male offspring will have hemophilia or that her female offspring will also be carriers. Because males only have one X chromosome, any male who receives the defective X chromosome has hemophilia. If a boy is born to a father with hemophilia and a mother without, he will not get the disease owing to the fact that males get their X chromosomes from their mothers. Conversely, all daughters born to men with hemophilia will become carriers. This is because they receive one X chromosome from each parent.
If no affected male children are born, hemophilia can go unnoticed for many successive generations. In such cases the hemophilia gene is carried by females who, because they have a second functional X chromosome, are not affected by the disease themselves. In other instances there is no family history of hemophilia, and the disease results from a spontaneous mutation.
Symptoms
Some female carriers neither have health problems nor show symptoms characteristic of the hemophilia gene. They are considered asymptomatic carriers. Most female carriers, on the other hand, experience some bleeding problems. They may suffer from excessive menstrual bleeding, bruising, nosebleeds, and bleeding after surgery, dental work, or childbirth. Stress, exercise, medicines, and changing hormone levels during menstruation and during and after pregnancy can all have adverse effects on the bleeding patterns of symptomatic carriers. If a female carrier experiences excessive bleeding they should be immediately seen by a doctor skilled in treating bleeding disorders.
During infancy the disease is not very troublesome. The actual birthing process does not pose a major threat to the baby's health, although an ensuing circumcision can result in prolonged bleeding. Similarly, as a baby learns to walk he/she will often incur bumps and bruises. These can cause bleeding into the soft tissue of the arms and legs, but these superficial bruises are easy to detect and usually not very serious. These bruises are only serious if a hard lump develops beneath the wound.
As a child with hemophilia gets older, the following increase in activity places them at greater risk of bleeding episodes. A few signs of possible deep bleeding are:
- a reluctance to use the limb
- if the child becomes irritable as bleeding continues
- if the child complains of a "pulled muscle"
If a child exhibits any of these symptoms it is necessary to evaluate the limb. It may be helpful to look at the other limb at the same time to see if there are any differences in swelling or skin temperature. It is possible for a bleeding episode in a muscle to affect other parts of the body. When this happens, swelling can place pressure on the nerves which can cause numbness, pain and an inability to move the limb. It can be difficult to detect when a bleeding episode spreads to another part of the body. As a result, it is important to go to a local hemophilia center for a checkup whenever these symptoms occur.
Bleeding into the joints happens more frequently as a person ages. Bruises are not usually associated with joint bleeds, so they can be rather difficult to detect. Some symptoms of joint bleeding are:
- a reluctance to use the limb
- swelling in the limb; the swelling sometimes feels "spongy"
- attempts to use the limb cause pain
- the limb feels warmer than the other limb
- when the person bends or flexes the limb to ease the pain
Although the tendency is to want to bend the joint, the problem with this is that flexing the joint opens up space which allows for more bleeding. The bleeding can go on until the area feels hot and ultra dense. Also, because the bleeding happens in a small enclosed area (the joint capsule), the blood has nowhere to go, which means that pressure produced by excessive bleeding often results in further pain. If not treated properly, prolonged bleeding can agitate the joint which often leads to arthritis.
Another symptom is mouth bleeding. Mouth bleeding is fortunately a lot less severe than it may look. Unless there is swelling of, or a bruise, beneath the tongue, it is a minor complication.
Besides symptoms, it is important to consider the various complications that are connected to hemophilia. One of the treatment methods involves using blood infusions to replace lost blood during a prolonged bleed. Consequently, hemophiliacs are treated with blood or blood products that could be exposed to blood-born viruses. In the early 1980s, around half of all individuals with hemophilia contracted HIV from blood products. Fortunately, while many of those persons developed full-blown AIDS, recently developed viral screening and purification methods have improved the safety of the blood supply.
Another concern for people getting a blood infusion during a bleeding episode is the contraction of hepatitis. Hepatitis is an inflammation of the liver that happens when the liver is injured or infected. Symptoms of hepatitis are: fatigue, nausea, vomiting, muscle and joint aches, liver tenderness and enlargement, and weight loss. Although there are six kinds of hepatitis, hepatitis A, B, and C make up for just less than 100% of all cases. When hepatitis is contracted as a virus, it can be passed through blood and blood products. While the blood supply's safety has improved due to increased sensitivity of testing methods, there is still some chance of hepatitis transmission during blood infusions. As a safety precaution, medical professionals advise that persons with hemophilia receive vaccines for both hepatitis A and B. Because there is no vaccine for C, they should get tested for this virus on a yearly basis.
Diagnosis/Treatment
If a medical professional suspects hemophilia, they will evaluate the person's ability to achieve hemostasis. In other words, the process of blood clotting involves platelets (blood clotting cells) gathering at the injured site at the same time the vessel tightens to minimize blood loss. The mission of the platelets is to form a platelet plug which will decelerate blood loss. Medical professionals use the phrase "primary hemostasis" to refer to the situation in which platelets have coagulated at the site of injury and slowed down bleeding. In most cases, the platelet plug is too temporary to last throughout the period needed for healing. The second stage of the coagulation process involves large amounts of fibrin, a kind of platelet cement, reinforcing the platelet plug. Once sufficient levels of fibrin are present at the injured site, then "secondary hemostasis" has been achieved. If this hemostasis cannot be reached, then the person has a "secondary hemostasis defect." Most people with hemophilia A and B have this defect.
The first step of diagnostic examinations is to find out whether or not the person has a low platelet count. At the same time, they often will assess bleeding time. Bleeding time is the duration of blood flow from the moment of injury to the moment the blood has successfully clotted. A bleeding time of nine minutes is average. Anything over this time duration suggests that the person has some kind of bleeding disorder. Physicians also examine the time it takes for partial thromboplastin to be completed. Partial thromboplastin is a test performed in a test tube, and it reveals how well the fibrin-making process is functioning. If partial thromboplastin takes longer than 35 seconds, doctors consider a blood clotting disorder such as hemophilia to be present.
When a bleeding episode occurs, treatment involves an infusion of clotting factor (the component in the blood responsible for coagulation) to replace the missing protein necessary for adequate blood clotting. Especially in the case of severe bleeding, repeated infusions may be needed. Some people with severe hemophilia rely on a preventive treatment called prophylaxis. Prophylaxis involves the regular use of blood clotting factor to prevent bleeds before they occur. Currently, clotting factors such as cryoprecipitate (the factor-rich component of blood) come packaged in a concentrated, freeze-dried form. This makes it easy to self-infuse frozen plasma, which means fewer hospitalizations and more advanced preventive treatment. Another recent advancement is genetically-engineered plasma. Because this substance is not made from human blood, but rather incorporates some human blood components along with other animal components, there is no risk of human blood-born viruses.
All factor replacement methods involve intravenous infusion. When clotting factor is introduced to the body, the body begins using it immediately. After eight hours the body has used up about half of the factor. The bleeding, by this time, should be well-managed. After 24 hours, when the entire factor infusion has been exhausted, a strong fibrin-reinforced clot should be in place at the site of the injury. A hemophiliac ought to keep in mind that a new bleeding episode can begin if the clot becomes dislodged.
Hemophiliacs should stay away from all products containing aspirin. Aspirin prolongs bleeding time even in people without hemophilia.
Because strong muscles reduce the frequency of bleeding episodes in the joints, it is suggested that hemophiliacs exercise regularly. At the same time, if left untreated, a bleeding episode can aggravate the joint surface which can cause arthritis.
Finally, if a person with hemophilia becomes unconscious, it is vital to seek medical attention immediately.
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