What is haemophilia?
Haemophilia is an inherited bleeding disorder, where essential clotting factors required for blood to clot normally are lacking.
These clotting factors are proteins that work with platelets (specific small blood cells) to allow the blood to clot. They help the platelets to stick together to plug cuts and breaks. As the blood does not clot normally, bleeding episodes will not only last for longer, bruising occurs after minor knocks and bumps, in addition to this, it is not uncommon for spontaneous bleeding to arise with know obvious cause.
Types of haemophilia
Sufferers of haemophilia A are lacking in clotting factor VIII and represent 90% of all those affected by haemophilia. Haemophilia B sufferers are lacking in clotting factor IX. There are three levels of severity; mild, moderate or severe.
70% of haemophilia A sufferers have severe haemophilia and they will have less than 1% of the right amount of clotting factors. A sufferer of moderate haemophilia will have 1% - 5% of clotting factors and again there may be few obvious signs when young. Mild haemophilia represents having 5% to 40% of the usual amount of clotting factors.
It may take years for symptoms to appear, for example after an accident, surgery or major dentistry.
Who has Haemophilia?
Haemophilia is an inherited X-linked recessive condition. The gene that causes haemophilia is carried by women and is passed on through the female line in the family. Males have the condition, and the gene that causes it is carried by women.
The genes responsible for clotting factors VIII and IX are found on the X chromosome. If the mother carries the haemophilia gene and the father does not have haemophilia: A male child will have a 50:50 chance of having haemophilia. A female child will have a 50:50 chance that she will carry the haemophilia gene.
If the father is affected by haemophilia and the mother is not a carrier:
A female child will be a carrier (she is known as an obligate carrier).
A male child will not be affected by the haemophilia gene and cannot pass haemophilia onto his future children.
Signs and Symptoms
- Big bruises;
- Bleeding into muscles and joints, especially the knees, elbows, and ankles;
- Prolonged bleeding after a cut, tooth removal, surgery, or an accident.
- Serious internal bleeding into vital organs, most commonly after a serious trauma
Bleeding in the joints is the most common problem.
- The symptoms of a joint bleed are as follows:
- Tightness in the joint with no real pain.
- Tightness and pain before any bleeding
- Swollen and hot to touch, hard to move
- All movement lost, severe pain
- Bleeding slows after several days when the joint is full of blood
There can be disabling arthritis if this is not treated.
Bleeding in the brain can lead to very serious complications after only a single bump. Signs and symptoms include:
- Difficulty walking
- Frequent vomiting
- Changes in behaviour
- Sleepiness
- Neck pain/stiffness
- Double vision
- Convulsions or seizures
Treatment
The main treatment for Haemophilia A and B is factor concentrate therapy. This is either given as a prophylaxis therapy (‘preventative’) or ‘on-demand therapy’, (stopping bleeding when it occurs). There is no way of permanently increasing or replacing the clotting factors.
For those affected by severe and moderate haemophilia A, clotting factor is given regularly to try to prevent bleeds, pain and joint damage. Those affected by haemophilia B, treatment is usually given twice a week. Children often use factor concentrate more quickly, therefore need more regular injections.
The amount of replacement therapy required depends on the type of Haemophilia, age, the site and severity of bleeding, weight and whether or not the person has developed the antibody that neutralises or knocks out the activity of the clotting factors. These antibodies (inhibitors) develop in 20% of individuals affected with haemophilia A but just 1% of individuals affected with haemophilia B.
Desmopressin (or DDAVP) can be used for sufferers of mild haemophilia. This will stimulate the release of clotting factor V111 and von Wilebrand factor therefore, increases the level of clotting factors in the blood. Von Wilebrand factor carries and binds factor VIII, so it stays in the blood longer.
Antifibrinolytic drugs, for example tranexamic acid and aminocaproic acid, can be given as a pill to keep clots from breaking down. These can be used before bleeding is likely to occur, for instance before sports, dentist, etc.
Vein access devices can be surgically implanted to make it easier to access a vein for treatment.
Other drugs must be avoided. For example, aspirin (and drugs containing aspirin) cannot be used, nor salicylates, ibuprofen and other nonsteroidal anti-inflammatory drugs, eg naproxen.
Home Treatment
Both preventive and demand therapy can be administered at home. There are many advantages to this. The treatment can be delivered quickly so fewer complications are likely. Fewer trips to the hospital are required, children can take responsibility for their own treatment and they are given independence and a sense of control.
Finally...
Advances in genetic science means that the use of gene therapy to treat bleeding disorders is a real possibility and good progress has been made in studies in this area. The research into haemophilia A & B is still at an early stage but gene therapy is a very encouraging prospect for the future.
