Monday, September 12, 2011

What is Haemophilia

Haemophilia is a group of inherited bleeding disorder resulting in an abnormal bleeding tendency and poor blood clotting. Patient will develop abnormalities related to high bleeding tendency. Haemophilia is an X-linked recessive genetic pattern and is more common in males than females. There are mainly two types of Haemophilia, they are Haemophilia A and Haemophilia B. Rarely there is another type of haemophilia known as haemophilia C.

What is haemophilia A, B and C?
Haemophilia A is caused by the deficiency of clotting factor VIII, B type is caused by the deficiency of clotting factor IX (Christmas Factor) and haemophilia C is caused by the deficiency of clotting factor XI. In all the above cases, patient will have abnormal bleeding tendency.

Incidence
Haemophilia A : 1: 5000 males. It is four times more common than Type B.
Haemophilia B: 1: 34,000 Males.
Haemophilia in girls is very rare condition. This condition develops in girls only when both the X genes are defective. If a girl has one defective X gene and a normal X gene, she is not affected but her male children have 50% chance of getting the disease.

Causes
Genetic mutation is the primary cause of the disease. As a result of defect in the genetic code that is responsible for formation of proteins that are essential for clotting mechanism, there will be an abnormality in the clotting factors. Symptoms of abnormal bleeding occurs as a result of this condition.

Blood clotting mechanism involves complex processes and 13 chemically different proteins are necessary for this mechanism to be effective. If any of these 13 factors are deficient, there will be abnormalities in clotting mechanism. As in type A, there will be a deficiency in clotting factor VIII, deficiency of clotting factor IX in type B and deficiency of factor XI in Type C.



Signs and symptoms
Signs and symptoms of Haemophilia varies according to the severity of the disease. Signs are same for all types of haemophilia. According to the factor activity, Haemophilia can be categorized as mild, moderate and severe.

When the factor activity is more than 5%, it said to be mild haemophilia. Bleeding occurs in response to injury or trauma. If the factor activity is 1 per cent to 5 per cent, it is moderate haemophilia and bleeding occurs in response to mild injuries and the onset is late. Severe haemophilia occurs when the factor activity is less than 1%. Spontaneous bleeding occurs anywhere in the body and the onset is early.

Common symptoms associated with this condition are
  1. Hemarthrosis: It is the bleeding into the joints. Ankles and knee joints are mostly affected. This caused intense pain on the joints, distension of joint space and eventually destruction of the joints occurs.
  2. Bleeding into muscles: This causes formation of hematoma and compartment syndrome. 
  3. Mouth and nose bleeds 
  4. Bleeding in gastro-intestinal tract (presence of blood in stools) 
  5. Blood in urine caused by bleeding in the urinary tract 
  6. Bleeding into brain and skull can cause mild to severe complications 
  7. Uncontrolled bleeding after surgery, invasive procedure or trauma.

Diagnosis
History collection is done to find out any family history of Haemophilia. If the patient is not having any family history, spontaneous genetic mutation of the gene will be the cause.

Platelet count, Prothrombin time, activated partial prothrombin time and specific tests for identifying the deficiency of clotting factor will confirm the diagnosis.

Genetic testing also can be done to find out the specific gene mutation responsible for haemophilia. This can be done in female to know if she is a carrier of the mutated gene.

Treatments
The primary treatment of haemophilia is the replacement therapy. The clotting factor must be replaced as needed to prevent or control the episodes of bleeding. This clotting factor may be purified concentrates from human donor blood or made in laboratory. With proper training, patient can perform replacement therapy in home as needed.

Drug Desmopressin is sometimes prescribed for patients with mild haemophilia which can be administered slowly through intra-venous route or as nasal preparation. This drug stimulates release of more clotting factor.

When pain is present, pain relievers are prescribed. Pain relievers such as Aspirin and non-steroidal anti-inflammatory drugs will further inhibits the clotting mechanism and must not be used in pain control. Acetaminophen is usually the drug of choice for Haemophilic patients for pain control.

Complications
Major complication of replacement therapy is the formation of antibodies against the infused clotting factors. These inhibitors will destroy the infused concentrates of clotting factor and the replacement therapy will be ineffective. Immune tolerance therapy may be necessary in cases of severe haemophilia with formation of inhibitors.

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