Haemophilia

The immediate process of stopping bleeding after injury is known as hemostasis and involves three events which are: blood vessel spasm, the formation of the platelet plug and the blood clot formation process; known as blood coagulation. Clotting of the blood occurs only when thrombin converts fibrinogen to fibrin clot.

Haemophilia A and B are conditions in which males are affected and it occurs when there are low levels of clotting factors in your blood. It causes heavy or unusual bleeding into the joints and other deep tissues. Von Willebrand’s disease is another common inherited bleeding disorder. It develops when the blood lacks von Willebrand factor, which helps the blood to clot. If the bleeding is superficial , then platelet function defect is suspected.

Clinicians frequently order coagulation tests, such as the prothrombin time (PT), activated partial thromboplastin time (aPTT), and correction studies to assess blood clotting function in patients. If platelet function defect is suspected then platelet count and bleeding time is advised. Depending on the history, physical examination and the results of screening tests, further tests such as factor assay or platelet function test are advised. Laboratory tests for hemostasis typically require citrated plasma derived from whole blood.

A coagulation profile includes bleeding time, platelet count, PT, APTT and thrombin time. It is a screening test for abnormal blood clotting because it examines the factors most often associated with a bleeding problem. It does not cover all causes of bleeding tendencies.

Haemophilia is diagnosed with blood tests to determine if clotting factors are missing or at low levels, and which ones are causing the problem. If you have a family history of haemophilia, it is important that your doctors know the clotting factor your relatives are missing.

Haemophilia A results from too little of a plasma protein called factor VIII, which helps blood clot. The greater the deficiency, the more severe the symptoms. Most people who have haemophilia A have moderate or severe symptoms.

Without proper treatment, haemophilia is crippling and often fatal. With modern treatment, most people with Haemophilia can lead full, active lives. Haemophilia is classified as severe, moderate or mild.

The bleeding symptoms arise because blood clotting is impaired. Haemophilia A is caused by a mutation in the gene for factor VIII, so there is deficiency of this clotting factor. Haemophilia B (also called Christmas disease) results from a deficiency of factor IX due to a mutation in the corresponding gene.

Factor VIII (FVIII) is an essential blood-clotting protein, also known as anti-hemophilic factor (AHF). In humans, factor VIII is encoded by the F8 gene. Defects in this gene result in hemophilia A, a recessive X-linked coagulation disorder.

A platelet plug is formed, and the external bleeding stops. Next, small molecules, called clotting factors, cause strands of blood-borne materials, called fibrin, to stick together and seal the inside of the wound. Eventually, the cut blood vessel heals and the blood clot dissolves after a few days.