Glanzmann Thrombasthenia

Glanzmann Thrombasthenia affects the ability of the blood platelets to gather around the site of a broken blood vessel. The platelets are sometimes present in normal quantity but are unable to work normally. This protein is needed so that platelets aggregate around an injury to a blood vessel. Because of the deficiency, platelets fail to form a plug to stop the bleeding.

Glanzmann Thrombasthenia has three categories of severity. Type I (Severe) is an individual with level less than 5% of normal. Type II (Less severe) is an individual with between 5% and 20% of normal and Type III (Least severe)is a variant of Thrombasthenia with levels of more than 50% of normal, but with major abnormalities in the way platelets aggregate.

What causes Glanzmann Thrombasthenia?

This is an inherited bleeding disorder which affects males and females equally. It is recessive, meaning you have to inherit the gene defects from both parents.

Very rarely, people can develop Glanzmann Thrombasthenia later in life. This is called acquired Glanzmann Thrombasthenia and is caused by the body developing antibodies to the IIb/IIa receptors that normally bind to fibrinogen. It is an autoimmune disorder, and can occur with other autoimmune disorders such as systemic lupus erythematosus. It sometimes also occurs because the person has another medical condition such as Hodgkin or non-Hodgkin lymphoma, or another platelet disorder called immune thrombocytopenic purpura.

What are the symptoms?

Common symptoms:

• Bleeding from the nose or gums (sometimes after losing baby teeth, during teething or even after vigorous brushing)
• Easy bruising
• Excessive bleeding after childbirth
• Excessive bleeding after surgery or injury
• Prolonged bleeding after dental or other surgery
• Very heavy periods.

Less common symptoms:

• Blood in the urine
• Bleeding into the head and brain (headache, neck ache, drowsiness, loss of consciousness
• Bleeding into the gastrointestinal tract (vomiting blood, bloody or black bowel movements).

How is it diagnosed?

Glanzmann Thrombasthenia deficiency is diagnosed by a variety of blood tests that should be performed by a specialist at a Haemophilia/bleeding disorders treatment centre.

How is it treated?

Generally, treatment is only needed when there is a bleed that cannot be controlled or if you are about to have surgery. Bruising may also need treatment, especially if extensive, raised haematomas or painful.

GT may be treated with:

• Antifibrinolytic drugs (tranexamic acid)
• Recombinant factor VIIa
• Platelet transfusions (only if bleeding is severe)
• Fibrin sealants
• Hormonal contraceptives (to control excessive menstrual bleeding)
• Some patients who have extremely severe bleeding may have a stem cell transplant to replace their bone marrow with one that
produces normal platelets.