Bleeding disorders Flashcards
What is the role of platelets?
To clump together to cause a platelet plug
What are platelets formed from?
Megakaryocytic
What is the lifespan of platelets?
7-10 days
What is the normal platelet count?
150-400x10^9/L
What is Thrombopoietin (TPO)?
They control platelet production. Stimulates the production of platelets by megokaryoctyes. Is produced in the Liver.
What is thrombocytopenia?
This is a deficiency of platelets in the blood. Can either be due to decreased production or increased destruction.
What factors could lead to thrombocytopenia due to decreased production of platelets?
This is usually due to problems with the bone marrow
- Congenital problems
- Infiltration of the bone marrow
- Reduced platelet production by the bone marrow
- Liver failure would cause reduced TPO - leading to reduced platelet production
What factors could lead to thrombocytopenia due a an increase in platelet destruction?
- Medications e.g methotrexate or heparin
- Alcohol excess
- Autoimmune e.g ITP
- Consumption of platelets e.g DIC and TTP
What is ITP?
Immune Thrombocytopenia Purpura. Thrombocytopenia due to immune destruction of platelets
The antibody-coated platelets are removed following binding to Fc receptors on macrophages
IgG antibodies form to platelets and megakaryocytes
What are the management options for ITP?
- Steroids
- IV immunoglobulins
- MAB e.g rutuximab
What are the signs of ITP?
- Easy bruising
- Epistaxis
- Menorrhagia (heavy menstruation)
- Purpura (red or purple spots on the skin caused by bleeding underneath the skin)
- Gum bleeding
- Major haemorrhage is rare
- Splenomegaly is rare
What would a bone marrow examination show in ITP?
Thrombocytopenia with increased or normal megokaryocytes
What is Thrombotic Thrombocytopenic Purpura?
Widespread adhesion and aggregation of platelets leads to microvascular thrombosis and thus consumption of platelets and thus profound thrombocytopenia
