When Haemopoiesis goes wrong Flashcards
What are Myeloproliferative neoplasms?
Group of diseases of Bone Marrow in which excess cells are produced (Cancers)
How do Myeloproliferative neoplasms arise?
Genetic mutations in the precursors of the myeloid lineage in the bone marrow
4 Major Types of Myeloproliferative neoplasms
-POLYCYTHAEMIA VERA (excess erthyrocytes)
-ESSENTIAL THROMBOCYTHAEMIA (Overproduce Megakaryocytes - too many platelets)
-PRIMARY MYELOFIBROSIS (Haematopoietic tissue replaced by connective tissue, generation of blood cells impaired PANCYTOPENIA OCCURS)
-CHRONIC MYELOID LEUKAEMIA (excess Granulocytes)
What is Polycythaemia?
Disease state
When volume percent of erythrocytes in blood (Haematocrit) exceeds:
-52% males
-48% females
What is Absolute Polycythaemia ?
How can it be caused?
Increase in the number of erythrocytes increases % RBC in blood
Primary - Bone marrow abnormality
Secondary - Increased erythropoietin
Relative Polycythaemia
Decrease in plasma volume causing increased % of Erythrocytes in blood
What Gene mutation causes (Primary) Polycythaemia Vera? (PV)
Mutation in JAK2 gene
Clinical Features associated with Polycythaemia vera basically from blood being thicker
Thrombosis
Haemorrhage
Headache dizziness
Splenomegaly
Gout
burning pain in hands and feet
Most common cause of morbidity and death associated with Polycythaemia Vera is?
Thrombosis
What is thrombosis?
When blood clots block arteries or veins
Treating Thrombosis
Phlebotomy (removing excess erythrocytes)
Aspirin (has anti-platelet effect)
Hydroxycarbamide (Inhibitts DNA synthesis and so replication)
What is secondary Polycythaemia?
Increase percentage of erythrocytes in blood due to increased production of ERYTHROPOIETIN
What are the Causes of Secondary Polycythaemia?
Something that leads to increased production of Erythropoietin
Chronic Hypoxia (living at high altitude, severe COPD, heavy cigarette use or cyanotic heart disease)
Renal disease
Tumours releasing Erythropoietin
What is Thrombocytosis?
Increased platelet count (above normal range)
Thrombocytosis is common reaction to
Infections
Inflammation
Thrombocytosis that is caused by a Myeloproliferative neoplasm is called
Essential Thrombocythaemia
What is Essential Thrombocythaemia?
Chronic blood cancer (myeoproliferative neoplasm)
Overproduction of platelets due to overproduction of Megakaryocytes
What causes Essential thrombocythaemia?
Mutations in JAK2 genes
Mutations in Thrombopoietin receptor
Symptoms of Essential Thrombocythaemia
Numbness of extremities
Thrombosis (stroke/peripheral gangrene)
Hearing and Vision disturbances (microvascular complications)
Head aches
Burning pains of hands and feet (Erythromelalgia)
Treating for Essential Thrombocythaemia
Low risk = Aspirin (anti-platelet properties)
High risk = Hydroxycarbamide
Anything that reduces platelet count
What is Thrombocytopenia?
Lower than normal range of platelets
Opposite of Thrombocythaemia/thrombocytosis
Inherited or Aquired
The general principles that causes Aquried thrombocytopenia?
Decreased platelet PRODUCTION
Increased platelet CONSUMPTION
Increased platelet DESTRUCTION
What is Immune thrombocytopenia purpura (ITP)
Autoimmune disease that causes Thrombocytopenia
Antiplatelet auto antibodies bind to platelets
T cell activit against platelets and megakaryocytes
What is Primary myelofibrosis?
Myeloproliferative neoplasm where proliferation of mutated Haematopoietic stem cells then cause replacement of bone marrow with scar tissue (collagen)
