Overproduction Flashcards
What can cause overproduction of cells?
Myeloproliferative disorders
Physiological reaction
What diseases come under myeloproliferative disorders?
Essential thrombocythaemia
Polycythaemia Vera
Myelofibrosis
Chronic Myeloid Leukaemia
What are features of myeloproliferative disorders?
Overproduction of one or more blood elements
Hypercellular marrow
Cytogenetic abnormalities
Extramedullary haemopoiesis
What is the genetic cause of myeloproliferative disorfers?
Point mutation on JAK2 on chromosome 9
Causes increased proliferation and survival of haematopoietic precursors
What is polycythaemia vera?
Too many red cells
What is the diagnostic criteria for PV?
High haematocrit
- > 0.52 in men
- > 0.48 in women
OR
Raised red cell mass
What are clinical features of PV?
Arterial thrombosis Venous thrombosis Haemorrhage into skin or GI tract Pruritis Splenomegaly
How is PV managed?
Venesection to maintain haematocrit <0.45
Aspirin 75mg
What is polycythaemia?
Increase in circulating red cell concentration typified by a persistently raised haematocrit
What is relative polycythaemia?
Normal red cell mass with decreased plasma volume
What is absolute polycythaemia?
Increased red cell mass
How can absolute polycythaemia be divided?
Primary = PV
Secondary = driven by EPO production
What is essential thrombocythaemia?
Too many platelets
What can cause a high platelet count?
Infection Inflammation Tissue injury Haemorrhage Cancer
How is essential thrombocythaemia managed?
Aspirin
Platelets lowered with hydroxycarbomide
