Haematology 4 - Chronic myeloproliferative neoplasms Flashcards
What is the target of imatinib?
Mutated tyrosine kinase (by BCR-ABL gene)
What is the normal role of janus kinases?
They activate the STAT pathway, which promotes cell growth and replication
How does JAK2 mutation cause uncontrollable replication?
No longer need growth factor to activate
In polycythaemia vera, what else will be abnormal on the FBC other than red cell count?
Pronounced thrombocytophilia and slight granulocytophilia
Recall some symptoms of polycythaemia vera
Due to hyperviscosity: - Headaches - visual disturbances - dyspnoea Due to increased histamine release: - peptic ulcer - aquagenic pruritis
Recall four clinical findings in polycythaemia vera
Plethora
Erythromelalgia (red, painful extremities)
Gout
Retinal vein engorgement
What is the expected level of erythropoietin in polycythaemia vera?
Low
What mutation is present in all patients with polycythaemia vera?
JAK2
How should pseudopolychthaemia and polycythaemia vera be differentiated?
Isotype dilution method
Recall 3 causes of increased EPO
Hypoxia
Uterine myoma
Renal cancer
Recall 3 causes of pseudopolycythaemia
Alcohol
Obesity
Diuretics
Recall 3 ways in which polycythaemia vera can be treated
- Venesection
- Cytoreductive therapy
- Aspirin to reduce thrombosis risk
What is idiopathic erythrocytosis?
An isolated erythrocytosis with low EPO, where JAK2 V617 mutation is absent (although JAK mutation in exon 12 may be present)
How should idiopathic erythrocytosis be treated?
Venesection only
How is essential thrombocytothaemia defined?
Chronic myeloproliferative neoplasm with a sustained thrombocytosis > 600 x 10^9/L
Which age group is most at risk of essential thrombocytothaemia?
Bimodal:
Small peak at 30y (M=F)
Larger peak at 55y (F>M)
What are the 2 most likely presentations for patients with essential thrombocytothaemia?
Thrombosis
or bleeding?? paradoxically
Is there a JAK2 mutation in essential thrombocytothaemia?
Yes in 50%
What is the best treatment for essential thrombocytothaemia?
Hydroxycarbamide
Which condition is “tear drop poikilocytosis” pathognemonic of?
Myelofibrosis
Which cells are hyperproliferating in myelofibrosis?
Mostly megakaryocytes and granulocytes
Recall 2 signs of myelofibrosis
Massive spleen
Anaemia
What is the best treatment for myelofibrosis?
Ruxolotinib - a JAK2 inhibitor
Recall 3 bad prognostic indicators in CLL
LDH raised
CD38+
11q23 deletion
Recall 3 good prognostic indicators in CLL
Hypermutated Ig gene
Low ZAP-70 expression
13q14 deletion
What is the 1st line treatment for CLL with a p53 deletion?
Ibrutinib