Myeloproliferative Disorders Flashcards
What is the one BCR-ABL 1 positive myeloprolifertaive disorder?
Chronic myeloid leukaemia?
What is the buzzword for CML?
Philadelphia chromosome
What are the 3 BCR ABL1 negative myeloproliferative disorders?
Essential thrombocythaemia
Idiopathic myelofibrosis
Polycythaemia rubra Vera
When should you consider a myeloprolifertaive disorder?
High granulocyte count
High Red cell count / Hb
High platelet count
Eosinophilia/basophilia
CML clinical features?
Asymptomatic Splenomegaly Hypermetabollic symptoms Gout Misc: problems due to hyperleucocytosis e.g. priapism
Blood count changes in CML?
Normal or Low Hb.
Leukocytes is with neutrophilia and myeloid precursors (myelocytes), eosinophilia, basophilia,
Thrombocytosis
What is the Philadelphia chromosome?
A translocation between the long arms of chromosome 9 and 22.
Clinical relevance of the genetics of the Philadelphia chromosome?
The Philadelphia chromosome results in a new gene : BCR-ABL1
The gene product is a tyrosine kinase which causes abnormal signalling.
Therefore tyrosine kinase inhibitors can be used e.g. Imatinib.
What are the secondary causes of polycythaemia?
Chronic hypoxia, smoking, EPO secreting tumour.
What is Polycythamie rubra Vera?
High Hb/HCT accompanied by an erythrocytosis (a true increase in red cell mass)
Note: can also have excessive production of other lineages.
Clinical features of PRV?
Headache, fatigue (remember blood viscosity raised not plasma viscosity)
Itch (aquagenic pruritus)
What mutation is prevalent in patients with polycythaemia rubra Vera?
JAK 2
2 commonly used investigations in polycythaemia?
CXR and O2 sats/ABG
Treatment of PRV?
Venesection to Haematocrit <0.45
Aspirin
Cytotoxic oral chemotherapy (hydroxycarbamide)
Essential thrombocythaemia diagnosis?
Exclude reactive thrombocytosis e.g. blood loss, malignancy etc.
Exclude CML.
Genetics: JAK 2 mutations (50%), CALR in those without JAK 2
Characteristic bone marrow appearance
