Myeloproliferative Disorders Flashcards
What are myeloproliferative disorders (MPD)?
Haemopoietic stem cell disorders involving increased production with preservation of maturation
What are the 2 groups/sub-types of myeloproliferative disorders?
BCR-ABL1 negative
BCR-ABL2 positive
Which MPD is BCR-ABL2 positive?
Chronic myeloid leukaemia
Which MPDs are BCR-ABL2 negative?
Essential thrombocythaemia
Polycythaemia rubra vera
Idiopathic myelofibrosis
When should an MPD be considered?
High granulocyte count (chronic myeloid leukaemia)
High red cell count (polycythemia rubra vera)
High platelet count (thrombocythaemia)
Eosinophilia/basophilia
Splenomegaly
What happens in chronic myeloid leukaemia?
Excess proliferation of myeloid cells (granulocytes, platelets)
3-5 years chronic phase followed by “blast” crisis akin to acute leukaemia which can be fatal
List some clinical features of chronic myeloid leukaemia
Asymptomatic Splenomegaly Sweats, fever Weight loss Bone pain Gout
Hb may be normal in chronic myeloid leukaemia. True/False?
True
Which chromosomes are affected in chronic myeloid leukaemia? What is the genetic change and resultant protein?
“Philadelphia” chromosomes
9 and 22 translocation
Produces tyrosine kinase which causes abnormal phosphorylation
How is polycythaemia rubra vera distinguished from secondary polycythaemia?
Secondary polycythaemia is caused by smoking, chronic hypoxia, erythropoietin-secreting tumours
How is polycythaemia rubra vera distinguished from pseudo-polycythaemia?
Pseudo-polycythaemia is caused by dehydration, diuretic therapy, obesity
i.e. plasma volume has shrunk which makes it seem like Hb is high but it is not
List some clinical features of polycythaemia rubra vera
Headache
Fatigue
Itch
MPD features
Splenomegaly will not be present in secondary polycythaemia. True/False?
True
Which gene mutation is important to investigate in polycythaemia?
JAK2 - present in most patients
How is polycythaemia rubra vera treated?
Venesection until haematocrit less than 0.45
Aspirin
Cytotoxic oral chemotherapy
What is essential thrombocythaemia?
Uncontrolled production of abnormal platelets, resulting in abnormal platelet function
What gene mutations can be present in essential thrombocythaemia?
JAK2
CALR
MPL
How is essential thrombocythaemia treated?
Aspirin
Cytoreductive therapy
Describe the appearance of a blood film in myelofibrosis
Leucoerythroblastic
Teardrop-shaped RBC’s in peripheral blood
Reactive causes of high cell counts are more common than myeloproliferative disordrs. True/False?
True
List some reactive causes of raised granulocytes
Infection
Post-surgery
Steroids
List some reactive causes of raised platelets
Infection Iron deficiency Malignancy Blood loss Post-splenectomy
List some reactive causes of raised red cells
Dehydration
Diuretics
Secondary polycythemia (hypoxia etc.)
