Myeloproliferative Disorders

Question 1

What are myeloproliferative disorders (MPD)?

Answer 1

Haemopoietic stem cell disorders involving increased production with preservation of maturation

Question 2

What are the 2 groups/sub-types of myeloproliferative disorders?

Answer 2

BCR-ABL1 negative

BCR-ABL2 positive

Question 3

Which MPD is BCR-ABL2 positive?

Answer 3

Chronic myeloid leukaemia

Question 4

Which MPDs are BCR-ABL2 negative?

Answer 4

Essential thrombocythaemia
Polycythaemia vera
Idiopathic myelofibrosis

Question 5

When should an MPD be considered?

Answer 5

High granulocyte count (chronic myeloid leukaemia)
High red cell count (polycythemia rubra vera)
High platelet count (thrombocythaemia)
Eosinophilia/basophilia
Splenomegaly

Question 6

What happens in chronic myeloid leukaemia?

Answer 6

Excess proliferation of myeloid cells (granulocytes, platelets)
3-5 years chronic phase followed by “blast” crisis akin to acute leukaemia which can be fatal

Question 7

List some clinical features of chronic myeloid leukaemia

Answer 7

Asymptomatic
Splenomegaly
Sweats, fever
Weight loss
Bone pain
Gout

Question 8

Hb may be normal in chronic myeloid leukaemia. True/False?

Answer 8

True

Question 9

Which chromosomes are affected in chronic myeloid leukaemia? What is the genetic change and resultant protein?

Answer 9

“Philadelphia” chromosomes
9 and 22 translocation
Produces tyrosine kinase which causes abnormal phosphorylation

Question 10

How is polycythaemia rubra vera distinguished from secondary polycythaemia?

Answer 10

Secondary polycythaemia is caused by smoking, chronic hypoxia, erythropoietin-secreting tumours

Question 11

How is polycythaemia rubra vera distinguished from pseudo-polycythaemia?

Answer 11

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

Question 12

List some clinical features of polycythaemia rubra vera

Answer 12

Headache
Fatigue
Itch
MPD features

Question 13

Splenomegaly will not be present in secondary polycythaemia. True/False?

Answer 13

True

Question 14

Which gene mutation is important to investigate in polycythaemia?

Answer 14

JAK2 - present in most patients

Question 15

How is polycythaemia rubra vera treated?

Answer 15

Venesection until haematocrit less than 0.45
Aspirin
Cytotoxic oral chemotherapy

Question 16

What is essential thrombocythaemia?

Answer 16

Uncontrolled production of abnormal platelets, resulting in abnormal platelet function

Question 17

What gene mutations can be present in essential thrombocythaemia?

Answer 17

JAK2
CALR
MPL

Question 18

How is essential thrombocythaemia treated?

Answer 18

Aspirin

Cytoreductive therapy

Question 19

Describe the appearance of a blood film in myelofibrosis

Answer 19

Leucoerythroblastic

Teardrop-shaped RBC’s in peripheral blood

Question 20

Reactive causes of high cell counts are more common than myeloproliferative disordrs. True/False?

Answer 20

True

Question 21

List some reactive causes of raised granulocytes

Answer 21

Infection
Post-surgery
Steroids

Question 22

List some reactive causes of raised platelets

Answer 22

Infection
Iron deficiency
Malignancy
Blood loss
Post-splenectomy

Question 23

List some reactive causes of raised red cells

Answer 23

Dehydration
Diuretics
Secondary polycythemia (hypoxia etc.)