Session 5- When Haematopoiesis goes wrong

Question 1

myeloproliferative neoplasms

Answer 1

a group of diseases of the
bone marrow in which excess cells are produced. They arise from
genetic mutations in the precursors of the myeloid lineage in the
bone marrow.

Question 2

what are the 4 types of MPN

Answer 2

1. Polycythaemia vera (excess erythrocytes)
2. Essential thrombocythaemia (overproduction of
   megakaryocytes leading to excess platelets)
3. Primary myelofibrosis (initial proliferative phase followed by
   replacement of haematopoietic tissue by connective tissue
   leading to impairment of the generation of all blood cells
   (pancytopenia))
4. Chronic myeloid leukaemia (excess granulocytes)

Question 3

what is polycythaemia

Answer 3

s a disease state in which the volume percent of
erythrocytes in the blood (the haematocrit) exceeds 52% (males) or
48% (females). This situation can arise from either an increase in the
number erythrocytes (termed absolute polycythaemia) or to a
decrease in the plasma volume (termed relative polycythaemia).

Question 4

relative polycythaemia

Answer 4

decrease in plasma volume

Question 5

absolute polycythaemia

Answer 5

increase in number of erythrocytes

Question 6

primary polycythaemia

Answer 6

abnormaility originates in bone marrow

Question 7

What causes secondary polycythaemia

Answer 7

caused by increased levels of erythropoeitin

• physiological response to hypoxia - high altitude, chronic lung disease
• abnormal production- renal carcinoma, renal artery stenosis

Question 8

polycythemia vera

Answer 8

specific form of polycythaemia which
arises from a myeloproliferative neoplasm in the bone marrow
resulting in overproduction of erythrocytes

caused by mutation of the gene coding for Janus
Kinase 2 (JAK2)

Question 9

clinical features associated with polycythaemia

Answer 9

• Thrombosis (venous & arterial)
• Haemorrhage (skin or GI tract)
• Headache and ‘dizziness’
• Plethora
• Burning pain in the hands or feet (Erythromelalgia)
• Pruritus
• Splenic discomfort, splenomegaly
• Gout
• Arthritis
• May transform to myelofibrosis or acute leukaemia

Question 10

treatment of polycythaemia vera

Answer 10

phlebotomy
aspirin
cytoreduction agents- hydroxycarbamide

Question 11

thrombocytosis

Answer 11

increase in the
platelet count compared to the normal
range of a person of the same gender
and age. Thrombocytosis is a common
reaction to infection and inflammation
and is seen often in hospitalised
patients

Question 12

essential thrombocythaemia

Answer 12

thrombocytosis as a result
of a myeloproliferative neoplasm- a rare chronic blood cancer characterised by the overproduction of platelets by megakaryocytes in bone marrow

Question 13

common symptoms of essential thrombocythaemia

Answer 13

• Numbness in the extremities
• Thrombosis (most often arterial e.g. stroke or peripheral
gangrene)
• Disturbances in hearing and vision (related to microvascular
complications)
• Headaches
• Burning pain in the hands or feet (Erythromelalgia)

Question 14

thrombocytopenia

Answer 14

abnormally low level of platelets

Question 15

symptoms of acquired thrombocytopenia

Answer 15

bleeding gums

nosebleeds

heavier or longer menstrual periods.

petechiae (small red/purple spots on the skin) are usually seen
on the feet, shins and forearms.

Question 16

causes of acquired thrombocytopenia

Answer 16

a decrease in platelet production, increased consumption
of platelets (e.g. due to DIC) or an increased destruction of platelets

Question 17

treatment of acquired thrombocytopenia

Answer 17

depends on the specific cause of the disease and focuses
on eliminating the underlying problem (e.g. discontinuing a drug or
treating underlying sepsis

Question 18

immune thrombocytopenic purpura (ITP)

Answer 18

an autoimmune disease characterised by isolated
thrombocytopenia which can take an acute (short-lived) or chronic
course

Question 19

primary myelofibrosis

Answer 19

a myeloproliferative neoplasm where the
proliferation of mutated hematopoietic stem cells results in reactive
bone marrow fibrosis eventually leading to the replacement of
marrow with scar tissue (collagen deposition).

Question 20

symptoms of myelofibrosis

Answer 20

• Hepatosplenomegaly
• Bruising
• Fatigue (and other symptoms related to anaemia)
• Weight loss
• Fever
• Increased sweating
• Portal hypertension

Question 21

treatment of myeolofibrosis

Answer 21

Hydroxycarbamide, folic
acid, and allopurinol may have some benefits and patients with
advance disease may require blood transfusions and sometimes
splenectomy.

recently ruxolitnib

Question 22

chronic myeloid leukaemia

Answer 22

unregulated growth of
myeloid cells in the bone marrow leading to the accumulation of
mature granulocytes (mainly neutrophils) as well as myelocytes in
blood

Question 23

aplastic anemia

Answer 23

a rare disease resulting in damage to bone
marrow and hematopoietic stem cells
leading to pancytopenia (a deficiency of all
three blood cell types: red blood cells
(anaemia), white blood cells (leucopenia),
and platelets (thrombocytopenia)

Question 24

aplastic

Answer 24

inability of the

stem cells to generate mature blood cells

Question 25

what causes aplastic anaemia

Answer 25

y genetic causes, autoimmunity or exposure to chemicals, drugs, or radiation.