Haematopoiesis

Question 1

Erythropoietin production

Answer 1

• Low O2 stimulates the liver and kidney to produce it

Question 2

7.5 Causes of low counts from underproduction

Answer 2

1. M​yeloma
2. Myelodysplasia
3. Metastatic malignancy
4. Myelofibrosis
5. Leukaemia
6. Lymphoma
7. Aplastic anaemia

.5 [H]aematinic deficiency

Question 3

Causes of low counts with normal bone marrow

Answer 3

• Immune cellular destruction
• Haemorrhage
• Hypersplenism

Question 4

Causes of high blood count

Answer 4

1. Primary - Abnormal bone marrow
   clonal stem cell disorder over producing cells outweigh the normal control mechanisms (malignancy) –> treat bone marrow
2. Secondary - Normal bone marrow
   being stimulated by the environment to produce extra blood cells

Question 5

Cause of low blood count

Answer 5

• Failure of production
• Ineffective production
• Increased removal/shortened lifespan
• Multifactorial

Question 6

Low blood count: causes of failure of production

Answer 6

• hormone deficiency (e.g. renal failure, hypothyroidism, hypopituitarism)
• marrow infiltration
• toxic effects of alcohol, infection, chemo drugs
• marrow aplasia - empty BM

Question 7

low blood count: causes of ineffective production

Answer 7

• iron deficiency
• B12/folate deficiency
• myelodysplasia
• thalassaemia major

Question 8

Low blood count: causes of increased removal/shortened lifespan

Answer 8

• immune-mediated - AIHA, ITP, neutropenia
• bleeding - red cells and platelets
• sickle cell and other red cell defects
• larger “storage organ” dysfunction - hypersplenism

Question 9

low blood count: multifactorial causes

Answer 9

E.g. elderly patient with impaired renal function on methotrexate

Question 11

Lymphoid cells include

Answer 11

Lymphocytes NK cells

Question 12

Myeloid cells include

Answer 12

WBCs - granulocytes platelets RBCs

Question 13

Kidneys’ role in haematopoiesis?

Answer 13

They produce EPO in response to hypoxia EPO acts on the BM to stimulate RBC production which increases circulating O2

Question 14

Function of spleen and liver

Answer 14

Spleen filters abnormal/old RBCs Increased abnormal cells causes splenomegaly (working overtime) Both used to be site of haematopoiesis (stops at 7mo when BM takes over) Both resume haematopoiesis in BM failure which lead to hepatosplenomegaly

Question 15

Lymphoid organs are

Answer 15

Sites of lymphocyte production and maturation Primary - generate lymphocytes from precursor cells e.g. thymus, BM Secondary/peripheral - maintain naive lymphocytes and start the adaptive response e.g. LN, spleen

Question 16

Non-specific symptoms of anaemia

Answer 16

• fatigue
• SOB
• palpitations
• angina
• headache
• tinnitus

Question 17

Signs of anaemia

Answer 17

• pale - hyperdynamic circulation: tachycardia, flow murmur, cardiomegaly - peripheral oedema (may be secondary to heart failure)