Haematology

Question 1

What cells are produced by lymphoid potential early progenitor cells?

Answer 1

NK cells (Pro-NK then Pre-NK then NK cell)

B cells (Pro-B, then Pre-B, then B cell)

T cells (Pro-T, then Pre-T, then T cell)

Question 2

What cells are produced by myeloid potential early progenitor cells?

Answer 2

Neutrophils

Monocytes

Eosinophils

Basophils

Platelets

Erythrocytes

Question 3

CFU-G cells arise from CFU-Mix cells. Which cells arise from CFU-G cells?

Answer 3

Myeloblasts which become neutrophils

Question 4

CFU-M cells arise from CFU-Mix cells. Which cells arise from CFU-M cells?

Answer 4

Monoblasts which become monocytes

Question 5

CFU-eo cells arise from CFU-Mix cells. Which cells arise from CFU-eo cells?

Answer 5

Eosinophiloblasts which become eosinophils

Question 6

CFU-b cells arise from CFU-b/M/E cells. Which cells arise from CFU-b cells?

Answer 6

Basophiloblasts which become basophils

Question 7

CFU-Mg cells arise from CFU-b/M/E cells. Which cells arise from CFU-Mg cells?

Answer 7

Megakaryoblasts which form platelets.

Question 8

CFU-E cells arise from CFU-b/M/E cells. Which cells arise from CFU-E cells?

Answer 8

Erythroblasts which become erythrocytes

Question 9

What cells are found in the bone marrow?

Answer 9

Haematopoietic cells and their product red and white blood cells

Adipocytes

Megakaryocytes

Question 10

What is a haemoglobin composed of and how many oxygen molecules does it carry?

Answer 10

Heme group is composed of Ferrous + protoporphyrin IX

Globin group is composed of 2 alpha and 2 beta chains

2, 3 DPG in central pocket

1 Hb carries 4 O2 molecules

Question 11

What does 2,3-DPG do?

Answer 11

2,3-diphosphoglyceric acid (conjugate base 2,3-diphosphoglycerate) (2,3-DPG) is present in human red blood cells (RBC; erythrocyte) at approximately 5 mmol/L. It binds with greater affinity to deoxygenated hemoglobin (e.g. when the red blood cell is near respiring tissue) than it does to oxygenated hemoglobin (e.g., in the lungs) due to conformational differences: 2,3-BPG (with an estimated size of about 9 Å) fits in the deoxygenated hemoglobin conformation (with an 11 angstroms pocket), but not as well in the oxygenated conformation (5 angstroms). It interacts with deoxygenated hemoglobin beta subunits and so it decreases the affinity for oxygen and allosterically promotes the release of the remaining oxygen molecules bound to the hemoglobin; therefore it enhances the ability of RBCs to release oxygen near tissues that need it most. 2,3-DPG is thus an allosteric effector.

Question 12

Where is haemoglobin produced prenatally?

Answer 12

The yolk sac until approximately 6 weeks of development.

The liver takes over from 6 weeks until 6 weeks after birth.

The spleen helps produce haemoglobin at 12 weeks until 6 weeks after birth.

The bone marrow starts to produce some of the haemoglobin at 18 weeks of development and becomes the only source of blood cell production from 6 weeks after birth onwards.

Question 13

What are the indices used in measuring anaemias?

Answer 13

RBC - Red Blood Cell Count

Hgb - Haemoglobin

MCV - Mean Corpuscular Volume

MCH - Mean Corpuscular Haemoglobin

MCHC - Mean Corpuscular Haemoglobin Concentration

RDW - Red cell Distribution Width

Question 14

What is the definition of anaemia? What does the WHO criteria define it as?

Answer 14

Decline in blood haemoglobin

WHO criteria is < 12 - 13 g or more than 2 standard deviations below the mean of normal range in an age- and sex- matched representative of the population

Question 15

What causes anaemia?

Answer 15

Blood loss

Inefficient erythropoiesis

Increased RBC destruction

Question 16

What are the types of anaemias in regards to proliferation?

Answer 16

Hypoproliferative where there is inadequate production

Hyperproliferative where there is increased clearing

Question 17

What are the types of hypoproliferative anaemias?

Answer 17

Microcytic MCV < 80

Normocytic MCV 80 - 95

Macrocytic MCV >95

Question 18

What are the types of hyperproliferative anaemias?

Answer 18

Haemolytic anaemia

Blood loss

Question 19

What causes hypoproliferative anaemias?

Answer 19

Inadequate production of RBC by bone marrow caused either by:

Primary bone marrow pathology (Red cell aplasia, aplastic anaemia, fanconi anaemia)

Inadequate supply of ingredients to make RBCs (Iron, folate, B12, erythropoitin deficiency)

Cytokine dysregulation

Question 20

What is the most common cause of microcytic anaemia? What are some other potential causes?

Answer 20

Iron deficiency anaemia

Could also be thalassemia, anaemia of chronic disease, sideroblastic anaemia, and lead poisoning

Question 21

What causes iron deficiency?

Answer 21

Blood loss

Decreased GI absorption (bariatric surgery and celiac disease)

Increased iron requirement (Such as in pregnancy and exogenous exposure)

Question 22

What are the clinical symptoms of iron deficiency anaemia?

Answer 22

Dizziness, fatigue, pallor, SOB, rapid HR

Symptoms associated with rapidly proliferating organs such as tongue (glossitis), the mouth (angular cheilitis), and the nails (Koilonychia).

Also causes pica which is a desire to consume non-nutritive things such as ice.

Question 23

How is iron deificiency anaemia diagnosed?

Answer 23

Ferritin (storage of ion) level. Diagnostic levels are <30micrograms/ml

Low serum iron

High TIBC (total iron binding capacity which is a reflection of transferritin)

FERRITIN LEVEL IS THE BEST DIAGNOSTIC TEST

Question 24

How is iron deficiency anaemia treated?

Answer 24

Find the cause

Then replace the iron orally or intravenously

Question 25

What causes normocytic anaemia?

Answer 25

It is the second most common form of anaemia caused by impaired absorption of iron from GI tract and is mediated by hepcidin.

Question 26

What is hepicidin?

Answer 26

Hepcidin is a key regulator of the entry of iron into the circulation in mammals. During conditions in which the hepcidin level is abnormally high, such as inflammation, serum iron falls due to iron trapping within macrophages and liver cells and decreased gut iron absorption.

Question 27

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Answer 27

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