Cell Lines Derived from Haematopoiesis

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Questions and Answers

What is the primary function of eosinophils in the immune system?

Chemotaxis and phagocytosis of microorganisms

Antibody-independent killing of phagocytosed cells

Antibody-dependent damage to parasites (correct)

Regulation of inflammatory response via cytokine release

What is the normal hemoglobin level for adult females?

110-130 g/L

130-160 g/L

120-140 g/L

120-155 g/L (correct)

What is the primary mechanism by which basophils modulate the inflammatory response?

Antibody-dependent activation of neutrophils

Release of cytokines and chemokines

Release of proteases and heparin (correct)

Antigen presentation to T-cells

What is the primary function of platelets in the body?

Primary haemostasis Signup and view all the answers

What is the primary factor that dictates the symptoms and signs of anemia?

Rate of anemia development Signup and view all the answers

What is the primary function of lymphocytes in the immune system?

Immune response and hematopoietic growth factors Signup and view all the answers

What is the primary mechanism of haemolysis in immune-mediated haemolytic anaemia?

IgG coating of red cells leading to phagocytosis Signup and view all the answers

What is the most common congenital defect in haemolytic anaemia?

Hereditary spherocytosis Signup and view all the answers

What is the primary role of haemoglobin in the body?

Oxygen transportation Signup and view all the answers

What is the composition of normal adult haemoglobin?

2 alpha and 2 beta chains Signup and view all the answers

What is the consequence of glucose-6-phosphate dehydrogenase deficiency?

Increased sensitivity to oxidative stress Signup and view all the answers

What is the characteristic feature of haemolytic anaemia on physical examination?

Pallor and jaundice Signup and view all the answers

What is the primary reason why iron is tightly managed in the body?

Because excess iron is potentially toxic Signup and view all the answers

What is the most common cause of microcytic anemia worldwide?

Iron deficiency anemia Signup and view all the answers

What is the primary mechanism of iron deficiency anemia in individuals with menorrhagia?

Increased loss of iron Signup and view all the answers

What is the characteristic of red blood cells in macrocytic anemia?

Large size Signup and view all the answers

What is the primary cause of normocytic anemia in individuals with chronic renal disease?

Reduced erythropoietin Signup and view all the answers

What is the primary mechanism of folate deficiency in individuals with coeliac disease?

Malabsorption Signup and view all the answers

What is the primary symptom of vitamin B12 deficiency in the nervous system?

Peripheral neuropathy Signup and view all the answers

What is the primary treatment for megaloblastic anemia?

Addressing underlying cause Signup and view all the answers

What is the primary characteristic of megaloblastic erythropoiesis?

Disordered DNA synthesis Signup and view all the answers

What is the primary mechanism of iron deficiency anemia in individuals with Crohn's disease?

Malabsorption Signup and view all the answers

Study Notes

Haematopoiesis and Blood Cells

7 cell lines arise from haematopoiesis:
- Red blood cells: transport O2 from lungs to tissues
- Neutrophils: chemotaxis, phagocytosis, killing of phagocytosed cells
- Eosinophils: neutrophil functions + antibody-dependent damage to parasites, immediate hypersensitivity
- Basophils: immediate hypersensitivity, modulate inflammatory response via proteases and heparin
- Monocytes and macrophages: chemotaxis, phagocytosis, killing of micro-organisms, antigen presentation and release of IL-1 and TNF
- Platelets: primary haemostasis (adhere to subendothelial connective tissue)
- Lymphocytes: immune response and haemopoietic growth factors

Haemoglobin Levels

Haemoglobin levels in adults:
- Adult males: 130-170 g/L
- Adult females: 120-155 g/L
- Pregnant females: 110-140 g/L
Children's haemoglobin levels:
- 6 months-6 years: 110-145 g/L
- 6 years-14 years: 120-155 g/L

Anaemia

Anaemia arises when there is a reduction in haemoglobin levels below the reference range for age and sex of the individual
Rate of anaemia development dictates the symptoms and signs
Symptoms of anaemia:
- Lassitude
- Fatigue
- Dyspnoea on exertion
- Palpitations
- Headache
- Chest pain
Signs of anaemia:
- Pallor
- Tachycardia
- Wide pulse pressures
- Systolic flow murmurs
- Congestive cardiac failure

Mechanisms of Anaemia Development

Blood loss
Decreased red cell lifespan (haemolytic)
Impairment of red cell formation
- Insufficient erythropoiesis
- Ineffective erythropoiesis
Pooling of and destruction of RBCs in spleen
Increased plasma volume (pregnancy)

Anaemia Morphology

Microcytic (small) anaemia:
- Iron deficiency
- Thalassaemias
Normocytic (normal) anaemia:
- Acute blood loss
- Anaemia of chronic disease
- Chronic renal failure
Macrocytic (big) anaemia:
- Alcoholism
- Folate deficiency
- Vitamin B12 deficiency
- Drugs

Iron Deficiency Anaemia

Most common cause of microcytic anaemia worldwide: iron deficiency anaemia
Iron is tightly managed in the body due to its potential toxicity
Mechanisms of iron deficiency:
- Poor dietary intake
- Malabsorption
- Increased loss of iron
Manifestations of iron deficiency:
- Koilonychia
- Angular chelitis
- Atrophic glossitis
- Recurrent oral ulceration
- Burning mouth
- Oesophageal web (Plummer-Vinson / Patterson-Brown Kelly syndrome)
Management of iron deficiency microcytic anaemia:
- Investigated via blood film and iron studies
- Treatment involves addressing underlying cause, oral supplementation, parenteral supplementation, and blood transfusion (in severe cases)

Thalassaemias

Inherited blood disorder causing reduced haemoglobin levels
Another cause of microcytic anaemia

Normocytic Anaemia

Associated with:
- Chronic inflammatory/connective tissue
- Chronic infections
- Chronic renal disease
- Malignancies

Macrocytic Anaemia

Divided into:
- Megaloblastic erythropoiesis (abnormal red cell development due to disordered DNA synthesis)
- Normoblastic erythropoiesis (normal red cell maturation)
Type of anaemia: macrocytic
Associated deficiencies:
- Folate (vitamin B9): essential for DNA synthesis, found in green leafy vegetables
- Vitamin B12: required for several enzymatic reactions, found in food only of animal origin
Causes of deficiencies:
- Folate: inadequate intake, malabsorption, increased requirement, increased loss, and drugs
- Vitamin B12: inadequate intake, inadequate secretion of intrinsic factor, inadequate release from food, diversion of dietary B12, and malabsorption
Clinical features of folate and vitamin B12 deficiencies:
- Generic symptoms and signs of anaemia
- Occasional mild jaundice
- Glossitis
- Oral ulceration
- Peripheral neuropathy (loss of proprioception and vibration sense)
- Demyelination with subacute combined degeneration of spinal cord
- Dementia
Management of megaloblastic anaemia:
- Investigations: blood film and serum folate and B12
- Treatment involves addressing underlying cause, oral supplementation, and parenteral vitamin B12 (in pernicious anaemia)

Normoblastic Macrocytosis

Causes:
- Alcohol excess
- Liver dysfunction
- Hypothyroidism
- Drugs (methotrexate, azathioprine)

Haemolytic Normocytic Anaemia

Divided into:
- Congenital
- Acquired
Defects in congenital haemolytic anaemias:
- Membrane defects
- Enzyme defects (e.g. G6PD deficiency)
- Globin defects
Defects in acquired haemolytic anaemia:
- Immune (autoimmune or alloimmune)
- Non-immune (mechanical trauma, infections, or drugs)
Clinical features of haemolytic normocytic anaemia:
- Pallor
- Jaundice (due to elevated bilirubin)
- Splenomegaly (enlargement of the spleen)
- Expansion of erythropoiesis leading to bone deformities (frontal bossing) and pathological features

Haemoglobin Function

Role of haemoglobin: oxygen transportation
Normal haemoglobin composition: 2 alpha and 2 beta chains
Compositions of adult haemoglobin:
- Hb A (normal) (alpha2beta2) 97%
- Hb A2 (alpha2delta2) 1.8-3.6%
- Hb F (alpha2gamma2)

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Description

This quiz covers the 7 cell lines that arise from haematopoiesis, including their functions and characteristics. Learn about the roles of red blood cells, neutrophils, eosinophils, basophils, monocytes, macrophages, and platelets.