Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Haematology > Red Cells 1 & 2 > Flashcards

Red Cells 1 & 2 Flashcards

1
Q

What is anaemia?

A

Reduction in red cells or their haemoglobin content

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which substances are required for RBC production in the bone marrow?

A
  • Metals: iron, copper, cobalt and manganese
  • Vitamins: B12, folic acid, thiamine, B6, C and E
  • Amino acids
  • Hormones: erythropoietin, GM-CSF, androgens and thyroxine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the process of red cell breakdown

A
  • Occurs in the reticuloendothelial system (macrophages in the spleen, liver, lymph nodes, lungs etc.)
  • Normal lifespan of RBCs is 120 days
  • Globin (amino acids) is reutilised
  • Haem: iron is recycled into haemoglobin and haem is brokendown into bilirubin
  • The bilirubin is bound to albumin in the plasma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the aetiology of congenital anaemias

A
  • Genetic defects in the cell membrane, enzymes and in the haemoglobin
  • Most reduce red cell survival and result in haemolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the pathophysiology of Hereditary Spherocytosis

A
  • Autosomal dominant
  • Defects in 5 different structural proteins: ankyrin, alpha spectrin, beta spectrin, band 3 and protein 4.2
  • Red cells are spherical
  • Removed from circulation by the RE system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the clinical presentation of hereditary spherocytosis?

A
  • Anaemia
  • Jaundice (neonatal)
  • Splenomegaly
  • Pigment gallstones
  • Less likely to be iron and B12 deficient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the treatment options for hereditary spherocytosis?

A
  • Folic acid
  • Transfusion
  • Splenectomy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List the rare membrane disorders

A
  • Hereditary elliptocytosis
  • Hereditary pyropoikilocytosis
  • South East Asian ovalocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name the two red cell enzymes that are important in red cell metabolism disorders

A
  • 2,3 DPG (glycolysis)

- Glucose 6-phosphate dehydrogenase (pentose phosphate shunt - protects from oxidative damage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the function of G6P dehydrogenase?

A
  • Protects the red cell from oxidative damage
  • Produces NADPH - vital for reduction of glutathione
  • Reduced glutathione scavenges and detoxifies reactive oxygen species
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the aetiology and pathophysiology of G6PD deficiency

A
  • Commonest disease causing enzymopathy: has many genetic variants
  • Cells vulnerable to oxidative damage
  • Confers protection against malaria
  • X Linked: affects males, females are carriers
  • Blister cells and bite cells under the microscope
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does G6PD deficiency present?

A
  • Variable degrees of anaemia
  • Neonatal jaundice
  • Splenomegaly
  • Pigment gallstones
  • Usually a precipitant: drugs, broad beans and infection
  • Intravascular haemolysis and haemoglobinuria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What triggers can cause haemolysis in G6PD deficiency?

A
  • Infection
  • Acute illness e.g. DKA
  • Broad beans
  • Drugs: antimalarials, antibacterials, analgesics (aspirin), antihelminthics, vitamin K analogues, probenecid and methylene blue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the pathophysiology of pyruvate kinase deficiency

A
  • Reduced ATP
  • Increased 2,3-DPG
  • Rigid cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the presentation of pyruvate kinase deficiency?

A

-Variable
-Anaemia
-Jaundice
Gallstones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the structure of normal adult haemoglobin

A
  • Haem molecule
  • 2 alpha chains (+ 2 alpha genes)
  • 2 beta chains (+ 2 beta genes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are haemoglobinopathies and what causes them?

A
  • Inherited abnormalities of haemoglobin synthesis
  • Reduced or absent globin chain production: thalassaemia
  • Mutations leading to structurally abnormal globin chain e.g. sickle cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the inheritance of haemoglobinopathies?

A

Autosomal recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the pathophysiology of sickle cell disease

A
  • Haemoglobin still has all the components but the beta chains have a point mutation
  • When the haemoglobin is exposed to low oxygen tension, the chain polymerises and this is what causes the sickle shape
  • Once sickling happens it is irreversible
  • Oxygen transport is unaffected
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the consequences of sickle cell disease?

A
  • Red cell injury, cation loss, dehydration
  • HAEMOLYSIS
  • Endothelial activation
  • Promotion of inflammation
  • Coagulation activation
  • Dysregulation of vasomotor tone
  • VASO-OCCLUSION
  • Acute chest syndrome, stroke, pain episodes etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does sickle cell disease present?

A
  • Painful vaso-occlusive crisis
  • Chest crisis
  • Stroke
  • Increased infection risk: hyposplenism
  • Chronic haemolytic anaemia: gallstones and aplastic crisis
  • Sequestration crises: spleen and liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How can sickle cell be managed?

A
  • Acute events/Painful crisis: analgesia, hydration, oxygen and consider antibiotics +/- blood transfusion
  • Life long prophylaxis: vaccination, penicillin, malarial prophylaxis and folic acid
  • Blood transfusion
  • Disease modifying drugs: hydroxycarbamide
  • Bone marrow transplantation
  • Gene therapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are thalassaemias?

A

Reduced or absent globin chain production (alpha and beta most important)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is an A+ mutation?

A

Two alpha chains from one parent but only one from the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is an A0 mutation?

A

Two alpha chains from one parent and none from the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What happens if two parents have A0 mutations and pass them on to the foetus?

A
  • This is not compatible with life

- The foetus cannot produce the alpha chains needed for foetal haemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the effect of a beta thalassaemia major?

A
  • No beta chains

- Transfusion dependent anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the effect of a thalassaemia minor?

A
  • Trait or carrier state

- Hypochromic microcytic red cell indices

29
Q

Describe the clinical presentation of beta thalassaemia major

A
  • Severe anaemia
  • Present at 3-6 months of age
  • Expansion of ineffective bone marrow
  • Bony deformities
  • Splenomegaly
  • Growth retardation
30
Q

How can beta thalassaemia major be treated?

A
  • Chronic transfusion support
  • Need to correct iron overloading: iron chelation
  • Iron Chelation therapy: S/C desferrioxamine or oral deferasirox
  • Regular monitoring
  • Ferritin and MRI scans
  • Bone marrow transplation - curative
31
Q

List the causes of sideroblastic anaemia that are a result of defects in the mitochondrial steps of haem synthesis

A
  • ALA synthase mutations
  • Hereditary
  • Acquired
32
Q

What causes porphyrias (build up of natural chemicals that produce porphyrins?

A

Defects in the cytoplasmic steps of haem synthesis

33
Q

Which factors effect the normal range of haemoglobin?

A
  • Age
  • Sex
  • Ethnic origin
  • Time of day (cortisol level)
  • Time taken to analysis (cells can swell)
34
Q

What are the normal ranges for haemoglobin?

A
  • Male 12-70 (140-180)
  • Male > 70 (116-156)
  • Female 12-70 (120-160)
  • Female > 70 (108-143)
35
Q

What are the clinical features of anaemia?

A
  • Tiredness/pallor
  • Breathlessness
  • Swelling of ankles
  • Dizziness
  • Chest pain
  • Evidence of bleeding: menorrhagia, dyspepsia and PR bleeding
  • Symptoms of malabsorption: diarrhoea and weight loss
  • Jaundice
  • Splenomegaly/lymphadenopathy
36
Q

What are the different pathophysiologies of anaemia?

A
  • Bone marrow: cellularity, stroma and nutrients
  • Red cell: membrane, haemoglobin and enzymes
  • Destruction: blood loss, haemolysis and hypersplenism
37
Q

Which red cell indices can give a morphological description of the anaemia?

A
  • Mean cell haemoglobin (MCH)

- Mean cell volume (MCV)

38
Q

In what three ways can the morphology of the anaemia be described?

A
  • Hypochromic and microcytic
  • Normochromic and normocytic
  • Macrocytic
39
Q

If an anaemia is hypochromic and microcytic which further test would you do?

A

Serum ferritin

40
Q

If an anaemia is normochromic and normocytic which further test would you do?

A

Reticulocyte count (helps differentiate whether the bone marrow is working or not)

41
Q

If an anaemia is macrocytic which further tests would you do?

A
  • B12/folate

- Bone marrow

42
Q

What are the causes of hypochromic microcytic anaemia?

A
  • Iron deficiency (low ferritin)

- Thalassaemia, secondary anaemia and sideroblastic anaemia (normal or increased ferritin)

43
Q

Describe the process of iron metabolism

A
  • Absorbed iron is bound to mucosal ferritin and sloughed off or transported across the basement membrane by ferroportin
  • It is then bound to transferrin in the plasma
  • Stored as ferritin (mainly in the liver)
44
Q

What is the role of hepcidin in iron metabolism?

A
  • It is synthesised in hepatocytes in response to increased iron levels and inflammation
  • Blocks ferroportin so reduces intestinal iron absorption and metabolism from reticuloendothelial cells
45
Q

What features would suggest a diagnosis of iron deficiency anaemia?

A
  • Dyspepsia/GI bleeding
  • Other bleeding e.g. menorrhagia
  • Diet
  • Increased requirement e.g. pregnancy
  • Signs of iron deficiency
  • Abdo and rectal exam: atrophic tongue, koilonychia, angular cheilitis
46
Q

What are the causes of iron deficiency anaemia?

A
  • GI blood loss
  • Menorrhagia
  • Malabsorption: gastrectomy and coeliac disease
47
Q

How can iron deficiency be managed?

A
  • Correct the deficiency: oral iron (IV if intolerant to oral)
  • Correct the cause: diet, ulcer therapy, gynae interventions, surgery etc.
48
Q

What are the causes of normochromic normocytic anemia?

A
  • Acute blood loss and haemolysis (increased reticulocyte count)
  • Secondary anaemia, hypoplasia and marrow infiltration (normal or low reticulocyte count)
49
Q

What is secondary anaemia and how is it caused?

A
  • Anaemia of chronic disease
  • Defective iron utilisation: increased hepcidin in inflammation and ferritin is often elevated
  • Underlying disease: infection , inflammation or malignancy
50
Q

Describe the process of haemolytic anaemia

A
  • Accelerated red cell destruction
  • Compensation by bone marrow (increased reticulocytes)
  • Haemoglobin level: balance between red cell production and destruction
51
Q

What are the causes of haemolytic anaemia?

A
  • Congenital: hereditary spherocytosis, G6PD and haemoglobinopathies etc.
  • Acquired: auto-immune haemolytic anaemia
  • Mechanical e.g artificial valve
  • Severe infection/DIC
  • PET/HUS/TTP
52
Q

Describe how a direct antiglobulin test works

A
  • Detects antibody or complement on the red cell membrane
  • Reagent either contains anti-human IgG or anti-complement
  • Reagent binds to Ab or complement on red cell surface and cause agglutination in vitro
  • Implies an immune basis for haemolysis
53
Q

In an immune haemolysis what is are the potential causes if the autoantibody is warm?

A
  • Auto-immune
  • Drugs
  • CLL
54
Q

In an immune haemolysis what is are the potential causes if the autoantibody is cold?

A
  • CHAD
  • Infections
  • Lymphoma
55
Q

In an immune haemolysis what is are the potential cause if it is an alloantibody?

A

Transfusion reaction

56
Q

What is likely to be seen under the microscope in an immune haemolysis?

A
  • Spherocytes on the film

- Agglutination in cold AIHA

57
Q

What is likely to be seen under the microscope in an intravascular haemolysis?

A

Red cell fragments - schistocytes

58
Q

What investigations should be done if a patient is suspected to have haemolytic anaemia?

A
  • FBC, reticulocyte count and blood film
  • Serum bilirubin and LDH
  • Serum haptoglobin
59
Q

What should be done to determine the cause of the haemolytic anaemia?

A
  • History and examination
  • Blood film
  • Direct antiglobulin test
  • Urine for haemosiderin/urobilinogen
60
Q

What is the management of haemolytic anaemia?

A
  • Support marrow function: folic acid
  • Correct cause: immunosuppression if autoimmune, remove site of red cell destruction (splenectomy)
  • Treat sepsis, leaky prosthetic valve, malignancy etc.
  • Consider transfusion
61
Q

What are the causes of macrocytic anaemia?

A
  • B12 and folate deficiency (megaloblastic)

- Myelodysplasia, marrow infiltration and drugs (non-megaloblastic)

62
Q

Describe how vitamin B12 is absorbed?

A
  • It binds to intrinsic factor in the stomach
  • B12-IF complex attaches to specific IF receptors in distal ileum
  • B12 is bound to transcobalamin II in the portal circulation for transport to bone marrow and other tissues
63
Q

How does B12/folate deficiency present?

A
  • Anaemia

- Neurological symptoms (subacute degeneration of the cord in B12 deficiency)

64
Q

What are the causes of B12 deficiency?

A
  • Pernicious anaemia

- Gastric/ilial disease

65
Q

What are the causes of folate deficiency?

A
  • Dietary
  • Increased requirements (haemolysis)
  • GI pathology (e.g. coeliac disease)
66
Q

What is pernicious anaemia?

A
  • Commonest cause of B12 deficiency
  • Antibodies against intrinsic factor and gastric parietal cells
  • Malabsorption of dietary B12
  • Symptoms take 1-2 years to develop
67
Q

How can B12 deficiency be treated?

A

B12 IM injection (loading dose + 3 monthly maintenance)

68
Q

How can folate deficiency be treated?

A
  • Oral folate replacement

- Ensure B12 is normal if there are neuropathic symptoms

69
Q

What are the other causes of macrocytosis?

A
  • Alcohol
  • Drugs: methotrexate, antiretrovirals and hydroxycarbamide
  • Disorder liver function
  • Hypothyroidism
  • Myelodysplasia

Haematology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions