Brainscape's Knowledge GenomeTM

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


See full index

Week 3 - haematology > Iron deficiency anaemia and anaemia of chronic disease > Flashcards

Iron deficiency anaemia and anaemia of chronic disease Flashcards

1
Q

What is required for normal red cell production?

A
  • Drive for erythropoiesis by erythropoietin produced by the kidney
  • the required globin genes for erythropoiesis
  • Iron, folate, B12 and other minerals
  • Functioning bone marrow
  • No increased loss or destruction of red cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the major roles of the red blood cells?

A
  • CO2 removal

* O2 delivery from lungs to the tissues

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

Explain the shape of red blood cells

A
  • Max surface area for gas exchange

* allows deformability so they can squeeze through capillaries

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

What structures are involved in the removal of CO2?

A
  • Red blood cells
  • Renal tubules
  • Lungs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the removal of CO2 by red blood cells

A
  • CO2 diffuses into the red blood cell and reacts with H2O to form H+ and HCO3- (catalysed by carbonic anhydrase)
  • H+ is buffered
  • HCO3- is removed from the cell
  • Chloride shift occurs to account for any change in charge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is one molecule of Hb made of?

A

4 globin chains (2 alpha and 2 beta) and 4 haem groups (1 per globin chain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is iron in the body?

A
  • The total body count is 4 grams
  • The bone marrow and red blood cells contain 3 grams
  • Macrophages in reticular endothelial system: 200-300mg
  • Enzymes contain 100mg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the enzymes that contain iron

A
  • Cytochromes
  • peroxidases
  • xanthine oxidase
  • catalases
  • RNA reductase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the transport of iron in the plasma

A
  • bound to the glycoprotein transferrin
  • Each transferrin has 2 iron binding domains
  • 30% are saturated with Fe
  • Transferrin delivers the iron to all the tissues, erythroblasts, hepatocytes and muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where is transferrin synthesised?

A

In the hepatocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the effect on transferrin if there is low iron?

A

Increased production of transferrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain erythroblast iron

A
  • Transferrin bound to iron binds to a transferrin receptor on the erythroblast surface
  • endocytosis
  • the Fe is stored as erythroblast ferritin or is converted to haem by the mitochondria via the ALA-S2 enzyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Explain macrophage iron

A
  • phagocytose red blood cells
  • globin is converted to amino acids
  • haem is converted to iron and stored as ferritin or haemosiderin or the haem is converted to bilirubin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain the use of serum ferritin to estimate iron stores in the body

A
  • Serum ferritin in proportional to reticular endothelial system
  • 1 mmol/l of serum ferritin = 8mg of reticular endothelial iron
  • The problem however is that ferritin is an acute phase protein so if there is inflammation or infection it will be inappropriately higher than what is in the stores
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the daily iron need?

A

1-2mg a day (2 for women)

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

Hereditary haemochromatosis

A
  • Absorb too much iron
  • Iron overload
  • Lose hepcidin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe iron absorption from the gut

A
  • Haem (from red meat) enters the enterocyte as haem oxygenase
  • Non-haem iron (white meat, cereals) =Fe 3+, is converted to Fe2+ via DCytb and is transported into cell via SMT1
  • Both enter the labile iron pool
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens to the labile iron pool within mature enterocytes?

A
  • Converted to ferritin, sent to mitochondria

* Or is transported out of the cell via FPN (requires hepcidin) then is converted to Fe3+ via Hp, transferrin in plasma

19
Q

What is the average lifespan of red blood cells?

A

120 days

20
Q

What removes effete red blood cells?

A

The reticuloendothelial system

21
Q

how is reticuloendothelial iron stored?

A

In ferritin or haemosiderin

22
Q

What does hepcidin do?

A
  • It reduces the levels of iron in the plasma
  • It does this by reducing the amount absorbed by binding to ferroportin and degrading it and decreasing iron release from the RES
23
Q

Where is hepcidin synthesised?

A

In the liver (requires the expression of HFE)

24
Q

Describe the blood film of iron deficiency anaemia

A

Pale, hypo chromic and microcytic cells

25
Q

What are the causes of hypo chromic, microcytic RBCs?

A
  • Iron deficiency anaemia (not enough haem)
  • Thalassaemia (not enough globin)
  • Anaemia of chronic disease
  • Sideroblastic anaemia (can’t form haem)
26
Q

What is the normal saturation percentage of transferrin?

A

approx 30%

27
Q

What is the saturation of transferrin in iron deficiency anaemia?

A

Less than 15%

28
Q

Describe the development of iron deficiency anaemia in terms of serum ferritin, RES iron stores and Hb

A
  • All normal
  • Latent iron deficiency in which there is compensation: serum ferritin and RES iron stores are decreased but Hb is normal
  • IDA: all decreased
29
Q

In what cases can serum ferritin be increased/ normal even if there is an iron deficiency anaemia?

A
  • In presence of tissue inflammation
  • Rheumatoid arthritis (blood loss from NSAIDs)
  • IBD
30
Q

List the clinical signs of iron deficiency anaemia

A
  • Koilonychia (spooning of the nails)
  • Atrophic glossitis (painless, lose papillae)
  • Angular stomatitis
31
Q

What are the causes of iron deficiency anaemia?

A
  • Dietary: especially in premature neonates and adolescent females (as periods develop/dieting)
  • Malabsorption
  • Blood loss
32
Q

What is the most likely cause of iron deficiency anaemia in males and post menopausal women?

A

GI blood loss

33
Q

What is the most common cause of iron deficiency anaemia in young women?

A

menstrual blood loss or pregnancy

only investigate GI causes if blood in the stool or GI symptoms

34
Q

Caecal carcinoma

A

Often asymptomatic, grow as a cauliflower, faecal matter fluid so can get past

35
Q

Symptoms of stricture in rectum

A

Apple core effect
•Obstruction
•Bleeding
•abdo pain

36
Q

Symptoms of diverticular disease

A
  • Bowel habit change
  • Blood in stool
  • Abdominal pain
37
Q

What is the treatment of iron deficiency anaemia?

A
  • Iron replacement
  • Ferrous sulphate
  • Ferrous gluconate (contains less elemental iron, better tolerated if experience GI symptoms from iron)
  • IV iron can be given if worried about compliance but it is no more effective than oral iron
  • Discover the cause of the anaemia
38
Q

What are the main uses of IV iron?

A
  • Intolerant of oral iron
  • Compliance
  • Renal anaemia and Epo (erythropoietin) replacement
39
Q

What are the causes of anaemia of chronic disease?

A
  • Infection
  • Inflammation
  • Neoplasia
40
Q

Why does anaemia of chronic disease happen?

A
  • Failure of iron utilisation
  • Iron trapped in reticular endothelial system
  • Raised levels of hepcidin
  • Reduced epo response by erythroblasts in the bone marrow
  • Depressed marrow activity, cytokine marrow depression
41
Q

What is the result of anaemia of chronic renal failure?

A

Anaemia of chronic disease and decreased Epo

42
Q

What are the lab values in anaemia of chronic disease?

A
  • MCV/MCH normal or decreased
  • ESR is increased
  • Ferritin is normal or increased
  • Iron is decreased
  • Total iron binding capacity (TIBC) decreased
43
Q

RBC rouleaux

A

Stack of coins appearance on a blood film - anaemia of chronic disaease

44
Q

What is the treatment of anaemia of chronic disease?

A

Treat the underlying cause

Week 3 - haematology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions