Anaemia Flashcards
(84 cards)
1
Q
Define anaemia
A
- reduced total red cell mass
2
Q
What markers can be used in anaemia?
A
- haemoglobin concentration
- haematocrit
3
Q
Normal haemoglobin and hamatocrit concentrations in males and females
A
- males (>130, Hct> 0.38)
- females (>120, hct>0.37)
4
Q
How is haemoglobin concentration measured in the lab?
A
- burst red cell
- stabilise Hb with cyan-metHb
- measure optical density
5
Q
What law describes the OD proportion to the concentration
A
- Beer’s law
6
Q
When might haemoglobin concentration not be accurate?
A
- immediately after trauma event with blood loss
- haemodilution with fluids
7
Q
What triggers reticulocytosis?
A
- hypoxia
- sensed by the kidneys
- erythropoietin released
8
Q
Explain reticulocytes?
A
- just left bone marrow
- young and larger
- stain purple/deep red
9
Q
What levels can be measured from a blood sample
A
- haemoglobin concentrations
- number of red cells
- size of red cells (MCV)
10
Q
What levels can be calculated from blood samples?
A
- haematocrit
- mean cell haemoglobin
- mean cell haemoglobin concentration
11
Q
2 main pathophysiologies of anaemia?
A
- decreased production (hypo-proliferation, maturation abnormality)
- increased loss or destruction (bleeding, haemolysis)
12
Q
Where is Hb synthesised?
A
- in the cytoplasm
13
Q
Explain microcytic anaemia?
A
- low mcv, low red cell numbers
- small and hypochromic
- deficient haemoglobin synthesis
14
Q
Causes of microcytic anaemia?
A
- TAILS
- Thalassaemia (globin deficiency)
- Anaemia of chronic disease
- Iron deficiency
- Lead posing
- Sideroblastic anaemias
15
Q
Where is iron absorbed
A
- proximal duodenum
16
Q
How is iron transported?
A
- transferrin
17
Q
How is iron stored
A
- ferritin
18
Q
Explain transferrin
A
- 2 binders for iron
- transfers from tissue to cells
- % saturation measured
19
Q
When might percentage saturation of transferrin be reduced?
A
- iron deficiency
- chronic disease
20
Q
When might transferrin saturation be increased?
A
- genetic haemachromatosis
21
Q
What is ferritin?
A
- storage form of iron
- may be high in infection or inflammation
22
Q
Blood results in iron deficiency
A
- low serum iron
- low hb
- low ferritin
- low MCV
23
Q
Iron deficiency may cause what type of anaemia?
A
- microcytic anaemia
24
Q
Epithelial changes in iron deficiency?
A
- dry skin
- koilonychia
- angular chelitis
25
causes of iron deficiency
- reduced dietary
- losing iron
- malabsorption
26
How can iron loss be estimated during blood loss?
- volume of blood loss/ 2 = iron loss
27
Treatment of iron deficiency?
- treat underlying cause
| - iron supplements
28
Complication of oral iron supplementation
- gut irritant
- dark stools and constipation
- may lead to poor compliance
29
Describe macrocytosis
- big increase in red cell size
30
Define macrocytic anaemia
- reduction in red blood cells
| - increase in volume
31
Normal MCV values
- microcytic < 80
- normocytic 80-100fl
- macrocytic > 100fl
32
How is MCV measured?
- light scatter beam
33
True macrocytosis may be ___ or ___
- megaloblastic
| - non-megaloblastic
34
Explain normoblast development
- pronomoblast
- early normoblast
- intermediate normoblast
- late normoblast
- reticulocyte
- erythrocyte
35
Describe megaloblast
- abnormally large
- immature nucleus
- reside in bone marrow
36
Descrive megaloblastic anaemia?
- lack or RBC
- Larger MCV
- megaloblasts in bone marrow
- reduced cell division
- increased apoptosis
- bone marrow hypercellular
37
Causes of megaloblastic anaemia?
- B12 deficiency
- folate deficiency
- anti-convulasants
38
Role of B12 and folate
- co factors
- nuclear maturity
- reduced = impairment to nervous system
39
Where is vit B12 found
- meat and egg
40
What binds to B12 for absorption
- intrinsic factor
41
What secretes intrinsic factor
- parietal cells
42
Where is vit b12 absorbed
- ileum
43
Causes of a vit b12 deficiency
- dietary
| - pernicious anaemia
44
What is pernicious anaemia
- autoimmune destruction of gastric parietal cells
- ass. with other autoimmune conditions
- less intrinsic factor = vit b 12 deficiency
- vit b12 IM
45
What is the body storage timeline of vit b12?
- 2-4yrs
46
Where is folate found?
- plant substances
47
Where is folate absorbed?
- proximal small bowel
48
Causes of a folate deficiency?
- dietary
- coeliac or chrons
- haemolysis
- pregnancy
- malignancy
49
Folate deficiency may cause what type of anaemia?
- macrocytic anaemia
50
Typical storage timeline of folate in the body
- 3 months
51
Symptoms of a vit b12 deficeincy
- anaemic
- weight loss
- diarrhoea
- pre hepatic jaundice
- neurological symptoms
52
In macrocytic anaemia blood film what else may be visible
- macrovalocytes
| - hyper-segmented neutrophils
53
Anti-gastric parietal antibody
- sensitive
- not specific
- pernicious anaemia
54
Anti-intrinsic factor
- specific
- not sensitive
- pernicious anaemia
55
Treatment of a folate deficiency
- folic acid
56
Non-megaloblastic macrocytosis causes?
- liver disease
- alcohol
- hypothyroidism
- marrow failure
57
Why might spurious macrocytosis occur?
- wrongly picked up as macrocytic anaemia
- reticulocytosis
- cold-agglutinin
58
Iron + porphyrin =
- haem
59
How might you biochemically distinguish between continued blood loss and poor compliance of iron tablets?
- reticulocyte count
60
Define haemolysis
- premature red cell destruction
61
Why are red cells specifically susceptible to damage?
- biconcave structure
- no mitochondria = limited metabolic reserve
- no nucleus = cannot generate new proteins
62
Describe compensated haemolysis?
- increased red cell production to even out destruction
| - normal Hb
63
Define decompensated haemolysis?
- destruction > production
| - low Hb
64
What are the consequences of haemolysis?
- erythroid hyperplasia
| - excess red cell breakdown products
65
What stains reticulocytes blue and why?
- new methylene blue stain
| - due to the presence of RNA
66
What are the consequences to the bone marrow of haemolysis?
- reticulocytosis
| - erythroid hyperplasia
67
Explain extravascular haemolysis?
- taken up by the spleen and liver
- commoner
- hyperplasia at site of destruction
68
Blood results in extravascular haemolysis?
- protoporphyrin
| - urobilinogenuria
69
Describe intravascular haemolysis?
- RBC destroyed within circulation
70
Causes of extravascular haemolysis
- haemolytic disease of the newborn
- delayed transfusion reaction
- hereditary spehrocytosis
- sickle cell
- thalasseamia
71
Intravascular haemolysis causes?
- ABO incompatible blood (acute)
- G6PD deficiency
- malaria
72
Blood results in intravascular haemolysis?
- haemoglobuminaemia
- methaemalbuminaemia
- haemosiderinuria
73
Investigations into haemolysis?
- FBC
- Reticulocyte count
- serum unconjugated bilirubin
- serum haemoglobin
- urinary urobilinogen
74
What is warm haemolysis mediated by?
- IgG
75
What is cold haemolysis mediated by?
- IgM
76
Causes of warm haemolysis
- idiopathic
- autoimmune (SLE)
- Drugs (penicillins)
- infection
77
Causes of cold haemolysis?
- idiopathic
| - infection (EBV)
78
What is Direct Coombs test?
- identifies antibody bound to own red cell
79
Immediate vs delayed autoimmune transfusion reaction?
- immediate (IgM)
| - delayed (IgG)
80
Examples of alloimmune haemolysis?
- haemolytic transfusion reaction
| - haemolytic disease of the newborn
81
What mechanical reasons may cause haemolytic anaemia?
- mechanical valve
| - burns related
82
Blood film in a severe burns patient?
- microspherocyte
83
Describe hereditary spherocytosis?
- defects in the proteins that aid red cell membrane flexibility
- splenomegaly and gallstones
- autosomal dominatn
84
Effect of a G6PD disease
- more suceptible to oxidative damage
| - problems with ATP generation
