Nutritional Anaemia Flashcards
1
Q
What is anaemia (according to WHO)?
A
Condition in which the number of RBCs (and their oxygen carrying capacity) is insufficient to meet the body’s physiologic needs
2
Q
What is haemoglobin?
A
- Iron containing oxygen transport metalloprotein
- Found within RBCs.
- Reduction in Hb = anaemia
3
Q
What are the elements found in blood?
A
- Red blood cells
- Platelets
- White blood cells
- Monocyte
- Lymphocytes
- Eosinophil
- Basophil
- Neutrophil
4
Q
What are the relative Hb levels and what do you need to look at when interpreting blood results?
A
- Age and biological gender
- Adolescents reach adult level of Hb
- Women who are not pregnant have lower amounts than men.
- Pregnant women naturally have decreased Hb due to increased circulating volume etc
5
Q
What should a normal blood film look like?
A
- A normal blood film will have round RBC with an area of central pallor.
- The central pallor has to be relatively small and the ring should be 1/3 of the diameter.
6
Q
What does maturation of RBCs need?
A
- Vitamin B12 and folic acid
- DNA synthesis
- Iron
- Haemoglobin
- Vitamins
- Erythropoeitin
- Healthy bone marrow environment
7
Q
What are the mechanisms of action of anaemia?
A
- Failure of haemoglobin production
- Ineffective erythropoeisis
- Decreased survival
8
Q
What does a failure of haemoglobin production cause?
A
- Hypoproliferation and reticulocytopenia
9
Q
What is reticulocytopenia?
A
- Not enough premature RBCs
10
Q
What causes ineffective erythropoiesis?
A
- Enough ingredients but wrong instructions
11
Q
What causes decreased survival of RBCs?
A
- Blood loss
- Haemolysis
- Reticulocytosis
12
Q
What does MCV stand for?
A
- Mean cell volume
13
Q
What does MCV mean (not stand for)?
A
- Average size of RBCs
14
Q
What does microcytic mean?
A
- Small MCV
15
Q
What does normocytic mean?
A
- Normal MCV
16
Q
What does macrocytic mean?
A
- Large MCV
17
Q
Which anaemias are microcytic?
A
- Iron deficiency
- Thalassaemia
- Chronic disease anaemia
18
Q
Which anaemias are normocytic?
A
- Anaemia chronic disease
- Aplastic
- Chronic renal failure
- Bone marrow infiltration
- Sickle cell disease
19
Q
Which anaemias are macrocytic?
A
- B12 deficiency
- Folate deficiency
- Myelodysplasia
- Alcohol induced
- Drug induced
- Liver disease
- Myxoedema
20
Q
What does reticulocyte count help us with?
A
Lets us know if bone marrow is working
21
Q
What does knowing MCV help with?
A
gives clues on what blood tests to do to predict possible conditions
22
Q
Which is the most abundant trace element in the body?
A
Iron - essential for oxygen transport
23
Q
What is your daily requirement for iron?
A
- Depends on gender and physiological needs
24
Q
How much iron is absorbed from the duodenum every day?
A
1-2mg/day
25
What is plasma transferrin?
Iron transport protein
26
Where does most of the iron in the body sit?
* In RBCs, bone marrow and spleen
27
How do you loose iron naturally?
* Sloughed mucosal cells in the duodenum
or
* menstruation
28
Where does iron regulation happen?
Absorption stage
29
What do reticuloendothelial macrophages do?
They:
* ingest senescent red cells
* catabolise haemoglobin to scavenge iron
* load the iron onto transferrin for reuse
30
What is the structure of Hb and how does this enable it to bind to oxygen?
Hb has 4 haem groups, 4 globin chains able to bind 4 O2
31
What are the stable form(s) of iron?
Ferric (3+)
Ferrous (2+)
32
What mechanism is iron absoption regulated by?
Negative feedback of GI mucosal cells and hepcidin
33
What is hepcidin?
Iron regulatory protein
34
How does hepcidin work?
Causes the internalisation and degredation of ferroportin, which decreases iron transfer into the blood plasma from the duodenum
35
What does iron do in plasma?
* Attaches to transferrin and then transported to bone marrow
* Binds to transferrin receptors on RBC precursors
36
What will iron deficiency do to ferritin/transferrin?
* Reduced ferritin stores
* increased transferrin
37
What does ferritin do?
Primary storage protein and providing reserve, water soluble
38
What does the transferrin saturation show you?
Ratio of serum iron and total iron binding capacity - revealing % age of transferrin binding sites that have been occuptied by iron
39
What is transferrin produced by?
Liver
40
What is transferrin production inversely proportional to?
Iron stores
41
What is total iron binding capacity?
* Measurement of the capacity of transferrin to bind iron
* Indirect measurement of iron
42
Why is the ferritin test so unreliable?
* Ferritin is also involved in immune response, so infection may artificially increase ferritin
43
With infection, how can you diagnose low ferritin?
* Increased transferrin
44
What are the causes of iron deficiency?
* Poor diet
* Malabsorption
* Increased physiological needs
* Loosing too much blood
45
What can cause you to loose too much blood?
* Menstruation
* GIT loss
* Parasites
46
How can you investigate iron deficiency?
* Full Blood Count (FBC)
* iron studies
* blood film
47
What are the symptoms of iron deficiency anaemia?
* Fatigue
* lethargy
* Dizziness
* Pale mucus membrane
* Bounding pulse
48
What are the lab signs of B12 and folate deficiency?
* Low Hb
* high MCV with a normal MCHC
49
What does megoblastic mean?
* Low reticulocyte count
50
What causes megaloblastic macrocytic anaemia?
* Vitamin B12/folic acid deficiency
* Drug related
51
What causes nonmegaloblastic macrocytic anaemia?
* Alcoholism
* Hypothyroidism
* Liver disease
* Myelodysplastic syndromes
* Reticulocytosis
52
What is a source of vit B12?
* Animal and dairy produce
53
What is a source of folate?
* Vegetables and liver
54
What is the adult daily requirement of vit B12?
* 1-2 mcg
55
What is the adult daily requirement of folate?
* 100-150mcg
56
Where is vit B12 absorbed?
* Ileum via intrinsic factor
57
Where is folate absorbed?
* Duodenum and jejunum
58
What are vit B12 and folate important for?
* RBC maturation
* DNA synthesis
* Thymidine triphosphate synthesis
59
What are megaloblastic cells characterised by on the peripheral smear?
* Macrovalocytes and hypersegmented neutrophils
60
What are the causes of folate deficiency?
* Increased demand
* decreased intake
* decreased absorption
61
What can cause increased folate demand?
* Pregnancy/breastfeeding
* Infancy and growth spurts
* Haemolysis and rapid cell turnover
* Disseminated cancer
* Urinary losses
62
What can cause decreased intake of folate?
* Poor diet
* Elderly
* Chronic alcohol intake
63
What can cause decreased folate absorption?
* Medication
* Coeliac
* Jejunal resection
* Tropical sprue
64
What is vitamin B12 important for?
* Cofactor for methylation in DNA and cell metabolism
65
Where is vitamin B12 sourced from?
* Fish, meat and dairy
66
What does vitamin B12 require the presence of to be absorbed into the terminal epithelium?
* Intrinsic factor
67
Where is intrinsic factor made?
* Parietal stomach cells
68
What molecules transport vitamin B12 to tissues?
* Transcobalmin II and I
69
What causes impaired vit B12 absorption?
* Pernicious anaemia
* Gastrectomy or ileal resection
* Zollinger-ellison syndrome
* Parasites
70
What causes decreased vit B12 intake?
* Malnutrition
* Vegan diet
71
What are some congenital causes of vitamin B12 deficiency?
* Intrinsic factor receptor deficiency
* Cobalamin mutation CG1 gene
72
What causes the increased vit B12 requirements?
* Haemolysis
* HIV
* Pregnancy
* Growth spurts
73
What medication causes vitamin B12 deficiency?
* Alcohol
* NO
* PPI, H2 antagonists
* Metformin
74
What is pernicious anaemia?
* Autoimmune disorder
75
What does pernicious anaemia cause?
* Lack of vit B12 absorption or intrinsic factor
76
Where is pernicious anaemia most prevelant?
* Low income areas
77
What does a LDH (lactate dehydrogenase) test show?
Breakdown of RBCs. In bone marrow, RBCs are so abnormal they don’t survive.
78
What are the clinical consequences of pernicious anaemia?
* Brain: cognition, depression, psychosis
* Neurology: sensory changes, spasticity, ataxia
* Infertility
* Cardiac cardiomyopathy
* Tongue: glossitis, taste impairment
* Blood: pancytopenia
