Anaemia 1

Question 1

Microcytic

Answer 1

small blood cells - low MCV

e.g. iron deficiency, chronic disease, thalassaemia, lead poisoning

Question 2

Normocytic

Answer 2

normal blood cells e.g. acute blood loss, chronic anaemia (sickle cell)

Question 3

Macrocytic

Answer 3

big blood cells e.g. B12/folate deficiency

divided into megaloblastic and non-megaloblastic, depending on bone marrow findings

Question 4

MCV

Answer 4

mean corpuscular volume

Question 5

erythropoiesis

Answer 5

red blood cell balance
-	Produced by bone marrow
-	Lifespan 120 days
-	Removal by spleen, liver, bone marrow, blood loss
Measure: serum reticulocytes

Question 6

What 2 paths can dietary iron take?

Answer 6

1. ferritin - protein-iron complex, intracellular iron store, released back into intestinal lumen when villi disintegrate
2. plasma transferrin - iron released into blood + circulates bound to this plasma protein

Question 7

What is Fe2+ used for in the body?

Answer 7

incorporated into myoglobin in muscle cells

(most of it) manufactured into haemoglobin

Question 8

What does hepcidin do?

Answer 8

inhibits action of ferroportin membrane protein = less Fe2+ allowed out of intestinal cell and into blood stream

high –> anaemic
low –> haemochromatosis

Question 9

Causes of iron deficiency anaemia

Answer 9

• blood loss
• increased demands
• decreased absorption
• poor intake

Question 10

anaemia

Answer 10

deficiency of red cells or haemoglobin in the blood

decrease in Hb level in the blood below the reference range for the age + sex of the idv.

accompanied by a fall in red cell count (RCC) and packed cell volume (PCV)

Question 11

consequences of anaemia

Answer 11

reduced o2 transport
tissue hypoxia
compensatory changes: increased tissue perfusion, increased 02 transfer to tissues 
tachycardia to shift O2 curve
increased blood cell production

Question 12

pathological compensations

Answer 12

myocardial fatty change
fatty change in liver
aggravate angina/claudication
skin + nail atrophic changes

Question 13

RFs for iron deficiency anaemia

Answer 13

female
pregnancy
children
elderly

Question 14

why may some anaemics be asymptomatic?

Answer 14

slowly falling Hb level allows for haemodynamic compensation + enhancement of the O2-carrying capacity of the blood

Question 15

presentation of anaemia

Answer 15

fatigue, faintness, breathlessness

pale skin + mucous membranes

may be a tachycardia + a systolic flow murmur

Question 16

additional clinical features in iron deficiency anaemia

Answer 16

(due to decreased epithelial cell iron)

• brittle hair and nails
• atrophic glossitis
• angular stomatitis

Question 17

what would FBC + film show in iron deficiency anaemia

Answer 17

microcytic
hypo chromic
variation in shape and size

Question 18

serum results for iron deficiency anaemia

Answer 18

serum ferritin is low

serum iron is low + total iron-binding capacity is high

Question 19

in men and post-menopausal women, what is iron deficiency almost always the result of?

Answer 19

chronic, often occult, GI blood loss

Question 20

Mx iron deficiency anaemia

Answer 20

find + treat underlying cause

oral iron e.g. ferrous sulphate

Question 21

S.Es of iron supplement

Answer 21

nausea
abd discomfort
diarrhoea
constipation

Question 22

what are megaloblasts?

Answer 22

developing RBCs in the BM with delayed nuclear maturation relative to that of the cytoplasm

Question 23

what is the underlying mechanism of megaloblastic anaemia?

Answer 23

defective DNA synthesis, which may also affect the white cells + platelets

Question 24

most common cause of megaloblastic anaemia?

Answer 24

deficiency of vit b12, or folate, both of which are necessary for DNA synthesis

Question 25

how is vitamin b12 liberated from protein complexes in food?

Answer 25

by gastric acid and pepsin | it binds to an 'R' binder derived from saliva

Question 26

how is vit b 12 absorbed

Answer 26

free b12 is released from the R binder by pancreatic enzymes + becomes bound to IF this complex --> terminal ileum where vitb12 is absorbed

Question 27

what carrier protein transports vitb12 to the tissues and where is bit b12 stored?

Answer 27

transcobalamin II the liver (stores of up to 2 years!)

Question 28

What is the autoimmune condition that is the most common cause of vitamin B12 deficiency? And how does it cause it?

Answer 28

pernicious anaemia atrophic gastritis with loss of parietal cells and hence failure of IF production and vitB12 malabsorption

Question 29

clinical features pernicious anaemia

Answer 29

insidious ``` glossitis angular stomatitis (inflammation of sides of mouth) mild jaundice - from excessive Hb breakdown ``` neurological- symmetrical damage to peripheral nerves + posterior + lateral columns of the spinal cord (-> a polyneuropathy)

Question 30

Blood count + film for vitamin b12 deficiency

Answer 30

macrocytic | hyperhsegmented neutrophil nuclei

Question 31

serum results for vit b 12 deficiency

Answer 31

serum vitb12 is low | parietal cell antibodies + IF antibodies

Question 32

Mx vit b 12 deficiency

Answer 32

intramuscular hydroxocobalamin (vit b12) or oral B12

Question 33

dietary sources of folate (vit b9)

Answer 33

green vegetables and offal e.g. liver + kidney

Question 34

where is folate absorbed

Answer 34

upper small intestine

Question 35

main cause of folate (vit b9) deficiency

Answer 35

poor intake | which may occur alone or in combo with excessive utilisation or malabsorption

Question 36

why do we need folate?

Answer 36

with b12, folate helps create normal RBCs

Question 37

Ix folate deficiency

Answer 37

serum folate is low

Question 38

Mx folate deficiency

Answer 38

treat underlying cause | oral folic acid

Question 39

Most common cause of macrocytic anaemia (non-megaloblastic)

Answer 39

alcohol excess