iron deficiency and anaemia of chronic disease

Question 1

where is iron present

Answer 1

some in myoglobin and other proteins, but most in Hb. thus low iron= low Hb= low anaemia

Question 2

iron homeostasis- how much we need per day

Answer 2

to produce RBC, iron is RECYCLED- however we lose it through dead cells of skin and gut, and bleeding (mainly menstruation)- thus men need 1mg/day, women 2

Question 3

iron in our diet

Answer 3

provides 15mg/day, mainly from meat/fish (already present as HAEM), veggies, cereal and chocolate: however most iron eaten NOT ABSORBED as in Fe3+ form

Question 4

factors affecting absorption

Answer 4

diet (increase in haem iron/ferrous iron)

intestine- acid

systemic- iron deficiency/anaemia/pregnancy (tend to absorb more)

Question 5

how iron regulated

Answer 5

when iron enters into enterocyte from gut lumen, it is stored in cell as FERRITIN, and enters blood via FERROPORTIN in basolateral membrane

when iron levels high, HEPCIDIN high, which breaks down ferroportin, thus iron can’t get into blood

Question 6

what happens to iron once in blood

Answer 6

binds to TRANSFERRIN- amount of transferrin known as TOTAL IRON BINDING CAPACITY amount of transferrin bound to iron is TRANSFERRIN SATURATION

Question 7

response of body to anaemia

Answer 7

there is tissue hypoxia, so erythropoeitin levels increase= increase red cell precursors,w which grow and differentiate

Question 8

what is anaemia of chronic disease

Answer 8

anaemia in ill patients- no obvious cause like bleeding, Fe/B12/folate deficiency or marrow issue, just fact that they’re ill

Question 9

signs of being ill

Answer 9

high C-reactive protien, high ERYTHROCYTE SEDIMENTATION RATE, and increases in ferritin, F8, fibrinogen and immunoglobulin (part of acute phase response)

Question 10

most common conditions associated with ACD

Answer 10

infections eg TB/HIV

inflammation eg rheumatoid arthritis

cancer and cardiac failure

Question 11

pathogenesis of ACD

Answer 11

increase in cytokines in body, which prevent flow of iron from duodenum to RBC, so iron can’t be used- also prevents increase of erythropoetin, increases RBC death and production of ferritin

Question 12

causes of iron deficiency

Answer 12

bleeding (menstrual/GI), increased use (during pregnancy/growth), dietary deficiency (vegetarian)+malabsorption (coeliac disease)

Question 13

lab investigations for iron deficiency

Answer 13

MCV (often low)

serum iron, ferritin, transferrin and transferrin saturation

Question 14

causes of low MCV

Answer 14

iron deficiency, thalassemia trait and ACD

Question 15

how to confirm thalassemia trait

Answer 15

haemoglobin electrophoresis

Question 16

typical lab results for iron deficiency vs ACD

Answer 16

low MCV, serum iron and low ferritin, but HIGH transferrin (to counteract low iron), thus low transferrin saturation

in ACD, low MCV and serum iron but HIGH/NORMAL ferritin and low transferrin and normal transferrin saturation

Question 17

further investigations for iron deficiency

Answer 17

do full GI INVESTIGATION (upper GI endoscopy ie oesophagus, stomach and duodenum and colonoscopy)- looks for source of bleeding, can have dysphagia, pain somewhere in GI, can be CANCER

also look at urinary blood loss and antibodies for coeliac disease

drugs that can cause bleeding eg antiplatelet drugs, non-steroidal anti-inflammatory drugs

Question 18

ppl where iron deficiency taken seriously

Answer 18

man of ANY age with low ferritin, post menopausal women

Question 19

blood film in iron deficiency

Answer 19

RBC with high central pallor, and thin long RBC as well

Question 20

problem with ferritin

Answer 20

in inflammatory conditions eg rheumatoid arthritis, it’s an acute phase protein, hence may go up in iron deficiency, even though normally low