Iron Flashcards
where is iron bound to porphyrin ring
mitochondria
what state is iron found in in mitochondria
Fe3+
where is iron mostly stored
in Hb
other places iron is found
plasma
erythroid marrow
macrophages
liver stores
where is iron abdorbed from
duodenum
through what transporter does iron enter enterocyte
DMT1
how is iron transported out of enterocyte
ferroportin
what picks up iron in blood
transferrin
what can affect expression of ferroportin
hepcidin - decreases expression of ferroportin
traps iron in enterocytes and macrophages
when is hepcidin produced
protein produced with increased iron load and in inflammation
what form is it easier to absorb iron in
ferrous Fe2+
what does ferritin act as
acute phase protein (increased in infection, malignancy, inflammation etc
why do people with chronic diseases become anaemic
increased ferritin as response to acute inflammation
hepcidin released in response
prevents iron binding to transferrin
less iron to marrow causing hypochromic red cells
measurement of functional iron
Hb conc
measurement of transport iron/iron supply to tissues
%transferrin saturation (normal is 20-50%)
measurement of storage iron
serum ferritin (requires tissue biopsy)
what kind of iron is transported by transferrin
Fe3+
what is holotransferrin
transferrin + iron
what is apotransferrin
unbound transferrin
epithelial changes of iron deficiency
koilonychia
angular stomatitis
what kind of anaemia does iron deficiency cause
microcytuc
causes of iron deficiency
insufficient diet
bleeding (menorrhagia, tumours, ulcers, NSAIDs)
malabsorption
how much blood loss can occur per day with no symptoms
8-10 ml
gene mutated in haemochromatosis
HFE
pathophysiology of haemochromatosis
decreased hepcidin production
increased unopposed iron absorption
clinical manifestations of haemochromatosis
weakness/fatigue joint pain impotence arthritis cirrhosis diabetes cardiomyopathy
penetrance of haemochromatosis
incomplete
management of haemochromatosis
weekly venesection (exhaust iron stores)
what are secondary causes of iron overloading
repeated cell transfusions
ineffective erythropoiesis (thalassaemia, sideroblastic anaemia)
hypoplasic anaemia
treatment of secondary iron overload
iron chelating agents -
desferrioxamine
deferiprone
deferasirox
