Haemachromatosis Flashcards
Why would free iron exist in the body?
If it exceeds binding capacity of transferrin in blood
exists as free iron
Why is free iron in the body dangerous?
Produces free radicals
- hydroxyl
- lipid
What happens to the free iron in the body?
Deposits in tissues as haemosiderin
What is haemachromatosis?
Excess iron
deposits in tissues
giving end organ damage
Where does free iron deposit? What are the effects?
Heart - cardiomyopathy
Liver - cirrhosis
Pancreas - diabetes mellitus
Gonads - hypogonadism
Joints - arthropy
Skin - pigmentation
What are the types of haemachromatosis?
Hereditary
Transfusion-associated
How is hereditary haemachromatosis inherited?
Autosomal recessive pattern
Which gene is affected in hereditary haemachromatosis?
HFE gene
How is the HFE protein affected in hereditary haemachromatosis?
Dysfunctional
What does the normal HFE protein do?
Competes with iron-transferrin
for transferrin receptor
so less iron-transferrin binds
reducing iron uptake by cell
How does the dysfunctional HFE protein cause excess iron?
Can’t bind to transferrin rceptor
so more iron-transferrin binds
more iron taken up by cell
How is hereditary haemachromatosis treated?
Venesection - removal of blood
What causes transfusion-associated haemachromatosis?
Regular transfusions
gives gradual accumulation of iron
How is transfusion-associated haemachromatosis controlled?
Using iron-chelating agents
What is an example of an iron-chelating agent?
Des ferri oxamine
