IRON OVERLOAD DISEASES
Iron is an essential mineral to the body. But the capacity of body to metabolize iron is limited so, in high doses it may turn toxic and adversely affect the body.
Iron overload diseases such as Thalassemia,
hemochromatosis are usually genetic and are extremely common
in many part of the world. In places, such as South East Asia it
constitutes a major public health problem. In Australia the gene
for hemochromatosis is carried by about 1% of the population.
Iron accumulate in the patients and precipitates in various
parts of the body in the form of the iron oxyhydroxide encapsulated
by the protein ferritin.
Iron is stored in the tissues in 2 forms which are Ferritin and
The excessive storage of both of these, leads to haemosiderosis. Accordingly the effects of
haemosiderin excess are as under.
i. Localised haemosiderosis :
This develops whenever there is haemorrhage into tissues
with lysis of red cells, haemoglobin is liberated which is taken up
by macrophages where it is degraded and stored as
Brown indurations lung
ii. Generalised haemosiderosis
Systemic overload with iron may result in generalized
Generalised or systemic overload of iron may occur due to
a. Increased erythropoietic activity
b. Excessive intestinal absorption
c. Excessive intake of dietary iron
Liver, Pancreas, Kidney, Heart, Skin
RE cell deposits:
Liver, Spleen, Bone marrow
Transmission electron – micrograph of iron particles
encapsulated in the spherical protein shell of ferritin. Each
particle is about 7nm across. The iron oxide particles appear
because they are electron dense.
An R2 image of an iron loaded human liver, superimposed
on a T2 weighted cross sectional image of the patient: The bright
region indicates areas of higher concentration. The darker areas
correspond to regions of lower iron concentration.
The blood test such as serum ferritin and transferritin
saturation are used for assessing the degree of iron overload in
these patients, these test can be confounded by factors such as
the presence of infection and inflammation. In order to make a
definitive measurement of the degree of iron overload, the widely
accepted method is chemical analysis of iron from liver Needle