Iron Studies in Microcytic Anaemia

Diagnosis	Serum Iron	Total Iron Binding Capacity	Transferrin1	Serum Ferritin2
Iron deficiency anaemis	Low	High or Normal	<16%	<12ng/mL
Anaemia of Chronic Disease	Normal	Low or Normal	≥16%	High or normal
β-Thalasaemia Trait, HbE, HbC	Normal	Normal	≥16%	Normal
Sideroblastic Anaemia	High	Normal	High	High

1. Two causes of microcytic anaemia may co-exist e.g. thalassaemia trait with iron deficiency anaemia or anaemia of chronic disease with iron deficiency anaemia. When iron deficiency exists with other forms of microcytic anaemia the transferrin saturation is <16%
2. Patients with low ferritin (<12ng/ml) always have iron deficiency. Higher values of ferritin do not exclude iron deficiency particularly in patients with anaemia of chronic disease. There are no guidelines about the ferritin levels that exclude iron deficiency in patients of anaemia of chronic disease. The reported values vary between 60-100ng/ml.