LABORATORY DIAGNOSIS OF IRON DEFICIENCY ANAEMIA: THE ROLE OF FERRITIN AND TRANSFERRIN SATURATION

Abstract

Iron deficiency anaemia (IDA) remains the most common cause of anaemia worldwide and the most prevalent micronutrient deficiency globally, currently estimated to affect approximately 1.2 billion people, with iron deficiency without anaemia thought to be at least twice as common but frequently underrecognised in clinical practice. Accurate laboratory diagnosis is essential, since the clinical presentation of IDA is often nonspecific and overlaps with anaemia of other aetiologies, including anaemia of chronic disease. Serum ferritin is widely regarded as the test of choice for the diagnosis of iron deficiency in the general population, as it reflects total body iron stores and demonstrates high specificity when low. Serum iron, total iron-binding capacity, and transferrin saturation are not considered routinely useful as standalone tests for investigating iron deficiency anaemia in the absence of accompanying inflammation, owing to their susceptibility to recent dietary intake and diurnal variation.