Diagnostic accuracy of Red Cell Distribution Width in the diagnosis of iron deficiency anemia and beta thalasshemia trait

Iron deficiency is the leading cause of anemia in developing countries like Pakistan, particularly in children and females of child bearing age. This is mainly due to inappropriate dietary iron intake and increased demand of iron during pregnancy. Iron is a major component of hemoglobin and lack of this essential element results in lower hemoglobin content in red cells. Complete blood count (CBC) can provide us with a better estimate of iron deficiency. Red cell distribution width (RDW) is a significant CBC parameter and a credible marker of variation in red cell size (anisocytosis) on many routine hematology analyzers. RDW is usually elevated in IDA due to variation in size of erythrocytes while it is normal in beta thalasshemia trait. Ferritin is a gold standard measure in IDA but as it is also an Acute Phase Reactant which tends to falsely elevate in various infections and inflammatory disorders. Therefore it is not of considerable significance in detection of IDA in such clinical conditions.