Laboratory Values in Microcytic Anemias Cheat Sheet

Only a few diseases need to be considered in the differential diagnosis of a microcytic hypochromic anemia. The thalassemias typically have a moderate to severe microcytosis with varying degrees of anemia but normal iron studies.
ACD presents a more common diagnostic dilemma. With long-standing chronic inflammatory illnesses such as rheumatoid arthritis, the defective iron supply can result in severe microcytic hypochromic anemia. Iron studies, especially the serum ferritin level, usually differentiate among true IDA, ACD, and thalassemia. Both IDA and ACD are associated with low serum iron levels. The ferritin level is normal or increased in ACD and decreased in IDA. The TIBC is normal or low in ACD and increased in IDA.