DIAGNOSTIC UTILITY OF SERUM TRANSFERRIN RECEPTORS MEASUREMENT IN ASSESSING IRON STATUS

Serum transferrin receptors (TfR) are a sensitive index of tissue iron availability increasing progressively in response to functional iron deficiency. Unlike conventional laboratory tests of iron status, serum TfR are unaffected by underlying acute or chronic infection. Therefor e, serum TfR measurement is particularly promising for evaluation of i ron status when iron deficiency is simultaneously present with overt o r subclinical infection or inflammation-a scenario often seen in patie nts seeking medical care, in elderly persons, and in persons living in developing countries. This test is also promising for assessment of i ron status in pregnancy because it is not confounded by gestational ef fects. With the exception of conditions associated with markedly enhan ced erythropoiesis which can increase TfR independently (e.g., megalob lastic anemia, thalassemia), serum TfR determination is a specific tes t of iron status. Serum TfR measurement is also reliable; a single, sm all amount of blood sample is adequate for its accurate determination. These sensitivity specificity, and reliability characteristics of ser um TfR measurement enable it to enhance confidence in iron status asse ssment in complex situations with the standard repertoire of laborator y tests.