Erythrocyte Indices as Differential Diagnostic Biomarkers of Iron Deficiency Anemia and Thalassemia.

ABSTRACT

INTRODUCTION: The most common causes of microcytic anemia are iron deficiency anemia (IDA) and thalassemia trait (TT). This study investigated the reliability of erythrocyte indices and formulas as screening tests in the differential diagnosis of IDA and TT before performing detailed tests for definitive diagnosis. MATERIALS AND METHODS: In total, 50 children with ß-TT, 31 with α-TT, 50 with IDA were included. For the 8 erythrocyte indices and formulas (red blood cells [RBC], red blood cell distribution width [RDW], red blood cell distribution width index [RDWI], Mentzer index [MI], Shine and Lal index [S&L], England and Fraser [E&F], Green and King index [G&K], Srivastava index) the sensitivity, specificity, positive and negative predictive values (PPVs and NPVs, respectively) were calculated according to the cutoff values in the literature and recalculated revised cutoff values. RESULTS: According to the cutoff values in the literature for the differential diagnosis of IDA and TT, the ranking of sensitivity, specificity, PPVs, and NPVs from the highest to the lowest was RDWI, RBC, E&F, G&K, MI, Srivastava, RDW, S&L. The sensitivity, specificity, PPVs, and NPVs of all the indices according to the revised cutoff values were higher than those according to the cutoff values in the literature. CONCLUSIONS: According to both the cutoff values in the literature and revised cutoff values, the most reliable indices were RBC and RDWI.