Predictive value of discrimination indices in differential diagnosis of iron deficiency anemia and beta-thalassemia trait.

OBJECTIVES: Iron deficiency anemia (IDA) and beta-thalassemia trait (B-TT) are the most common causes of hypochromic microcytic anemias. Many indices have been defined to quickly discriminate these similar entities via parameters obtained from automated blood count analyzers. The purpose of the study was to evaluate the predictive value of these indices in differential diagnosis of IDA and B-TT in adult cases.

METHODS: This study consists of 45 IDA cases, 36 women and nine men, whose mean age is 33.87 +/- 11.59 (mean +/- SD) (range 17-57 yr) and 66 B-TT cases, 41 women and 25 men, whose mean age is 33.26 +/- 13.36 (mean +/- SD) (range 14-74 yr). IDA cases with Hb value <8.7 g/dL have been excluded because these cases are not confused with B-TT cases in practice. Patient groups have been evaluated according to red blood cell (RBC), red blood cell distribution width (RDW), Mentzer index, Shine and Lal indices, England and Fraser indices, Srivastava index, Green and King indices, RDW index and Ricerca index. Sensitivity, specificity, positive and negative predictive values and Youden's index have been calculated.

RESULTS: Finally, none of these different formulations are superior to RBC value obtained from automated analyzers in adult cases with IDA and B-TT.

CONCLUSIONS: Total body iron status and hemoglobin A(2) level should be obtained for accurate differential diagnosis of IDA and B-TT until more efficient tools develop.