Iron deficiency anemia (IDA) and thalassemia minor are two of the most common causes of microcytic anemias worldwide. Because of similar red blood cell count parameters and blood picture, it was imperative to develop other measures that would differentially and correctly diagnose these two anemias. Several mathematical formulas and simple RBC indices have been introduced as simple, fast and inexpensive means of providing differential diagnosis for IDA and thalassemia minor. The Objective of this study was to apply and compare nine well-documented discriminant functions on a population of 153 confirmed cases of microcytic anemias (IDA n = 56, beta-thalassemia minor n = 47 and alpha-thalassemia n = 50) and to measure validity using Youden's Index. The results show that England and Fraser (E & F) Index had the highest Youden's Index value (98.2) in correctly differentiating between IDA and alpha- and beta-thalassemia minor, while Shine and Lal Index was found ineffective in differentiating between microcytic anemias in our population. E & F Index showed with great sensitivity and specificity to be the best discriminant function to differentiate between IDA and thalassemia minor cases.

Homozygous beta-thalassemia is a common genetic disorder in the Arabian Peninsula and an important cause of morbidity in Kuwait. The anemia is so severe that chronic blood transfusions, and the resulting iron overload, cause a shift in immunoregulatory balances and a deficiency in zinc. It was reported that individual immunological profile of CD8+ T-lymphocytes may have a modifying effect on the severity of iron overload in HFE homozygous hemochromatosis patients, with low numbers being negatively correlated with the total amount of body iron stores. This has not been tested in thalassemia major patients. This study was designed to utilize flow cytometric immunophenotyping to characterize effects of regular blood transfusion, and high serum ferritin levels because of irregular use of iron chelation therapy on T lymphocytes (CD2, CD3, CD4 and CD8), B lymphocytes (CD19) and natural killer cells (CD56) and zinc levels in the blood of patients with thalassemia major (n = 49) and healthy normal controls (n = 60) in Kuwait. None of the patients had active infections. T-cell markers' percentage levels were comparable between patients and controls (P > 0.05), while B cell marker (CD19) was significantly higher in patients (P = 0.007). Patients had lower percentage levels of CD56 cells (P = 0.007) and normal serum zinc. All patients had high serum ferritin levels with no significant correlation to CD8+ T lymphocytes (P > 0.05). High iron stores did not have an effect on T lymphocytes' profile, with normal zinc levels perhaps related to non compliance with chelation therapy. The high B cell marker may be indicative of stimulation of antibody producing cells as a result of regular blood transfusions.