RESUMO
Screening for iron deficiency anemia (IDA) in infants is usually carried out by hemoglobin (Hb) level and mean corpuscular volume (MCV). A coinherited thalassemia carrier may confound the diagnosis of IDA. This study aimed to characterize the hematologic parameters in infants with IDA and in thalassemia carriers, and to study the use of red cell parameters in IDA screening in a thalassemia-endemic area. Healthy infants, 6 to 12 months of age were enrolled. Blood samples were taken for complete blood count, ferritin level, Hb analysis, and polymerase chain reaction for alpha-thalassemia. IDA was defined as Hb <11.0 g/dL and ferritin <12 µg/L. Formulae calculated from red cell parameters to distinguish thalassemia carriers were analyzed. Eighty-five infants, 8.3±2.4 months of age, including 48 (56.5%) male infants were enrolled. Sixteen infants (18.8%) had IDA. There were 25 thalassemia carriers (29.4%), 1 Hb H disease, and 1 homozygous Hb E. Hb levels and MCV in the IDA and thalassemia carrier groups were significantly lower than those in the normal group. Area under the curve of Mentzer index (MCV/red blood cell count <13) to suggest thalassemia carriers was 0.867 (95% confidence interval: 0.784-0.951), and the sensitivity and specificity were 92.6% and 72.4%, respectively. In conclusion, both Hb level and Mentzer index are recommended for screening of IDA and thalassemia carriers in the population.
