RESUMO
INTRODUCTION: Iron-deficient erythropoiesis attributable to nutritional deficiency is the most common cause of anemia in early childhood. Beckman Coulter has proposed new parameters: red blood cell size factor (RSf) and low hemoglobin density (LHD%). [Formula: see text] The aims of the present communication were to establish reference ranges (RR) for RSf and LHD% in a healthy pediatric population; to evaluate clinical utility of these parameters in the diagnosis of iron-deficiency anemia (IDA); and to compare RSf and LHD% with RET-He. METHODS: Two hundred healthy infants and 51 with IDA were analyzed on Coulter LH750 and Sysmex XT2000i analyzers. RESULTS: RR for RSf in children aged 0.5-6 years, 82.2-102.0 and 83.7-103.1 fl in the group aged 6-18 years. RR for LHD% was 1.1-9.0%. ROC analysis for RSf and LHD% in the diagnosis of IDA showed an AUC 0.8460 and 0.8654, respectively. The best RSf value to detect a restricted erythropoiesis was 89fl, sensitivity 92%, specificity 81%. LHD% optimal cutoff point was 6.0%, sensitivity 80%, and specificity 88%. Good correlation was observed between these parameters with Ret-He, r = 0.888 and r = -0.790, respectively. CONCLUSION: RSf and LHD% could be useful tools in the screening of IDA. These parameters can be obtained in the course of routine blood counts, with no additional cost or need for more blood sampling.
