Reticulocyte hemoglobin content to diagnose iron deficiency in children

Context Early identification of iron deficiency in children is essential to prevent the damaging long-term consequences of this disease. However, it i s not clear which indices should be included in a diagnostic panel for iron deficiency and iron deficiency anemia in children. Objective To develop an effective approach for the diagnosis of iron defici ency and iron deficiency anemia in young children. Design and Setting Retrospective laboratory analysis, carried out over 7 we eks in 1996, using blood samples ordered by pediatricians and sent to a lar ge metropolitan hospital for analysis. Patients A total of 210 children (mean [SD] age, 2.9 [2.0] years; 120 were male) who had a lead screening test (complete blood cell count and plasma l ead level) ordered by a primary care pediatrician. Main Outcome Measures Levels of hemoglobin (Hb), iron, transferrin, transfe rrin saturation (Tfsat), ferritin, and circulating transferrin receptor and reticulocyte Hb content (CHr) among patients with and without iron deficie ncy, defined as Tfsat of less than 20%, and iron deficiency anemia, defined as Tfsat of less than 20% and Hb level of less than 110 g/L. Results Of the 210 subjects, 43 (20.5%) were iron deficient; 24 of these ha d iron deficiency anemia. Reticulocyte Hb content and Hb levels were the on ly significant predictors of iron deficiency (likelihood ratio test [LRT] = 15.96; P<.001 for CHr, and LRT=6.59; P=.01 for Hb), and CHr was the only s ignificant multivariate predictor of iron deficiency anemia (LRT = 30.43; P <.001). Plasma ferritin level had no predictive value (P=.97), Subjects wit h CHr of less than 26 pg (optimal cutoff value based on sensitivity/specifi city analysis) had lower Hb level, mean corpuscular volume, mean corpuscula r Hb level, serum iron level, and Tfsat, and increased red blood cell distr ibution width vs those with CHr of 26 pg or more (P<.001 for all). Conclusions Reticulocyte Hb content level was the strongest predictor of ir on deficiency and iron deficiency anemia in children. It holds promise as a n alternative to biochemical iron studies in diagnosis.