title: Reticulocyte haemoglobin content as a marker of iron deficiency.
abstract: OBJECTIVE
  To evaluate reticulocyte haemoglobin content (CHr), compared with ferritin, transferrin saturation (TS) and mean corpuscular volume (MCV), as a marker of iron deficiency (ID).
  
  
  METHODS
  Retrospective analysis of clinically indicated blood samples taken between February 2010 and October 2012.
  
  
  METHODS
  Single-centre neonatal care unit.
  
  
  METHODS
  210 very preterm (gestational age <32 weeks) or very low birthweight infants (birth weight <1500 g) at 3-4 months corrected age.
  
  
  METHODS
  Complete blood count, CHr, ferritin and TS determined as part of a standard follow-up examination. To detect the optimal CHr cut-off, ID was defined by the presence of more than two of the following three criteria: MCV <75 fL, TS <10%, ferritin <30 µg/L.
  
  
  RESULTS
  210 preterm infants were included at a corrected age of (median (IQR)) 3.5 (3.0-4.0) months and with a CHr of 29.7 (28.6-30.7) pg. There were correlations between CHr and MCV (r=0.54, p <0.0001) and between CHr and TS (r=0.44, p <0.0001). There were 27 (13.4%) iron-deficient infants, and two infants (1%) fulfilled criteria of ID-anaemia. CHr was lower in infants with ID (26.4 (23.8-28.7) pg) than in those without (29.9 (29.0-30.8) pg, p <0.0001). The optimal CHr cut-off for detecting ID was 29 pg (sensitivity 85%, specificity 73%). Areas under the receiver operating characteristic curve for detection of ID tended to be higher for CHr compared with ferritin (0.92 vs 0.75), TS (0.90 vs 0.82) and MCV (0.81 vs 0.72).
  
  
  CONCLUSIONS
  CHr seems to be a suitable marker for latent ID in preterm infants at 3-4 months corrected age and may be superior to ferritin, TS and MCV.
authors.affiliation: Department of Neonatology, University Children's Hospital of Tübingen, University of Tübingen, Tübingen, Germany.
authors.forename: Laila
authors.initials: L
authors.lastname: Lorenz
authors.affiliation: Department of Neonatology, University Children's Hospital of Tübingen, University of Tübingen, Tübingen, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Arand
authors.affiliation: Department of Neonatology, University Children's Hospital of Tübingen, University of Tübingen, Tübingen, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Büchner
authors.affiliation: Department of Neonatology, University Children's Hospital of Tübingen, University of Tübingen, Tübingen, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Wacker-Gussmann
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, Metabolism, Pathobiochemistry and Clinical Chemistry, University of Tübingen, Tübingen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Peter
authors.affiliation: Department of Neonatology, University Children's Hospital of Tübingen, University of Tübingen, Tübingen, Germany.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Poets
authors.affiliation: Department of Neonatology, University Children's Hospital of Tübingen, University of Tübingen, Tübingen, Germany Center for Pediatric Clinical Studies, University Children's Hospital of Tübingen, University of Tübingen, Tübingen, Germany.
authors.forename: Axel R
authors.initials: AR
authors.lastname: Franz
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D004909:Erythrocyte Indices; D005260:Female; D005293:Ferritins / Q000097:blood; D005865:Gestational Age; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis; D019102:Infant, Very Low Birth Weight; D008297:Male; D012156:Reticulocytes / Q000737:chemistry*; D012189:Retrospective Studies; D014168:Transferrin / Q000032:analysis; D015430:Weight Gain
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D014168:Transferrin; D005293:Ferritins
keywords: Biochemistry; Haematology; Monitoring; Neonatology; Neurodevelopment