title: Late-onset neutropenia in very low birthweight infants.
abstract: OBJECTIVE
  To evaluate the incidence and duration of late-onset neutropenia (defined as an absolute neutrophil count (ANC) <1500 mm(-3) at a postnatal age of >3 wk) in a population of infants with birthweight <2000 g, and to determine whether copper deficiency, a possible cause of both anemia and neutropenia, may be associated with this complication.
  
  
  METHODS
  Complete blood cell count and differential were assessed in 247 low (LBW) and very low birthweight (VLBW) infants who were discharged after 3 wk of life. In neutropenic infants plasma copper and ceruloplasmin levels were also measured.
  
  
  RESULTS
  Late-onset neutropenia was detected in 11 out of 147 VLBW infants (7.5%) and in 7 out of 127 LBW infants (5.5%). A neutrophil count of <1000 mm(-3) was observed in 14 infants (5.1%). A significantly lower gestational age was found in neutropenic infants compared with non-neutropenic infants. In neutropenic infants ANCs were significantly correlated with hemoglobin and hematocrit. In addition, a significant negative correlation was found between neutrophil and reticulocyte counts. Plasma copper concentration was significantly correlated with birthweight. Oral copper sulfate was administered to infants with plasma copper concentration <50 microg dl(-1), and did not seem to affect ANC, hemoglobin, hematocrit or reticulocyte counts.
  
  
  CONCLUSIONS
  Late-onset neutropenia appears to be a benign condition that is not associated with any particular complication and does not require specific treatment. Reference ranges after the early neonatal period and during the first few months of life in LBW and VLBW infants should probably be set at lower values.
authors.affiliation: Division of Neonatology and Neonatal Intensive Care, Spedali Civili, Brescia, Italy. gaechir@tin.it
authors.forename: G
authors.initials: G
authors.lastname: Chirico
authors.forename: M
authors.initials: M
authors.lastname: Motta
authors.forename: P
authors.initials: P
authors.lastname: Villani
authors.forename: A
authors.initials: A
authors.lastname: Cavazza
authors.forename: M L
authors.initials: ML
authors.lastname: Cardone
mesh_terms: D001772:Blood Cell Count; D016022:Case-Control Studies; D003300:Copper / Q000097:blood; D005260:Female; D006801:Humans; D015994:Incidence; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal; D007558:Italy / Q000453:epidemiology; D007958:Leukocyte Count; D016014:Linear Models; D008297:Male; D009503:Neutropenia / Q000175:diagnosis* / Q000453:epidemiology*; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D003300:Copper