Adult and child automated immature granulocyte norms are inappropriate for evaluating early-onset sepsis in newborns.
OBJECTIVE
Automated haematology analysers are increasingly being used. Normal ranges for automated immature granulocyte counts (IG%) are described in adults and children as <1%, but are not reported for newborns, who often have complete blood count with differential in evaluation for early-onset sepsis. Therefore, this study aimed to describe IG% during the first 48 hours of life (HOL) in newborns and determine the clinical factors affecting IG%.


METHODS
We carried out retrospective chart reviews for newborns ≥35 weeks gestational age with one or more complete blood count with differential in the first 48 HOL. Clinical history and automated haematology results were reviewed.


RESULTS
Forty-seven of 215 subjects had two or more complete blood counts within 48 h. In the first 48 HOL, IG% ranged from 0 to 8.4% (95th percentile 5.2%). At <12 h, 70% of samples had IG% >1%. IG% appears to decrease over time. Earlier hour of life and higher birth weight were independently associated with higher IG%.


CONCLUSIONS
Immature granulocyte counts in newborns appeared to be higher than reported for other age groups. Use of adult and child norms for IG% would not be appropriate for newborns being evaluated for early-onset sepsis.
Department of Paediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
Emily L
EL
Wiland
Linda M
LM
Sandhaus
Zhanna
Z
Georgievskaya
Claudia M
CM
Hoyen
Mary Ann
MA
O'Riordan
Mary L
ML
Nock
D000328:Adult; D015415:Biomarkers / Q000097:blood; D002648:Child; D005260:Female; D006098:Granulocytes / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D007958:Leukocyte Count; D016014:Linear Models; D008297:Male; D012015:Reference Standards; D012016:Reference Values; D012189:Retrospective Studies; D018805:Sepsis / Q000097:blood / Q000175:diagnosis*
D015415:Biomarkers
Immature granulocyte; Left shift; Leucocyte differential; Newborn; Sysmex XE-5000