Comparing automated vs manual leukocyte differential counts for quantifying the 'left shift' in the blood of neonates.
The neutrophil 'left shift' can be measured via the immature to total (I/T) neutrophil ratio or the absolute bands per μl using a manual differential count. It can also be measured from an automated differential count by the immature granulocyte percentage (IG%) or the absolute IG per μl. In neonates, it is unknown if the manual or automated differential count is superior.



We directly compared complete blood counts (CBCs) with manual and automated differential counts from infants <90 days old, and documented whether or not each neonate was infected. We developed reference intervals for I/T ratio, bands per μl, IG% and IG per μl using values from non-infected neonates.



The database had 10 714 CBCs. The upper reference interval for I/T ratio was 0.29 in the first 48 h and 0.31 thereafter; bands per μl was 3710 μl(-1) in the first 48 h and 1785 μl(-1) thereafter. IG% was 6.2% then 4.2%; IG per μl was 1460 μl(-1) then 613 μl(-1). Statistical performances of the four methods were equivalent for identifying infection.



We developed reference intervals for four methods of quantifying a neonate's 'left shift'. The information from automated differentials is not inferior to that from manual differentials in identifying infections, but automated differentials have the advantages of a larger sample size, being less expensive, and faster performance times.
Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.
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BC
MacQueen
Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.|Women and Newborn's Clinical Program, Intermountain Healthcare, Salt Lake City, UT, USA.|Division of Hematology/Oncology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.
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Christensen
Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.|Women and Newborn's Clinical Program, Intermountain Healthcare, Salt Lake City, UT, USA.
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Yoder
Women and Newborn's Clinical Program, Intermountain Healthcare, Salt Lake City, UT, USA.|Institute for Healthcare Delivery Research, Salt Lake City, UT, USA.
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Henry
Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.|Women and Newborn's Clinical Program, Intermountain Healthcare, Salt Lake City, UT, USA.
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Baer
Intermountain Medical Center, Department of Pathology, Murray, UT, USA.
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Bennett
Division of Hematology/Oncology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.
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HM
Yaish
D005260:Female; D006098:Granulocytes / Q000166:cytology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007958:Leukocyte Count / Q000379:methods; D012016:Reference Values