title: Neutrophil left shift and white blood cell count as markers of bacterial infection.
abstract: Neutrophil left shift and white blood cell (WBC) count are routine laboratory tests used to assess neutrophil state, which depends on supply from the bone marrow and consumption in the tissues. If WBC count is constant, the presence of left shift indicates an increase of neutrophil consumption that is equal to an increase of production. A decrease in WBC count indicates that neutrophil consumption surpasses supply. During a bacterial infection, large numbers of neutrophils are consumed. Thus, from onset of infection to recovery, dynamic changes occur in WBC count and left shift data, reflecting the mild to serious condition of the bacterial infection. Although various stimuli in healthy and pathological conditions also cause left shift, a change as sudden and significant is only seen in bacterial infection. Left shift does not occur in the extremely early or late phases of infection; therefore, assessing data from a single time point is unsuitable for diagnosing a bacterial infection. We argue that time-series data of left shift and WBC count reflect real-time neutrophil consumption during the course of a bacterial infection, allowing more accurate evaluation of patient condition.
authors.affiliation: Department of Laboratory Medicine, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan; Department of Laboratory Medicine, Shinshu University Hospital, Asahi 3-1-1, Matsumoto 390-8621, Japan. Electronic address: thondat@shinshu-u.ac.jp.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Honda
authors.affiliation: Department of Laboratory Medicine, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan; Department of Laboratory Medicine, Shinshu University Hospital, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Uehara
authors.affiliation: Department of Laboratory Medicine, Shinshu University Hospital, Asahi 3-1-1, Matsumoto 390-8621, Japan; Division of Infection Control, Shinshu University Hospital, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Matsumoto
authors.affiliation: Department of Laboratory Medicine, Shinshu University Hospital, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Shinpei
authors.initials: S
authors.lastname: Arai
authors.affiliation: Department of Laboratory Medicine, Shinshu University Hospital, Asahi 3-1-1, Matsumoto 390-8621, Japan.
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Sugano
mesh_terms: D001424:Bacterial Infections / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D001772:Blood Cell Count; D006801:Humans; D009504:Neutrophils / Q000166:cytology*
chemical_list: D015415:Biomarkers
keywords: Bacterial infection; Band neutrophil; Left shift; Metamyelocyte; Myelocyte; Neutrophil; Segmented neutrophil