How is neutropenia defined?
The white blood cell count (WBC) is the number of white blood cells in a volume of blood. The normal range for the WBC varies slightly among laboratories but is generally between 4,300 and 10,800 cells per microliter or cubic millimeter (cmm). The WBC can also be referred to as the leukocyte count and can be expressed in international units as 4.3 x 109to 10.8 x 109 cells per liter. The percentage of the different types of white blood cells in the WBC is called the WBC differential. The absolute neutrophil count (ANC) is determined by the product of the white blood cell count (WBC) and the fraction of neutrophils among the white blood cells as determined by the WBC differential analysis. For example, if the WBC is 10,000 per microliter and 70% are neutrophils, the ANC would be 7,000 per microliter. An ANC of less than 1500 per microliter (1500/microL) is the generally accepted definition of neutropenia. Neutropenia is sometimes further classified as: • mild if the ANC ranges from 1000-
