Absolute neutrophil count

In medicine and hematology, the absolute neutrophil count (ANC) measures the number of neutrophils per cubic microliter of blood. Traditionally, the white blood cell differential has been part of the complete blood count, but it reported only the percentage of each white cell type in the blood, not considering the number of cells. Even though there might be an adequate percentage of neutrophils, if the overall count was low, the body might not be able to fight infection.

More modern automated blood analyzers directly count the cell types. When such analysis is not available, however, the ANC can be calculated from values in the differential, along with the total white cell count (WBC).

The differential traditionally reports:

• Percentage of adult neutrophils, also called polymorphonuclear (PMN) or segmented neutrophils
• Percentage of immature neutrophils, called band cells

Neutrophils make up 50 to 70 percent of the white blood cell count. Leukopenia means a low white blood cell count while neutropenia represents a lowered neutrophil count. Neutrophils can also be abnormally high in leukemias.

Absolute neutrophil count is cakculated as:

(% of neutrophils + % of bands) X WBC count = ANC

For example, if the WBC is 1,000 and the percentage of neutrophils is 70 percent, and there are no young white blood cells (bands) present, the ANC would be 700.