The formula to calculate the absolute neutrophil count (ANC) is:
\[ \text{ANC} = 10 \times \text{WBC count} \times (\% \text{PMNs} + \% \text{Bands}) \]
Note: Assumes WBC count in 1,000s (i.e., x 10³ cells/µL, also equivalent to x 10³ cells/mm³).
WBC count: White blood cell count, measured in thousands of cells per microliter (x 10³ cells/µL).
% PMNs: Percentage of polymorphonuclear leukocytes (neutrophils) in the blood.
% Bands: Percentage of band cells (immature neutrophils) in the blood.
Normal patient:
CBC shows WBC 9.2 (units are x 10³ cells/µL), 33% neutrophils, and 1% bands.
ANC = 10 x 9.2 x (33 + 1) = 3,128 cells/µL → normal, no neutropenia
Neutropenic patient:
CBC shows WBC 1.0 (units are x 10³ cells/µL), 11% neutrophils, and 5% bands.
ANC = 10 x 1 x (11 + 5) = 160 cells/µL → severe neutropenia
| ANC (cells/µL) | Classification |
|---|---|
| > 1,500 | Normal |
| 1,000 - 1,500 | Mild Neutropenia |
| 500 - 999 | Moderate Neutropenia |
| < 500 | Severe Neutropenia |
| > 7,700 | Neutrophilia |