Absolute neutrophil count (ANC) is a measure of the number of
neutrophil granulocytes
Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying ...
(also known as polymorphonuclear cells, PMN's, polys, granulocytes, segmented neutrophils or segs) present in the
blood. Neutrophils are a type of
white blood cell
White blood cells, also called leukocytes or leucocytes, are the cell (biology), cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and de ...
that fights against
infection.
The ANC is almost always a part of a larger
blood panel called the
complete blood count. The ANC is calculated from measurements of the total number of white blood cells (WBC), usually based on the combined percentage of mature neutrophils (sometimes called "segs," or segmented cells) and
bands, which are immature neutrophils.
Clinical significance
The
reference range for ANC in adults varies by study, but 1500 to 8000 cells per microliter is typical. An ANC less than 1500 cells/µL is defined as neutropenia and increases risk of infection.
Neutropenia
Neutropenia is an abnormally low concentration of neutrophils (a type of white blood cell) in the blood. Neutrophils make up the majority of circulating white blood cells and serve as the primary defense against infections by destroying bacteria ...
is the condition of a low ANC, and the most common condition where an ANC would be measured is in the setting of chemotherapy for cancer.
Neutrophilia indicates an elevated count. While many clinicians refer to the presence of neutrophilia as a "left shift," this is imprecise, as a left shift indicates the presence of immature neutrophil forms, but neutrophilia refers to the entire mass of neutrophils, both mature and immature. Neutrophilia can be indicative of:
* Premature release of myeloid cells from the bone marrow.
* A leukemoid reaction.
Calculation
ANC =
or
ANC = (''Absolute-Polys + Absolute-Bands'')
Ranges
Related tests
In some cases, a ratio is reported in addition to the sum. This is known as the "I/T ratio".
References
External links
Absolute Neutrophil Count (ANC){{Myeloid blood tests
Blood tests