Neutrophils are white blood cells (WBC) that move from the blood into the cells to kill invading bacteria and fungi. If neutrophil levels become too high, neutrophilia results. Neutrophilia is the most common form of leukocytosis – a condition involving an increased number of leukocytes in the blood. Absolute neutrophilia refers to the increase in the total number of leukocytes in the blood as well as an increased percentage of neutrophils. This results in a neutrophil count of over 8,000.
are produced in the bone marrow
, released into the blood, circulate briefly, and migrate into tissue spaces and onto epithelial surfaces.
Causes and Development
There are many possible causes for an abnormally high neutrophil
count. The most common and important cause of neutrophilia
is infection, and most infections cause neutrophilia.
One basic cause of a high neutrophil count is when a high level of stress is placed on the body. The stress can due to many factors such as nervousness, exercise, or seizures
movements due to overexcitement of nerve cells in the brain).
Corticosteriods, whether from stress or when using drugs like prednisone, cause increased bone marrow
release of mature neutrophils
, movement into the CNP, and decreased tissue migration. An increase in white blood cells
occurs 4 to 8 hours after elevation of stress hormones or steroid
use and return to normal 1 to 3 days after later. Lymphopenia can occur concurrently.
Aside from those listed below, other causes include:
- (Acute) bacterial infection
- Fungal infection
- Trauma, damage or inflammation of tissues, for example burn injuries or a heart attack.
- Loss of blood cells through bleeding or hemolysis
- Cold or heat
- Rheumatic fever is a myeloproliferative disorder that causes proliferation of bone marrow cells.
- Cancer that is spreading
- Surgical removal or drainage of a source of bacterial infection (e.g. a boil) may increase neutrophilia
- Sudden kidney failure
Inflammation stimulates bone marrow release of neutrophils to the site of inflammation. The time for production of new cells from the bone marrow is 4 to 6 days and neutrophils circulate for about 10 hours. Neutrophils move into tissues randomly and are destroyed in the spleen
, and bone marrow after performing their function.
, and immune-mediated disease can cause increased tissue demand and increased bone marrow release of neutrophils. Leukocytosis
(at levels of 15,000 to 30,000), neutrophilia
with a high neutrophils to lymphocytes ratio, toxic neutrophils, lymphopenia, eosinopenia, and variable monocytosis are seen often at the same time.
Diagnosis and Tests
In a complete blood count
) report, neutrophils
may be referred to as polymorphonuclear cells (polys) or neutrophils. The absolute neutrophil
count (ANC) is a measure of the total number of neutrophils present in the blood. The normal range for the neutrophil count is 1,500 to 8,000 cells per cubic mm. The ANC can be calculated by multiplying the total WBC
by the percent of neutrophils.Neutrophilia
is defined as an increase in circulating neutrophils in the peripheral blood. The absolute neutrophil count (ANC) defines neutrophilia. ANC is found by multiplying the percentage of bands and neutrophils on a differential by the total white blood cell
count. An abnormal ANC is more than 8,000 cells per cubic mm.