White blood Cell  (leukocyte) count  WBC

4.5~11.0 X 10³/µL (SI units: 4.5~11 X10⁹/L

New born: 900 ~ 30,000/µL

2 weeks old: 500 ~ 20,000/µL

1 year old:  6000 ~ 18,000/µL

4 years old: 5500 ~ 17,000/µL

10 years old: 4500 ~ 13,5000/µL

Determines the percentage of each type of white blood cell in a sample.

To get the actual number of each type of white blood cell in the sample, multiply the percentage of the different white cells by the total count of white blood cells.

Pediatric Reference Range

Newborns: same as adult .

4 weeks: Neutrophils drop to 40%; Lymphocytes rise to 45% .

10 months -20 years: a gradual return to adult ratio.

 Purposes of the Test

1. Diagnosing diseases

2. Evaluating the stages of a particular disease as in monitoring the the patient's progress and the effects of chemotherapy.

Interfering Factors

Drugs that decrease the eosinophil count: corticosteroids.

Drugs that decrease the Lymphocyte count: corticosteroids, and chemotherapeutic agents.

Drugs that increase the neutrophils count: epinephrine, digitalis, heparin, and corticosteroids.

Time of the blood sample drawn: low in the morning and high in the afternoon.

Band: Immature neutrophil.

Basophil: White blood cell that increases in response to parasitic infections and allergic reactions.

Differential: Blood test that determines the percentage of each type of white blood cell in a person's blood.

Eosinophil: White blood cell that increases in response to parasitic infections and allergic reactions.

Leukocytosis: A white count increased to over 10,000/L.

Leukopenia: A white count decreased to less than 4,000/L.

Lymphocyte: White blood cell that fights viral and some bacterial infections by direct attack or the production of antibodies.

Monocyte: It removes debris and microorganisms by phagocytosis.

An increased number of monocytes in the blood (monocytosis) occurs during a variety of conditions including severe infections, chronic infections, auto-immune disorders, blood disorders, and cancers. A low number of monocytes in the blood (monocytopenia) can occur in response to the releasing of toxins into the blood by certain types of bacteria, receiving chemotherapy or corticosteroids.

Neutrophil: White blood cell that increases in response to bacterial infection. It removes and kills bacteria through phagocytosis. A low number of neutrophil increases the risk of infection.

Segmented neutrophils (polymorphonuclear leukocytes, or segs) are the mature phagocytes that migrate through tissues to destroy microbes and respond to inflammatory stimuli.

Phagocytosis: A process by which a white blood cell envelopes and digests debris and microorganisms to remove them from the blood.

   ventilator-associated pneumonia and CRP levels,  temperature and WCC

Back to Complete Blood  Cell Count

How white cell cannabalize virus infected cells.