Table of contents
White blood cells
The white blood cell count is expressed as WBC in laboratory tests. It is also called the leukocyte count in the blood. Leukocytes are a unique group of blood cells and are cells that fight infections in the blood. The WBC value is the total number of cells in this group in a given volume. Their number increases in the presence of infection in the body or in some rare diseases. In some cases, their numbers may decrease.
What cells does the WBC (White blood cell) group consist of?
- neutrophils
- lymphocytes
- monocytes
- Eosinophils
- basophils
What is the normal leukocyte (WBC) count in the blood?
If the number of leukocytes in the blood is below the normal range, it is called leukopenia, and if it is above the normal range, it is called leukocytosis.
- Normally, leukocytes are expected to be between 5000-10.000/mm3 in the blood of adults.
- 000 -25.000 / mm3 in newborn
- Baby ( 1 year old ) 6000 – 18,000 / mm3
- Children (4-7 years) 6000 -15.000 / mm3
The normal values of white blood cell groups in adults are as follows:
- Neutrophil ………….2500 – 7500 / mm3 (45-74%)
- Lymphocyte…………..2000 -5000 /mm3 (16-45%)
- Monocyte………….200-800 / mm3 (4-10%)
- Eosinophil……………….60-400 /mm3 (0-7%)
- Basophil ……………………….<100 / mm3 (0-2%)
An increase in the number of leukocytes in the blood means an increase in all cell types in the leukocyte subgroups. Leukocytosis is expressed as an increase in the total number of these cells. Individual cells may increase alone or together. These situations are also examined in our other articles. Leukocytosis is most often due to increased neutrophil count. However, it may also be due to an increase in lymphocytes, eosinophils, monocytes and very rarely basophils. The definition of leukocytosis should be based on age and population-related neutrophil, lymphocyte, monocytes and eosinophil averages. Let’s briefly summarize these situations:
- Leucomoid reaction: It is defined as the leukocyte count exceeding 50 000/uL for reasons other than leukemia.
- Neutrophilic Leukocytosis: Leukocyte count over 11 000/uL, neutrophil count two standard deviations above the mean (over 7 700/uL for adult)
- Lymphocytic Leukocytosis: Lymphocyte count over 4000/uL
- Monocytic Leukocytosis: The total number of monocytes is over 800/uL
- Eosinophilic Leukocytosis: Eosinophil count above 450/uL
- Basophilic Leukocytosis: Basophil count above 200/µL
A leukocyte count over 10,000/mm3 in the blood is called leukocytosis. Leukocytosis usually develops in response to any inflammatory condition. Sometimes, the number of cells per unit area may have increased due to the decrease in blood volume. This condition is called reactive leukocytosis. It should not be confused with true leukocytosis. However, true causes of leukocytosis are causes in themselves and must be identified.
The most common causes of leukocytosis are:
- Physiological causes
- Newborn (maximum 38,000/mm3)
- Heavy exercise
- Emotional disorders, fear, agitation
- Ovulation, childbirth, pregnancy
- Acute infections
- Metabolic causes
- Diabetic coma
- Acidosis
- Prolonged hunger
- Overactivity of the thyroid gland
- Burns
- Acute gout attack
- Convulsion
- Drugs and chemical poisoning
- Steroids
- Epinephrine
- Lithium
- Serotonin
- Histamine
- Heparin
- Acetylcholine
- Lead poisoning
- Mercury poisoning
- Acute bleeding
- Cancers
- Carcinomas
- Sarcomas
- Lymphomas
- Connective tissue diseases
- Rheumatic fever
- Rheumatoid arthritis
- Inflammatory bowel disease
- Hematological diseases
- Leukemia
- Hemolytic anemia
- Transfusion reactions
- Infectious mononucleosis
You can find more detailed information about the reasons and situations related to the increase in the number of each cell that makes up the leukocytes in the blood, in our articles under special headings.