White blood cells, also called leukocytes, are key functionaries of the immune system. There are several types of white blood cells and each is specialized for certain types of immune response.
White blood cell levels are useful for pointing to many conditions. They can be high or low for many reasons. They are commonly used to determine whether or not a patient has an infection. A “left shift” in the white count indicates presence of high numbers of immature white cells, often called bands. A left shift can occur for a number of reasons. It is a natural response to infection as the body tries to make enough white cells to fight the infection. A “right shift” refers to the absence or low level of bands, new white cells. This indicates suppression of bone marrow.
Normal range for white blood cell count:
- 0-11.0 x 109 cells/L
Types of white blood cells can be quantified as either a percentage of total white cells or as an absolute count. Normal white cell count varies with age, especially neutrophils, lymphocytes and monocytes.
Normal range for neutrophil count:
- 8-7.7 x 109 cells/L
- 35-80% of total white cells
Normal range for eosinophil count:
- 0-0.8 x 109 cells/L
- 0-4% of total white cells
Normal range for lymphocyte count:
- 8-4.8 x 109 cells/L
- 18-44% of total white cells
Normal range for monocyte count:
- 2-0.9 x 109 cells/L
- 7-12.5% of total white cells
Normal range for basophil count:
- 0-0.1 x 109 cells/L
- 0-1.2% of total white cells