Differential WBC Count There are five different kinds of WBCs
Normal Values
(Male or Female)
Neutrophils
40 – 75%
Eosinophils
1 – 4%
Basophils
0 – 1%
Lymphocytes
20 – 45%
Monocytes
2 – 8%
Significance of the WBC Count
When there is an increase in eosinophils it is known as eosinophilia. It is observed in chronic inflammatory conditions, asthma, parasitic infestations, and in hypersensitivity reactions.
When there is a decrease in lymphocytes, it is known as lymphopenia. It is observed in acute stages of infections and where there is an excessive irradiation.
When there is an increase in neutrophils, it is known as neutrophilia. The common cause is pyogenic (pus forming) bacterial infections. When there is a decrease in neutrophils it is known as neutropenia. It is observed in bacterial infections such as typhoid, viral infection such as measles, influenza etc. It is also found in anemias (aplastic, megaloblastic, iron deficiency) and in suppression of bone marrow by various drugs and radiation.
When there is an increase in lymphocytes it is known as lymphocytosis. Lymphocytosis can be of two types, relative or absolute.
Relative Lymphocytosis: In this, the actual no of lymphocytes has not changed, but due to a decrease in neutrophils, the differential count shows an increase in lymphocytes.
Absolute Lymphocytosis:
It is seen in:
Children.
Also seen when there are infections such as tuberculosis, typhoid, mumps, measles, cough, influenza syphilis and other chronic infections.
Infectious mononucleosis.
Chronic lymphatic leukemia.
When there is an increase in the number of monocytes, it is known as monocytosis. It is observed in tuberculosis, malaria, sub–acute bacterial endocarditis, typhoid and in Kala Azar.
A differential count is useful in identifying changes in the distribution of WBCs, which may be related to specific types of disorders. It also helps to know the severity of the disease and the degree of the response of the body.
