TOTAL LEUCOCYTE COUNT

Adults:

• 4000-11000 cells /mcL

New born:

• 10000-25000/ mcL

Infants:

• 6000-18000/ mcL

Children:

• 5000-15000/ mcL

• Leucocytes (WBC) are nucleated cells that are involved in the defence mechanism of the body. Unlike red blood cells, white cells use the blood stream primarily for transportation to their place of function in the body tissues. They help protect against infections and also have a role in inflammation and allergic reactions.
• Leucocytes are classified into granulocytes and agranulocytes. Granulocytes are neutrophils, eosinophils and basophils. Agranulocytes are lymphocytes and monocytes.
• Whenever there is an infection or inflammatory process in the body, bone marrow produces more WBCs and they migrate (chemotaxis) to the site of injury in response to chemo attractants released by microorganisms or by the injured or infected cells, and acts by phagocytosis. All granulocytes, especially neutrophils and monocytes kill the organisms by phagocytosis.
• Total leucocyte count is a part of the routine haematological investigation. It is performed to assess the subject’s ability to defend the body against microbial invasions.
• Total leucocyte count is done to assess the nature & severity of an infection, extent of spread of disease, the body’s defense capability. It is usually done with differential leucocyte count to make actual diagnosis.

• WBC count is done as a part of Complete Blood Count (CBC)
• When there is s/s of Infection and /or inflammation (Fever, chills, body ache, pains, Headache)
• When there is s/s of autoimmune disorder

Physiological

• Newborns & infants
• Physical exercise- due to shift leukocytosis
• After food intake - body metabolism increase, body temperature increases, circulation improves, leads to disruption of margination of leucocytes, resulting in leukocytosis
• Exposure to sun and increased environmental temperature
• Pregnancy
• Parturition (due to tissue injury, haemorrhage and severe exertion)
• Pain, nausea & vomiting
• Emotion & anxiety

Pathological:

• Acute bacterial infection e.g. boils, abscess, and pneumonia
• Chronic bacterial infection e.g. TB
• Allergic Responses
• Lymphoma
• Auto immune disorders
• Tissue injury e.g. Infarction, Burns, and Surgery
• Haemorrhage
• Neoplasia
• Stress states & hyperactivity- Convulsions, Severe colic
• Inflammatory disorders- Certain collagen disorders, Rheumatic fever
• Metabolic disorders e.g. Diabetic ketoacidosis
• Corticosteroid therapy

Physiological

• Very rare
• Sometimes exposure to severe cold

Pathological:

• Infections - Typhoid fever, Paratyphoid fever, Early phases of many viral infections e.g. infectious hepatitis
• Replacement of haemopoietic tissue in the bone marrow by neoplastic infiltrative cells - Acute Leukemia , Lymphoma, Multiple myeloma, Myelofibrosis
• Aplastic anemia
• Cytotoxic therapy
• Drugs - Chloramphenicol, Sulphur drugs, Aspirin,
• Hypersplenism
• Starvation & malnutrition