Synonym
Tubes
- Lavender top tube
- 5 mL of whole blood
Info
For detailed information on each type of WBC go to the specific section on each type of WBC:
The WBC count and differential are a routine part of the complete blood count (CBC) test.
- WBC's (also known as leukocytes) are produced in bone marrow and are part of the primary defense mechanism against foreign organisms, tissues, and other substances.
- WBC's produce, transport, and distribute antibodies as part of the immune response to a foreign substance or antigen.
- WBC's are categorized into Granulocytes (which can secrete biologically active substances such as histamines or cyclooxigenase) and agranulocytes (which do not have granules that can be secreted).
- Leukocytes or WBCs are differentiated into 5 different types:
- Basophils
- Eosinophils
- Lymphocytes
- Monocytes
- Neutrophils
1. Basophils:
Granulocytes whose function is not fully understood. They are capable of ingesting foreign particles and secreting histamine. Basophils are associated with mast cells, express IgE and play a role in allergic inflammatory disease.
2. Eosinophils:
Granulocytes that dispose of cellular debris; but also seems to be involved in allergic responses. These cells have a potent cytotoxic effect, especially on parasites, by the release of destructive proteins (major basic protein, eosinophil cationic protein and eosinophil derived neurotoxin) into the extracellular space.
3. Lymphocytes:
Agranulocyte that is separated into B-lymphocytes (make antibodies to attack bacteria/toxins) and T-lymphocytes (responsible for cell-mediated immunity such as attacking cells infected by viruses or attacking cancerous cells).
4. Monocytes:
Agranulocyte that seeks antigens in the blood stream and eventually migrates to the tissues and becomes a macrophage. Monocytes serve as an antigen-presenting cell for T lymphocytes.
5. Neutrophils:
Granulocyte that is typically the most common leukocyte in circulation. These cells are involved in inflammatory processes and in the phagocytosis and destruction of bacteria. Total neutrophil count is made up of the total number of segmented neutrophils plus band forms.
Clinical
The White blood cell (WBC) count and differential may be clinically useful in:
- Evaluation of infection or inflammation
- Assist in determination of viral versus bacterial infection
- Assist in evaluation of the stage and severity of an infection
- Detect allergic response or parasitic infections (elevated eosinophils)
- Evaluation for hematologic malignancy/disorders
- Detecting and identifying various types of myelopoietic disorders
- Detecting and identifying various types of leukemia
- Evaluating bone marrow depression
- Evaluation of need for further tests, such as manual WBC differential or bone marrow biopsy
- Evaluation of drug effects, response to chemotherapy or radiation
- Evaluation of effect of cytotoxic agents
- Screening test as part of a CBC on admission to a health care facility or before surgery
Additional information:
- See the "Information" section for details of the activities of each cell type
- The interpretation of a normal, high or low result of any given WBC type requires the context of the patient's clinical condition, history and physical examination
- Specific patterns of leukocyte response are seen in various types of diseases as determined by the differential count
- The life span of leukocytes is normally 11–16 days; with the majority of this spent in the bone marrow maturing. After release into circulation; the WBC life span is just hours. Thereafter, the cells are destroyed in the lymphatic system and are excreted from the body in fecal matter.
- Approximately 90% of WBCs are in storage in the bone marrow with just 2-3% in circulating blood and 7-8% in tissues.
Nl Result
Consult your laboratory for their normal ranges as these may vary somewhat from the ones listed below.
Total WBC Count
| Conv. Units
(cells/mm3) | Conv. Units
(cells/103/mm3) | SI Units
(Cells x 109/L) |
|---|
| Birth | 9,000-30,000 | 9.0-30.0 | 9.0-30.0 |
| 2-8 weeks | 5,000-21,000 | 5.0-21.0 | 5.0-21.0 |
| 2-6 months | 5,000-19,500 | 5.0-19.5 | 5.0-19.5 |
| 7-12 months | 6,000-17,500 | 6.0-17.5 | 6.0-17.5 |
| 1-5 years | 5,500-15,500 | 5.5-15.5 | 5.5-15.5 |
| 6-17 years | 4,500-14,000 | 4.5-14.0 | 4.5-14.0 |
| Adult | 4,500-11,000 | 4.5-11.0 | 4.5-11.0 |
WBC Differential (%) [Conventional Units]
| Segmented
Neutrophils
(Polys/Segs) | Bands
(Stabs) | Lymphocytes | Eosinophils | Basophils | Monocytes |
|---|
| Birth | 32-62% | 10-18% | 26-36% | 0-2% | 0-1% | 0-6% |
| 2-8 weeks | 15-35% | 7-16% | 38-71% | 0-3% | 0-1% | 0-9% |
| 2-6 months | 15-35% | 5-11% | 42-72% | 0-3% | 0-1% | 0-6% |
| 7-12 months | 13-33% | 6-12% | 46-76% | 0-3% | 0-1% | 0-5% |
| 1-5 years | 13-33% | 5-11% | 46-76% | 0-3% | 0-1% | 0-5% |
| 6-17 years | 32-54% | 5-11% | 27-57% | 0-3% | 0-1% | 0-5% |
| Adult | 50-65% | 3-5% | 25-40% | 0-4% | 0-1% | 2-8% |
WBC Differential (fraction) [SI Units]
| Segmented
Neutrophils
(Polys/Segs) | Bands
(Stabs) | Lymphocytes | Eosinophils | Basophils | Monocytes |
|---|
| Birth | 0.32-0.62 | 0.10-0.18 | 0.26-0.36 | 0-0.02 | 0-0.01 | 0-0.06 |
| 2-8 weeks | 0.15-0.35 | 0.07-0.16 | 0.38-0.71 | 0-0.03 | 0-0.01 | 0-0.09 |
| 2-6 months | 0.15-0.35 | 0.05-0.11 | 0.42-0.72 | 0-0.03 | 0-0.01 | 0-0.06 |
| 7-12 months | 0.13-0.33 | 0.06-0.12 | 0.46-0.76 | 0-0.03 | 0-0.01 | 0-0.05 |
| 1-5 years | 0.13-0.33 | 0.05-0.11 | 0.46-0.76 | 0-0.03 | 0-0.01 | 0-0.05 |
| 6-17 years | 0.32-0.54 | 0.05-0.11 | 0.27-0.57 | 0-0.03 | 0-0.01 | 0-0.05 |
| Adult | 0.50-0.65 | 0.03-0.05 | 0.25-0.40 | 0-0.04 | 0-0.01 | 0.02-0.08 |
A critical result relates to the clinical scenario; however, WBC's above 100,000 per mm3 (100 X 109 /L) are a medical emergency due to risk of brain infarction (due to sludging) and hemorrhage.
High Result
Increased total WBC's is called leukocytosis.
The line of cells (e.g. neutrophils, lymphocytes, etc) that is elevated is important (see the specific sections on those subtypes of WBC for further information).
WBC's>100,000/mm3 is a medical emergency and immediate hematology/oncology consultation is needed.
Conditions that cause leukocytosis include:
- Allergic reactions
- Burns
- Drugs/toxins:
- Corticosteroids
- Digitalis
- Epinephrine
- Heparin
- Histamines
- Lithium
- Other agents (see section by subtype of WBC)
- Hematologic disorders
- Acute hemorrhage
- Hemolytic anemia
- Myeloproliferative disorders
- Leukemia
- Sickle cell anemia
- Hypoxia/Anoxia
- Infections (Typically acute)
- Inflammatory disorders
- Acute rheumatoid arthritis
- Hypersensitivity reactions
- Myositis
- Rheumatic fever
- Vasculitis
- Metabolic
- Adrenal crisis
- Cushing's disease
- Diabetic ketoacidosis
- Eclampsia
- Thyroid storm
- Uremia
- Neurologic
- Head trauma
- Intracranial hemorrhage
- Seizure
- Myocardial infarction
- Physiological
- Anger
- Crying babies
- Electric shock
- Excitement
- Exercise
- Exposure to extreme heat or cold
- Fear
- Menstruation
- Obstetric labor and delivery
- Stress (Major)
- Vomiting
- Post operative period
- Splenectomy (Post splenectomy there is often a leukocytosis for weeks to months)
- Trauma
Low Result
Decreased total WBC's is called leukopenia.
The line of cells (e.g. neutrophils, lymphocytes, etc) that is decreased is important (see the specific sections on those subtypes of WBC for further information).
Conditions that cause leukopenia include:
- Acute severe infection or inflammation
- Chemical and physical agents
- Bone marrow depressants
- Benzene
- Cytotoxic drugs
- Radiation
- Drugs
- Amitriptyline
- Alprazolam
- Asparaginase
- Aspirin
- Benzodiazepines
- Bupropion
- Captopril
- Cefdinir
- Cefpodoxime
- Ceftriaxone
- Chlorambucil
- Chloramphenicol
- Clozapine
- Corticotropin
- Cyclosporine
- Desipramine
- Dexamethasone
- Eprosartan
- Erythropoietin
- Ethosuximide
- Fludarabine
- Folic acid
- Furosemide
- Glucocorticoids
- Hydrocortisone
- Ibuprofen
- Indomethacin
- Irinotecan
- Levetiracetam
- Levofloxacin
- Lithium
- Mechlorethamine
- Mirtazapine
- Muromonab-cd3
- Nelfinavir
- Niacin
- Niacinamide
- Nortriptyline
- Ofloxacin
- Olsalazine
- Pamidronate
- Pentostatin
- Phenothiazines
- Phenytoin
- Procainamide
- Quazepam
- Rabeprazole
- Rifampin
- Sirolimus
- Sulfamethoxazole
- Terbinafine
- Thiamine
- Thiopental
- Trastuzumab
- Triazolam
- Immunodeficiency syndromes
- AIDS
- Congenital defects of cell mediated immunity
- Immunosuppressive medication
- Infections
- Bacterial
- Brucellosis
- Paratyphoid
- Septicemia - mainly gram negative
- Typhoid fever
- Viral
- Chickenpox
- Colorado tick fever
- Hepatitis
- HIV infection
- Infectious mononucleosis
- Influenza
- Measles
- Rubella
- Others
- Protozoa – malaria
- Rickettsia
- Myeloid hypoplasia
- Agranulocytosis
- Aplastic anemia
- Space-occupying bone marrow lesions
- Vitamin B12 and folic acid deficiency
- Other conditions
- Alcoholism
- Autoimmune neutropenia
- Benign familial leukopenia
- Collagen-vascular diseases as lupus erythematosus
- Cyclic neutropenia
- Hypersplenism
- Liver disease
- Storage diseases
- Hypothermia
- Myelodysplasia
- Rheumatoid arthritis
- Severe congenital neutropenia - Kostmann's syndrome
- Starvation
- Severe debilitating diseases
- Miliary tuberculosis
- Hodgkin's disease
- Lupus erythematosus
- Terminal carcinoma
- Renal failure
References
- Abramson, N. Leukocytosis: Basics of Clinical Assessment. Am Fam Phy. 2000 Nov 1;62(9):2053-60.
- Amar D et al. Leukocytosis and increased risk of atrial fibrillation after general thoracic surgery. Ann Thorac Surg. 2006 Sep;82(3):1057-61; discussion 1061-2.
- Behrman: Nelson Textbook of Pediatrics, 17th ed. Chapter 710.
- Falcone FH et al. The 21st century renaissance of the basophil? Current insights into its role in allergic responses and innate immunity. Exp Dermatol. 2006 Nov;15(11):855-64.
- LabTestsOnline®. White Blood Cell Count. [Homepage on the Internet] © 2001-2006. Last reviewed on May 6, 2005. Last accessed onOctober 17, 2006. Available at URL: http://www.labtestsonline.org/understanding/analytes/wbc/#how
- Mariani M et al. Significance of total and differential leucocyte count in patients with acute myocardial infarction treated with primary coronary angioplasty. Eur Heart J. 2006 Aug 21; [Epub ahead of print]
- Sanchez-Ramon S et al. Low blood CD8+ T-lymphocytes and high circulating monocytes are predictors of HIV-1-associated progressive encephalopathy in children. Pediatrics. 2003 Feb;111(2):E168-75.
- Sezer M et al. Association of Hematological Indices with the Degree of Microvascular Injury in Patients with Acute Anterior Wall Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention. Heart 2006 Aug 29; [Epub ahead of print].
- Tsegaye A et al. Immunophenotyping of blood lymphocytes at birth, during childhood, and during adulthood in HIV-1-uninfected Ethiopians. Clin Immunol. 2003 Dec;109(3):338-46.
- Vroonhof K et al. Differences in mortality on the basis of complete blood count in an unselected population at the emergency department. Lab Hematol. 2006;12(3):134-8
- http://www.med-ed.virginia.edu/courses/path/innes/wcd/leukocytosis.cfm
- http://www.med-ed.virginia.edu/courses/path/innes/wcd/leukopenia.cfm