White Blood Cell (WBC) Differential
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- Also Known As:
- Leukocyte Differential Count
- Peripheral Differential
- WBC Count Differential
- Diff
- Blood Differential
- Differential Blood Count
- CBC with Diff

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At a Glance
Why Get Tested?
To help determine the cause of abnormal results on a white blood cell (WBC) count; to help diagnose and/or monitor an illness affecting your immune system, such as an infection or inflammatory condition, or cancers that affect your white blood cells, such as leukemia or lymphoma
When To Get Tested?
When you have a complete blood count (CBC) done as part of a routine health examination; when results of a CBC fall outside the reference range; when you have signs and symptoms related to a condition affecting white blood cells, such as infection, inflammation, or cancer; when you are receiving treatment that is known to affect WBCs, such as chemotherapy
Sample Required?
A blood sample drawn from a vein or blood collected by a pricking a fingertip (fingerstick) or the heel of an infant (heelstick)
Test Preparation Needed?
None
You may be able to find your test results on your laboratory’s website or patient portal. However, you are currently at Testing.com. You may have been directed here by your lab’s website in order to provide you with background information about the test(s) you had performed. You will need to return to your lab’s website or portal, or contact your healthcare practitioner in order to obtain your test results.
Testing.com is an award-winning patient education website offering information on laboratory tests. The content on the site, which has been reviewed by laboratory scientists and other medical professionals, provides general explanations of what results might mean for each test listed on the site, such as what a high or low value might suggest to your healthcare practitioner about your health or medical condition.
The reference ranges for your tests can be found on your laboratory report. They are typically found to the right of your results.
If you do not have your lab report, consult your healthcare provider or the laboratory that performed the test(s) to obtain the reference range.
Laboratory test results are not meaningful by themselves. Their meaning comes from comparison to reference ranges. Reference ranges are the values expected for a healthy person. They are sometimes called “normal” values. By comparing your test results with reference values, you and your healthcare provider can see if any of your test results fall outside the range of expected values. Values that are outside expected ranges can provide clues to help identify possible conditions or diseases.
While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents, and techniques. This is a reason why so few reference ranges are provided on this site. It is important to know that you must use the range supplied by the laboratory that performed your test to evaluate whether your results are “within normal limits.”
For more information, please read the article Reference Ranges and What They Mean.
White Blood Cell (WBC) Differential Reference Range
The reference ranges1 provided here represent a theoretical guideline that should not be used to interpret your test results. Some variation is likely between these numbers and the reference range reported by the lab that ran your test. Please consult your healthcare provider.WBC diff | Conventional Units2 | SI Units3 | ||
Component | Percentage | Absolute counts (per microliter) | Mean number fraction | Absolute counts X 109 per liter |
Segs | 40-70 | 1800-7800 | 0.56 | 1.8-7.8 |
Eos | 0-4 | 0-450 | 0.027 | 0-0.45 |
Baso | 0-2 | 0-200 | 0.003 | 0-0.20 |
Lymphs | 22-44 | 1000-4800 | 0.34 | 1.0-4.8 |
Monos | 0-7 | 0-800 | 0.04 | 0-0.80 |
What is being tested?
White blood cells (WBCs), also called leukocytes, are cells that circulate in the blood and the lymphatic system that help protect the body against infections. They are an important part of the body’s immune system and also have a role in inflammation, allergies, and protection against cancer. A WBC differential categorizes the numbers of each of the different types of WBCs in sample of your blood.
There are five main types of white blood cells, each with different functions. The differential shows if:
- The different types of WBCs are present in normal proportion to one another
- The numbers of the different cell types are normal, increased or decreased
- Abnormal and/or immature WBCs are present
This information is helpful in diagnosing specific types of illnesses that affect the immune system and the bone marrow.
A differential may be performed along with or following a complete blood count (CBC), a test often used as a general health check, or it may be performed in follow-up to abnormal results on a CBC. Most often, a differential is performed on an automated blood analyzer. Occasionally, it is performed manually by a trained laboratory professional who examines a blood smear using a microscope.
Types of White Blood Cells
The bone marrow produces five main types of WBCs, neutrophils, lymphocytes, monocytes, eosinophils, and basophils.
- Neutrophils (neu) normally make up the largest number of circulating WBCs. They move into an area of damaged or infected tissue, where they engulf and destroy bacteria or sometimes fungi.
- Lymphocytes (lymphs) exist in both the blood and the lymphatic system. They are broadly divided into three types, but the differential does not distinguish among them. The differential counts and reports all lymphocytes together. Separate specialized testing (like immunophenotyping) must be done to differentiate the three types:
- B lymphocytes (B cells) are produce antibodies that help protect against infections. Plasma cells are fully differentiated B-cells that produce antibodies, immune proteins that target and destroy bacteria, viruses and other “non-self” foreign antigens.
- T lymphocytes (T cells) finish maturing in the thymus and consist of a few different types. Some T cells help the body distinguish between “self” and “non-self” antigens. Others initiate and control the extent of an immune response, boosting it as needed and then slowing it as the condition resolves. Other types of T cells directly attack and neutralize virus-infected or cancerous cells.
- Natural killer cells (NK cells) directly attack and kill abnormal cells such as cancer cells or those infected with a virus.
- Monocytes (mono), similar to neutrophils, move to an area of infection and engulf and destroy bacteria. They are associated more often with long-term (chronic) rather than acute infections. They are also involved in tissue repair and other functions involving the immune system.
- Eosinophils (eos) respond to infections caused by parasites, play a role in allergic reactions (hypersensitivities), and control the extent of immune responses and inflammation.
- Basophils (baso) usually make up the fewest number of circulating WBCs and are thought to be involved in allergic reactions.
What does a differential tell you?
A WBC differential can give clues about your condition or what is causing a low or high WBC count. When there is an infection or an inflammatory process somewhere in the body, the bone marrow produces more WBCs, releasing them into the blood. Depending on the cause of infection or inflammation, one particular type of WBC may be increased as opposed to other types. As the condition resolves, the bone marrow produces fewer of that type of WBC and the number drops back to normal levels.
In addition to infections and inflammation, there are a variety of conditions that can affect the production of WBCs by the bone marrow or their survival in the blood, resulting in either increased or decreased numbers. The differential, along with the other components of the CBC, alerts the healthcare provider to possible health issues. Results are often interpreted along with additional tests such as a blood smear exam, which can show the presence of abnormal and/or immature WBCs.
In a few serious diseases, some immature forms of the cells are released from the bone marrow into the circulation and may be detected by the WBC differential. This may occur with bacterial infection, leukemia, myelodysplastic syndrome, or myeloproliferative neoplasms, for example. Some immature cells that may be detected include metamyelocytes, myelocytes, promyelocytes, and/or blasts.
If results indicate a problem, a wide variety of other tests may be performed in order to help determine the cause. A health care provider will typically consider your signs and symptoms, medical history, and results of a physical examination to decide what other tests may be necessary. For example, as needed, a bone marrow biopsy might be performed because that is where WBCs normally are produced and where they mature.
Common Questions
Health Professionals – LOINC
LOINC Observation Identifiers Names and Codes (LOINC®) is the international standard for identifying health measurements, observations, and documents. It provides a common language to unambiguously identify things you can measure or observe that enables the exchange and aggregation of clinical results for care delivery, outcomes management, and research. Learn More.
Listed in the table below are the LOINC with links to the LOINC detail pages.
LOINC | LOINC Display Name |
---|---|
30395-8 | Granulocytes/100 WBC (Bld) |
19023-1 | Granulocytes/100 WBC Auto (Bld) |
30394-1 | Granulocytes (Bld) [#/Vol] |
20482-6 | Granulocytes Auto (Bld) [#/Vol] |
51588-2 | Granulocytes Manual cnt (Bld) [#/Vol] |
26511-6 | Neutrophils/100 WBC (Bld) |
770-8 | Neutrophils/100 WBC Auto (Bld) |
23761-0 | Neutrophils/100 WBC Manual cnt (Bld) |
71676-1 | Neutrophils/Leukocytes Auto (Bld) [Pure # fraction] |
71671-2 | Neutrophils/Leukocytes Manual cnt (Bld) [Pure # fraction] |
26499-4 | Neutrophils (Bld) [#/Vol] |
751-8 | Neutrophils Auto (Bld) [#/Vol] |
753-4 | Neutrophils Manual cnt (Bld) [#/Vol] |
26450-7 | Eosinophils/100 WBC (Bld) |
713-8 | Eosinophils/100 WBC Auto (Bld) |
714-6 | Eosinophils/100 WBC Manual cnt (Bld) |
71679-5 | Eosinophils/Leukocytes Auto (Bld) [Pure # fraction] |
71674-6 | Eosinophils/Leukocytes Manual cnt (Bld) [Pure # fraction] |
26449-9 | Eosinophils (Bld) [#/Vol] |
711-2 | Eosinophils Auto (Bld) [#/Vol] |
712-0 | Eosinophils Manual cnt (Bld) [#/Vol] |
30180-4 | Basophils/100 WBC (Bld) |
706-2 | Basophils/100 WBC Auto (Bld) |
707-0 | Basophils/100 WBC Manual cnt (Bld) |
71680-3 | Basophils/Leukocytes Auto (Bld) [Pure # fraction] |
71675-3 | Basophils/Leukocytes Manual cnt (Bld) [Pure # fraction] |
26444-0 | Basophils (Bld) [#/Vol] |
704-7 | Basophils Auto (Bld) [#/Vol] |
705-4 | Basophils Manual cnt (Bld) [#/Vol] |
26478-8 | Lymphocytes/100 WBC (Bld) |
736-9 | Lymphocytes/100 WBC Auto (Bld) |
30365-1 | Lymphocytes/100 WBC FC (Bld) |
737-7 | Lymphocytes/100 WBC Manual cnt (Bld) |
71678-7 | Lymphocytes/Leukocytes Auto (Bld) [Pure # fraction] |
71673-8 | Lymphocytes/Leukocytes Manual cnt (Bld) [Pure # fraction] |
26474-7 | Lymphocytes (Bld) [#/Vol] |
731-0 | Lymphocytes Auto (Bld) [#/Vol] |
30364-4 | Lymphocytes FC (Bld) [#/Vol] |
732-8 | Lymphocytes Manual cnt (Bld) [#/Vol] |
4662-3 | Lymphocytes+Monocytes/100 WBC (Bld) |
35081-9 | Lymphocytes+Monocytes (Bld) [#/Vol] |
32350-1 | Basophils+Eosinophils+Monocytes/100 WBC (Bld) |
32155-4 | Basophils+Eosinophils+Monocytes/100 WBC Auto (Bld) |
32349-3 | Basophils+Eosinophils+Monocytes (Bld) [#/Vol] |
32154-7 | Basophils+Eosinophils+Monocytes Auto (Bld) [#/Vol] |
26485-3 | Monocytes/100 WBC (Bld) |
5905-5 | Monocytes/100 WBC Auto (Bld) |
744-3 | Monocytes/100 WBC Manual cnt (Bld) |
71677-9 | Monocytes/Leukocytes Auto (Bld) [Pure # fraction] |
71672-0 | Monocytes/Leukocytes Manual cnt (Bld) [Pure # fraction] |
26484-6 | Monocytes (Bld) [#/Vol] |
742-7 | Monocytes Auto (Bld) [#/Vol] |
743-5 | Monocytes Manual cnt (Bld) [#/Vol] |
View Sources
Sources Used in Current Review
2015 review performed by Nicole Ziegler, MT (ASCP) and the Testing.com Editorial Review Board.
Harmening D. Clinical Hematology and Fundamentals of Hemostasis, Fifth Edition, F. A. Davis Company, Philadelphia, 2009, Pp 305-328.
Holland, K. (Updated 2013 June 14). White Blood Cell Count and Differential. Healthline Reference [On-line information]. Available online at http://www.healthline.com/health/white-blood-cell-count-and-differential#Overview1. Accessed September 2015.
Curry, C. (Updated 2015 January 14). Differential Blood Count. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/2085133-overview. Accessed September 2015.
Muniz V., Weller P., et al. Eosinophil crystalloid granules: structure, function, and beyond. Journal of Leukocyte Biology. 2012 August 92(2). Pp 281-288. Available online at http://jleukobio.org/content/92/2/281.long. Accessed September 2015.
Legrand F., Driss V., et al. Human Eosinophils Exert TNF-α and Granzyme A-Mediated Tumoricidal Activity Toward Colon Carcinoma Cells. Journal of Immunology. 2010 December 15 185(12). Pp 7443-7451. Available online at http://jimmunol.org/content/185/12/7443. Accessed September 2015.
Sources Used in Previous Reviews
Thomas, Clayton L., Editor (1997). Taber’s Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].
Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby’s Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.
Susan J. Leclair, PhD, CLS(NCA). Professor of Medical Laboratory Science, Department of Medical Laboratory Science, University of Massachusetts, Dartmouth, MA.
Pagana, Kathleen D. & Pagana, Timothy J. (© 2007). Mosby’s Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 1003-1008.
Harmening D. Clinical Hematology and Fundamentals of Hemostasis, Fifth Edition, F.A. Davis Company, Philadelphia, 2009, Pp 305-328.
Henry’s Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, Pp 547-559.
Wintrobe’s Clinical Hematology. 12th ed. Greer J, Foerster J, Rodgers G, Paraskevas F, Glader B, Arber D, Means R, eds. Philadelphia, PA: Lippincott Williams & Wilkins: 2009, Pp 170-402, 1528-1533.
(Feb 1 2011) National Heart Lung Blood Institute. What is lymphocytopenia? Available online at http://www.nhlbi.nih.gov/health/health-topics/topics/lym/. Accessed April 2012.
(Jan 23 2012) American Cancer Society. Acute Lymphocytic Leukemia. Available onlne at http://www.cancer.org/Cancer/Leukemia-AcuteLymphocyticALLinAdults/DetailedGuide/leukemia-acute-lymphocytic-what-is-all. Accessed April 2012.
(Dec 7 2010) American Cancer Society. Acute Myeloid Leukemia. Available online at http://www.cancer.org/Cancer/Leukemia-AcuteMyeloidAML/DetailedGuide/leukemia-acute-myeloid-myelogenous-what-is-aml. Accessed April 2012.
(Oct 25 2010) American Cancer Society. Non-Hodgkin Lymphoma. Available online at http://www.cancer.org/Cancer/Non-HodgkinLymphoma/DetailedGuide/non-hodgkin-lymphoma-what-is-non-hodgkin-lymphoma. Accessed April 2012.
(January 8 2010) Kempert P. White Blood Cell Function, Overview of the Immune System. Medscape Reference article. Available online at http://emedicine.medscape.com/article/960027-overview. Accessed April 2012.
(January 26, 2010) Naushad H. Leukocyte Count (WBC). Medscape Reference article. Available online at http://emedicine.medscape.com/article/2054452-overview#aw2aab6b2. Accessed April 2012.
(Updated December 5, 2011) Nader N. Neutrophilia. Medscape Reference article. Available online at http://emedicine.medscape.com/article/208576-overview. Accessed April 2012.
(May 24, 2011) Godwin J. Neutropenia. Medscape Reference article. Available online at http://emedicine.medscape.com/article/204821-overview. Accessed April 2012.
(August 25, 2011) Liss M. Eosinophilia. Medscape Reference article. Available online at http://emedicine.medscape.com/article/199879-overview. Accessed April 2012.
(January 14, 2015) Curry C. White Blood Cell Differential. Medscape Reference. Available online at http://emedicine.medscape.com/article/2085133-overview#a2. Accessed July 10, 2015.
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