Please Remove Adblock
Adverts are the main source of Revenue for DoveMed. Please remove adblock to help us create the best medical content found on the Internet.

Lymphocytes Blood Test

Last updated June 11, 2019

Approved by: Maulik P. Purohit MD, MPH

The Lymphocytes Blood Test helps measure the levels of T cells and B cells in blood.

What are other Names for this Test? (Equivalent Terms)

  • Lymphocyte Marker Studies Blood Test
  • Lymphocyte Subset Typing Blood Test
  • T and B Lymphocytes Blood Test

What is Lymphocytes Blood Test? (Background Information)

  • Lymphocytes are specialized immune cells that comprise the body’s adaptive immune response. The adaptive immune system is acquired through exposure to specific disease-causing agents during the course of one’s life
  • This is made possible by the T and B lymphocytes (or T cells and B cells)
    • T cells are formed in the thymus, a small organ positioned between the lungs. These cells provide cell-mediated immunity, also called cellular immunity. The T cells destroy pathogens present inside cells, examples of which include bacteria and viruses. However, in certain situations, they can also be responsible for organ rejection (during a transplant) and autoimmune diseases
    • B cells are formed in bone marrow, the spongy tissue inside certain bones. They provide humoral immunity, which is immunity against pathogens circulating in blood (outside of cells). These cells transform into plasma cells, which are antibody-producing factories. Antibodies then circulate throughout the blood, helping to rid the body of foreign invaders
  • In contrast to the adaptive immune system, the innate immune system is present at birth. It defends the body from a wide array of offending agents, and does not distinguish between them. It is made up of phagocytes, neutrophils, and other generalized cells
  • The Lymphocytes Blood Test helps measure the levels of T cells and B cells in blood. It helps diagnose autoimmune disorders and blood cell cancers. It may also be used to guide immunosuppressant treatment

What are the Clinical Indications for performing the Lymphocytes Blood Test?

Following are the clinical indications for performing the Lymphocytes Blood Test:

  • Monitoring immunosuppressant therapy
  • Frequent and prolonged infections
  • Serious infection by pathogens including yeasts, such as Candida albicans (oral/genital candidiasis, thrush), which are normally trivial; these pathogens do not usually cause severe infections in individuals with well-functioning immune system
  • Fever, chills
  • Fatigue
  • Rapid weight loss
  • Nausea, diarrhea, and vomiting

How is the Specimen Collected for Lymphocytes Blood Test?

Following is the specimen collection process for Lymphocytes Blood Test:

Sample required: Blood

Process of obtaining a blood sample in adults:

  • A band is wrapped around the arm, 3-4 inches above the collection site (superficial vein that lies within the elbow pit)
  • The site is cleaned with 70% alcohol in an outward spiral, away from the zone of needle insertion
  • The needle cap is removed and is held in line with the vein, pulling the skin tight
  • With a small and quick thrust, the vein is penetrated using the needle
  • The required amount of blood sample is collected by pulling the plunger of the syringe out slowly
  • The wrap band is removed, gauze is placed on the collection site, and the needle is removed
  • The blood is immediately transferred into the blood container, which has the appropriate preservative/clot activator/anti-coagulant
  • The syringe and the needle are disposed into the appropriate “sharp container” for safe and hygienic disposal

Preparation required: No special preparation is needed prior to the test.

What is the Significance of the Lymphocytes Blood Test Result?

The significance of the Lymphocytes Blood Test is explained:

  • A high T cell value (more than 2400 cells/µL) for the test may point to a diagnosis of autoimmune disease, such as Graves’ disease
  • A high B cell value (more than 250 cells/µL) for the test may point to a diagnosis of:
    • Acute and chronic lymphocytic leukemia
    • Multiple myeloma
    • Waldenstrom’s macroglobulinemia
  • A low T cell value (less than 600 cells/µL) for the test may point to a diagnosis of:
    • Lymphoma
    • Systemic lupus erythematosus (SLE)
    • Thymic hypoplasia (DiGeorge’s syndrome)
    • Acute viral infections
    • Immunodeficiency disorders
  • A low B cell value (less than 50 cells/µL) for the test may point to a diagnosis of:
    • IgG, IgA, and/or IgM deficiency
    • Lymphoma
    • Nephrotic syndrome
    • Sex-linked agammaglobulinemia
    • Immunodeficiency disorders

The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.

Additional and Relevant Useful Information:

Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider of the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.

Please visit our Laboratory Procedures Center for more physician-approved health information:


References and Information Sources used for the Article:

Helpful Peer-Reviewed Medical Articles:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: June 4, 2016
Last updated: June 11, 2019