Lymphocyte Activity Profile
Also known as: Lymphocyte Act. Profile; T cell count; CD4 count; lymphocyte subsets; TBNK; CD4/CD8 count; B cell count; CD19 count; CD20 count
This test measures percentages and absolute numbers of lymphocytes, CD3 T cells, CD4 T cells and CD8 T cells and in lymphocyte subsets also B cells and NK cells.
Lymphocytes in peripheral blood (circulation) are heterogeneous and can be broadly classified into T cells, B cells, and natural killer (NK) cells. There are various subsets of each of these individual populations with specific cell-surface markers and function. This assay provides absolute and relative quantitation for the main categories of T cells, B cells, and NK cells.
Each of these lymphocyte subpopulations have distinct effector and regulatory functions and are maintained in homeostasis under normal physiological conditions. Each of these lymphocyte subsets can be identified by a combination of one or more cell surface markers.
The CD3 antigen is a pan-T-cell marker, and T cells can be further divided into 2 broad categories, based on the expression of CD4 or CD8 coreceptors.
B cells can be identified by expression of CD19, while NK cells are typically identified by the coexpression of CD16 and CD56.
The absolute counts of lymphocyte subsets are known to be influenced by a variety of biological factors, including hormones, the environment, and temperature.
Abnormalities in the number and percent of T (CD3, CD4, CD8), B (CD19), and NK (CD16+CD56) lymphocytes have been described in a number of different disease conditions. In patients who are infected with HIV, the CD4 count is measured for AIDS diagnosis and for initiation of antiviral therapy. The progressive loss of CD4 T lymphocytes in patients infected with HIV is associated with increased infections and complications. The Public Health Service has recommended that all patients who are HIV-positive be tested every 3 to 6 months for the level of CD4 T lymphocytes.
Lymphocyte subset quantitation is also very useful in the evaluation of patients with primary immunodeficiencies of all ages, including follow-up for newborn screening for severe combined immunodeficiency and immune monitoring following immunosuppressive therapy for transplantation, autoimmunity, or any other relevant clinical condition where immunomodulatory treatment is used.
It is also helpful as a preliminary screening assay for gross quantitative anomalies in any lymphocyte subset, whether related to malignancies or infection.
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Biomarkers included in this panel:
The proportion of all immune cells that are T cells. This figure is rarely used for making treatment decisions.
Learn moreThe CD4 percentage (CD4%) is the percentage of white blood cells (lymphocytes) that are CD4 cells. The immune system contains lots of different cells. The two main types of lymphocytes are T cells and B cells. CD4 cells are a type of T cell. So th
Learn moreThe proportion of all T cells that are CD8 cells. CD8 cells are also called cytotoxic T-lymphocytes. They help fight cancer and germs that live inside your cells (intracellular pathogens). The CD8 percentage is sometimes more reliable than the
Learn moreThis test is used to detect soluble IL-2Rα in human plasma or serum produced in response to increased activation of B and T cells and immune system activation. Studies show elevated levels of sIL-2Rα in serum with the onset of rejection e
Learn moreThe CD57 test is offered in some clinical laboratories and is being used by some health practitioners to evaluate and follow patients diagnosed with chronic Lyme disease.
Learn moreThe percentage of natural killer (NK) cells expressing CD56 and CD16, also known as % NK (CD56/16), is a significant parameter in the characterization of different subsets of human NK cells. CD56 is a marker for NK cells, and its expression can vary
Learn moreAb NK (CD56/16) refers to the antibody staining of natural killer (NK) cells to detect the presence of specific surface markers, CD56 and CD16. CD56 is a neural cell adhesion molecule, and CD16 is an Fc receptor. Ab NK (CD56/16) analysis is crucial i
Learn moreCD25 is the receptor for IL2 and is expressed on activated T cells, B cells, and macrophages. CD25 is expressed in certain types of B-cell lymphoma (hairy cell leukemia) and T-cell lymphoma (adult T-cell lymphoma/leukemia [ATLL]).
Learn moreWhy use the CD57 test? The CD57 test is offered in some clinical laboratories and is being used by some health practitioners to evaluate and follow patients diagnosed with chronic Lyme disease. What is Lyme disease? Lyme disease, the most co
Learn moreCD3+ cells are all T-lymphocytes, which includes both CD4+ and CD8+ lymphocyte cells. This figure is rarely used for making treatment decisions.
Learn moreThe CD4 cells are Helper T-cells expressing both CD3 and CD4. CD4 T-cells levels are a criterion for categorizing HIV-related clinical conditions by CDC's classification system for HIV infection. The measurement of CD4 T-cell levels has been u
Learn moreThis figure is rarely used for making treatment decisions. CD4 and CD8 are two types of white blood cells in your blood. CD4 cells are also called T-helper cells, T-suppressor cells, and cytotoxic T-cells. They help the body fight infections. CD8
Learn moreCD19 is a protein that serves as a cell surface marker found on B-lymphocytes (B-cells), which are a type of white blood cell crucial to the adaptive immune system. As part of the B-cell receptor complex, CD19 functions as a co-receptor that enhances
Learn moreCD2 is a type I transmembrane glycoprotein that is expressed on the surface of T cells, natural killer cells, thymocytes, and dendritic cells. The CD2 protein is also a costimulatory receptor that plays a role in T cell activation and signaling.
Learn moreCD20 is a cell surface protein primarily found on B-lymphocytes (B-cells), which are essential white blood cells in the adaptive immune system. CD20 plays a crucial role in regulating B-cell activation, growth, and differentiation, particularly in th
Learn moreThe proportion of all immune cells that are T cells. This figure is rarely used for making treatment decisions.
Learn moreThe CD4 percentage (CD4%) is the percentage of white blood cells (lymphocytes) that are CD4 cells. The immune system contains lots of different cells. The two main types of lymphocytes are T cells and B cells. CD4 cells are a type of T cell. So th
Learn moreThis test looks at the ratio of two important types of white blood cells in your blood. Lymphocytes are a type of white blood cell in your immune system. This test looks at two of them, CD4 and CD8. CD4 cells lead the fight against infecti
Learn moreCell surface antigen CD5 is a marker for activated human B cells. CD5 is a T-cell associated marker that is also expressed by two B-cell neoplasms; lymphocytic leukemia and mantle cell lymphoma. CD5 antigen is expressed in 95% of thymocytes and 72
Learn moreCD7 is a transmembrane protein highly expressed in acute T-cell leukemia (T-ALL) and in a subset of peripheral T-cell lymphomas. Normal expression of CD7 is largely confined to T cells and natural killer (NK) cells, reducing the risk of off-target-or
Learn moreThe proportion of all T cells that are CD8 cells. CD8 cells are also called cytotoxic T-lymphocytes. They help fight cancer and germs that live inside your cells (intracellular pathogens). The CD8 percentage is sometimes more reliable than the
Learn moreCD16, also known as FcγRIII, refers to a cluster of differentiation molecule found on the surface of various immune cells, including natural killer cells, neutrophils, monocytes, macrophages, and certain T cells. CD16 has been identified as two
Learn moreCD16, also known as FcγRIII, refers to a cluster of differentiation molecule found on the surface of various immune cells, including natural killer cells, neutrophils, monocytes, macrophages, and certain T cells. CD16 has been identified as two
Learn moreThe CD19 antigen (aka B-lymphocyte antigen CD19 or Cluster of Differentiation 19) plays an important role in clinical oncology. It’s a protein found on the surface of B-cells, a type of white blood cell.
Learn moreCD3+ cells are all T-lymphocytes, which includes both CD4+ and CD8+ lymphocyte cells. This figure is rarely used for making treatment decisions.
Learn moreThe CD4 cells are Helper T-cells expressing both CD3 and CD4. CD4 T-cells levels are a criterion for categorizing HIV-related clinical conditions by CDC's classification system for HIV infection. The measurement of CD4 T-cell levels has been u
Learn moreThis test looks at the ratio of two important types of white blood cells in your blood. Lymphocytes are a type of white blood cell in your immune system. This test looks at two of them, CD4 and CD8. CD4 cells lead the fight against infecti
Learn moreCD56 is an adhesion molecule mediating homophilic and heterophilic adhesion in neurons, natural killer cells, and a small subset of CD4- and CD8-positive T cells. It is expressed in tumors with neuroendocrine differentiation (small cell lung carcinom
Learn moreCD56 is an adhesion molecule mediating homophilic and heterophilic adhesion in neurons, natural killer cells, and a small subset of CD4- and CD8-positive T cells. It is expressed in tumors with neuroendocrine differentiation (small cell lung carcinom
Learn moreCD56+CD3- % is a key immunological marker identifying natural killer (NK) cells, essential in innate immunity. Elevated levels can indicate an active immune response or certain malignancies, while decreased levels may suggest impaired immunity, as se
Learn moreCD56+CD3- (absolute) cells are crucial in the immune system, primarily acting as natural killer (NK) cells. Their unique combination of CD56 positivity and CD3 negativity makes them essential for defending against pathogens and cancer cells. These ce
Learn moreThis figure is rarely used for making treatment decisions. CD4 and CD8 are two types of white blood cells in your blood. CD4 cells are also called T-helper cells, T-suppressor cells, and cytotoxic T-cells. They help the body fight infections. CD8
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