CD20 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 the immune response to pathogens.

The proportion of all immune cells that are T cells. This figure is rarely used for making treatment decisions.

The 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 the CD4% looks at the CD4 count in relation to other immune cells.

CD4% is sometimes a more stable indication of whether there has been a change in the immune system. If the percentage hasn’t changed the change in the absolute count is not important.

This 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 infections. CD8 cells can kill cancer cells and other invaders.

Cell 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% of peripheral blood lymphocytes. In lymph nodes, CD5 is mainly reactive with Tcells. It has been shown to react with thymic carcinomas, but rarely in thymomas. It has also been observed in a subset of intravascular large B-cell lymphomas and marks some anaplastic large cell lymphomas. CD5 has proven very useful in marking mantle cell lymphoma when used in tandem with CD23, cyclin D1, and CD10 (CD10 is negative; CD5, cyclin D1 are positive for mantle cell lymphoma).

CD7 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-organ toxicity. 

The 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 absolute count of CD8 because it tends to vary less.

CD15s expression (LAD 2), as part of a Leukocyte Adhesion Deficiency (CD15s, CD18) panel from Quest Diagnostics, plays a critical role in diagnosing Leukocyte Adhesion Deficiency Type II (LAD II). This condition is a rare genetic disorder that affects the immune system's ability to function properly. In healthy individuals, CD15s (also known as sialyl-Lewis X) is a specialized molecule present on the surface of white blood cells (leukocytes) that facilitates their adhesion, or sticking, to blood vessel walls during inflammation or infection. This process is essential for the immune response, as it allows leukocytes to exit the bloodstream and enter affected tissues to combat pathogens.

CD16, 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 different receptors: FcγRIIIa (CD16a) and FcγRIIIb (CD16b). These receptors participate in signal transduction and are involved in antibody-dependent cellular cytotoxicity (ADCC), which is a process where immune cells target and destroy cells coated with specific antibodies.

CD16, 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 different receptors: FcγRIIIa (CD16a) and FcγRIIIb (CD16b). These receptors participate in signal transduction and are involved in antibody-dependent cellular cytotoxicity (ADCC), which is a process where immune cells target and destroy cells coated with specific antibodies.

CD1656 are an important NK (Natural killer) cell subset.

- NK cells are best known for killing virally infected cells, and detecting and controlling early signs of cancer. As well as protecting against disease, specialized NK cells are also found in the placenta and may play an important role in pregnancy.

- Natural killer T (NKT) cells represent a specialized T-cell population that is distinct from conventional T cells. They express an invariant T-cell receptor (TCR) that recognizes self and bacterial glycosphingolipid antigens presented by the MHC class I-like molecule, CD1d.

- Human natural killer (NK) cells can be subdivided in several subpopulations on the basis of the relative expression of the adhesion molecule CD56 and the activating receptor CD16. 

- NK cells serve an important role in host defense against viral infections, as well as tumor surveillance. They are also a component of the adaptive immune response through cytokine production.

- NK cell functions are governed by a balance between activating receptors and inhibitory receptors.

The marker "CD18 Expression (LAD 1)" on a Leukocyte Adhesion Deficiency (CD15s, CD18) panel from Quest Diagnostics is a crucial test for diagnosing Leukocyte Adhesion Deficiency Type 1 (LAD-1), a rare genetic disorder. In this condition, CD18, a protein that is part of a complex necessary for white blood cells (leukocytes) to adhere to and migrate through blood vessel walls during an immune response, is either missing or malfunctioning. CD18 expression is vital because it facilitates the process by which white blood cells exit the bloodstream to reach sites of infection, inflammation, or injury.

The 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.

The 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.

CD19+CD27+IgM+IgD+ refers to a specific subset of B cells characterized by the expression of the cell surface markers CD19, CD27, IgM, and IgD. These markers help categorize B cells into different subsets based on their developmental stage and function.

In this context, the percentage of CD19+CD27+IgM+IgD+ cells (% of CD27+) likely refers to the proportion of B cells with this specific phenotype within the total CD27+ B cell population. It represents a subset of memory B cells with unique characteristics.

Naive B cells CD19+CD27-CD21-CD38- are a specific subset of B cells with distinct surface marker characteristics:

• CD19+: This marker indicates that these cells express the CD19 antigen, which is commonly found on B cells.

• CD27-: The absence of CD27 expression suggests that these B cells are not memory B cells. CD27 is typically expressed on memory B cells.

• CD21-: The absence of CD21 expression may indicate that these B cells have reduced levels of complement receptor 2 (CR2), which can affect their ability to respond to complement-mediated signals.

• CD38-: The absence of CD38 expression suggests that these B cells have lower levels of CD38, which is involved in various B cell functions, including activation and differentiation.

Naive B cells, characterized as CD19+CD27-IGM+IGD+, are a subset of B cells that have not yet encountered an antigen. Here's a breakdown of their characteristics:

• CD19+: This marker signifies that these cells express the CD19 antigen, which is a common B cell marker.

• CD27-: Naive B cells lack CD27 expression. CD27 is a marker used to distinguish between memory B cells and naive B cells. The absence of CD27 indicates that these B cells have not undergone the differentiation and class-switching that typically occurs in memory B cells.

• IGM+ and IGD+: Naive B cells express both IgM and IgD immunoglobulin isotypes on their surface. IgM and IgD are B cell receptors and are important for antigen recognition. Naive B cells carry both to allow them to respond to a wide range of antigens effectively.