CD15 is a cluster of differentiation

Cluster of differentiation

The cluster of differentiation is a protocol used for the identification and investigation of cell surface molecules present on white blood cells, providing targets for immunophenotyping of cells...

 antigen - an immunologically significant molecule. CD15 is a carbohydrate adhesion molecule (not a protein) that can be expressed on glycoproteins, glycolipids and proteoglycans.

Function

CD15 mediates phagocytosis and chemotaxis

Chemotaxis

Chemotaxis is the phenomenon in which somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food by swimming towards the highest concentration of food molecules,...

, found on neutrophils; expressed in patients with Hodgkin disease, some B-cell chronic lymphocytic leukemias, acute lymphoblastic leukemias, and most acute nonlymphocytic leukemias. It is also called Lewis x and SSEA-1 (stage-specific embryonic antigen

Antigen

An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

 1) and represents a marker for murine pluripotent stem cells, in which it plays an important role in adhesion and migration of the cells in the preimplantation embryo. It is synthezised by FUT4

FUT4

Fucosyltransferase 4 also known as FUT4 is an enzyme which in humans is encoded by the FUT4 gene.- Function :...

 (fucosyltransferase 4) and FUT9

FUT9

Alpha--fucosyltransferase is an enzyme that in humans is encoded by the FUT9 gene.-Further reading:...

.

Diagnostic relevance

CD15 is present on almost all Reed–Sternberg cells, including their rare mononuclear variants, and, as such, can be used in immunohistochemistry

Immunohistochemistry

Immunohistochemistry or IHC refers to the process of detecting antigens in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and...

 to identify the presence of such cells in biopsies. The presence of these cells is diagnostic of Hodgkin's lymphoma

Hodgkin's lymphoma

Hodgkin's lymphoma, previously known as Hodgkin's disease, is a type of lymphoma, which is a cancer originating from white blood cells called lymphocytes...

. Reed-Sternberg cells display a characteristic pattern of CD15 positivity, with membranous staining combined with staining of the golgi apparatus

Golgi apparatus

The Golgi apparatus is an organelle found in most eukaryotic cells. It was identified in 1898 by the Italian physician Camillo Golgi, after whom the Golgi apparatus is named....

. Immunohistochemical panels for the diagnosis of Hodgkins disease typically employ CD15 along with CD30

CD30

CD30, also known as TNFRSF8, is a cell membrane protein of the tumor necrosis factor receptor family and tumor marker.This receptor is expressed by activated, but not by resting, T and B cells. TRAF2 and TRAF5 can interact with this receptor, and mediate the signal transduction that leads to the...

 and CD45

CD45

Protein tyrosine phosphatase, receptor type, C also known as PTPRC is an enzyme that, in humans, is encoded by the PTPRC gene. PTPRC is also known as CD45 antigen , which was originally called leukocyte common antigen.- Function :The protein encoded by this gene is a member of the protein tyrosine...

; the latter does not stain Reed-Sternberg cells, but does stain almost all other lymphoid cells. CD15 is also present in about 50% of adenocarcinoma

Adenocarcinoma

Adenocarcinoma is a cancer of an epithelium that originates in glandular tissue. Epithelial tissue includes, but is not limited to, the surface layer of skin, glands and a variety of other tissue that lines the cavities and organs of the body. Epithelium can be derived embryologically from...

 cells and can be used to distinguish such conditions from mesothelioma

Mesothelioma

Mesothelioma, more precisely malignant mesothelioma, is a rare form of cancer that develops from the protective lining that covers many of the body's internal organs, the mesothelium...

, which is typically negative.