CD15

WKP

Definition: CD15 (3-fucosyl-N-acetyl-lactosamine) is a cluster of differentiation antigen - an immunologically significant molecule. CD15 is a carbohydrate adhesion molecule (not a protein) that can be expressed on glycoproteins, glycolipids and proteoglycans.

CD15 is a carbohydrate adhesion molecule (not a protein) that mediates phagocytosis and chemotaxis.

It is also called Lewis x and SSEA-1 (stage-specific embryonic antigen 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.

CD15 is synthezised by FUT4 (fucosyltransferase 4) and FUT9.

Synthesis

CD15 synthesis is directed by FUT9 (MIM.104230) in lymphoid cells and mature granulocytes and by FUT4 (MIM.606865) in promyelocytes and monocytes. See FUT4 (MIM.104230) and FUT9.

Function

CD15 mediates phagocytosis and chemotaxis, found on neutrophils.

CD15 is expressed in patients with Hodgkin disease, some B-cell chronic lymphocytic leukemias, acute lymphoblastic leukemias, and most acute nonlymphocytic leukemias.

Immunochemistry

 membranous labeling
 diffuse cytoplasmic or Golgi staining in classic Hodgkin lymphoma

CD15 is expressed on Reed-Sternberg cells of Hodgkin’s disease and by various other cell types including myeloid cells and epithelial cells.

Antibodies to CD15 recognize a pentasaccharide sequence occurring in lacto-N-fucopentaose III ceramide (also referred to as X
hapten of Lex) found in higher glycolipids and glycoproteins.

A review by Arber et al. has reported that antibodies to CD15 demonstrate positive staining in 87% of Hodgkin’s disease including nodular sclerosing, mixed cellularity, and lymphocyte depletion, whereas the lymphocyte predominant variant exhibits a lower rate of positivity (37%).

Among non-Hodgkin’s lymphoma, 13% express CD15 including
4.1% B-cell, 21% T-cell, and 17% null-cell.

CD15 expression has also been demonstrated in acute myeloid leukemia (65%) and chronic myelogenous leukemia (96% chronic phase and 54% blast phase).

A relatively low level of CD15 expression has been reported in acute
lymphoblastic leukemia (5.7% overall) with positivity observed in 7.7% common or precursor B-cell, 0% B-cell, 7.7% T-cell and 17.3% nullcell.

Carcinomas derived from various organs have also been shown to be CD15 positive (56%) including adenocarcinomas, squamous cell
carcinomas and undifferentiated large and small cell carcinomas.

Diagnosis

 Hodgkin lymphoma

• Reed-Sternberg cells

 help differentiate between classic Hodgkin lymphoma (CD15+) and anaplastic large cell lymphoma (usually CD15-)
 help differentiate between adenocarcinoma (CD15+) and mesothelioma (CD15-)

CD15 is present on almost all Reed–Sternberg cells, including their rare mononuclear variants, and, as such, can be used in immunohistochemistry to identify the presence of such cells in biopsies.

Hodgkin lymphoma

The presence of these cells is diagnostic of Hodgkin’s lymphoma. Reed-Sternberg cells display a characteristic pattern of CD15 positivity, with membranous staining combined with staining of the golgi apparatus.

Immunohistochemical panels for the diagnosis of Hodgkins disease typically employ CD15 along with CD30 and CD45; the latter does not stain Reed-Sternberg cells, but does stain almost all other lymphoid cells.

Adenocarcinomas

CD15 is also present in about 50% of adenocarcinoma cells and can be used to distinguish such conditions from mesothelioma, which is typically negative

Positive immunostaining

 Reed-Sternberg cells (classic Hodgkin lymphoma and follicular Hodgkin lymphoma)
 15% of peripheral T cell lymphoma
 50% of carcinomas
 5% of B cell lymphomas

• some B-CLL
• some pre-pre B ALL
• some AML
• occasionally anaplastic large cell lymphoma (usually negative)

Negative immunostaining

 non-activated lymphocytes
 basophils
 platelets
 erythroid cells
 L& H cells in nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL)
 diffuse large B cell lymphoma
 granulocytic sarcoma
 systemic mastocytosis
 pleural epithelial mesothelioma
 hairy cell leukemia
 malignant meningioma
 malignant histiocytes
 Langerhans cell histiocytosis

See also

 Sialyl Lewis X