Tuesday 9 November 2004
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.
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.
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.
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.
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.
- Reed-Sternberg cells
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.
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.
CD15 is also present in about 50% of adenocarcinoma cells and can be used to distinguish such conditions from mesothelioma, which is typically negative
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)
L& H cells in nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL)
diffuse large B cell lymphoma
pleural epithelial mesothelioma
hairy cell leukemia
Langerhans cell histiocytosis
Sialyl Lewis X