CD 11


CD 11a
Ancell (38), Biodesign (MEM 25, SPV-L7), Cymbus Bioscience (38), Dako (MHM24), Gen Trak, Immunotech (25.3), Sanbio (MEM 25), Serotec (B-B15) and Pharmingen (2D7).

CD 11b
Ancell (44), Biodesign (44, Bear-1), Biogenex, Boehringer Mannheim, Cymbus Bioscience, Dako (2LPM19c), GenTrak, Immunotech (Bear-1), Japan Tanner, Research Diagnostics (CD 44), Sanbio (Bear-1), Seralab (44), Serotec (ED7) and Pharmingen (M1/70).

CD 11c
Ancell (3.9), Becton Dickinson (Leu M5), Biodesign (FK24, BU15), Cymbus Bioscience, Dako (KB90), Gen Trak, Immunotech (BU15), Oncogene (3.9), Research Diagnostics (CD39), Sanbio (FK24), Seralab (Fk24) and Serotec (3.9).

Current antibodies are only immunoreactive in fresh-frozen tissue.

Each of the CD11 subtypes represents a differentb chain which forms one of theb2 family of integrin adhesion receptors when linked non-covalently tob2 (CD 18) to form a heterodimer. CD 11a, leukocyte function-associated protein (LFA-1) with a molecular weight of 180 kD, is present on B cells, T cells, NK cells, monocytes, granulocytes, megakaryocytes and activated platelets. CD 11b (Mac-1), the C3bi receptor, has a molecular weight of 165 kD and it is present on granulocytes, monocytes and some histiocytes. CD 11c, which has a molecular weight of 150 kD, is present on monocytes, tissue macrophages, granulocytes, some suppressor/cytotoxic T cells and a subset of B cells. It is usually positive on true histiocytic malignancies and some B-cell lymphomas including hairy cell leukemia and monocytoid B-cell lymphoma (Chadburn et al, 1990).
CD 11/CD 18 integrins have a function in intercellular communication between lymphocytes and between lymphocytes and endothelial cells. The interaction between leukocytes and endothelial cells involves CD 11/CD 18 integrins which bind to intercellular adhesion molecules ICAM-1 (CD 45) and ICAM-2 (Albelda et al, 1994).

Currently, the diagnostic applications for this marker are very limited and available antibodies are reactive only in frozen sections. Differential expression of CD 11a (LFA-1) has been described in small cell lymphocytic lymphoma and CLL and has been used to account for the difference in peripheral blood involvement in these entities but the findings require confirmation. In the immunophenotypic separation of monocytoid B-cell lymphoma from other small cell lymphomas such as plasmacytoid small cell lymphoma, CLL and mantle cell lymphoma, CD 11c has been suggested to be a useful discriminant, being more frequently expressed in monocytoid lymphoma.

•Albelda SM, Smith CW, Ward PA 1994. Adhesion molecules and inflammatory injury. FASEB Journal 8: 504-12.

•Chadburn A, Inghirami G, Knowles DM 1990. Hairy cell leukemia-associated antigen Leu M5 (CD 11c) is preferentially expressed by benign activated and neoplastic CD8 cells. American Journal of Pathology 136:29-37.

Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.