CD 43

Useful in the diagnosis of lymphomas, particularly with antibody testing small lymphocytic lymphomas, mantle cell lymphoma, and marginal zone lymphoma. CD43 is expressed by normal T lymphocytes, granulocytes, and granulocyte precursors, monocytes, macrophages, plasma cells, and megakaryocytes. In normal tonsil, CD43 will mainly show staining in T lymphocytes and plasma cells in interfollicular areas. Human CD43 (leukosialin) is a cell surface sialoglycoprotein that is involved in cell adhesion, differentiation and activation. The CD43 antigen is expressed on most leukocytes, i.e., T cells, NK cells, granulocytes, monocytes, and macrophages, on hematopoietic stem cells, and on platelets, but not on erythrocytes. Among B cells, CD43 is expressed on activated B cells and plasma cells but not on resting B cells, e.g., naive B cells. In bone marrow, CD43 is found on pro-B cells but is down-regulated during transition to the pre-B cell stage. CD43 is expressed on different myeloid and lymphoid tumors, including some B cell malignancies.