Syndecan‐1 (CD138) expression in human non‐Hodgkin lymphomas

Syndecan‐1, an important transmembrane heparan sulphate proteoglycan, is expressed in distinct stages of differentiation of normal lymphoid cells : in pre‐B cells and Ig‐producing plasma cells; however, its normal function, or presence in lymphoid malignancies, is still largely unknown. The expression of syndecan‐1 (CD138) was studied in 57 human non‐Hodgkin lymphomas using immunocytochemistry and immunohistochemistry. Positive expression of syndecan‐1 was found in the plasma cells in chronic lymphoblastic leukaemia (B‐CLL) cases, in different plasmocytoid lymphomas as well as in myeloma. All normal and malignant T cells, or CD5+ cells other than B‐CLL proved to be negative. These results strongly suggest that syndecan‐1 expression is a characteristic phenotypic marker for B‐CLL and lymphoplasmocytoid lymphomas and could be used for diagnostic purposes.