Lymphoid cell markers. Their distribution and usefulness in the immunophenotypic analysis of lymphoid neoplasms
Lymphoma, Large B-Cell, Diffuse
We discussed the distribution of the conventional lymphoid cell markers on B- and T-lymphocytes, monocytes/macrophages, and dendritic cells; methodologic approaches employed to demonstrate them; and a large number of monoclonal antibodies which recognize distinctive B- and T-lymphocyte-associated differentiation antigens. The latter monoclonal antibodies can be utilized to probe the early and late stages of lymphocyte differentiation and delineate the subset of origin and the stage of differentiation of the neoplastic cells which comprise the lymphoproliferative malignancies. In the case of the T-cell neoplasms, we can clearly apply monoclonal antibodies to divide the tumors into distinct phenotypes which corresponds to functionally distinct T-cell subsets and to normal stages of T-cell differentiation. Although the large panel of monoclonal antibodies directed at B-lymphocyte differentiation antigens can divide B-cell neoplasms into early and late stages of differentiation, there is considerable overlap, making precise delineation of normal stages of B-cell differentiation difficult to define. Nonetheless, we can now utilize the conventional lymphoid cell markers, in conjunction with the more recently developed monoclonal antibodies, better to relate each of the major categories of lymphoid malignancy to a particular B- or T-lymphocyte subset or stage of differentiation, or in rare instances, to the monocyte/macrophage of dendritic cell lineage. There is no doubt that, given time, additional reagents will be developed which will further facilitate the analysis of lymphocyte differentiation. It is hoped that the combined phenotypic and functional characterization of the lymphoid malignancies will ultimately provide us with new and more precise clinicopathologic correlations as well as a better understanding of lymphocyte heterogeneity, differentiation, and function.