Nodular sclerosing, mixed cellularity and lymphocyte-depleted variants of Hodgkin's disease are probable dendritic cell malignancies.

The normal counterpart of the Reed-Sternberg cell and its mononuclear variant, collectively referred to as Hodgkin's cells (HC), remains controversial. The possibility that HC are malignant dendritic cells was tested by using a panel of 38 monoclonal antibodies to phenotype the cells from 16 cases of Hodgkin's disease (HD), excluding lymphocyte-predominant HD, and the Hodgkin's cell line L428. The results were then compared with the known phenotype of human dendritic cells. HC stained strongly for HLA Class I and Class II antigens. The leucocyte common antigen was weakly expressed in most cases. Expression of T and B cell markers was unusual, with the exception of the CD40 antigen which was found on a majority of HC. HC commonly expressed the CD11a, CR4 (CD11c), CD15, CD18 and a number of activation antigens but did not stain with a variety of macrophage-specific antibodies. The antigenic phenotype of L428 and the HC of case material were similar. This immunocytological analysis failed to support a lymphocyte or macrophage origin for HC. Instead the antigenic phenotype of the Reed-Sternberg cell and its mononuclear variant more closely resembles that of dendritic cells than of any other haemopoietic cell normally resident in lymph nodes.