Anti-BLA.36 monoclonal antibody shows reactivity with Hodgkin's cells and B lymphocytes in frozen and paraffin-embedded tissues.

A newly developed monoclonal antibody, anti-BLA.36, raised against a Hodgkin cell line, was shown to have reactivity with Reed-Sternberg cells and activated B lymphocytes and appears to be distinct from other antibodies which identify antigens of hematopoietic cells. Anti-BLA.36 was evaluated in B5-fixed paraffin-embedded tissue from 16 cases of Hodgkin's disease of various types and 35 cases of non-Hodgkin's lymphomas representative of the different major subtypes. The specificity of anti-BLA.36 was compared with other antibodies that have been used to mark Hodgkin's cells and B lymphocytes: namely, L26, LN-1, Leu-M1 and Ber-H2, as well as UCHL-1, a pan-T lymphocyte marker. In addition, a subset of the cases was evaluated using frozen tissue in order to validate the staining characteristics of anti-BLA.36 as observed in fixed paraffin sections. Anti-BLA.36 was found to react with Hodgkin's cells more consistently than the other antibodies used in this panel. The antibody reacted with an antigen on Reed-Sternberg cells and their variants (Hodgkin's cells) in all four subtypes of Hodgkin's disease, and with a subset of reactive and malignant B lymphocytes, but not with T lymphocytes. It may, therefore, be useful in the evaluation of non-Hodgkin's lymphomas. Finally, this is the first antibody raised to a Hodgkin's cell line which also consistently marks reactive and malignant B cells, but not T cells. The implications of this observation are discussed in relation to the cellular origin of the Reed-Sternberg cell and the overall nature of Hodgkin's disease.