Immunohistological analysis of the immunoreactivity of normal lymphoid cells and lymphomas with the monoclonal antibody OPD4.

OPD4 is a recently described monoclonal antibody that recognizes a fixation-resistant 200 kD antigen restricted to a subset of T cells. Immunolabelling with OPD4 in paraffin sections of normal lymphoid tissues and cases of malignant lymphoma was compared with that of other antibodies in common use, including the T-cell restricted antibodies MT1 and UCHL1 and the B-cell restricted antibodies MB1, F8-11-13, and L26. OPD4 showed similar immunoreactivity to UCHL1 in normal tissues. OPD4 did not stain Reed-Sternberg cells in Hodgkin's disease. In non-Hodgkin's lymphomas, OPD4, like UCHL1, reacted with only 2/22 B-cell lymphomas. OPD4 was, however, less useful as a marker of T-cell lymphomas, staining only 11/32 cases, while UCHL1 stained 22/32 cases. We conclude that OPD4 is not a useful antibody for the routine diagnosis of T-cell lymphoma.