COSTIMULATORY MOLECULES (CD80 AND CD86) ON REED-STERNBERG CELLS ARE ASSOCIATED WITH THE PROLIFERATION OF BACKGROUND T-CELLS IN HODGKINS-DISEASE

To elucidate the relationship between Reed-Sternberg (R-S) cells and b ackground T cells, the expression of CD80 and CD86 of R-S cells in Hod gkin's disease (HD), and the ligand CD28 expression and the MIB-1 inde x of background T cells were immunohistochemically investigated. CD80 and CD86 were found to be expressed on R-S cells in almost all cases o f HD. CD28 was expressed with strong intensity on many background T ce lls around R-S cells. The MIB-1 index of background T cells was 30.3% (range, 15.5-38.9%) and was much higher than 10.9% (range, 9.8-11.7%) in B cell lymphomas. These results suggest that the interaction betwee n CD80 and CD86 on R-S cells, and CD28 on background T cells may induc e T cell proliferation and be associated with tumor mass of HD.