Proliferation of T-cell lines C6 and D1 in response to different autologous stimulator cells. Both T-cell lines specifically recognized the autologous HCL cells in an HLA class II-restricted way, without reactivity against autologous PBMC, PHA blasts, and EBV-LCL in the PLT. The PLT was performed in sixfold, and the SD of the means were lower than 15%.