Donor Lymphocyte Infusion

Has anyone had a donor lymphocyte infusion. My boyfriend is 2 years out of a bone marrow transplant that did not succeed against his PTCL NOS. He has undergone the latest chemo treatment and, like all the other chemos, worked at first but grew to be resistant. We have been battling for 3 years now and he has become resolved to the idea of the cancer winning. I, however, am not. He is 37 years old and we have lots of plans for the future! The doctors have been giving us conflicting information on the DLI. He was suppose to have it last winter but his tumor became active before they could do it. They told us that if we had it done while it was active it would kill him. So we had this last chemo to break it down once again. If there was is remaining activity they are going to do radiation. Hopefully this DLI is the answer we are waiting for. Any information or experience with it anyone has to share would be greatly appreciated!!