Donor lymphocyte infusions can result in sustained remissions in patients with residual or relapsed lymphoid malignancy following allogeneic haemopoietic stem cell transplantation.

We treated 17 patients with refractory (n = 7) or relapsed lymphoid malignancy (n = 10) following allogeneic HSCT with donor lymphocyte infusions (DLI). Patients with low-grade disease received DLI alone (n = 7) or following radiotherapy (n = 1). Patients with aggressive disease (n = 9) received prior chemotherapy. Nine out of 15 patients receiving DLI from sibling donors responded after one (n = 6), two (n = 2) and three (n = 1) infusions. Both MUD recipients achieved CR after two and three DLI. In all, 10/17 patients achieved CR including 3/4 patients with chronic lymphatic leukaemia (CLL), 4/4 with mantle cell lymphoma (MCL), 3/4 with follicular NHL but 0/5 with aggressive NHL/Richters. The median CD3 cell dose to achieve CR for siblings was 2 x 10(7)/kg. One patient with CLL had a second transplant following DLI-induced aplasia and is in CR at 14 months giving a final CR rate of 64%. Grade II-IV acute GVHD developed in 45% and chronic GVHD in 8/9 evaluable patients. Of the 11 patients finally achieving CR, one patient with MCL relapsed at 18 months post-DLI but all others remain in remission with a median follow-up of 40 months (range 12-64 months). Low-grade NHL and MCL have a high response rate and sustained remissions following DLI. Aggressive disease responds poorly however, despite pre-DLI chemotherapy.