Two patients with persistent disease after allografting for multiple myeloma received donor T-cell lymphocyte infusion (DLI) (1.5 x 10(8) and 7 x 10(7)) to induce a graft-vs.-myeloma effect for further tumour regression after withdrawal of immunosuppression. The interval between stem cell transplantation and DLI was 8 and 14 months respectively. Both patients converted from partial to complete remission, lasting 12+ and 28+ months. Immunofixation became negative after 3 and 4 months. The main toxicity was grade II and III acute graft-vs.-host disease (GvHD) and limited or extensive chronic GvHD in each patient. We conclude that DLI induced further tumour reduction in patients with persistent disease after allografting for multiple myeloma.
