Escalating-dose HLA-mismatched DLI is safe for the treatment of leukaemia relapse following alemtuzumab-based myeloablative allo-SCT.
Innes AJ., Beattie R., Sergeant R., Damaj G., Foroni L., Marin D., Kanfer E., Mielke S., Milojkovic D., MacDonald D., Pavlu J., Rahemtulla A., Roberts I., Slade D., Bray E., Goldman J., Apperley J., Szydlo R., Dazzi F., Rezvani K.
Although the feasibility of using HLA-mismatched unrelated donors as an alternate graft source for haematopoietic SCT (HSCT) has been shown, little is known about the safety of HLA-mismatched DLI for the treatment of relapse. We examined the outcome of 58 consecutive leukaemia patients who received escalating-dose DLI for treatment of relapse after alemtuzumab-conditioned myeloablative unrelated donor HSCT at our institution. High-resolution HLA typing on stored DNA samples revealed mismatches in 28/58 patients who were considered HLA-matched at the time of transplantation. Following DLI from HLA-matched (10/10) (n=30) or -mismatched (7-9/10) (n=28) unrelated donors, we found no significant difference in the incidence of acute GVHD (17.2% versus 23.1%, P=0.59), probability of remission at 3 years (62.1% versus 63.9%, P=0.89) or 5-year OS (89.8% versus 77.7%, P=0.22). We conclude that escalating-dose DLI can be safely given to HLA-mismatched recipients following T-depleted myeloablative HSCT.