Abstract
Background The aim of this study was to investigate preservation of anti-leukemic activity and protection from opportunistic infections after transplantation of allogeneic CD34+ cells in patients with hematologic malignancies and bad prognosis.
Methods Thirty-three patients [median age 42 years, range 23–55 years, diagnosis AML/myelodysplastic syndrome (MDS) 14, ALL nine, CML seven and multiple myeloma (MM) three] received myeloablative conditioning followed by infusion of selected CD34+ cells from matched unrelated donors (31) or HLA-identical siblings (two). Early donor lymphocyte infusions (DLI; 0.5 and 1.0×106 CD3+ cells/kg) were given while patients were on immunosuppressive therapy.
Results Ninety-seven per cent of patients engrafted and 24 of 29 patients surviving more than 30 days received at least one pre-emptive DLI. Three patients (10%) developed acute (a)GvHD (two grade I–II, one grade III–IV) spontaneously, and 16 patients (67%) developed aGvHD after DLI (12 grade I–II, four grade III–IV). Eight of 24 evaluable patients developed chronic (c)GvHD (33%, six limited, two extensive). After a median follow-up of 590 days (range 138–1610 days) 18 patients were alive (55%), 16 in complete remission (CR), one in hematologic and one in molecular relapse. Seven patients died after relapse (21%) and eight died from transplantation-related causes (24%). Patients with myeloid malignancies had a significantly better survival than patients with ALL or MM (74%±10 vs. 30%±13, P<0.05).
Discussion Early pre-emptive low-dose DLI following transplantation of selected CD34+ cells from unrelated donors after myeloablative conditioning is feasible and effective without undue toxicity, especially in patients with myeloid malignancies.