Selected CD34 blood cell allografts for older patients: low transplant-related mortality, graft failure and acute GvHD

Long-term results after transplantation of CD34+ selected (CellPro) versus unselected peripheral blood progenitor cells (PBPC) from related allogeneic donors

PURPOSE

To determine the long-term outcome of patients after allogeneic transplantation of T-cell depleted versus unmanipulated hematopoietic stem cell grafts with respect to incidence of GvHD and overall survival in 50 consecutive patients.

METHODS

In this prospective phase II study utilizing biological randomization, 50 sibling donors were mobilized with G-CSF. Positive selection of CD34+ cells (Ceprate SC; CellPro, USA) was performed in good mobilizers (n = 25; group A), but not in poor mobilizers (n = 25; group B). Patients had hematological malignancies. Median patient age was 44 years (range, 19-57). Numbers of CD3+ cells were 0.5 ± 0.4 × 10(6)/kg in group A and 216 ± 127 × 10(6)/kg in group B.

RESULTS

Hematological recovery was rapid in both groups. Patients in group A had no grade III-IV acute GvHD, whereas 6 out of 22 evaluable patients in group B had grade III-IV acute GvHD with fatal outcome in four cases (P < 0.01). Similarly, the incidence of chronic GvHD was lower in patients in group A (35 vs. 65%). However, there was a higher relapse rate in group A (11/25) versus group B (4/25, P < 0.05). At a follow-up of 10 years after transplantation, eight (32%) and 10 patients (40%) were relapse-free and alive in groups A and B, respectively.

CONCLUSIONS

Risk factors for survival in a multivariate analysis were remission status prior to transplantation (CR vs. no CR), occurrence of acute and chronic GvHD, and relapse. The use of the CellPro device for CD34 positive selection per se did not have an influence on overall survival.

Transplantation of allogeneic CD34+-selected cells followed by early T-cell add-backs: favorable results in acute and chronic myeloid leukemia

BACKGROUND

The aim of this study was to investigate preservation of anti-leukemic activity and protection from opportunistic infections after transplantation of allogeneic + 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 x 10(6) 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.