Low T-cell chimerism is not followed by graft rejection after nonmyeloablative stem cell transplantation (NMSCT) with XXXX -selected PBSC.

@entity1 @entity131 @entity5 @entity786 @entity3118 @entity1358 @entity205 @entity618 @entity1583 @entity2098 @entity1778 @entity2280 @entity405
We investigate the feasibility of @entity2280 -selected peripheral blood stem cell (PBSC) transplantation followed by pre-emptive @entity405 -depleted donor lymphocyte infusions (DLI) after a minimal conditioning regimen. Six @entity1 with advanced @entity1583 ineligible for a conventional myeloablative transplant (n=5) or metastatic @entity1358 (n=1), and with an HLA-identical (n=4) or alternative (n=2) donor were included. The nonmyeloablative conditioning regimen consisted in 2 Gy @entity131 alone (n=4), 2 Gy @entity131 and @entity3118 ( @entity1358 @entity1 , n=1) or @entity786 and @entity3118 ( @entity1 who had previously received 12 Gy @entity131 , n=1). Post transplant immunosuppression was carried out with @entity205 (CyA) and @entity618 ( @entity2098 ). Initial engraftment was achieved in all @entity1 . One out of six @entity1 (17%) experienced grade > or =2 acute GVHD only after abrupt @entity205 discontinuation and alpha interferon therapy for life-threatening @entity5 progression. T-cell chimerism was 23% (19-30) on day 28, 32% (10-35) on day 100, 78% (49-95) on day 180 and 99.5% (99-100) on day 365. Three out of four @entity1 who had measurable disease before the transplant experienced a complete response. We conclude that @entity2280 -selected NMSCT followed by @entity405 -depleted DLI is feasible and preserves engraftment and apparently also the graft-versus- @entity1778 (GVL) effect. Further studies are needed to confirm this encouraging preliminary report.
