Effects of Rapid Donor T-lymphocyte Engraftment on Disease Control and Graft versus Host Disease in Persons Undergoing Reduced-Intensity Conditioning Allotransplantation for Advanced CLL

摘要

Eradication of minimal residual disease (MRD) after allotransplantation in persons with chronic lymphocytic leukemia (CLL) is associated with lower rates of relapse. Rapid engraftment of donor lymphocyte elements may contribute to MRD control but it remains unclear if this strategy will benefit patients. Here we report incidence of MRD eradication and graft versus host disease (GvHD) in persons with rapid versus later donor T-lymphocyte engraftment after lymphodepleting chemotherapy and reduced intensity conditioning (RIC) allotransplantation. Twenty-seven subjects received lymphodepleting chemotherapy to facilitate donor engraftment followed by fludarabine and cyclophosphamide RIC and a blood cell allograft. MRD was monitored by multicolor flow cytometry post transplantation. Complete donor T-lymphoid (TLC) and myeloid (MC) chimerism were achieved in 25 subjects at a median of 28 days (range 14–60 days) and 21 days (range 14–180 days). Achieving complete donor TLC by day 14 versus day ≥28 correlated with occurrence of ≥grade-2 acute GvHD (90% [95% confidence interval (CI), 78–100%] versus 35% [95% CI, 16–54%], P=0.014) and better control of minimal residual disease in the bone marrow at day 100, median 0% (range, 0–0.1%) versus 8.5% (range, 0–92%; P=0.016). Among 11 persons with early donor TLC none had progressive disease (PD) and 7 died of treatment related mortality (TRM). In persons with later development of TLC 8 of 16 had PD and 2 died of TRM. Time to donor myeloid chimerism had no impact on outcomes. Rapid establishment of donor TLC results in more complete eradication of early MRD but greater incidence of acute GvHD and TRM in persons with CLL undergoing RIC allotransplantation.