Comparison of non-myeloablative conditioning regimens for lymphoproliferative disorders

Hematopoietic cell transplantation (HCT) with non-myeloablative (NMA) conditioning for lymphoproliferative diseases (LD) includes fludarabine with and without low-dose TBI. Transplant outcomes were compared among patients aged ⩾40 years with LD who received a HCT with TBI ( N =382) or no-TBI ( N =515) NMA from 2001 to 2011. The groups were comparable except for donor, graft, prophylaxis for GVHD, disease status and year of HCT. Cumulative incidences of grades II–IV GVHD at 100 days were 29% and 20% ( P =0.001) and of chronic GVHD at 1 year were 54% and 44% ( P =0.004) for TBI and no-TBI, respectively. Multivariate analysis of progression/relapse, treatment failure and mortality showed no outcome differences by conditioning. Full donor chimerism at day 100 was observed in 82% vs 64% in the TBI and no-TBI groups, respectively ( P =0.006). Subsets of the four most common conditioning/GVHD prophylaxis combinations demonstrated higher rates of grades II–IV acute ( P