Influence of lymphocyte recovery on outcome of haploidentical transplantation for hematologic malignancies.

Unmanipulated human leukocyte antigen (HLA)-mismatched/haploidentical blood and marrow transplantation is an established treatment for patients without HLA-matched related or unrelated donors. However, the prognostic significance of early lymphocyte recovery in this transplant setting is not defined. In this study, we investigated the association of day 30 absolute lymphocyte count (ALC-30) with outcome after unmanipulated HLA-mismatched/haploidentical transplantation. We prospectively analyzed the relationship between ALC-30 and transplant outcomes in 206 patients with hematologic malignancies receiving T-cell-replete transplantation from HLA-mismatched/haploidentical related donors. Multivariate analysis showed that ALC-30 above the cutoff value of 300 cells/microL was associated with improved overall survival (hazard ratio [HR], 0.258; 95% confidence interval [CI], 0.141-0.472; p < 0.0001); improved cancer-free survival (HR, 0.289; 95% CI, 0.166-0.501; p < 0.0001); reduced relapse (HR, 0.370; 95% CI, 0.161-0.853; p = 0.020); and decreased transplant-related mortality (HR, 0.211; 95% CI, 0.097-0.457; p < 0.0001). Our results suggest that the recovery of ALC-30 might have an influence on transplant outcomes following unmanipulated HLA-mismatched/haploidentical transplantation.