Rapid early recovery of absolute lymphocyte counts at day 30 can predict reduced risk of relapse in acute lymphoblastic leukemia following haploidentcial allogeneic stem cell transplantation

Abstract

Objective To explore the impact of early recovery of absolute lymphocyte counts at day 30 post transplantation on transplant outcome in patients with acute lymphoblastic leukemia(ALL)following unmanipulated haploidentical allogeneic blood and marrow transplantation (HBMT).Method A total of 62 patients with acute lymphoblastic leukemia receiving unmanipulated HBMT between Jan.2003 and Sep.2009 at Peking University Institute of Hematology were evaluated for the occurrence of early recovery of absolute lymphocyte counts at day 30 (ALC-30).Patients were subgrouped into ALC-30≥300/μl group (n =29) and ALC30 ＜300/μl group (n =33) based on the cutoff value of lymphocyte count at day 30 following transplantation to explore the effect of ALC-30 on transplant outcomes,including ALL relapse,transplantation related mortality (TRM),overall survival rate(OS),and ALL leukemia free survival rate (LFS).Result Univariate and multivariate analysis showed that compared to those in ALC-30＜300/μl group,patients in ALC-30≥300/μl group had lower TRM rate (10.5％ ± 5.7％ vs.30.8％ ± 8.1 ％,P =0.046) and ALL relapse rate (14.7％±6.8％ vs.59.1％± 10.3％,P=0.002),therefore had higher OS (79.3％ ±7.5％ vs.45.1％ ±8.7％,P=0.006) and LFS (79.3％±7.5％ vs.28.4％ ± 8.0％,P＜0.001).Conclusion Early recovery of ALC-30 can predict clinical outcomes in ALL patients following unmanipulated HBMT. Key words: Hematopoietic stem cell transplantation; Acute lymphoblastic leukemia; Lymphocyte recovery