Abstract

Acute lymphocytic leukemia (ALL) is a life threatening disease with high rate of relapse. To date, there is no ideal treatment for ALL. Recently, stem cell transplantation has been used as a potential therapy. However, it is unclear what the best source of donor stem cells is and whether it is safe or effective to use these regimens in human patients. In this study, we evaluated the safety and outcomes of 22 patients with ALL after umbilical cord blood transplantation (UCBT) or bone-marrow from related donors (RD). Eleven patients received stem cells from HLA 0–2 (A,B,DRB1) mismatched UCBT (median infused dose, 3.77×107 nucleated cell NC/kg; range, 3.40– 7.49 ×107 NC/kg). The other 11 patients received stem cells from bone marrow from RD (median infused dose, 4.08×108 NC/kg; range, 1.86–9.82×107 NC/kg). All patients in both groups were comparable, as shown in Table 1. All patients received myeloablative conditioning (busulfanum/cyclophosphamide was used for the RD transplantation and anti-thymus globulin 7.5 mg/kg was used for the UCB transplantation) followed by infusion of allogenetic hematopoietc stem cells from either bone marrow or cord blood. Cyclosporine A (CsA) and mycophenolate mofetil (MMF) were administered for the prophylaxis of graft-versus-host disease (GVHD). Overall survival (OS), leukemia-free survival (LFS), transplantation-related mortality (TRM) and relapse rate between RD and UCB were shown in Table 2. The results demonstrated that despite the higher HLA mismatch rate and lower number of infused hematopietic stem cells, OS, LFS, TRM and relapse rate in UCB group were 81.8%, 81.8%, 0% and 18.2% which were significantly better than in the RD group. These data strongly suggest that UCBT could be a safe and effective therapy for patients with ALL.

Table 1

The Profiles of Patients

RDUCBT
High Risk ALL 7/11 7/11 
HLA 0/6 Mismatched (%) 72.7 9.1 
HLA 1/6 Mismatched (%) 27.3 81.8 
HLA 2/6 Mismatched (%) 9.1 
Median Age (years, range) 30 (8–63) 25 (3–38) 
Median Body Weight (kg, range) 51 (26–70) 40 (13–84) 
RDUCBT
High Risk ALL 7/11 7/11 
HLA 0/6 Mismatched (%) 72.7 9.1 
HLA 1/6 Mismatched (%) 27.3 81.8 
HLA 2/6 Mismatched (%) 9.1 
Median Age (years, range) 30 (8–63) 25 (3–38) 
Median Body Weight (kg, range) 51 (26–70) 40 (13–84) 
Table 2

Outcomes of ALL patients after UCB transplantation

RDUCBP value
Number of patients 11 11  
Median follow up (years) 2.0 2.0  
OS 2 yr % (95% CI) 36.4 81.8 <0.05 
LFS 2 yr % (95% CI) 27.3 81.8 <0.05 
Relapse 1yr % (95% CI) 27.3 <0.05 
TRM 1 yr % (95% CI) 63.6 18.2 <0.05 
RDUCBP value
Number of patients 11 11  
Median follow up (years) 2.0 2.0  
OS 2 yr % (95% CI) 36.4 81.8 <0.05 
LFS 2 yr % (95% CI) 27.3 81.8 <0.05 
Relapse 1yr % (95% CI) 27.3 <0.05 
TRM 1 yr % (95% CI) 63.6 18.2 <0.05 

Author notes

Disclosure: No relevant conflicts of interest to declare.