CD34+ Cell Count and Disease Free Survival in Patients with Diffuse Large B Cell Lymphoma Who Have Received Autologous Stem Cell Transplantaion

Background

There are still varied opinions on the course of disease for patients who have received autologous stem cell transplantation (ASCT) depending on the dose amount of infused CD34+. Some studies report that higher amount of infused CD34+ cell dose would increase recurrence rates. On the other hand, some other studies suggest higher infused CD34+ cell leads to less recurrence and increase in DFS. We tried to identify the difference in recurrence with ASCT patients depending on the dose amount of infused CD34+ cell.

Methods

We conducted a retrospective analysis of 158 diffuse large B cell lymphoma (DLBCL) patients who underwent ASCT in a single center from March 1996 to May 2017. We excluded Primary CNS lymphoma patients who received upfront ASCT. We compared the disease free survival (DFS) by dividing patients into five groups: less than 3x10⁸/kg (group1), between 3x10⁸/kg and 5x10⁸/kg (group2), between 5x10⁸/kg and 6x10⁸/kg (group3), between 6x10⁸/kg and 10x10⁸/kg (group4) and more than 10x10⁸/kg (group5) depending on the amount of infused CD34+dose.

Results

The number of patients in each group was 5(group1), 13(group2), 47(group3), 57(group4) and 36(group5). Baseline sex, age, stage at diagnosis, number of extranodal involvement, IPI score, whether Germinal center B-cell like diffuse large B-cell lymphoma or not, treatment type did not differ in each group. There was no statistical difference in the number of induction chemotherapy line before ASCT between group1 and group5 (p -value=0.196) as well as between each other groups.

Mean DFS was 2.36, 18.0, 19.33, 27.16 and 56.21 months in group1, 2, 3, 4, 5, respectively. There were statistically significance in the difference of DFS between group1 and group3 (p -value=0.029), between group1 and group4 (p -value=0.033), between group1 and group5 (p -value=0.008) and between group3 and group5 (p -value=0.044). DFS value seemed to increase with the increasing amount of infused CD34+ cell dose.

Conclusions

In our study, DFS had an increasing tendency with increasing amounts of infused CD34+ cells. The recurrence rate decreased as the infused CD34+ cell dose was higher. These data suggest that higher amount of infused CD34+ cells may increase DFS in patients with DLBCL who undergo ASCT.