Impact on Transplant Outcome of Karyotyping Analysis in Apheresis Products for Autologous PBSC Transplantation in De Novo Acute Leukemias (AL).

Autologous stem cell transplantation as consolidation therapy for de novo AL is able to improve long-term survival especially after second complete remission (CR). In this study, we retrospectively analyzed the karyotyping results performed in 79 out of 101 harvested autologous PBSC from 38 de novo AML patients and 8 de novo ALL in CR. We secondly, analyzed their impact on overall survival (OS) and event-free survival (EFS) post-transplant. All patients had abnormal medullar karyotype at diagnosis. We determined two groups of patients: (1) group 1 with chromosomal abnormalities in harvested PBSC included 10 AML [4 males and 6 females, median age: 53 years (45–66.5)] with at diagnosis 3 favorable, 4 intermediate and 3 unfavorable-risk karyotype ; 2 M0, 3 M2, 1 M3, 2 M4, 2 M5 according to Fab classification ; and 9 autotransplanted patients in CR1 and 1 in CR2 and (2) group 2 without any chromosomal abnormalities in harvested PBSC including 27 AML+ 9 ALL [22 males and 14 females, median age : 44 years (19–70)] ; 1 M0, 1 M1, 4 M2, 5 M3, 11 M4, 5 M5 with at diagnosis 18 favorable prognosis, 1 intermediate and 8 unfavorable-risk karyotype ; among ALL patients, 7 B ALL and 2 T ALL and at transplant, 29 autotransplant in CR1, 6 in CR2 and 1 in CR3]. Cytapheresis products collected contained a median number of 7.7x 10⁸/Kg (5.2–17.3) and 6.79x10⁸/Kg (1.26–16.4) mononuclear cells and 19x10⁶/Kg (3–43) and 20.5x10⁶/Kg (1–4O) CD34+ cells in group 1 and in group 2 respectively. All PBSC harvested were reinfused. Conditionning regimen was quite similar in the two groups and most of the patients of group 1 (60%) and group 2 (70%) received cyclophosphamide and TBI. The hematopoietic reconstitution was similar in the 2 groups [neutrophiles > 0.5 G/l: 26 days in group1 versus 19 days in group 2 (p=0,86)]. At 3 years after transplant, there was a trend for a better OS (54.7% CI 95% 40–74.8) (p=0.06) and EFS (52.5% 95%CI 39.6–74) (p=0.05) in patients who received PBSC without any chromosomal abnormalities compared to patients receiving PBSC with abnormal karyotype (OS : 30% 95% CI 11.6–77.3 ; EFS : 30% 95% CI 11.6–77.3). In conclusion, results observed from autologous harvested PBSC karyotyping are promising but a larger number of patients and a longer follow-up could enable to reach a more important significance.