Objective: To explore the benefit of autologous transplantation of interleukine-2 activated bone marrow (ABM) in acute promyelocytic leukemia (APL) as consolidation therapy.
Methods: 31 patients with APL, 27 in first complete remission (CR1), 3 in CR2, and 1 in partial remission (PR) after the second relapse, were treated with autologous transplantation of ABM. The conditioning regimens included MACC protocol (Melphalan, Ara-C, CTX, and CCNU) in 26 patients and TBI + CY protocol in 5 patients. The PML/RARa fusion gene was measured by fluorescence in situ hybridization. Kaplan-Meier survival analysis model was used to estimate the disease-free survival (DFS) rate at 5 years post-transplantation and COX regression model was used to analyze the DFS-influencing factors, including sex, PML/RARa positive state, pre-transplantation state (CR1, CR2, or PR), white blood cell (WBC) count, and platelet (PBC) count.
Results: The 27 patients in CR1 had a DFS time of 3 to 113 months (with a mean DFS time of 46 months), and a 5-year DFS rate of 100%; none of them suffered a relapse after transplantation. One of the 3 patients in CR2 relapsed in 19 months after the transplantation and the other two patients had been in DFS state for 7 and 33 months respectively. The patient in PR obtained CR and relapsed 8 months after the transplantation. All the patients showed reconstitution of hematopoiesis. None of the patients died of transplantation-related complication. Multivariate analysis showed that long-term survival was correlated with the pre-transplantation statues and not with sex, positivity of PML/RARa, and WBC and PBC counts.
Conclusion: Autologous transplantation of ABM reduces the relapse and increases the long-term survival in the patients with APL in CR, especially in CR1.