Use of Non-Cryopreserved Peripheral Blood Stem Cells Is Associated with Adequate Engraftment in Patients with Multiple Myeloma Undergoing an Autologous Transplant.

Autologous transplantation is the standard of care for transplant-eligible patients with multiple myeloma. Toward making this treatment accessible in developing countries, there are significant challenges like resource constraints and access to cryopreservation facilities. We performed a retrospective analysis of patients with multiple myeloma who underwent autologous transplantation using granulocyte colony-stimulating factor (G-CSF)-mobilized non-cryopreserved grafts at our institution from January 1995 to December 2014. Peripheral blood stem cells (PBSCs) were harvested over 1 to 2 days after G-CSF mobilization. After apheresis, PBSCs were stored at 4°C in a blood bank refrigerator for up to 72 hours. During the study period, 224 patients with multiple myeloma underwent autologous transplantation using G-CSF-mobilized non-cryopreserved grafts. The number of days of stem cell harvest was 1 in 91 patients (40.6%) and 2 in 133 patients (59.4%). The median CD34 cell dose was 4.87 × 106/kg (range, 1.15 to 23.7). All patients except 1 engrafted. The median time to neutrophil engraftment was 12 days (range, 9 to 22). The median time to platelet engraftment was 17 days (range, 10 to 44). In a resource-limited setting, the use of G-CSF-mobilized non-cryopreserved grafts results in adequate engraftment for most patients with multiple myeloma undergoing autologous stem cell transplantation.

Outcomes Following Allogeneic Stem Cell Transplantation Using Non-sibling Family Donors.

For patients requiring allogeneic stem cell transplant, in the absence of a HLA-matched sibling, an extended donor search within the family may yield a suitable donor especially in societies with a high prevalence of consanguinity. We describe outcomes in transplants with non-sibling family donors, and compare outcomes with controls having a sibling donor transplant. Retrospective analysis of all matched related (non-sibling) donor transplants between 1995 and 2015. For comparison, appropriate age, sex and disease-matched patients were chosen from the sibling transplants (MSD) performed during the same time period (± 2 years). Comparison between the fully matched non-sibling donor cohort and age, sex and disease-matched sibling donor transplants showed a significant increase in complications in the family donor group (viral infections, acute GVHD and rejection). Event-free survival and overall survival were significantly lower in the non-sibling donor cohort, and HLA disparity (1-2 antigen) further worsened the adverse impact. Though there was a significantly lower event-free and overall survival at 3 years in the family donor cohort, this did not retain significance in the multivariate analysis. This data on allogeneic transplants using family donors showed higher complication rates and poorer outcomes. However in situations where financial constraints prevent access to matched unrelated donor sources, extended family searches may be fruitful in yielding a donor, and modifications in conditioning regimens and improvement in supportive care may help in improving the outcomes in family donor transplants.

Clinical Outcomes in Multiple Myeloma Post-Autologous Transplantation-A Single Centre Experience.

There is paucity of data from developing countries on the clinical outcomes in myeloma post-autologous transplantation. In this retrospective study, we used hospital records to retrieve data of patients with multiple myeloma undergoing autologous stem cell transplantation (ASCT) from January 1995 to December 2014 at our centre. During the study period, 245 patients underwent ASCT for myeloma. Of these, 19%, 37% and 37% were in complete response, very good partial response and partial response respectively at the time of ASCT. Only in 14 (5.7%) patients, the stem cells were cryopreserved. The transplant related mortality was 2.86%. The median follow up was 40.7 months (range 0-237.4 months). The 5-year overall survival (OS) and progression-free survival (PFS) for the entire cohort was 61.6% ± 3.8% and 37.2% ± 3.9% respectively. Independent predictors of OS included mononuclear cell dose infused, pre- and post-transplant response; and the use of maintenance therapy. Independent predictors of PFS included age at diagnosis, pre- and post-transplant response; and the use of maintenance therapy. In a resource limited setting, ASCT for myeloma is associated with low transplant related mortality. Pre- and post-transplant response and maintenance therapy are predictors of survival.

Arsenic Trioxide Enhances the NK Cell Cytotoxicity Against Acute Promyelocytic Leukemia While Simultaneously Inhibiting Its Bio-Genesis.

Natural killer cells (NK) contribute significantly to eradication of cancer cells, and there is increased interest in strategies to enhance it's efficacy. Therapeutic agents used in the treatment of cancer can impact the immune system in a quantitative and qualitative manner. In this study, we evaluated the impact of arsenic trioxide (ATO) used in the management of acute promyelocytic leukemia (APL) on NK cell reconstitution and function. In patients with APL treated with single agent ATO, there was a significant delay in the reconstitution of circulating NK cells to reach median normal levels from the time of diagnosis (655 days for NK cells vs 145 and 265 days for T cells and B cells, respectively). In vitro experiments demonstrated that ATO significantly reduced the CD34 hematopoietic stem cell (HSC) differentiation to NK cells. Additional experimental data demonstrate that CD34+ sorted cells when exposed to ATO lead to a significant decrease in the expression of IKZF2, ETS1, and TOX transcription factors involved in NK cell differentiation and maturation. In contrast, exposure of NK cells and leukemic cells to low doses of ATO modulates NK cell receptors and malignant cell ligand profile in a direction that enhances NK cell mediated cytolytic activity. We have demonstrated that NK cytolytic activity toward NB4 cell line when exposed to ATO was significantly higher when compared with controls. We also validated this beneficial effect in a mouse model of APL were the median survival with ATO alone and ATO + NK was 44 days (range: 33-46) vs 54 days (range: 52-75). In conclusion, ATO has a differential quantitative and qualitative effect on NK cell activity. This information can potentially be exploited in the management of leukemia.