Utilization of ‘Rainy Day' Autologous Peripheral Blood Stem Cells.

Abstract

High-Dose myeloablative therapy in conjunction with Autologous Peripheral Blood Stem Cell (APBSC) transplantation is an effective first line treatment in patients with haematological malignancies including Multiple Myeloma (MM) and Non-Hodgkin Lymphoma (NHL). With sufficient resources, APBSC's can be harvested in patients during remission or consolidation treatment for subsequent transplantation if required (‘Rainy Day' Collection). We investigated the eventual transplantation of ‘Rainy Day' collections at our centre to assess the utilization of this strategy. We defined ‘Rainy Day' collections as those that were not intended to be used as part of initial therapy and in general, patients were not planned to be transplanted within the 12 months following harvest. For collections that were transplanted within 12 months following harvest, ‘Rainy Day' collections were differentiated based on the utilization intent at time of collection. Any collections infused within 3 months following harvest were excluded from the analysis. Over a 6 year period, we collected APBSC's from 365 patients with the intent of ‘Rainy Day' storage. Primary disease indications included NHL (45%, n=166), MM (12%, n=44), Acute Myeloid Leukaemia (AML) (8%, n=29) and Chronic Myeloid Leukaemia (CML) (7%, n=25). To date, 23% (n=84) of these ‘Rainy Day' collections have been subsequently infused. NHL has been the most common disease requiring Rainy Day collections and has resulted in 41 subsequent transplants (24% utilization) with a median time between collection and infusion of 1.74 years (SD =1.60). Mean days until platelets > 20x109/L=15 (SD=7.0) and days until ANC > 0.5x106/L=10 (SD=1.7). Follicular Non-Hodgkin Lymphoma (fNHL) has accounted for the majority of NHL transplants (37%, 5/15), with 5 of 15 patients exhibiting transformation of fNHL into Diffuse Large B-Cell Lymphoma and an average time between collection and infusion of 2.07 years (SD 2.01). Peripheral T-Cell Lymphoma (T-NHL) has contributed to 15% (n=6/41) of transplanted NHL ‘Rainy Day' collections with a mean time between collection and infusion being shorter at 1.53 years (SD=0.97). 23% of MM patients (n=44/202) have had APBSC's collected for potential ‘Rainy Day' utilization compared with 53% of NHL (n=166/309), 86% of AML (n=29/34) and 100% of CML (25/25). MM has shown to have the highest ‘Rainy Day' APBSC utilisation with 55% (n=23/44) of patients resulting in transplantation. The average time between collection and infusion has been 2.79 years (SD=1.65) with mean days until platelets > 20x109/L=14 (SD =6.9) and days until ANC > 0.5x106/L=10 (SD=1.7). We conclude that it is clinically feasible and safe to perform ‘Rainy Day' collections although more stringent criteria would result in a more efficient use of this resource intensive strategy.