Maximizing hematopoietic progenitor cell collections by apheresis

Abstract

The timing of the initiation of peripheral blood stem cell collection or apheresis varies considerably among oncologists and institutions. Some physicians may choose to initiate apheresis based on the peripheral white blood cell count (WBC), number of days post chemotherapy, or number of days post initiation of high dose growth factor administration. At Kosair Children’s Hospital, it was noted that the timing of the initiation of apheresis was very subjective, which led to inconsistent and at times unsuccessful collections. Some children were harvested over many days with poor CD34+ collections and other children needed only 1 day to obtain an adequate product yield. We began collecting data on all the apheresis patients, which included the performance of a peripheral CD34+ count and a CBC prior to every apheresis collection. The results demonstrated that when a donor’s circulating CD34+ cells/ul were below 4.5 cells/ul, the product yield was found to be unacceptable (below 1 × 106CD34+ cells/kg). When a donor’s circulating CD34+ cells/ul fell between 4.5 cells/ul and 9.0 cells/ul, the product yield did not consistently contain adequate cells for transplant, and apheresis was left to the transplant physician’s discretion. When the donor’s circulating cell count/ul was 9.0 cells/ul and greater, the CD34+ collection was always adequate (>1 × 106CD34+ cells/kg), and the donor should undergo apheresis that day. Changes were made in our decision process for initiating apheresis. Now, all donors undergo peripheral CD34+ testing with a CBC, and they are not evaluated for apheresis until the absolute CD34+ cells/ul are above 4.5 cells/ul. Since implementation, our patients have received a more cost-effective stem cell collection, and one that is also less time consuming for the staff, institution, and above all the family. This poster presentation will: (1) Demonstrate the correlation between the CD34+ count and the WBC in relation to the amount of stem cells collected. (2) Illustrate the improvement in stem cell collections as seen in the CD34+ cell count of the products and the reduction in the number of days required to collect a sufficient quantity of stem cells. The timing of the initiation of peripheral blood stem cell collection or apheresis varies considerably among oncologists and institutions. Some physicians may choose to initiate apheresis based on the peripheral white blood cell count (WBC), number of days post chemotherapy, or number of days post initiation of high dose growth factor administration. At Kosair Children’s Hospital, it was noted that the timing of the initiation of apheresis was very subjective, which led to inconsistent and at times unsuccessful collections. Some children were harvested over many days with poor CD34+ collections and other children needed only 1 day to obtain an adequate product yield. We began collecting data on all the apheresis patients, which included the performance of a peripheral CD34+ count and a CBC prior to every apheresis collection. The results demonstrated that when a donor’s circulating CD34+ cells/ul were below 4.5 cells/ul, the product yield was found to be unacceptable (below 1 × 106CD34+ cells/kg). When a donor’s circulating CD34+ cells/ul fell between 4.5 cells/ul and 9.0 cells/ul, the product yield did not consistently contain adequate cells for transplant, and apheresis was left to the transplant physician’s discretion. When the donor’s circulating cell count/ul was 9.0 cells/ul and greater, the CD34+ collection was always adequate (>1 × 106CD34+ cells/kg), and the donor should undergo apheresis that day. Changes were made in our decision process for initiating apheresis. Now, all donors undergo peripheral CD34+ testing with a CBC, and they are not evaluated for apheresis until the absolute CD34+ cells/ul are above 4.5 cells/ul. Since implementation, our patients have received a more cost-effective stem cell collection, and one that is also less time consuming for the staff, institution, and above all the family. This poster presentation will: (1) Demonstrate the correlation between the CD34+ count and the WBC in relation to the amount of stem cells collected. (2) Illustrate the improvement in stem cell collections as seen in the CD34+ cell count of the products and the reduction in the number of days required to collect a sufficient quantity of stem cells.