Platelet harvest, cryopreservation and infusion; re-expanding the resources of the BMT lab

Abstract

A 53 year old multiparous woman with a hepatic mass was found to have AML. She proceeded to induction chemotherapy resulting in complete remission by day 28. Between cytarabine consolidation cycles, she received 3 TACE procedures for presumed hepatocellular carcinoma. During first cycle, she developed platelet refractoriness with no platelet increment one hour post transfusion. Testing confirmed the presence of an HLA antibody. HLA matched platelet transfusions did not give a satisfactory platelet increment. The decision was made to harvest and cryopreserve her platelets, then reinfuse post chemotherapy. The patient was scheduled to have plateletpheresis with a goal of 10 x 1011platelets to be harvested and cryopreserved, allowing for 4 infusions as support over the nadir post-chemotherapy. This was to be repeated to support the final round of chemotherapy. Once platelet count reached>150, 4 collections were performed over 2.5 months yielding between 3.1 to 5.5 x 1011 platelets per harvest, irradiated at 25Gy, and cryopreserved in 5% DMSO using a controlled rate freezer. Studies on her post-thaw platelets using PRP impedance indicated a 50% reduction in functionality compared with fresh platelets. Four infusions were performed 11-20 days post consolidation 2 chemotherapy and three infusions 11-19 days post consolidation 3. No adverse reactions were reported. Platelet counts increased typically from 11-29 (1.6 to 2.6 fold) within 24 hours of infusion. HLA matched platelets gave no increase (pre-infusion count of 8, to post of 9, within 24 hours). There were no clinically significant bleeding complications and she was able to finish her scheduled rounds of chemotherapy. We have presented a case study requiring harvest, cryopreservation and infusion of autologous platelets. Incorporating archived platelet protocols into current practices was easily and safely achieved by the BMT laboratory. The methodology, equipment and processes involved required little change from the traditional role of progenitor cell work and this can safely extend the services offered by BMT laboratories with minimal additional costs for equipment or consumables.