Autologous CD34⁺ cell transplantation for patients with advanced lymphoma: effects of overnight storage on peripheral blood progenitor cell enrichment and engraftment

Abstract

In order to demonstrate the feasibility of mobilization, enrichment and engraftment of autologous peripheral blood CD34⁺ cells in patients with relapsed lymphoma, 59 peripheral blood progenitor cell (PBPC) collections from 21 patients were enriched for CD34⁺ cells using CEPRATE SC (CellPro, Bothell, WA, USA) immunoaffinity column. Following high-dose chemotherapy, a mean of 17 × 10⁸ (range, 3–34) nucleated cells/kg containing 8.7 × 10⁶ (0.3–26) CD34⁺ cells/kg were re-infused. Blood cell recovery in these patients was compared to engraftment capacity of unenriched PBPCs in a cohort of lymphoma patients treated with an identical high-dose chemotherapy regimen. Neutrophil and platelet engraftment was rapid in both groups including five patients who received ⩽1 × 10⁶ CD34⁺ cells/kg. After infusion of CD34⁺ enriched cells, neutrophils exceeded 0.5 × 10⁹/l in 11 (8–14) days and platelets exceeded 20 × 10⁹/l (untransfused) in 15 (9–39) days. In order to optimize the immunoaffinity column utilization we stored the first PBPC collections overnight at 4°C and combined them with the next day’s collection prior to the CD34⁺ enrichment procedure in 11 patients. This maneuver resulted in a significant decrease in the CD34⁺ cell recovery (resulting in reinfusion of a mean of 42% less CD34⁺ cells). Although overnight storage did not affect neutrophil engraftment, platelet engraftment was prolonged in this group of patients even when >2.0 × 10⁶ CD34⁺ cells/kg were re-infused. The overnight storage procedure should be further evaluated for its effects on the CD34⁺ immunoaffinity enrichment procedure, megakaryocyte progenitors and platelet engraftment. We conclude that CD34⁺ cells enriched from peripheral blood result in rapid engraftment after high-dose chemotherapy in patients with advanced lymphoma that is comparable to that of patients receiving unenriched PBPCs.