Automated cell processing device to eliminate DMSO: experience of Policlinico Tor Vergata

Abstract

Introduction: DMSO is the most important cryoprotectant used during cryopreservation. At room temperature, DMSO is toxic for hematopoietic progenitor cells (HPCs) and its infusion during transplant is associated with mild (nausea, vomiting, flushing, rash, abdominal pain or hypotension) or severe (neurological complications, renal failure, cardiovascular disorders) adverse effects. There are several methods to reduce the amount of DMSO; we present our experience in automatic washing of DMSO in cryopreserved HPCs. Methods: From July 2013, 21 autologous HPC infusions were performed using automatic washing procedure with Sepax (Biosafe). For each procedure we evaluated: total nucleated cell (TNC) and total CD34+ cell counts; TNC and CD34+ cell viability; clonogenic assays (CFU-GM, CFU-Tot; microbial contamination of washed product; neutrophil (at least 0.5×109/L) and platelet (stable PLT counts >20×109/L) engraftment. Results: The median pre-wash counts of TNC and CD34+ cells were respectively: 48.5×109 (range 11.9–488) and 5.45×108 (range 3.24–12.2). The median post-wash count of TNC and CD34+ cells were respectively: 37.1×109 (range 10.6– 481) and 4.89×108 (range 2.59–16.5). Post-wash viability of CD34+ cells was (median value): 88% (range 32–99). Median recovery of TNC and CD34+ cells after washing procedure was respectively: 94% (range 36–105) and 97% (80–103). The median values of CFU-GM and CFU-Tot were 27.1×104/kg (range 11.9–100.8) and 57.6×104/kg (range 33.3– 200.6). Median time until neutrophil engraftment with peripheral blood neutrophils counts was 13 days (range 2–19). Median time until PLT engraftment was 16 days (range 8–35). No microbial contamination in washed product. No adverse events detected during infusion. Discussion: Our experience shows that washing of cryopreserved HPCs is a safe and effective procedure that decreases the frequency of adverse events during stem cell infusion. Automatic DMSO-depletion keeps the CD34+ cell numbers and viability as well as their engraftment potential.