RESUMO
BACKGROUND: Products cryopreserved with dimethyl sulfoxide (DMSO) in stem cell transplant (SCT) often cause many adverse effects during their infusion (major cardiovascular events, dyspnea even death). These are especially frequent in pediatric patients. We tested if a fully automated and closed wash procedure (Sepax S-100, Biosafe) allowed us to maintain the absolute CD34+ cell number, cell viability, and engraftment potential, decreasing the untoward reactions. STUDY DESIGN AND METHODS: Forty-six washes of DMSO cryopreserved peripheral blood hematopoietic progenitor (HP) apheresis were studied. Blood aliquots were taken both after thawing and after washing to assess the total nucleated and CD34+ cell counts, as well as cell viability. The washed products were infused in 26 autologous SCTs (ASCTs). Results were compared with the 53 previous SCTs performed without DMSO removal. RESULTS: After washing there were no significant differences between the pre- and postwashing CD34+ cell counts (p=0.08) or viability (p=0.68). No significant differences were observed between washed and nonwashed infusions in relation to the day of the neutrophil (p=0.46) and platelet (p=0.26) engraftment. One adverse event, abdominal pain, occurred during the washed cells infusions. When compared with the 14 untoward reactions that took place during the nonwashed HP infusions, significance was reached (p=0.00043). CONCLUSIONS: The automatic method described is effective in terms of CD34+ cell recovery and viability in ASCT. Moreover, Sepax decreased significantly the untoward reactions during the infusion.