Post-thaw removal of DMSO does not completely abrogate infusional toxicityor the need for pre-infusion histamine blockade

Background The infusion of PBSC or BM cells cryopreserved with DMSO is associated with frequent, but generally minor, toxicity. The incidence and severity of inf usion-related toxicity is proportional to the amount of DMSO infused. In an attempt to reduce the incidence of symptoms reported by patients receiving cryopreserved PBSC and to avoid the necessity of diphenhydramine pre-medic ation, we studied the infusion of PBSC components from which the DMSO was d epleted after thawing. Methods This was a Phase I/II study of post-thaw removal of DMSO. Patients undergoi ng autologous PBSC transplantation with components cryopreserved using 10% DMSO were eligible. The PBSC components were thawed, diluted with 10% dextr an-40 and 5% HSA, centrifuged to remove the DMSO, resuspended in dextran an d HSA, and infused without prior medication of the patient. Visual analog s cale questionnaires were used for measurement of infusion-related symptoms. Results Five patients were enrolled on this study and received washed PBSC componen ts. One patient experience severe infusion-related toxicity and the study w as stopped for safety reasons. Events experienced by these patients includi ng flushing (two patients), emesis (three patients), and post-infusion rigo rs (two patients). Two patients reported an increase in nausea after the in fusion. All patients achieved granulocyte engraftment (an ANC > 0.5 x 10(9) /L) at a median of 14 days and platelet engraftment (platelet count without transfusion > 20 x 10(9)/L) at a median of 11 days. No patient required in fusion of additional cells because of engraftment failure. Discussion In theory, the post-thaw reduction of DMSO should reduce the risk of infusi on-related toxicity that is commonly attributed to DMSO. Although not demon strated by the data developed from this study, effective reduction in DMSO could also eliminate the need for pre-infusion histamine blockade. However; the technique used in this study was not adequate and a mor rigorous deple tion technique must be developed to completely abrogate clinical infusion-r elated toxicity.