Seizures During Infusion of Autologous Peripheral Blood Stem Cells Are Related to High White Blood Cell Concentration in the Peripheral Blood Stem Cell Product and Can Be Prevented by Dilution of Product with Autologous Plasma

We then prospectively correlated WBC counts midway and at the end of PBSC collections. Fourteen pts. had 15 apheresis using the Fresenius. Mid- and post-WBC concentrations were 64 +/− 23 × 10³/μl and 69 +/− 20 × 10³/μl, respectively. Fifty-one pts. had 66 apheresis using COBE, with WBC counts obtained midway and at the end of collection of 287 +/− 150 × 10³/μl and 273 +/− 144 × 10³/μl, respectively. Mid-WBC accurately correlated with WBC at the end of the collection in both the COBE and Fresenius cohorts (r² = 0.940 and r² = 0.904, respectively). Using this information, we prospectively evaluated 65 pts. who underwent 80 PBSC collections in anticipation of an autologous (n=44) or allogeneic (n=7) stem cell transplant between June 2009 and January 2010. Collections for these pts. were performed using the COBE (n=66) or the Fresenius (n=15). Mid-WBC were obtained and products with mid-collection WBC concentration > 450 × 10³/uL (n=29) had additional autologous plasma collected at the time of collection for final product dilution to < 450 × 10³/uL prior to cryopreservation. Pts weight, volume of PBSC product and CD34+ cells/kg infused did not differ between the pts who received diluted PBSC product and those who did not. There were also no differences in either ANC (12 ± 1.3 days vs. 11.5 ± 1.3 days, dilution vs. non-dilution, p = 0.760) or in platelet engraftment (18 ± 3.7 days vs. 16 ± 2.7 days, dilution vs. non-dilution, p = 0.561). No serious adverse infusion effects were observed in either group. In conclusion, high number of WBC in COBE collections is a possible cause of PBSC infusion related seizures. No seizures were observed after dilution of PBSC with high WBC concentration.