Infusion of P-Capt prion-filtered red blood cell products demonstrate acceptable in vivo viability and no evidence of neoantigen formation
Article first published online: 14 APR 2011
© 2011 American Association of Blood Banks
Volume 51, Issue 10, pages 2228–2236, October 2011
How to Cite
Cancelas, J. A., Rugg, N., Pratt, P. G., Worsham, D. N., Pehta, J. C., Banks, K., Davenport, R. D. and Judd, W. J. (2011), Infusion of P-Capt prion-filtered red blood cell products demonstrate acceptable in vivo viability and no evidence of neoantigen formation. Transfusion, 51: 2228–2236. doi: 10.1111/j.1537-2995.2011.03133.x
- Issue published online: 10 OCT 2011
- Article first published online: 14 APR 2011
- Received for publication October 26, 2010; revision received February 10, 2011, and accepted February 16, 2011.
BACKGROUND: Transmission of variant Creutzfeldt-Jacob disease (vCJD) is a major concern in blood transfusion. The P-Capt filter has been shown to remove around 4 log ID50 prion infectivity from prion-spiked human red blood cells (RBCs).
STUDY DESIGN AND METHODS: Two independent, single-center, randomized, open-label studies were designed to analyze the safety of P-Capt–filtered RBCs. RBCs prepared from leukoreduced whole blood from 43 eligible subjects were randomly assigned to P-Capt filtration and/or storage in plasma or SAGM and stored for 28 or 42 days. Stored RBCs were analyzed for in vivo 24-hour recovery, hemolysis, metabolic variables, blood group antigen expression, neoantigen formation, and safety after autologous infusion.
RESULTS: Mean P-Capt filtration times for leukoreduced RBCs were 41 (SAGM) to 51 (plasma) minutes. Thirteen of 14 subjects receiving P-Capt–filtered RBCs had 24-hour RBC recoveries of 75% or more after 42-day storage, with a mean hemolysis of less than 0.6%. No loss of RBC antigen expression or formation of neoantigens was observed. In both studies, RBCs had white blood cell counts of less than 1 × 106/unit after leukofiltration. P-Capt prion filtration provided an additional greater than 0.8 log leukoreduction. No serious or unexpected adverse events were observed after infusion of P-Capt–filtered full-volume RBC units.
CONCLUSIONS: P-Capt–filtered, stored RBCs demonstrated acceptable viability and no detectable neoantigen expression, immunogenic responses. or safety issues after infusion of a complete unit. The additional filtration time and modest reduction in RBC content are within acceptable levels for implementation in countries with transfusion transmission of vCJD.