Removal of Prions by Plasma Fractionation Processes. Henry Baron, M.D. Senior Director Medical and Scientific Affairs Aventis Behring. CJD/vCJD and Human Blood: Key Message.
Henry Baron, M.D.
Senior Director Medical and Scientific Affairs
Currently no scientific evidence to substantiate that persons with pre-clinical or clinical CJD, including vCJD, carry infectious prions in their blood or have transmitted them through blood or plasma products. Therefore, this risk is considered theoretical.
Two Lancet publications report that prions were undetectable in blood, plasma and buffy coat of patients with vCJD, despite detection of prions in their lymphoid tissues.
Bruce et al. Detection of variant Creutzfeldt-Jakob disease infectivity in extraneural tissues. Lancet, 2001; 358:208-209.
Wadsworth et al. Tissue distribution of protease resistant prion protein in variant Creutzfeldt-Jakob disease using a highly sensitive immunoblotting assay. Lancet, 2001; 358:171-180.
Experimental Process is Equivalent to Manufacturing Process.
Clearance = Prove - Effluent
PrP or infectivity clearance data for various plasma protein and biotechnology processing steps is plotted.
For all cases presented, log clearance of either PrPSc (Western blot) or infectivity (bioassay) is similar.
Lee et al, Transfusion vol 41, April 2001
> Designates the limits of PrPSc detection for the assay
Variant CJD and other human TSE agents partition similarly
to the rodent-adapted sheep scrapie (263K strain)
Prion Clearance Study - Cohn Coupled Series Steps
Fr I Paste
Fr III Paste
Partitioning determined for independent steps
is consistent with partitioning determined for
Removal of prions by plasma manufacturing processes: