Article

Reduction in infectivity of endogenous transmissible spongiform encephalopathies present in blood by adsorption to selective affinity resins

Veterans Affairs Maryland Health Care System, VA Medical Center, University of Maryland at Baltimore, MD 21201, USA.
The Lancet (Impact Factor: 39.21). 01/2007; 368(9554):2226-30. DOI: 10.1016/S0140-6736(06)69897-8
Source: PubMed

ABSTRACT Transmissible spongiform encephalopathies (TSE) can be contracted through blood transfusion. Selective adsorption of the causative agent from donated blood might be one of the best ways of managing this risk. In our study, affinity resin L13, which reduces brain-derived infectivity spiked into human red blood cell concentrate by around 4 log(10)ID(50), and its equivalent, L13A, produced on a manufacturing scale, were assessed for their ability to remove TSE infectivity endogenously present in blood.
500 mL of scrapie-infected hamster whole blood was leucoreduced at full scale before passage through the affinity resins. Infectivity of whole blood, leucoreduced whole blood (challenge), and the recovered blood from each flow-through was measured by limiting dilution titration.
Leucoreduction removed 72% of input infectivity. 15 of 99 animals were infected by the challenge, whereas none of the 96 or 100 animals inoculated with the final flow-throughs from either resin developed the disease after 540 days. The limit of detection of the bioassay was 0.2 infectious doses per mL. The overall reduction of the challenge infectivity was more than 1.22 log10ID. The results showed removal of endogenous TSE infectivity from leucoreduced whole blood by affinity ligands. The same resins adsorb normal and abnormal prion protein from human infections with variant, sporadic, and familial Creutzfeldt-Jakob disease, in the presence of blood components.
TSE affinity ligands, when incorporated into appropriate devices, can be used to mitigate the risks from TSE-infected blood, blood products, and other materials exposed to TSE infectivity.

1 Follower
 · 
76 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Five cases of variant Creutzfeldt-Jakob disease (vCJD) infections were attributed to infusion of contaminated blood components, turning to real the interhuman transmissibility of this prion disease from asymptomatic carriers. Preventive policies rely on exclusion from blood donation and benefit of leukoreduction initially implemented against leukotropic viruses. In the absence of available antemortem diagnostic tests, the updated prevalence of silent vCJD infections (1/2000 in the United Kingdom) urges the necessity to enforce blood safety with more efficient active measures able to remove the remaining infectivity. Several affinity resins were demonstrated to reduce high levels of brain-spiked infectivity from human leukoreduced red blood cells (L-RBCs). One was integrated in a device adapted to field constraints (volumes, duration) of human transfusion. We assessed here the ability of the resulting removal filter, termed P-Capt, to remove infectivity from human L-RBC units spiked with scrapie-infected hamster brain (≥10,000 infectious units/mL), through inoculation of hamsters with pre- and post-blood filtration samples. Incubation periods of recipient animals suggest around a 3-log removal of brain-derived prion infectivity by filtration through the P-Capt. On brain-derived spiked infectivity, the P-Capt filter provided a performance similar to the resin packed in columns used for initial proof-of-concept studies, suggesting an appropriate scale-up to efficiently remove infectivity from an individual human blood bag. According to the ability of resin to completely remove apparent endogenous infectivity from hamster leukoreduced blood, the implementation of such a filter, now commercially available, might seriously improve blood safety toward prions.
    Transfusion 10/2013; 54(4). DOI:10.1111/trf.12420 · 3.57 Impact Factor
  • Source
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel strategy is presented for the identification of cyclic peptide ligands from combinatorial libraries of reversible cyclic depsipeptides. A method for the solid-phase synthesis of individual cyclic depsipeptides and combinatorial libraries of these compounds is proposed, which employs lactic acid (Lact) and the dipeptide ester (Nα-Ac)-Ser(Ala)- as linkers for dilactonization. Upon alkaline treatment of the beads selected by screening a model library, the cyclic depsipeptides are linearized and released from the solid support to the liquid phase, to be sequenced via single step MS/MS. The protocol presented for library synthesis provides for wide structural diversity. Two model sequences, VVWVVK and AAWAAR, were chosen to present different structural examples for depsipeptide libraries and demonstrate the process of sequence determination by mass spectrometry. Further, a case study using the IgG binding cyclic depsipeptide cyclo[(Nα-Ac)-S(A)-RWHYFK-Lact-E] is presented to demonstrate the process of library screening and sequence determination on the selected beads. Finally, a method is shown for the synthesis of the irreversible cyclic peptide corresponding to the proposed depsipeptide structure, to make the ligand stable to the aqueous acid and alkaline conditions encountered in affinity chromatographic applications. The cyclic peptide ligand was synthesized on a polymethacrylate resin and used for chromatographic binding of the target IgG.
    Analytical Chemistry 09/2013; 85(19). DOI:10.1021/ac401954k · 5.83 Impact Factor

Full-text (2 Sources)

Download
35 Downloads
Available from
May 26, 2014