PrPTSE detection

Endogenous Blood Infectivity Tool

Comparison of bioassay, Scrapie Cell-Assay and Protein Misfolding Cycle Assay performances for detection of endogenous Prion in sheep blood

2009: 1 years / Grant: 34 000 euros

Project: As Prion detection in blood demonstrates a crucial need for transfusion risk assessment and diagnosis of incubating patients, the aim of the “Endogenous Blood Infectivity Tool” project was to compare the performances of three different methods of prion detection in blood: Animal bioassay, scrapie cell assay (SCA), and PMCA.

Main results and related published data: The assays to be compared were performed on blood and blood-derived products(white blood cells: WBC) taken at differentstagesin prion infected sheep. PMCA and bioassays in Tg(338) mice expressing the ovine PrP were the most efficient methods for identifying infected animals at anytime in the disease course, even when samples were taken during the asymptomatic phase of the disease. SCA using cells expressing the ovine PrP (ovRK13 cells) also allowed the detection of prion infectivity in WBC of asymptomatic sheep. Recently this study was completed with the evaluation of the Cerebellar Organotypic Slice Culture Assay (COSCA) using cerebellar slices from Tg(338) mice which gave results similar to those obtained with SCA. Even though PMCA and bioassay were shown to be robust toolsfor the detection of prion particles during asymptomatic phases, exvivo toolssuch as SCA and COSCA were also shown to be relevant for the detection of PrPTSE in WBC.