Detection of infectious prions in urine

Abstract

Prions are the infectious agents responsible for prion diseases, which appear to be composed exclusively by the misfolded prion protein (PrP^Sc). The mechanism of prion transmission is unknown. In this study, we attempted to detect prions in urine of experimentally infected animals. PrP^Sc was detected in ∼80% of the animals studied, whereas no false positives were observed among the control animals. Semi‐quantitative calculations suggest that PrP^Sc concentration in urine is around 10‐fold lower than in blood. Interestingly, PrP^Sc present in urine maintains its infectious properties. Our data indicate that low quantities of infectious prions are excreted in the urine. These findings suggest that urine is a possible source of prion transmission.