Variant CJD

Abstract

It is now 18 years since the first identification of a case of vCJD in the UK. Since that time, there has been much speculation over how vCJD might impact human health. To date there have been 177 case reports in the UK and a further 51 cases worldwide in 11 different countries. Since establishing that BSE and vCJD are of the same strain of agent, we have also shown that there is broad similarity between UK and non-UK vCJD cases on first passage to mice. Transgenic mouse studies have indicated that all codon 129 genotypes are susceptible to vCJD and that genotype may influence whether disease appears in a clinical or asymptomatic form, supported by the appearance of the first case of potential asymptomatic vCJD infection in a PRNP 129MV patient. Following evidence of blood transfusion as a route of transmission, we have ascertained that all blood components and leucoreduced blood in a sheep model of vCJD have the ability to transmit disease. Importantly, we recently established that a PRNP 129MV patient blood recipient with an asymptomatic infection and limited PrP^Sc deposition in the spleen could readily transmit disease into mice, demonstrating the potential for peripheral infection in the absence of clinical disease. This, along with the recent appendix survey which identified 16 positive appendices in a study of 32 441 cases, underlines the importance of continued CJD surveillance and maintaining control measures already in place to protect human health.

Keywords:

• prion
• variant Creutzfeldt–Jakob disease
• transmissible spongiform encephalopathy
• prion protein

Disclosure of Potential Conflicts of Interest

No potential conflicts of interest were disclosed.

Acknowledgments

We are grateful to our colleagues at The Roslin Institute, the National CJD Research and Surveillance Unit, and the Edinburgh Brain Bank for help in these studies.

Funding

The work described here has been supported by BBSRC, Medical Research Council, and Department of Health. This report is independent research commissioned and funded by the Department of Health, Policy Research Programme. The views expressed in this publication are those of the authors and not necessarily those of the Department of Health.