The prevalence of variant Creutzfeldt-Jakob disease: new data and plans for a tonsil archive

A paper published in the British Medical Journal has provided new information on the prevalence of preclinical variant Creutzfeldt-Jakob disease (vCJD) in the United Kingdom (UK) (1,2). A distinctive feature of vCJD is the widespread distribution of an abnormal prion protein in peripheral lymphoid tissue (3,4), which may be detectable before any symptoms develop (5). The authors looked retrospectively for the presence of abnormal prion protein in 8318 appendectomy and tonsillectomy samples and found one positive appendix. It is not known if an asymptomatic person with detectable abnormal prion protein will go on to develop vCJD but, as discussed in the paper, 19 of 20 appendixes removed at autopsy from patients with vCJD have shown accumulation of abnormal prion protein, as did the appendixes removed from two patients prior to disease onset (5). Whilst the paper does report the first estimate of the prevalence of abnormal prion protein based on population testing, larger studies are needed to provide a more precise estimate.