Tonsil study provides estimate of the number of people in the
UK who could be incubating vCJD
A study providing an estimate of the number of individuals
in the United Kingdom (UK) who may be incubating variant Creutzfeldt-Jakob
disease (vCJD), has recently been published . A distinctive feature of
this disease is the distribution of abnormal prion protein in the peripheral
lymphatic system, particularly in tonsil tissue, which may be detected during
the preclinical phase [2,3].
Researchers used immunohistochemistry to test for the presence of abnormal
prion protein in 12 674 appendix and tonsil samples, which were collected
from histopathology departments across the UK and anonymised prior to testing.
Three of the samples showed evidence of the abnormal prion protein associated
with vCJD. An extrapolation of these findings provides an estimate that
approximately 3800 individuals within the UK population could be incubating
After consideration of these results and the advice of a scientific committee
of the Medical Research Council (http://www.mrc.ac.uk/)
and the Department of Health for England (http://www.doh.gov.uk),
the Health Protection Agency (http://www.hpa.org.uk)
was commissioned to undertake a much larger study, which involves establishing
a national prospective archive of tonsil tissue for studies of detectable
abnormal prion protein - the National Anonymous Tonsil Archive (NATA) .
Leftover tonsil tissue from 100 000 people of all ages removed during routine
tonsillectomies will be collected. Once anonymised, these specimens will
be tested for the presence of the abnormal prion protein that causes vCJD,
and the results of this study should provide more precise estimates of the
number of people with asymptomatic vCJD infection. These refined estimates
will enable further interventions to limit the impact of vCJD and care provision
for those who may develop the disease to be planned.