Molecular
testing in Wakefield's own lab rebutted the basis
for his attack on MMR
This page is
research from an investigation by Brian Deer for the UK's Channel 4 Television
and The Sunday Times of London into a campaign
linking the MMR children's
vaccine with autism. | Go to part I:
The Lancet scandal | Go to part II:
The Wakefield factor
Even as Andrew Wakefield launched his attack on
MMR in 1998, at a press conference and in a
video, coinciding with a Lancet paper, he knew that his own
laboratory had tested his theory: that the
ultimate culprit for the children's autism was
measles virus in the vaccine. Royal Free
researcher Nick Chadwick, carrying out
sophisticated molecular analysis of samples from
the children, using methods agreed by
Wakefield,
found no trace of measles virus.
Wakefield has since claimed that these were
"false negatives"
Below is the
abstract from Dr Chadwick's Ph.D thesis, dated
February 1998, and a table of results on 22
autistic children - including children reported
in the Lancet and announced to the world to be
evidence of a link between the MMR vaccine and
autism - revealing findings only finally released
to the public on November 18 2004 with the
Channel 4 documentary, MMR: What they
didn't tell you
ABSTRACT
Hypothesis.
i) Atypical exposure to measles virus is
a factor in the aetiology of inflammatory
bowel disease (IBD). ii) Measles,
mumps and rubella (MMR) vaccination is a
factor in the aetiology of autistic
enteropathy.
Aims.
i) To compare a range of molecular
techniques for measles RNA
amplification. ii) To develop a
sensitive and robust method for the
detection of measles RNA. iii) To
analyse clinical samples from IBD
patients for the presence of measles
RNA. iv) To analyse clinical
samples from autistic enteropathy
patients for the presence of measles,
mumps and rubella RNA.
Methods
development. Three RNA
amplification methods were compared in
terms of their sensitivity and fidelity
for the detection of measles RNA and
nucleic acid sequence-based amplification
(NASBA) was found to be the most
sensitive. In a preliminary study,
NASBA did not detect any measles RNA in a
coded series of IBD and control
intestinal tissues.
In
order to improve the detection
sensitivity, the use of hybrid capture,
using measles-specific oglionucleotides
linked to paramagnetic solid phase
supports, was investigated. Hybrid
capture was found to increase the measles
RNA detection sensitivity 100-fold when
followed by RT-PCR. An internal
modified transcript was developed which
could be co-amplified with measles RNA as
an internal positive control.
IBD
samples. Resection samples from
20 IBD and control patients were used for
measles hybrid capture followed by
RT-PCR, in addition to peripheral blood
mononuclear cells (PBMCs) from 13 IBD and
control patients.
Autistic
enteropathy samples. Biopsies,
PBMCs and Vero/PBMC cocultures were
analysed from 22 patients with autistic
enteropathy and 6 controls.
Results.
Hybrid capture and RT-PCR could detect 104
molecules of a measles RNA
transcript added to control tissue
homogenates. The fidelity of NASBA,
in terms of its nucleic acid error rates,
was found to be comparable with that of
RT-PCR. All samples were found to
be positive for a housekeeping RNA
species and internal modified positive
control RNA. None of the samples
tested positive for measles, mumps or
rubella RNA, although viral RNA was
successfully amplified in positive
control samples.
Conclusion.
The results do not support previous data
implicating persistent measles virus
infection with the aetiology of IBD or
autistic enteropathy.
Table:
RT-PCR results on samples from autistic children,
carried out in Andrew Wakefield's lab by Nick
Chadwick, under Wakefield's supervision and using
a methodology agreed by Wakefield. These results
were in before Wakefield and the Royal Free
launched the MMR scare in February 1998. All
samples tested were negative for measles virus [N
and H genes], as well as for rubella and mumps:
From:
Molecular Strategies for the Detection of Measles
Virus in Inflammatory Bowel Disease, a thesis
submitted for the degree of doctor of philosophy,
by Nicholas Charles Chadwick, Royal Free Hospital
School of Medicine, Faculty of Medicine,
University of London
|
