Fresh doubts cast on MMR study data

The Sunday Times, April 25 2004

Brian Deer

SERIOUS concerns have been raised about a key study cited by Dr Andrew Wakefield and campaigners as crucial evidence that the MMR vaccine causes autism in children.

The High Court in London has requested that the Irish courts order Professor John O’Leary, the Dublin pathologist who carried out the study, to hand over all the raw data so it can be re-examined by experts.

It follows claims made in the High Court of anomalies in O’Leary’s laboratory reports on samples from hundreds of autistic children who are allegedly victims of the MMR vaccine. Along with earlier research by Wakefield, which was discredited in February after a Sunday Times investigation, O’Leary’s tests have been seen as critical to the claim linking the vaccine with autism.

Unigenetics, O’Leary’s private company, found that 80% of the 91 autistic children it tested had traces of measles in their bodies, presumably as a result of being given MMR. This data is being relied on by parents who believe MMR caused autism in their children and are suing three manufacturers of the vaccine — GlaxoSmithKline, Merck and Aventis Pasteur.

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INVESTIGATION WAS CHECKED

Experts for the three companies, who have had access to some of O’Leary’s raw data, have claimed in court that the samples could have been contaminated and were incorrectly reported. If this is so, it would be a big blow to the families’ case and to Wakefield’s campaign for single jabs to replace the MMR triple inoculation.

O’Leary’s data provided Wakefield with the linchpin evidence that was central to his theory,” said Dr Stanley Plotkin, of the Wistar Institute in Philadelphia, who is a world expert on vaccines. “If that falls away, all you have is a hypothesis unsubstantiated by anything . . . the whole thing falls into the water.”

Wakefield first sparked controversy over a possible link between MMR and autism six years ago with the publication of a study in The Lancet. The paper’s key finding was withdrawn last month following a Sunday Times investigation that revealed Wakefield’s involvement in the vaccine lawsuit.

The O’Leary study, co-authored by Wakefield, was published in the journal Molecular Pathology in April 2002. They claimed to have found fragments of the measles virus in samples from the intestines of children with autism. This research and further tests by O’Leary were described by the judge presiding over the MMR litigation as “pivotal” to the case.

However, questions were raised over the research when two other laboratories, testing samples from the same children, apparently failed to confirm O’Leary’s findings. One, at Edinburgh University, had been commissioned by the drug companies, and the other, at Queen Mary medical school, London, by the children’s lawyers.

O’Leary’s results were generated from a machine called TaqMan PCR, which amplifies molecular DNA sequences. Since 2000, Unigenetics has been paid £800,000 for this work by the UK legal aid fund.

Further experts were asked to investigate O’Leary’s methodology and results. Led by Dr Stephen Bustin, of Queen Mary, they visited O’Leary’s laboratory last year and were given 20% of the raw data recorded by the PCR machine.

But after comparing this data with O’Leary’s reports, Bustin’s team claims it found instances of different results. “These findings are raising very serious concerns,” Charles Gibson QC, counsel for one of the MMR manufacturers, told a court hearing this month.

Bustin claims the PCR machine used by O’Leary found traces of measles in control samples — such as those containing distilled water — that should have been negative. He also claims some of the controls were wrongly reported as negative when the machine had found positive traces of the virus.

“Bustin is beginning to find a mismatch between the raw data which he is examining and the experimental reports that relate to that,” claimed Gibson.

Measles is among the most infectious agents known. In tests such as O’Leary’s, some materials are intentionally infected — acting as positive controls to be sure the machine is working — and it is thought that this may have been a cause of the contamination.

In a statement issued on Friday, O’Leary strongly disputed the claim that contamination might have occurred and said that positive controls used in the research were “prepared in a separate building”. He said that had contamination occurred “all the samples would have tested positive, and that clearly was not the case”.

O’Leary claimed that any differences between the reports and raw data were because of “the use of different software” by those checking his data.

The lawyers in the MMR litigation had agreed informally last July that O’Leary should allow Bustin to collect the remaining 80% of data from the machine. Bustin says the exercise is as simple as copying a home computer disk.

But Bustin, a specialist in PCR technology, and a fellow expert claim they have met a number of obstacles and Unigenetics put forward numerous reasons why the data could not be produced. O’Leary insists he has gone to “considerable lengths” to help Bustin retrieve the data.

Yesterday Dr Richard Smith, editor of the British Medical Journal, which publishes Molecular Pathology, said: “If it turned out to be true that the results were contaminated, then I imagine that O’Leary himself would want us to retract that paper, because clearly it would be delivering a false message.”