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Autism Case Hearing Still to Produce Clinching Evidence on Vaccine Linkage

by Medindia Content Team on Jun 19 2007 2:12 PM

It is a week since the US Court of Federal Claims, began hearing the compensation claims from the families of autistic children who are faulting childhood vaccines containing thimerosal. Commentators suggest that so far the autism activists have not been able to establish a firm link between the vaccines in question and the disease.

The first case being heard is that of Michelle Cedillo’s. Her parents, Theresa and Michael, charge that the presence of thimersal, a preservative in the vaccines administered to their daughter, weakened her immune system and prevented her body from clearing the measles virus after she was immunized for the disease at age 15 months.

Today, Michelle suffers from a long list of health problems, including severe autism, inflammatory bowel disease, glaucoma and epilepsy. The 12-year-old girl’s parents demand payment under the National Vaccine Injury Compensation Program, a no-fault system that has a $US2.5 billion ($A2.9 billion) fund built up from a tax on vaccines of 75 cents a dose.

On Monday, an experienced heavy metals toxicologist named H. Vasken Aposhian presented a theory of how thimerosal could have damaged the girl's immune system in a way that set her up for autism. But none of Cedillo's other witnesses had much specialized knowledge in mercury or other metals, and the focus quickly shifted to the theory that the attenuated measles virus had created a persistent infection in her gut, causing a severe inflammation that resulted in brain damage and other injuries.

Aposhian, who has more than 100 publications on heavy metal poisoning to his name, is hard of hearing and was obstreperous at times during his cross-examination on Monday. For example, he insisted that in vitro studies were nearly always reproducible in animals, and that animal studies were nearly always reliable models for human effects. This is not a belief to which most toxicologists would subscribe.

Also under cross-examination, Aposhian said that he was not an immunologist and that he had composed his theory of thimerosal-induced immunological damage "three or four weeks ago." When government attorney Vincent Matanoski tried to get Aposhian to acknowledge that most if not all cases of clinical mercury poisoning in the past had involved doses hundreds or thousands of times higher than what was administered to children in vaccines, the toxicologist insisted that dose was not necessarily important.

When the mercury was administered, and his or her genetic susceptibility were more relevant issues, he argued. In order to win their case, it seems likely that Cedillos will have to convince the three special masters -- the judges, in effect, in the special "vaccine court" at the U.S. Court of Claims -- of the reliability of the witnesses' account that measles RNA was detected in her bowel and cerebrospinal fluid.

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RNA is a nucleic acid found in all living cells and it is this complex compound that controls cellular function and heredity. A biopsy from Michelle Cedillo's gastrointestinal trct was sent in 2003 to Unigenetics, an Irish laboratory headed by Dr. John O'Leary, which reported finding the RNA. O'Leary and his colleagues had published a paper a year earlier that disclosed the discovery of measles RNA in the guts of several autistic children.

The lab also was said to have found evidence of measles in spinal taps of autistic children, but those results were never published. Last year, two journal articles reported an inability to replicate the O'Leary lab's findings. An expert report commissioned by a British court has found problems in Unigenetics' testing of the samples.

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In testimony that followed Aposhian this past week, five additional witnesses for Cedillo expressed full support for the Unigenetics findings. Those witnesses were gastroenterologist Arthur Krigsman, molecular biologist Karin Hepner, immunologist Vera Byers, virus immunologist Ronald C. Kennedy and Marcel Kinsbourne, a pediatric neurologist who has testified in vaccine court hundreds of times.

The Cedillo family's argument for how vaccines hurt their child was presented most efficiently by Kennedy, a virus immunologist at Texas Tech University. He posited that the 112.5 millionths of a gram of thimerosal contained in six vaccines administered to Michelle during her first seven months of life had damaged her immune system. When she received an MMR vaccine at 16 months, shortly before Christmas 1995, the weakened vaccine virus lodged in her gut, causing an inflamed bowel and eventually damaging her brain.

Michelle is very ill. In addition to her autism she suffers from inflammatory bowel disease, a seizure disorder and chronic eye inflammations that have left her 90 percent blind. She was pushed into the courtroom in a wheelchair because arthritis has left her unsteady on her feet, her mother testified. But the theory that vaccines caused all this pain and suffering is shaping up as a very hard sell.

According to testimony in the trial, Michelle was a healthy baby prior to receiving the MMR vaccine. If the thimerosal she received had damaged her immune system prior to that, there were no manifestations of it. Michelle's parents first brought the case, in 1998, with a theory of damage from MMR. Thimerosal was tacked onto the claim, one of her attorneys said, after news accounts in 1999 of the Centers for Disease Control's request that the drug industry stop selling vaccines containing the preservative.

Perhaps one in 500,000 children who receives the MMR vaccination suffers a severe brain inflammation that can lead to lifelong mental disability -- presumably including autism. The vaccine court has awarded several dozen such children over the past two decades. Michelle's parents might have brought their claim under this theory; according to her mother's testimony and medical records, she suffered an intermittent high fever, up to 106 degrees, and severe diarrhea following the shot.

However, before it agrees to compensate children for a so-called MMR encephalopathy, the court generally requires evidence that the child lost consciousness for an extended period following the shot. Michelle does not seem to have had a seizure or loss of consciousness. Though concerned about the fever, her mother did not bring Michelle to the doctor until 10 days after it first spiked.

The Justice lawyers picked at the expertise of the witnesses and their source articles. They pointed out discrepancies in Dr. Byers' resume and problems Dr. Krigsman has had with the Texas medical board. However, they made little effort to refute Unigenetics' findings. It seemed clear, however, that that job would be left to some of the 12 respondent witnesses who are scheduled to testify next week.

The defendant (called the respondent in vaccine court) in this case is the Department of Health and Human Services, which for the past 18 years has assumed responsibility for compensating the families of children damaged by vaccines. The Department of Justice represents HHS in the courtroom. Doctors and vaccine manufacturers are watching these cases anxiously. They fear that the autism-vaccination claims, despite being discredited by researchers, will scare parents out of vaccinating their children. This appears to have happened in other countries, such as Britain, leading to mini-epidemics of diseases such as measles (which, ironically, can cause brain damage).

Source-Medindia
LIN/J


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