Ped Med: Seeking Allies in Autism Fight

September 28, 2006

By Lidia Wasowicz

Parents' push for progress in autism research and discovery has meant a pull for political allies.

As families of children with the disorder and their supporters appear before federal committee hearings and state health panel reviews to demand long-overdue attention and action, some congressional and community leaders are starting to line up behind their cause.

Among others, Rep. Dave Weldon, R-Fla., a medical doctor and persistent critic of the use of thimerosal in vaccines, has sponsored legislation to ban the mercury-based preservative from flu shots. The compound has been phased out of most childhood vaccines.

Rep. Dan Burton, R-Ind., called congressional hearings in April 2002, when he was chairman of the House Government Reform Committee, to investigate an autism link to childhood vaccines after his grandson was diagnosed with the disorder.

Regardless of its scientific merit, the idea of a vaccine connection to the disorder appears to have garnered broad grassroots interest, he said, noting 47 percent of parents who contacted their representatives believe in such a link.

Among those testifying, Dr. Andrew Wakefield -- whose controversial research suggests the measles virus may be linked to inflammatory bowel disease in children with developmental disorders -- described finding traces of the microorganism in the small intestines of 75 of 91 youngsters with autism but in only five of 70 children without the disorder.

Although the study did not look at the role of the measles-mumps-rubella vaccine, and in fact did not even determine whether the children had received the immunization, it set off a wave of speculation implicating the attenuated virus contained in the shot in neurodevelopmental disorders -- a notion the American Medical Association and other major health groups discount.

Perhaps because the stakes are so high or the passions run so deep, in the last decade few pediatric disorders have managed to capture as much attention on the political stage and in the popular and professional press as has autism.

Even so, fewer still leave so many vital issues fluttering in the wind of uncertainty.

When it comes to this perplexing disorder, which affects an estimated 48 million people worldwide, questions of causes, cures and even counts continue to elicit an unsettlingly diverse range of interpretations.

This is troublesome because disagreement on one key piece of the puzzle translates to lack of consensus on the bigger picture. Getting a fix on the range of a problem, for example, is a critical step toward reaching its roots and rectifying its remedies.

When the long- and widely held notion of autism as a response to cold-hearted parents was finally nixed in the late 1960s, a view of the disorder as an unavoidable genetic fate took hold in its place.

But that theory, too, simply doesn't add up if the reported exponential expansion in case numbers represents a true peak in prevalence. No hereditary factor alone could cause such a dramatic rise in rates over a single generation. In short, there is no such thing as a genetic epidemic.

"(The issue of numbers) is a really important question because from the standpoint of cause ... it's going to be difficult to explain a ten-fold or even five-fold increase or any increase based on genes; they don't change in a decade," said Dr. Thomas Insel, director of the National Institute of Mental Health in Bethesda, Md.

Thus, if the autism numbers are correct, scientists must look for additional, non-genetic influences to explain them.

"Research suggests environmental factors may combine with genetic predispositions to contribute to the increased incidence in autism," said Judy Van de Water, associate professor of rheumatology, allergy and clinical immunology at the University of California, Davis, School of Medicine and Medical Center and the M.I.N.D. Institute.

While a strong genetic component in autism is now generally accepted, there's no consensus on the non-hereditary contributors to the disorder.

"We are always wanting to look at what would be the environmental change over this period that could lead to this increase," Insel said.

"The way to disentangle that is to find places where it hasn't happened. I haven't yet heard of a place where ... someone can say, well, you know, the rate was one in 1,000 in 1990, and in (2006), it's still one in 1,000."

As it is, experts can't even uniformly say whether the enormous inflation in reported autism cases in the United States in fact represents a swelling rate of the nation's children affected by the disorder.

The question is a central one in the vaccine debate.

If in fact the disorder has strikingly increased in prevalence -- not just in recognition -- then the idea that it's primarily a genetic condition doesn't hold up.

But if there have always been people with autism in reasonably similar numbers, then the notion that a new trigger, like childhood shots, is behind it begins to look implausible if not impossible.

Problem is that question has not been settled.

"Alarm over the possible 'epidemic' of autism, fueled by new epidemiological studies and fanned by the rapid proliferation of Internet and media coverage of the research, has prompted the medical community to clarify this trend and its causes," one group of researchers wrote in a report that called attention to a troubling spike over the previous dozen years in the number of children diagnosed with and receiving disability benefits for a wide array of conditions that fall under the "autism spectrum disorders" umbrella.

"This leaves us to grapple with troubling questions: Is there a true increase in the prevalence of ASD? If yes, why? If not, what explains the growing number of studies that report alarming rates?"

Citing lack of evidence of its involvement, the one suspect the scientists crossed off their list was the MMR vaccine.

In that, they weren't alone.

Having come up empty-handed, numerous investigators also have dropped their case against the shot. These include groups that compared autism rates in children who had and had not received the immunization in the United States and Denmark and scientists following up on British youngsters who did and did not develop the disorder after being inoculated against the triple infectious threat.

In addition, a comparison between children with and without autism showed little difference in the age at which both groups received their first MMR vaccination.

Despite those votes of confidence, the shot does not appear to be entirely off the hook.

Other teams, including one taking a second look at the widely cited Denmark study of more than half a million children, have come to less certain conclusions and have called for further investigation.

The government has indicated a willingness to oblige.

Emphasizing the preponderance of current scientific research fails to show a connection between the MMR vaccine and autism, the Centers for Disease Control and Prevention nevertheless concedes on its Web site that it "recognizes there is considerable public interest in this issue, and therefore supports additional research regarding this hypothesis."

Others have put forth a mix of other factors -- improved diagnosis, greater parental and professional awareness, the emergence of new services and incentives for children to receive them, a broadened definition that takes in youngsters with milder symptoms as well as possible unknown genetic or environmental influences -- to help explain at least part of the dramatic increase in the autism caseload.

(Note: In this multi-part installment, based on dozens of reports, conferences and interviews, Ped Med is keeping on eye on autism, taking a backward glance at its history and surrounding controversies, facing facts revealed by research and looking forward to treatment enhancements and expansions.)

Source: Free Market News Network