US Government officials are finally getting serious about studying all potential environmental factors in autism, and I for one applaud them heartily for leaving no etiological stone unturned.
Five years ago I wrote in the introduction to Evidence of Harm that "something in our modern world" was causing autism in a small number of susceptible kids. And though that book was mostly about vaccines and the mercury-containing preservative thimerosal, I also wrote that other environmental "triggers" should be considered, including "mercury in fish, pesticides, PCBs, flame retardants, jet fuel, live viruses in vaccines or some as-yet unidentified virus, and even rampant cell phone use."
Now, in one of the largest, boldest studies of its kind, researchers in Philadelphia, Baltimore and Northern California will begin collecting data on many potential risk factors, both prenatally and during early childhood -- including vaccines, thimerosal, and heavy metals.
This brings to seven the total number of approved or recommended new Federal studies to gather data on immunization as a possible risk factor for autism spectrum disorder (ASD).*
This latest effort, the Early Autism Risk Longitudinal Investigation (EARLI), comprises a network of NIH agencies and affiliated ASD research sites that will follow some 1,200 pregnant women who already have a child with autism. The goal is to identify the earliest potential causes of autism by looking at "possible environmental risk factors and their interplay with genetic susceptibility during the prenatal, neonatal and early postnatal periods," according to a statement from the network.
The 10-year project is probably the first ever to collect data on a multitude of genetic and environmental factors in autism in real time. Some preliminary results may be available within four years of enrollment.
"It is a very exciting study," lead investigator Dr. Craig Newschaffer, a department chair at the Drexel University School of Public Health told me today. "You might be able to come up with some environmental factor that we did not include, but it would be difficult. The list is extremely comprehensive."
Dr. Newschaffer added that the EARLI study is operating on the assumption that "for a substantial proportion of autism cases, there's going to be genetic and environmental interaction at play."
He said that researchers chose to study women who already had an ASD child because the risk of having a second child with the disorder could be as high as 15-20%. That means that somewhere between 180 and 240 of the 1,200 children in the EARLI study are expected to develop some type of ASD. In the general population -- assuming the CDC's estimate of 1-in-150 children with ASD is correct -- one would expect to find only eight cases.
One drawback to this approach is evidence suggesting that multiplex ASD children have a distinct genetic profile (they appear to be a different ASD "phenotype") than simplex children, and they might be susceptible to different environmental risk factors as well.
"It's definitely an issue, there is no one perfect study," Dr. Newschaffer conceded. "But even in light of that, this type of study is especially valuable. To find the environmental factors, it makes sense to increase your statistical power as much as possible."
Mothers who enroll in the study will be given two questionnaires during pregnancy, and a third while the child is an infant. It is a long survey. Investigators seem to have thought of virtually everything they could possibly ask.
Included on the list are prenatal exposures to medications and vaccinations, including the flu shot -- which has not been studied for fetal effects, should only be given during pregnancy "if clearly needed," and contains 25 mcg of ethylmercury, which for a 110 pound woman is five times over the EPA daily limit for mercury exposure.
Researchers will also comb through each child's medical records at different intervals, and look closely at vaccination history and other medications given.
"We absolutely want to collect data on vaccines," Dr. Newschaffer said. "Regardless of where you are on that debate -- in the yes or the no box -- having that information in the mix of larger questions about immune-mediated mechanisms in pregnancy and in early life, with the idea of analyzing it, is a sensible thing to do."
The questionnaires will also inquire about mercury exposures through ambient air pollution, seafood consumption, dental amalgams in the mother and dental work during pregnancy, and even thimerosal exposure through contact lens solutions and other over-the-counter products.
Researchers will also take biological samples from mothers -- and from newborns from birth through two years of age -- including blood, saliva, breast milk, urine, umbilical cord and placental material and "meconium," a baby's first stool, in which toxins may have accumulated over time. They will be tested for a variety of potential risk factors and biomarkers for ASD, and stored for further analysis in a national autism data-sharing program.
Umbilical cord blood will surely be of particular interest, given that the US EPA has estimated that one in six children born each year already have high enough mercury levels in their cord blood to potentially cause some type of neurodevelopmental disorder.
But investigators will be looking at much more than just exposure to mercury: Other metals, pesticides, PCBs, flame retardants, and many other "persistent organic pollutants" are also on the list of data to collect.
Researchers will eventually use a vast variety of data taken from pregnancy to infancy, looking for different toxins. They will look at the parents' occupational history for exposures to metals, pesticides, or other chemicals, they will look at maternal bio markers for exposure in blood and urine, and analyze questionnaires about household chemical use. They will test household dust and ambient air for the presence of those same toxins, and look for them in meconium samples and in breast milk, to see if there has been any postnatal transfer of toxic material from mother to child.
Nothing will be left out: Data on diet, health and beauty products, cleaning products and so much more will be gathered and eventually analyzed.
The EARLI study will also examine prenatal events such as fever and illness during pregnancy. It will also take three blood samples during pregnancy, looking for things like inflammatory parameters and infection response, Dr. Newschaffer said.
Researchers will also be looking for "novel biomarkers and epigenetic changes in the mother during pregnancy," he said. Again, that prenatal data will be gathered in real time, which is unprecedented in autism clinical research.
In some cases, it may be possible to correlate toxic body burden with pollution levels in each birth tract. For example, one CDC-funded study in the San Francisco Bay Area found that children born in the most polluted districts -- and especially those exposed to heavy metals -- were significantly more likely to develop an ASD diagnosis.
"We can look at the Bay Area data at the group level, but we will also have individual exposure levels to compare them with," Dr. Newschaffer said. "And while we don't have soil samples included, we would like to get more money for soil and water testing."
The EARLI study is currently being funded with a $14 million "Autism Centers of Excellence" grant from the National Institute of Environmental Health Sciences, National Institute of Mental Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development and National Institute of Neurological Disorders and Stroke, all NIH agencies. Autism Speaks contributed an additional $2.5 million in anonymously donated funds to the project.
The Drexel University School of Public Health in Philadelphia will coordinate the network, which includes a local research site at Drexel University School of Public Health/Children's Hospital of Philadelphia (CHOP), home to Dr. Paul Offit, who has condemned anyone who suggested a vaccine-autism link, downplayed environmental factors in ASD in favor of genetic causes, and rejected the idea of an autism "epidemic."
One can only speculate what went through Dr. Offit's mind this morning when he read in his hometown paper, the Philadelphia Inquirer, that "vaccines are among the many environmental factors that will be examined in the new study."
Other research sites will be located at the University of California at Davis/MIND Institute; Johns Hopkins Bloomberg School of Public Health/Kennedy Krieger Institute; and the Kaiser Permanente Division of Research in Oakland, CA.
For now, the main focus of the EARLI study is to gather data, though some preliminary analysis could take place, such as examining immune responses and inflammatory issues during pregnancy.
"It's a funding thing," Dr. Newschaffer explained. "This is expensive. The vast majority of dollars we have right now is to establish enrollment and begin building a biological archive for the first five years."
But more grant money is anticipated for further analyses, and independent scientists could also write proposals for ancillary grants to examine some data during the collection period, before the full data-sharing program begins. "Those scientists with appropriate expertise could propose a partnership with program researchers to work on samples that we are developing," Dr. Newschaffer said.
"I would love to see every bit of this data analyzed," he said when asked about examining links between vaccines and autism. "It is so unlikely that it (immunization) will not be analyzed. We are not collecting this information just to sit on it."
*Note: Approved studies include CDC's CADDRE investigation into thimerosal exposures and autism, and the HHS/EPA National Child Study, which is looking at vaccines and autism, among many other things. And last week, the National Vaccine Advisory Committee, which includes members from HHS, NIH and CDC, unanimously recommended a feasibility study on vaccinated-vs-unvaccinated children, plus three types of vaccine-autism studies on mitochondrial dysfunction, regressive ASD cases, and certain vaccine injures that might also show a correlation with ASD).
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