Here at the Beach, Still Hearing about Vaccines and Autism
August 19, 2008 by Kristina Chew, PhD
Filed under Health
Yes, we’ve been on vacation; meanwhile, the usual back and forth about vaccines and autism rages: CBS news say they’ve unearthed “details of a third case of vaccine injury in a child born in 1974″—as Kev’s noted, Kathleen Seidel described this same case five months ago on the Neurodiversity blog, CBS news is catching up in these dog days of summer.
No mention of autism and vaccines is complete without a nod to mercury: Translating Autism reviews a recent study in Journal of Toxicology and Environmental Health, Part A, entitled An Investigation of Porphyrinuria in Australian Children with Autism. Here’s his summary:
The study examined urinary porphyrins as a measure of mercury exposure in children with autism. Porphyrinuria, or the excess urinary excretion of porphyrin, is purported to reflect heavy metal exposure and in particularly mercury. Two previous studies (Nataf et al., 2006, and Geier & Geier, 2007) used this urinary measure and reported increased levels of porphyrins in children with autism when compared to typically developing children. In the current study the authors examined urinary samples of 41 patients with ASD (detailed diagnostic procedure information was not provided). The age of the sample ranged from 1 to 16 (average 6). There were 30 boys and 11 girls. The authors did not include a control group. That is, no local comparison group of typically developing children was used. Instead, the authors compared the levels of porphyrins of the Australian sample with the control samples (typically developing kids) used by the two previous studies as well as to ‘normative’ laboratory ranges obtained from a French laboratory and the normative ranges published in a 1996 European study (Minder and Schneider-Yin, 1996).
The authors reported that the ratio of uroporphyrin to coproporphyrin (CP to UP) was significantly higher in the Australian ASD group when compared to all control samples of the previous studies.
All that this study proves, as Translating Autism points out, is that there is a “strong difference in the CP to UP ratio between the Australian sample and typically developing children in the USA and France” and that is all, not that mercury causes or is linked to autism.
Remains to be seen how others “read” these results.
Without having read the full text, the lack of a local control/typical comparison group seems to be a significant limitation to this study.
That’s a point that Translating Autism makes several times.
Hello friends -
I just read that the other day. I was pleased, because previously the other duplication porphyrin profiles observed by Nataf was by the Geiers, who have obvious credibility issues.
If the ‘mercury militia’ is guilty of overplaying the role of vaccines (they are, IMO), the neurodiverse can be just as guilty of underplaying the importance of our increasing dataset on the biology of autism in regards to external agents. The analysis that this paper proves nothing about casaulity, or vaccines, is dead on; but that doesn’t mean we should discard xenobiotics as potential problems in children with autism. Treating this additional knowledge as flippant runs the same risk as shouting that it proves mercury causes autism; a sense of bias when evaluating science.
We now have three clinical analysis showing abnormal porphyrin profiles in children with autism as compared to ‘normal’ children. In at least one study, (Nataf), administration of chelating agents resulted in a normalization of porphryin profiles.
Two sets of researchers have found that having mutations in a gene responsible for glutathione encoding roughly doubles the risk of developing autism. Likewise, glutathione levels and precurosor chemicals in children with autism have been found to be abnormal when compared to normal children.
The Wong/Desoto debacle told us that kids with autism do have more mercury in their blood than their peers. As Epiwonk nicely pointed out in a recent blog entry, the clinical significance of the rise is unknown, but the increase is not in dispute. Kids with autism are more likely to have higher levels of mercury than undiagnosed children.
While none of this means mercury causes autism, it does mean that the physiology of people with autism tends to lend itself poorly to dealing with mercury; and a host of other agents. Getting a better understanding of what has been observed is good for children with autism; the more we know the more we can help.
Remains to be seen how others “read” these results.
So true.
- pD
-pD
Yes, we all consume small amounts of mercury all the time — methylmercury in the water, in fish, and elsewhere.
“Now, CBS News has obtained details of a third case of vaccine injury”. Wow, sounds like real investigative reporting. What a joke.
The government has been as open as the law allows in posting details from the vaccine court. CBS just figured out it is on the web site.
pD – long time no see
– I think the Porphyrin thing is a bit of a dead horse to be honest. Even Liz Mumper, clinical director of DAN! (I think thats her title) has admitted that the Porph results she and other DAN!s are seeing from the Nataf lab indicate no real difference between NT kids and autistic kids. From her Autism Omnibus testimony:
Hi Kev –
I’ve been trying, with marginal success, to focus on things other than arguing with people on the Internet lately. I have noticed the updates to leftbrainrightbrain and am generally impressed with the production qualities. [if not, at times, how you treat my biomed buddies]
Anyways, in any case, I would agree that diagnosing mercury toxicity based on porphyrins is not supporable right now. But remember, the study in question used reference ranges from several other studies of normal children, and found very significant differences against control in all cases, including studies completely unrelated to autism. If a big flaw of this study is the lack of a local control group, I’d say drawing conclusions based on court testimony and the statement that ’some’ normal children also have abnormal patterns is very risky stuff.
To start with, we’d have to understand the number of children that ’some’ children means, and how much their profiles varied from normal.
If I am not mistaken, you tend to take a poor view of discarding applied scientific findings based on unpublished, heard it by mouth findings by DAN doctors. Would you agree with Mumper that we can use porphyrin analysis to detect differential toxicities? It does seem clear that there are good number of studies showing differential porphyin values in people who have known mercury, or other environmental agent exposure.
There very well could be things other than environmental agents that could cause a backup in porphryin components; but we’d need to find a mechanism to explain why chelating agents got values to normalize.
Such an explanation would also do nothing in so far as our ability to explain away the re-analysis of Wong/DeSoto and/or increased relative risks for autism by means of mutations in glutathione encoding genes.
- pD
Just a question – do people think the environment is more toxic now than in the past, say during the hey day of Ancient Rome when they were polluting the environment with copper smelting or during the Industrial Revolution? I’ve often thought that, as bad as we are today, we’ve got to be better than when there was absolutely NO regulation whatsoever, but I could be naive.