Wednesday, September 28, 2011

Has a Cause for Autism Been Found?

Yesterday I happened to be looking at the Fox News health page when I noticed the headline "Doctors Find Link Between Lyme Disease, Autism" which would certainly be significant news. Of course, Autism Spectrum Disorder (ASD) has been of prominent interest over the past decade as diagnoses have continued to increase, its alleged association with vaccines and the subsequent scientific and ethical demolition of the researcher that promoted this hypothesis. In the end Andrew Wakefield's co-authors of the paper in the Lancet that purportedly showed a link between the MMR vaccine and autism withdrew their names, the paper was retracted, and Wakefield was banned from practicing medicine in his home of England. Thus far, based on my understanding of the evidence, researchers are still looking at possible factors that lead to ASD.


Thus given the current state of research, along with the fact that I was reading Fox News in the back of my mind, I was skeptical to say the least, though eager to see what the doctors found to support a link between lyme disease and autism.

Sadly, the article relays the story of a young woman that has been diagnosed with ASD since she was two.  After suffering from suffered from undiagnosed digestive problems, skin infections and internal problems for 17 years she was taken to an un-named autism specialist [note - the Fox article mentions a Dr. Lynne Mielke, however from the context of the article, namely that the mother refers to the specialist as a 'he' whereas Dr. Lynne Mielke is clearly female, she doesn't appear to be the specialist who diagnosed the daughter] who, after learning that the young woman's mother had found two ticks on her before she got pregnant, ordered a lyme disease test for the mother.  The test came back positive.

Let's stop here and examine what we know: the mother of a child with ASD happened to find two ticks on her before the pregnancy.  We don't know how long before the pregnancy the ticks were found or what kind of ticks they were.  But perhaps more importantly, there is no indication in the article that the mother had any symptoms that would point to lyme disease, which makes the fact that she was tested for lyme disease rather curious.
"If a child has autism from birth, many times it's because the child inherited an infection from the mother. I do think that Lyme disease, especially congenital Lyme is a cause of autism ," said Autism Specialist Dr. Lynne Mielke. 
Dr. Miekle says Mary contracted Lyme disease from Tina through pregnancy and she believes the Lyme played a big role in the development of Mary’s autism

Certainly, to suspect, based on the fact that the mother at some point in time found a tick on her, that the mother may have developed lyme disease and carried it for 19 years without any symptoms and possibly transmitted it to her daughter thereby causing her ASD, seems specious at best.

Specious hypotheses aside, notice that the article is completely devoid of any discussion of the actual evidence for or against this hypothesis.  There is no mention of clinical or epidemiological studies.  I did a PubMed search for "Lyme Autism" and came back with four results, three of which didn't address the hypothetical link.  The abstract of the one that did indicates that infectious diseases "may have direct effects" on fetal development, unsurprisingly.  Though the abstract doesn't indicate how many subjects were studied or what level of  correlation might exist.  The study may be solid, but without seeing the full text it is difficult to know.  However, more tellingly perhaps, is the dirth of studies replicating the results.  As such, it would seem entirely premature to conclude that "Lyme is a cause of autism", as Mielke does.

So what we have is an anecdote of a diagnosis on a very questionable basis from an unnamed doctor, which is justified by the opinion of a single doctor.  

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An you might be wondering about Dr. Lynne Meilke. Turns out she is the founder of the Developmental Spectrums clinic which employs several dubious medical treatments including chelation therapy as well as promoting the use of supplements (which the clinic also happens to sell). But most notably, as it relates to the discussion of autism, the clinic is equivocative in its stance on the discredited link to vaccines.
Many anti-vaccine advocates feel that vaccines are dangerous and don’t even work. But that hasn’t been my experience, nor is it my understanding based on all available research.
This is somewhat incongruously followed by this string of questions:
Does a child with autism have a greater risk of suffering a vaccine reaction (or as some parents would say, another vaccine reaction) if he continues to get more vaccines? And what about any younger siblings that come along? Should the parents vaccinate their next baby(ies)? That’s the bigger question. Is there a point where, for certain families, the risk of vaccines could outweigh the benefits of disease protection for that particular family? It would be nice if we could screen newborns for genetic and metabolic susceptibilities to severe vaccine reactions. We could then vaccinate such babies more carefully and find ways to avoid these reactions. But we don’t have that technology yet. So what is a family with autism to do? If they don’t vaccinate their subsequent children, does that put their child, and society as a whole, at risk?

Given that the alleged link between vaccines and autism has been shown to be illusory at best (and completely fabricated at worst), these equivocate statements are ostensibly reasonable, but don't have any basis in the published literature (if they do, there is no citation of their sources).

If Meilke had stopped typing there, we might give her the benefit of the doubt as a concerned, but not well educated on the state of the current research. However, we learn that her child has autism, which must be truly difficult for a parent. But her hand is tipped:
For any mainstream pro-vaccine person reading this, you are probably not happy to hear me make that statement. But I feel that the chemicals and immune-modulating properties of vaccines may cause further neurological, inflammatory, or autoimmune changes within that child (who already is dealing with such issues) and possibly make the autism worse. Now, do I have any science to back up my statement? Not directly, no.
And there you have it.  What can you say to that?  I don't have evidence for my claim, but I believe it nevertheless.

This highlights the extensive damage that Andrew Wakefield's 1998 study, motivated by his patent to sell an alternative to the vaccine schedule, has done to the state of child vaccination.  I only hope that this issue continues to get the attention it deserves in the blogosphere, the media, and in public policy so that these decisions are science-based and rational.