Friday, 17 August 2012

Vitamin D and autoimmunity and autism

Heavens above @ Paul Whiteley
They're at it again. The very marvellous Saudi-Egyptian autism research tag-team that is Gehan Mostafa and Laila Al-Ayadhi and another very, very interesting article titled: Reduced serum concentrations of 25-hydroxy vitamin D in children with autism: relation to autoimmunity* (full-text here).

I'd kinda been waiting for an article like this to come along given the shifting Eye of Sauron onto a possible role for the sunshine vitamin in cases of autism. You can find a little more background on the whole vitamin D-autism research base in a previous post I wrote some while back (here). I might also at this point plug a few other previous posts focused on vitamin D: leaky gut? (here), mental health and vitamin D deficiency? (here) and synthesis of vitamin D and the "evil" cholesterol (here). OK, stop with the self-promotion already.

The latest paper is full-text but to briefly summarise:

  • This wasn't just a study to see whether children with autism were deficient in vitamin D, or rather the active form of the vitamin, 25-hydroxy vitamin D, but rather also some inspection of any link between vitamin D levels and a feature of autoimmunity given the proposed immunological effects of vitamin D and the previously discussed suggestion of a link between autoimmunity and cases of autism.
  • Fifty children with autism (aged 5-12 years) were compared against 30 asymptomatic control children. Sunshine exposure data were collected, supplementation controlled for, and serum levels of 25-hydroxy vitamin D were ascertained during the spring/summer months (April-September).
  • Levels of anti-myelin-associated glycoprotein (anti-MAG) auto-antibodies were also measured in both groups. The presence of anti-MAG antibodies is basically a sign that the body is attacking myelin associated glycoproteins; myelin being an essential part of proper neuronal functioning. Elevations in anti-MAG antibodies is a sign that brain tissue is being targeted by the bodies own immune system.
  • The results: as a group, the children with autism presented with lower levels of 25-hydroxy vitamin D than controls (P<0.001), with about 40% of the autism group being classified as vitamin D deficient (<10ng/mL). None of the controls fell into the deficient range (although about 20% were classified as being 'insufficent' <30ng/mL). These results were based on pretty much equivalent sunshine exposure between the groups. There was also a suggestion of a negative correlation between 25-hydroxy vitamin D levels and scores on the CARS.
  • Children with autism as a group also presented with significantly higher levels of anti-MAG auto-antibodies compared to controls (P<0.001). Indeed increased levels were found in about 70% of participants with autism.
  • Serum 25-hydroxy vitamin D levels also significantly negatively correlated with anti-MAG auto-antibodies in children with autism.

Accepting that the participant groups were relatively small and the findings based on children I assume of Saudi origin, it is quite telling that children with autism living in a country where sunshine is probably not in short supply were still in the majority deficient in the active form of vitamin D. Appreciating the health advice that is provided nowadays when it comes to being 'sun aware' I still find some difficulty in accepting the fact that people in this region might not be getting enough sunshine to synthesise vitamin D as a way of accounting for the results. Could it be that autism, some cases of autism, confer problems with the biological synthesis and metabolism of vitamin D or even with the functioning of vitamin D receptors? If so, what are the implications for supplementation for example?

Anti-MAG antibodies is a new one for me in the autism research arena. Linked to a variety of autoimmune peripheral neuropathies, anti-MAG antibodies have actually been reported previously in cases of autism** (by the same authors). In that study, the authors introduced the possibility that "autism could be, in part, one of the pediatric autoimmune neuropsychiatric disorders". I'm not going to get too bogged down in the potential impact of anti-MAG antibodies and autism at this point though as more reading on my part is required.

So in short, a few more potential pointers for further investigations from the Saudi-Egyptian research team and another intriguing connection between vitamins and autism.  

To finish, I'm in the mood for a little Stranglers at the moment and a lovely tune called Gordon Brown... sorry, Golden Brown to at least remember what the sun looks like.

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* Mostafa G. & Al-Ayadhi LY. Reduced serum concentrations of 25-hydroxy vitamin D in children with autism: relation to autoimmunity. Journal of Neuroinflammation. August 2012.

** Mostafa GA. et al. Serum anti-myelin—associated glycoprotein antibodies in Egyptian autistic children. Journal of Child Neurology. 2008; 23: 1413-1418.

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  ResearchBlogging.org
Mostafa G, & Al-Ayadhi L (2012). Reduced serum concentrations of 25-hydroxy vitamin D in children with autism: relation to autoimmunity Journal of Neuroinflammation
DOI: 10.1186/1742-2094-9-201