Viral exposure and autism

A whole slew of articles published by Ivan Gentile and colleagues based at the University of Naples (Italy) brought me to writing this post looking at some of the literature on viral exposures and autism. Viruses, in case you didn't know, are some of nature's survivors, infecting host cells and reproducing, onwards hopeful of finding more (un)willing cells/organisms to infect. Humankind have developed various biological defence mechanisms against the viral (and bacterial) onslaught that we all face as part of daily life, part of which is the production of antibodies. Antibodies are all about identification, action and memory and form the basis for why we vaccinate against various disease causing viruses. Sometimes antibodies also take part in a process called neutralisation which is all about rendering a virus ineffective when it comes to infectivity.

A founder of virology @ Wikipedia 

I've talked previously on this blog about viruses and their possible connection to some cases of autism (see here for example). I've also discussed how traces of the viruses of yesteryear (many, many yesteryears) can still be found in our genome and how such fossil viruses may, in some cases, still impact on our health and wellbeing (see here and see here). But enough of all this idle chatter...

The specific papers under discussion today include:

• Prevalence and Titre of Antibodies to Cytomegalovirus and Epstein-Barr Virus in Patients with Autism Spectrum Disorder [1]
• Exposure to Varicella Zoster Virus Is Higher in Children with Autism Spectrum Disorder than in Healthy Controls. Results from a Case-control Study [2]
• Prevalence of Herpes Simplex Virus 1 and 2 Antibodies in Patients with Autism Spectrum Disorders [3]

Let's call them paper 1, paper 2 and paper 3 respectively for convenience.

All were published in the journal In Vivo and follow some history looking at viral infections and autism by this research group [4] including those most contentious of viral infections when it comes to autism: measles, mumps and rubella [5]. I might also add that some speculations from this group looking at linking genetic predisposition, vitamin D deficiency and infection potentially correlating with a "a deranged immune response" with some autism in mind [6] might not be as outlandish as once thought. Indeed, that review paper [6] is probably one of the best I've read in a long time drawing on the available data on immune function and autism bearing in mind the emerging vitamin D story (see here).

Anyhow:

• Papers 1-3 all relied on the same participant groups, that is: 54 children diagnosed with an autism spectrum disorder (ASD) and 46 asymptomatic controls. 
• Exposure (seropositivity) rates and antibody titer levels to Cytomegalovirus (CMV) and Epstein-Barr Virus (EBV) (paper 1), Varicella Zoster Virus (VZV) (paper 2) and Herpes Simplex Virus 1 (HSV1) and Herpes Simplex Virus 2 (HSV2) (paper 3) were measured and compared between groups.
• Paper 3 detailing the findings on HSV1 and HSV2 concluded: "Seropositivity rate and levels of anti-HSV1/2 were not dissimilar between cases and controls". In other words, nothing to see there in this cohort.
• Paper 1 looking at CMV and EBV came to a similar conclusion as that of paper 3, although the authors note: "considering only patients with ASD, those seropositive for CMV tended to test worse to the major severity scales than the seronegative ones". With my recent interest in CMV and autism (see here), I'm intrigued...
• Paper 2 provides something of a more 'positive' result with it's analysis of VZV, the virus linked to chickenpox and shingles, in connection to the autism grouping. Authors concluded: "The exposure rate and titer of anti-VZV antibodies were significantly higher in children with ASD compared to controls (59% vs. 39% and 694 mIU/ml vs. 94 mIU/ml, respectively)". Further: "exposure to VZV was found to be independently associated with ASD".

We do have to be a little bit careful when it comes to these studies on the basis of their small participant numbers and the applicability of results to other groups whether in age or geography. As per some previous chatter about the other Gentile paper on MMR antibodies and autism (see here) not every study agreed with their findings [7]. Likewise, these latest results say nothing about 'causation' in terms of autistic presentation outside what is already suspected with something like CMV and autism in mind [8]. Correlation is not the same as causation, as if you needed telling.

That all being said I do think there is more to do in this area. There is some research history when it comes viral infection and autism as per the review by Libbey and colleagues [9] and in amongst that literature is mention of varicella [10] including "cases of autism associated with postnatal varicella encephalitis" [11]. The quite stark disparity in mean antibody titers to VZV between autism and control groups suggests that something might be afoot outside of just some healthy immunity to something like chicken pox.

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[1] Gentile I. et al. Prevalence and Titre of Antibodies to Cytomegalovirus and Epstein-Barr Virus in Patients with Autism Spectrum Disorder. In Vivo. 2014 07-08;28(4):621-626.

[2] Gentile I. et al. Exposure to Varicella Zoster Virus Is Higher in Children with Autism Spectrum Disorder than in Healthy Controls. Results from a Case-control Study.  In Vivo. 2014 07-08;28(4):627-631.

[3] Gentile I. et al. Prevalence of Herpes Simplex Virus 1 and 2 Antibodies in Patients with Autism Spectrum Disorders. In Vivo. 2014 07-08;28(4):667-671.

[4] Gentile I. et al. Prevalence of HHV-6 and HHV-8 antibodies in patients with autism spectrum disorders. In Vivo. 2013 Nov-Dec;27(6):843-9.

[5] Gentile I. et al. Response to measles-mumps-rubella vaccine in children with autism spectrum disorders. In Vivo. 2013 May-Jun;27(3):377-82.

[6] Gentile I. et al. Etiopathogenesis of autism spectrum disorders: fitting the pieces of the puzzle together. Med Hypotheses. 2013 Jul;81(1):26-35.

[7] Singh VK. et al. Abnormal measles-mumps-rubella antibodies and CNS autoimmunity in children with autism. J Biomed Sci. 2002 Jul-Aug;9(4):359-64.

[8] Sakamoto A. et al. Retrospective diagnosis of congenital cytomegalovirus infection in children with autism spectrum disorder but no other major neurologic deficit. Brain Dev. 2014 Apr 22. pii: S0387-7604(14)00094-1.

[9] Libbey JE. et al. Autistic disorder and viral infections. J Neurovirol. 2005 Feb;11(1):1-10.

[10] Deykin EY. & MacMahon B. Viral exposure and autism. Am J Epidemiol. 1979 Jun;109(6):628-38

[11] Knobloch H. & Pasamanick B. Some etiologic and prognostic factors in early infantile autism and psychosis. Pediatrics. 1975 Feb;55(2):182-91.

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Gentile I, Zappulo E, Bonavolta R, Maresca R, Messana T, Buonomo AR, Portella G, Sorrentino R, Settimi A, Pascotto A, Borgia G, & Bravaccio C (2014). Prevalence and Titre of Antibodies to Cytomegalovirus and Epstein-Barr Virus in Patients with Autism Spectrum Disorder. In vivo (Athens, Greece), 28 (4), 621-626 PMID: 24982232


Gentile I, Zappulo E, Bonavolta R, Maresca R, Riccio MP, Buonomo AR, Portella G, Settimi A, Pascotto A, Borgia G, & Bravaccio C (2014). Exposure to Varicella Zoster Virus Is Higher in Children with Autism Spectrum Disorder than in Healthy Controls. Results from a Case-control Study. In vivo (Athens, Greece), 28 (4), 627-631 PMID: 24982233


Gentile I, Zappulo E, Bonavolta R, Maresca R, Riccio MP, Buonomo AR, Portella G, Vallefuoco L, Settimi A, Pascotto A, Borgia G, & Bravaccio C (2014). Prevalence of Herpes Simplex Virus 1 and 2 Antibodies in Patients with Autism Spectrum Disorders. In vivo (Athens, Greece), 28 (4), 667-671 PMID: 24982239

Intravenous vitamin C therapy and Epstein-Barr antibodies?

Just before you click away from this post based on the title mumbling the name 'Linus Pauling' with reference to his advocacy of high dose vitamin C for all-manner of symptoms and conditions, I'd like to point out that I am not suggesting that vitamin C is a cure-all for Epstein Barr virus (EBV) or anything else outside of the current recommendations. Medical or clinical advice is not given or intended on this blog.

An orange a day... @ Wikipedia 

That being said, I do want to talk today about the paper by Mikirova & Hunninghake [1] (open-access here) reporting a: "reduction in EBV EA [early antigen-diffuse] IgG and EBV VCA [viral capsid antigen] IgM antibody levels over time during IVC [intravenous vitamin C] therapy that is consistent with observations from the literature that millimolar levels of ascorbate hinder viral infection and replication in vitro". Outside of any interest in how vitamin C might affect the process of viral infection, I was drawn to this paper because of the focus on Chronic Fatigue Syndrome (CFS) in the author's particular patient group, following some other discussions on this blog about the [possible] connection between CFS and EBV (see here and see here).

So:

• Take a patient history database housed at a "nutritional medicine treatment and research clinic" and do a few things: (a) look through a subset of 35 cases where "EBV EA IgG levels before and after treatments" are available to analyse for the possibility of a response to IVC therapy, and (b) look at whether there may be correlations to be had between EBV antibodies and plasma levels of vitamin C and the sunshine vitamin/hormone that is vitamin D.
• Results: well bearing in mind that this a case series report and not a clinical trial of IVC intervention (so not randomised nor double-blind nor placebo-controlled), there are a few interesting trends that were noted. Outside of any focus on individual patients (or any 'typical patient' - see Figure 1), there did seem to be a general trend of decreasing EBV EA IgG levels correlating with use of various dosages of IVC administration. "The average EBV EA IgG level before treatment was 80±55 (SD) AU, while the average after treatment was 46±43 (SD) AU. This was an average improvement of roughly forty percent, and the difference was highly statistically significant (p=0.001)". 
• Then to the correlations. "We also found evidence that EBV antibody expression correlates with plasma ascorbic acid concentrations". Ascorbic acid is a vitamer of vitamin C by the way. That and the fact that "vitamin D concentration correlates with EBV AG IgG antibody levels" (this was a negative correlation BTW).

There are a few important caveats to make about these results before anyone gets too carried away at this time. Outside of the study type mentioned previously, there is one very important detail missing from this current paper: what happened to patient symptoms as a result of their IVC intervention? I'm not only talking about their symptoms in terms of CFS or other condition and how that played out over the intervention period and whether there was any correlation between symptom presentation and EBV antibody load, but also the question of any adverse reactions or side-effects to the infusions. I'm also minded to point out the length of time between before and after IVC interventions in terms of antibodies, and whether one might reasonably assume that lots of other factors might also have affected EBV antibody load when talking about there being between 24 and 243 days between pre and post testing? I don't know enough about the path of EBV infection and antibody responses to definitively answer this question, so just leave it hanging there for now.

With all those factors in mind, I would however reiterate my interest in the Mikirova / Hunninghake findings and where they could potentially take us. I note that one of the authors of the paper has blogged about the use of IVC and the "successful treatment of viral infections". I don't want to get too carried away with any sweeping generalisations about what vitamin C might or might not be able to do to viral infections so am not going to provide any grand review of this area in this post. What I will say is that specifically with EBV in mind, there is a dearth of research on the use of vitamin C outside of the paper by Shatzer and colleagues [2] reporting mixed results. When it comes to vitamin D however, there is a little more reading material to peruse [3] but again, with the important caveat about more investigation(s) required. 

I know that things can get a little 'heated' when discussions about the effects of vitamins and minerals are conducted and big sweeping statements are made. I don't think we should forget that it wasn't so long ago that a condition called scurvy was not an infrequent visitor for quite a few people. Indeed, going back to my more usual research home of autism, even in modern times there are still reports of scurvy being diagnosed (see here) something I'm gonna talk about in coming weeks. Above and beyond the effect of vitamin C depletion and scurvy however, there may be some merit in continuing research on the use of vitamin C in a more controlled manner when it comes to things like EBV. Certainly if one considers that there may be a link between CFS and EBV (among other pathogens), and the often dramatic effects that CFS can have on a person's wellbeing and day-to-day life, anything that potentially might alleviate the effects of that condition has to be worthy of further investigation.

Music to close. As we all said goodbye to Rik Mayall: 'everyone everywhere stop snogging'...

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[1] Mikirova N. & Hunninghake R. Effect of high dose vitamin C on Epstein-Barr viral infection. Med Sci Monit. 2014 May 3;20:725-32.

[2] Shatzer AN. et al. Ascorbic acid kills Epstein-Barr virus positive Burkitt lymphoma cells and Epstein-Barr virus transformed B-cells in vitro, but not in vivo. Leuk Lymphoma. 2013 May;54(5):1069-78.

[3] Salzer J. et al. Epstein-Barr virus antibodies and vitamin D in prospective multiple sclerosis biobank samples. Mult Scler. 2013 Oct;19(12):1587-91.

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Mikirova N, & Hunninghake R (2014). Effect of high dose vitamin C on Epstein-Barr viral infection. Medical science monitor : international medical journal of experimental and clinical research, 20, 725-32 PMID: 24793092