Tuesday 30 April 2013

Lyme and soda: hold the autism risk?

I've talked about the mighty tick previously on this blog and some speculation on how a tick harbouring the bacteria Borrelia burgdorferi (or a close relation) bites and transmits said bacteria to humans which can lead to Lyme disease and whether this might be implicated in some cases of autism.

 Tickety boo @ Wikipedia  
The suggestion from that post was that whilst the data was speculative and relatively sparse at that time on whether Lyme disease is common in cases of autism or indeed could 'cause' autism, there might be some room to test one or two hypotheses regarding a possible link between the two conditions.

Two years on, I'm happy to report that someone has finally looked at the possibility of a connection in the form of a letter by Mary Ajamian and colleagues* published in the journal JAMA. The results: no link between Lyme disease and autism in a sizeable cohort of children/young adults with autism or indeed Lyme disease and control participants.

The ins-and-outs of the study have been quite widely reported, for example with headlines like: 'Autism-Lyme Correlation Debunked' and 'Autism And Lyme Disease Link Is Bunk, Study Says'. Using a two-tiered assay based on initial screening for antibodies to B.burgdorferi (IgG and IgM) and Western blotting for antibodies in suspect cases, the authors were systematically able to test for signs of infection and found pretty much nothing.

Interestingly, the authors are quoted as saying that their study, whilst well-powered and based on the US CDC advice for screening for Lyme disease, might not necessarily spell the end of any association between Lyme disease and autism. To quote from this news source: "The researchers also pointed out that their analysis did not address the question of whether Lyme disease might cause autism-like behavioral deficits". That for example earlier infection during infancy or even in-utero might be linked to cases of autism was not part and parcel of the Ajamian study. Certainly with all the recent speculation turning to the earliest time of life being linked to autism risk - think folate and valproate for example - I don't think we are in a position to yet discount such possibilities. That and the renewed focus on the tetracyclines with autism in mind (used to treat Lyme disease).


The Ajamian study must be seen as compelling evidence that no current infection pertinent to Lyme disease exists in cases of autism or controls, or at least the cases that were under investigation. I know infection is still quite a hot potato when it comes to autism risk (remembering this study by Hornig and colleagues** and all that XMRV overspill into autism spectrum disorders) bearing in mind the continued speculation on all those possible in-utero exposures whether viral or bacterial. I would bring you back to that most classical of autism risk factors - congenital rubella as per the study by Chess and colleagues*** - as evidence that external agents might be associated with autism onset and how the wider search for potentially linked pathogens should not be tarnished by the latest findings.

Update (10/05/13) And just a few days later... Lack of serum antibodies against Borrelia burgdorferi in children with autism by Burbelo and colleagues****.


* Ajamian M. et al. Serologic markers of Lyme Disease in children with autism. JAMA. 2013; 309: 1771-1773.

** Hornig M. et al. Lack of association between measles virus vaccine and autism with enteropathy: a case-control study. PLoS ONE. 2008; 3: e3140.

*** Chess S. et al. Behavioral consequences of congenital rubella. J Pediatr. 1978; 93: 699-703.

**** Burbelo PD. et al. Lack of serum antibodies against Borrelia burgdorferi in children with autism. Clin Vaccine Immunol. May 2013.


ResearchBlogging.org Mary Ajamian, Barry E. Kosofsky, Gary P. Wormser, Anjali M. Rajadhyaksha, & Armin Alaedini (2013). Serologic Markers of Lyme Disease in Children With Autism JAMA, 309 (17), 1771-1773

Monday 29 April 2013

Autism and the folding placenta

Men don't generally talk about placentas it has to be said. But today, in the name of blogging, I'm going to.

I'm going to start by telling you how the placenta really is a marvel of biological engineering. An absolutely vital part of our existence in-utero that nourishes us and protects us during our earliest days living in the amniotic sac. Little wonder that whole nations have come to revere the placenta as mother, sibling even doubles of ourselves (see here). Although I have to say I do draw the line at placenta pate.
 Folding time @ Wikipedia  

The reason for all this appreciation of the placenta follows the publication of a paper by Cheryl Walker and colleagues* who, as part of the MARBLES initiative (don't you just love these acronyms), reported that looking for trophoblast inclusions (TIs) in the placenta "could serve as a predictor for children at elevated risk for autism spectrum disorder (ASD)".

Trophoblasts by the way, are a specialised group of cells which play an important role in processes like embryo implantation. Trophoblast inclusions are abnormal cell cluster which form, "a distinctive microscopic placental morphological abnormality" linked to tissue folding described by some of the same authors in earlier work in this area**.

In the most recent paper, the authors detail the blinded examination of 117 placentas (used of course) from "at-risk" siblings of children already diagnosed with an autism spectrum disorder (ASD) compared with 100 control specimens for the frequency of TIs. Whereas control placentas had no more than 4 TIs, the at-risk sibling placentas "had an eight-fold increased odds of having two or more TIs" according to accompanying press.

Prediction values, as in blinded prediction of those at-risk siblings compared to controls were reported according to the number of TIs identified. In other accompanying press literature on this study, a figure of 90%+ accuracy is reported "to identify without prior knowledge which of the placentas came from the younger sibling of a child with autism, and which from another study participant who did not have autism in the family".  This however was offset by corresponding issues with sensitivity. The implication for this work being that examining placentas might yield either important information about the subsequent risk of a child developing autism or an ASD and/or lead to new clues about the prenatal environment linked to cases of autism.

I highlighted the previous paper by some of the authors in this area and note how in that study they were actually looking at archived placental tissue from those who were subsequently diagnosed with ASD (n=13). Indeed in that study, TIs were reported as present in 5 of the 13 samples from participants with ASD (38%) compared with 8 of 61 controls (13%). You can perhaps see from these figures that we are probably not talking about an all-or-nothing relationship when it comes to TIs 'predicting' autism or not.

There's no doubt that the Walker results are interesting and potentially informative if reproducible bearing in mind I'm still a little unclear on the hows and whys of TIs and autism risk. Sure, the authors speculate that this might be part and parcel of some of the genetic landscape of autism, given the link between TIs and chromosomal disorders***, but that might not be the whole story**** (thanks Natasa) and with some interesting knock-on effects***** (open-access). Please note I am not making links between any specific infection, autism and TIs at this point.

I'm very interested in this whole area of pregnancy and gestation as perhaps being critical times for autism, sorry the autisms; recognising that this area of investigation might not cover every case of autism - think regression for example. I'm minded also to take you back to the Barker hypothesis (see this post) and think whether or not one might extrapolate some of the work on placental functioning****** to overlap with autism risk? Just thinking out loud as others eminently more qualified than I already have.


* Walker CK. et al. Trophoblast inclusions are significantly increased in the placentas of children in families at risk for autism. Biol Psychiatry. April 2013.

** Anderson GM. et al. Placental trophoblast inclusions in autism spectrum disorder. Biol Psychiatry. 2007; 61: 487-491.

*** Kliman HJ. Structural abnormalities in the placenta. BMC Pregnancy and Childbirth. 2012; 12(Suppl 1): A3.

**** Banks J. et al. Chlamydia trachomatis infection of mouse trophoblasts. Infection & Immunity. 1982; 38: 368-370.

***** de la Torre E. et al. Chlamydia trachomatis infection modulates trophoblast cytokine/chemokine production. J Immunol. 2009; 182: 3735–3745.

****** Henrikson T. & Clausen T. The fetal origins hypothesis: placental insufficiency and inheritance versus maternal malnutrition in well-nourished populations. Acta Obstetricia et Gynecologica Scandinavica. 2008; 81: 112–114.


ResearchBlogging.org Walker, C., Anderson, K., Milano, K., Ye, S., Tancredi, D., Pessah, I., Hertz-Picciotto, I., & Kliman, H. (2013). Trophoblast Inclusions Are Significantly Increased in the Placentas of Children in Families at Risk for Autism Biological Psychiatry DOI: 10.1016/j.biopsych.2013.03.006

Saturday 27 April 2013

A vaccine for autism symptoms? Not exactly

"Vaccine". "Autism".

I'm struggling to think of two words in combination which, in modern times, are any more likely to stir up emotion, debate and even argument. Indeed in these times of measles outbreaks and seemingly daily news reporting on the very, very strong requirement for vaccination to protect against the disease, it is coincidental that two research papers should now land in my inbox which mention both of those words in the title.
Paradise in Zakynthos @ Wikipedia  

The first paper is by Ivan Gentile and colleagues* reporting on seropositivity rates to measles, mumps and rubella in cases of autism spectrum disorder (ASD) following MMR vaccination. The second paper, by Brittany Pequegnat and colleagues**, discusses the concept and early development of a vaccine targeting a specific type of gut bacteria which the authors speculate might have some interesting knock-on effects to some of the signs and symptoms linked to cases of autism.

Although pertinent to the current measles news, I'm not on this occasions heading too far into the Gentile paper. My reasoning is two-fold: (i) the paper is fairly explanatory in that "children with ASD have a similar level and seropositivity rate of antibodies against the MMR vaccine to same-age controls" (bearing in mind the small participant numbers) and, (ii) I'm not really qualified to go into any heavy duty discussions on how this fits into the existing scientific literature on this topic; bearing in mind a similar finding previously published*** and a contrary one****. All I will say is that vaccination saves lives as per this CDC flier.

The Pequegnat paper has received some media attention with headlines like: "Vaccine To Help Autism Symptoms Developed" and "Scientists develop first vaccine to help control autism symptoms". As one might expect, headlines which don't necessarily reflect the actual science reported so far...

The long-and-short of the research is that based on some earlier findings of a specific gut bacterium being discovered in a group of children with autism***** - Clostridium bolteae previously called Clostridium clostridioforme (see here******) but renamed, I think, after Ellen Bolte******* - the authors applied some established know-how to begin formulating a vaccine targeting the surface sugars, polysaccharides, of C.bolteae. If you want to see the human face of the researchers involved, look no further than this article from 2012.

All that talk of this research helping to 'control' autism symptoms is, at the moment, more speculation than fact. As far as I can see, the authors got no further than providing the "first description of a C.bolteae immunogen" following some initial investigation in rabbits. It is therefore a significant jump to say that this vaccine will affect the behavioural presentation of autism. Indeed, no-one really knows if it will impact on any gastrointestinal (GI) symptoms either.

That being said, I am quite interested in their report and the concept that we could artificially stimulate immunity to 'undesirables' such as specific types of gut bacteria. As well as being particularly interested in all things bacteria on this blog (see here and here), a quick trawl of the scientific literature suggests that the future is now as per the paper by Sougioultzis and colleagues******** (open-access) on a C.diff toxoid vaccine. One wonders whether we might also apply similar logic to other bacterial findings related to autism such as that very interesting Sutterella work?

I am also drawn to the polysaccharide bit of the Pequegnat paper and whether or not it is useful to link back to the work of Harumi Jyonouchi and colleagues on the presence of specific polysaccharide antibody deficiency (SPAD) comorbid to some cases of autism. If I am interpreting this correctly, the suggestion is that SPAD interferes with correct antibody formation to polysaccharide coated bacteria which could have implications I assume, for vaccination to/against bacteria like C.bolteae also. I could be wrong though.

I'm gonna stop with this post shortly. There are other things I could say, for example, discussing the method of vaccine delivery (nanoparticle anyone?) including doing away with the big scary needle in favour of something a little more 'ouchless' (microneedles or even inhaled delivery). But that is perhaps fodder for another day.

Oh, and just so you know, on purpose I posted a lovely serene picture from the beautiful island of Zakynthos instead of one of those pictures of big needles complete with crying child which, as other commentators have pointed out, might not necessarily be the best platform on which to discuss the topic of vaccination.


* Gentile I. et al. Response to Measles-Mumps-Rubella vaccine in children with autism spectrum disorders. In Vivo. 2013; 27: 377-382.

** Pequegnat B. et al. A vaccine and diagnostic target for Clostridium bolteae, an autism-associated bacterium. Vaccine. April 2013.

*** Baird G. et al. Measles vaccination and antibody response in autism spectrum disorders. Arch Dis Child. 2008; 93: 832-837.

**** Singh VK. et al. Abnormal measles-mumps-rubella antibodies and CNS autoimmunity in children with autism. J Biomed Sci. 2002; 9: 359-364.

***** Finegold SM. et al. Gastrointestinal microflora studies in late-onset autism. Clin Infect Dis. 2002; 35 (Supplement 1): S6-S16.

****** Song Y. et al. Real-time PCR quantitation of Clostridia in feces of autistic children. Appl. Environ. Microbiol. 2004; 70: 6459-6465.

******* Bolte ER. Autism and Clostridium tetani. Med Hypotheses. 1998; 51: 133-144.

******** Sougioultzis S. et al. Clostridium difficile toxoid vaccine in recurrent C. difficile–associated diarrhea. Gastroenterology 2005; 128: 764–770.


ResearchBlogging.org Pequegnat B, Sagermann M, Valliani M, Toh M, Chow H, Allen-Vercoe E, & Monteiro MA (2013). A vaccine and diagnostic target for Clostridium bolteae, an autism-associated bacterium. Vaccine PMID: 23602537

Thursday 25 April 2013

Prenatal valproate exposure and autism: reloaded

When does the the term 'correlation does not equal causation' become a moot point? It's a question I've often pondered, having discussed the issue quite a few times on this blog for all manner of correlations and associations linked to autism (sorry, the autisms).

The weight of the heart @ Wikipedia  
Is there, for example, a recognised tipping point where the weight of evidence correlating A with B might actually lead to the consensus that A causes B either wholly or partially?

Yes, I know that science deals with probabilities not absolutes (something which we are all guilty of forgetting from time to time) and that science is generally quite reserved about its findings. But surely as per the example of smoking and lung cancer, there must be a time when the likelihood that A causes B creeps over the 'chance' explanation to something a little more concrete and directional?

The reason for the question(s) follows the publication of a study by Jakob Christensen and colleagues* (open-access) which suggested that in large and pretty well-defined Danish cohort "maternal use of valproate during pregnancy was associated with a significantly increased risk of autism spectrum disorder and childhood autism in the offspring". Regular readers might remember that quite recently there was some similar chatter on this antiepileptic medication based on the Bromley paper (see here) but on an altogether smaller scale compared with the current dataset.

There has been some media attention paid to the recent trial (see here and here) which is perhaps not surprising given the suggestion that approximately 1 in 20 mothers who were using valproate during pregnancy to control epilepsy or seizure disorders subsequently had a child with autism or an autism spectrum disorder (ASD). The actual risk (absolute risk) was quoted as 2.5% and 4.4% respectively based on the 508 children exposed to valproate in-utero. Even the latest 'survey' figures of 1 in 50 children presenting with an ASD in the US are seemingly dwarfed by the Christensen findings.

There are obviously caveats to all this talk about risk, and how risk is risk, not certainty. That also valproate is actually quite effective in controlling cases of epilepsy** is a point which should not get lost in any discussions on risk. Indeed when one reads such studies linking drug A to condition B, it's all too easy to forget that drug A is being taken for a reason; often a very important reason. Physicians generally do not enter lightly into such clinical decisions, particularly in light of past scandals of medication and pregnancy (see here). Not forgetting too that epilepsy can, in extreme cases kill***.

Outside of the autism-valproate link (if I can call it that) the Christensen data also includes some other potentially interesting factoids, as per the suggestion that among children of mums with epilepsy who were not exposed to valproate during pregnancy (n=6152), the absolute risk of a diagnosis of autism and ASD were 1.02% and 2.44% respectively. I hasten to add that I'm not an expert on risk, absolute risk, but 2.44%, by my reckoning, equates as roundabout 1 in 40 with an ASD born to mums with epilepsy. I'm cautious not to read too much into this just in case I've got it completely wrong but if it is correctly interpreted, might imply some greater connection between offspring autism and a maternal history of epilepsy as per previous findings****.

I'm not going to go through all the possible weaknesses in the Christensen paper because the manuscript does that quite well enough itself including some discussion on that folate-autism link. Likewise my previous post on valproate and offspring autism talked about some of the possible mechanisms to account for any effect, so again no need to cover all that ground. There is one tidbit to pick up on: "Valproate is a fatty acid derivative" so the authors report. I've often wondered about this point and the suggested mechanism of seizure control in some cases by use of the ketogenic diet impacting on fatty acids (see the paper by Chang and colleagues*****). Assuming the Chang findings are accurate, does this place more emphasis on the HDAC inhibition side of things when it comes to valproate and offspring autism risk?

The question still remains about the 'correlation does not equal causation' mantra with prenatal valproate exposure and offspring autism in mind. The Christensen paper at the very least, makes a really strong case for a lot more detailed inspection of this potential association as once again the use of pharmacotherapy during pregnancy comes under the spotlight.

Oh, and just in case you thought I was singling out valproate for special attention in relation to autism, have a look at the recent paper by Dheeraj Raj and colleagues****** (open-access) on prenatal antidepressant exposure and offspring autism risk again adding to the previous literature. Indeed it makes me wonder if that environmental exposome fish experiment carried out a while back might well be a model, albeit with revisions, we need to revisit.

A song to close methinks. Something vintage and snazzy today.... Elvis and Viva Las Vegas.


* Christensen J. et al. Prenatal valproate exposure and risk of autism spectrum disorders and childhood autism. JAMA. 2013; 309: 1696-1703.

** Marson AG. et al. The SANAD study of effectiveness of valproate, lamotrigine, or topiramate for generalised and unclassifiable epilepsy: an unblinded randomised controlled trial. Lancet. 2007; 369: 1016–1026.

*** Berg A. Mortality in epilepsy. Epilepsy Curr. 2001; 1: 28.

**** Leonard H. et al. Maternal health in pregnancy and intellectual disability in the offspring: a population-based study. Ann Epidemiol. 2006; 16: 448-454.

***** Chang P. et al. Seizure control by ketogenic diet-associated medium chain fatty acids. Neuropharmacology. 2013; 69: 105-114.

****** Raj D. et al. Parental depression, maternal antidepressant use during pregnancy, and risk of autism spectrum disorders: population based case-control study. BMJ. 2013; 346: f2059


ResearchBlogging.org Jakob Christensen, Therese Koops Grønborg, Merete Juul Sørensen, Diana Schendel, Erik Thorlund Parner, Lars Henning Pedersen, & Mogens Vestergaard (2013). Prenatal Valproate Exposure and Risk of Autism Spectrum Disorders and Childhood Autism JAMA

Tuesday 23 April 2013

Autism and the methylome

Q: When is an identical twin not an identical twin? A: Pretty much all the time (at least according to some people) as our increasing understanding of the complexity of genetics stretches and modifies long-held beliefs about the building blocks of life and their role in our health and wellbeing.
DNA methylation differences? @ Wikipedia  

Today I'm talking about identical (monozygotic) twins - siblings derived from one fertilised egg - and how the science of epigenetics might have some interesting implications for autism research as per the study by Chloe Wong and colleagues* (open-access). I should perhaps also direct you to some other interesting research recently discussed in this area too (see here) which might be relevant.

Regular readers will probably already know about my amateur interest in epigenetics (see here and here) and how the area of the epigenome - those chemical marks which have the ability to influence the expression of the genome - has started to yield some potentially important observations. At times I'll admit to being slightly too over-excited at the possibilities of epigenetics. Subsequently brought back down to earth by more sobering accounts (see here**) but not yet ready to poo-poo the whole science just yet***.

I don't want to rehash the whole epigenetic story in this one post, so instead am going to concentrate on the particular area covered by Wong et al and their analysis of the methylome (yes, another -ome for you) which is concerned with the addition of methyl groups to various regions of the genome and how that subsequently alters the expression of genes. DNA methylation has been a sort of peripheral topic in relation to cases of autism for quite some time now; brought to the forefront by all that folic acid (see here) and MTHFR research (see here) and the availability of those lovely methyl groups. Suffice to say that we are still very much at the beginning when it comes to looking at the relationship between all these elements and very complicated conditions like autism.

Anyhow, after that very long introduction (I am only an amateur science blogger after all), a few details from the Wong paper might be in order, bearing in mind it is open-access:

  • Part of the UK TEDS initiative and partly sponsored by Autism Speaks who were involved in that recent environmental epigenetics symposium (see here), researchers looked at 50 monozygotic (MZ) twin pairs. It wasn't just a case of 25 twin pairs where one twin was diagnosed with an autism spectrum disorder (ASD) compared with 25 twin pairs where both were concordant for ASD. No, instead the authors looked at a variety of phenotypic combinations based on concordance/discordance for ASD and various core traits based on the Childhood Autism Symptom Test (CAST) schedule. Supplementary table 1 shows the combinations (see here).
  • A genome-wide analysis of DNA methylation was undertaken on blood samples provided by participants. I can't pretend to intimately know all the techniques that were employed so won't profess to do so. What I can glean from the paper is that both DNA methylation differences between MZ twin pairs discordant for ASD and analyses between groups scoring high and low on the various core symptom areas were completed with "the aim of identifying real, biologically relevant within-twin and between group DNA methylation differences".
  • Results: "ASD is not associated with systemic differences in global DNA methylation". In other words, within the twins, there is quite a high degree of similarity when it comes to patterns of DNA methylation. This might tie in with other work looking at methylation in cases of autism and other family members (see here). 
  • When looking at DNA methylation patterns between twin pairs discordant for ASD, specific sites of the genome however seemed to show some variability as a function of ASD diagnosis or not. The authors list the top 50 "differentially methylated CpG sites" (see here) showing gene and position, with a combination of hyper- and hypo-methylated regions identified. Top of the methylation differences pops was the NFYC promoter which was "consistently hypermethylated in affected individuals" (see here for some additional papers on this gene). Hypermethylation by the way, generally means gene silencing as per its function when it comes to transposons (think HERVs). 
  • Various other data are presented based on either syndrome or trait specific differences across the twins. I'm not going to go through all of these because, well because that's called plagiarism. I will draw your attention to one particular finding which might be important as they identified "one MZ twin pair, concordant for a very severe autistic phenotype, that appear to represent epigenetic outliers at multiple CpG sites across the genome". I'm immediately drawn back to my autism or autisms post and that all-important phenotypic variability as potentially being relevant here too. That and the tie-up with more structural changes to the genome as per the mention of CNVs and hotspots.

I know I've gone on a bit in the post but this is potentially a very important paper. Not only does it put the epigenome, or at least one part of the epigenome, firmly on the autism research map, but it offers something of a partial explanation for [some of] that 'missing heritability' which was talked about not so many years ago (see here).

The fact also that methylation patterns might be variable both intra-twins and intra-ASD is also important; suggesting that as with more traditional genomic findings in relation to autism, there isn't going to be just one epigenomic factor affecting risk or presentation, but rather a plethora of sites which are hyper- or hypo-methylated, potentially also linked to (affecting?) more structural changes to the genome in cases of ASD.

Don't get me wrong, the same questions remain as are seen in other areas of biological functioning with autism in mind: the heterogeneity, the reliance on diagnosis by observation and note-taking, the (elevated) risk of comorbidities, etc. All of which cloud the waters of association. Distinct however from the question of whether there is anything that can be done when structural changes to the genome are observed (outside of gene therapy for example), when talking about methylation, one speculates that this might be something that lends itself to pharmacotherapy as per the already use of DNA methyltransferase inhibitors for example. Yes, going back to that folic acid-autism link work, the possibility also that environment might help shape gene function and some new light on other external factors (noting that I am not advocating anything at the current time).

So endth the lesson for today.


* Wong CC. et al. Methylomic analysis of monozygotic twins discordant for autism spectrum disorder and related behavioural traits. Molecular Psychiatry. April 2013.

** Ptashne M. Epigenetics: core misconcept. PNAS. April 2013.

*** Fraga MF. et al. Epigenetic differences arise during the lifetime of monozygotic twins. PNAS. 2005; 102: 10604-10609.


ResearchBlogging.org Wong, C., Meaburn, E., Ronald, A., Price, T., Jeffries, A., Schalkwyk, L., Plomin, R., & Mill, J. (2013). Methylomic analysis of monozygotic twins discordant for autism spectrum disorder and related behavioural traits Molecular Psychiatry DOI: 10.1038/mp.2013.41

Sunday 21 April 2013

All eyes on minocycline

Minocycline, the tetracycline antibiotic, is probably not something that most people would traditionally link with autism or conditions presenting with autism-like behaviours. Indeed, the suggestion that antibiotics or antimicrobials if you prefer, may be able to modify either the behaviour or linked biochemistry of the autism spectrum disorders (ASDs) or even influence the onset and expression of ASD is quite frankly a little bit unusual.
Minocycline (for chemists) @ Wikipedia  

But unusual is what often crops up on this blog. And how if one assumes that autism, sorry the autisms, are not just conditions solely pertaining to the grey-pinkish matter floating inside our skull, one starts to see how behaviour and physiology might provide some interesting perspectives. Say for example, when one starts to look at the gut microbiome...

On today's post I'm considering a few reports which recently cropped up on the research radar including the results of placebo-controlled trial of minocycline for Fragile X syndrome (FXS) published by Mary Jacena Leigh and colleagues* (open-access), a small open-trial of minocycline reported by Carlos Pardo and colleagues** (open-access) and although not autism-related, the results of a study by Parvin Ataie-Kachoie and colleagues*** (open-access) on what happened to an ovarian cancer cell line when minocycline was added, specifically with the cytokine IL-6 in mind. A bit of a mixed bag of studies by all accounts but with some potential common threads.

The Leigh study has already been covered by some media (see here) so no grand description needed from me. Suffice to say that there is a suggestion from this MIND Institute study, that minocycline might have some modest positive impact on various aspects of behaviour in paediatric cases of FXS with the requirement for further research. As per some previous chatter on this blog, this is not necessarily new news for FXS as per studies like the one by Paribello and colleagues**** (open-access). Interestingly, the Paribello results also mention something called matrix metalloproteinase-9 (MMP-9) as a particular target of minocycline which has also been discussed on this blog (see here). So, potentially (potentially!) there may be some merit in looking at minocycline for cases of FXS; although as per my blog caveat, I'm not recommending anything.

Moving on. The Pardo study (see here for the trial record), whilst small in participant numbers, looked more directly at the use of minocycline - and vitamin B6 - with ten children diagnosed with an ASD. The focus was on autism with a regressive aetiology linked to presentation, and alongside various behavioural measures, there was also analyses of various biological fluids for "markers of neuroinflammation". The study was open and unblinded so not exactly the same calibre as the Leigh trial.

The main result of the trial, er... no clinical improvements following minocycline use, even after six months of use. Indeed not only were no significant changes to behaviour reported but a variety of respiratory and gastrointestinal (GI) side-effects correlated with minocycline use. The efficacy and safety profile was not particularly great based on these study results allowing for the lack of any control group and the dosage used.

There were however, a few reported changes to some of the biochemistry under investigation, specifically with brain derived neurotrophic factor (BDNF) and hepatocyte growth factor (HGF) in mind but not in the more classically related parameters such as that MMP-9 connection. This lack of effect of minocycline on MMP-9 is slightly unusual but potentially revealing. Certainly the review by Siller & Broadie***** (open-access) hints that MMP inhibition might be a key part of the effects of minocycline in FXS. It's possible a few scenarios might pertain with regards to the biological/genetic differences between autism and FXS. One might even speculate that there is some involvement for the TIMPs (tissue inhibitors of metalloproteinases) in that non MMP inhibitory effect noted from minocycline in autism, but much more work is perhaps needed.

Indeed the authors very overtly noted that "minocycline exerted biological effects that were not translated into behavioral or neurological changes" which certainly questions the link between some of the biochemistry that was seemingly affected and presented symptoms assuming there wasn't more subtle behavioural changes.

Finally, there is the Ataie-Kachoie study on minocycline application to ovarian cancer cell lines. I'll freely admit that I know even less about cancer cell lines than I do about autism so please excuse any widely inaccurate statements that I might make. The long-and-short of it was that in the lab, minocycline seems to have an interesting effect on "the IL-6 signaling pathway" at least in ovarian cancer cells such that minocycline might reduce IL-6 or at least prevent increases after certain events. As part of my learning jounrney through this paper I did not know that IL-6 was for example being linked to cancer metastasis as discussed by Tawara and colleagues****** for example. Seemingly this metastasis might correlate with those MMPs (particularly MMP-2 and MMP-9).

I know I'm moving further and further away from my autism and FXS purpose with the Ataie-Kachoie data, but there may be some lessons to be learned. That for example minocycline might affect cases of FXS by means of impacting on MMP-9 is already under discussion. The added suggestion that minocycline might also be working on cytokines like IL-6 in an anti-inflammatory fashion is certainly another source of discussion. Indeed, I note from the Pardo autism study, that in Table 3 showing the pre- and post-treatment effects on biochemistry, the value reduction for serum IL-6 just managed to escape that magical significance point coming in at p=0.08. The change in another interesting cytokine, TNF-alpha, was even closer (p=0.074).

This has been a post comparing apples and pears to a large extent and reiterating my earlier caveat, I am by no means advocating minocycline for anything other than it's intended use with appropriate medical physician support and supervision. Outside of the discussions already included, what this post does serve to show is that (a) the actions of medicines are not necessarily restricted to what's printed on the patient information leaflet, and (b) some of those 'extra' actions might yet hold some promise for some presenting with autism or autism-like behaviours across the autisms and indeed other conditions.

To close, while recently watching the excellent film 'The Sting' I was again entranced by the piano genius of Scott Joplin's 'The Entertainer'.


* Leigh MJ. et al. A randomized double-blind, placebo-controlled trial of minocycline in children and adolescents with Fragile X Syndrome. J Dev Behav Pediatr. 2013; 34: 147–155.

** Pardo CA. et al. A pilot open-label trial of minocycline in patients with autism and regressive features. Journal of Neurodevelopmental Disorders 2013: 5: 9.

*** Ataie-Kachoie P. et al. Minocycline suppresses Interleukine-6, its receptor system and signaling pathways and impairs migration, invasion and adhesion capacity of ovarian cancer cells: In Vitro and In Vivo studies. PLoS ONE. 2013; 8: e60817.

**** Paribello C. et al. Open-label add-on treatment trial of minocycline in fragile X syndrome. BMC Neurol. 2010; 10: 91.

***** Siller SS. & Broadie K. Matrix metalloproteinases and minocycline: therapeutic avenues for Fragile X Syndrome. Neural Plasticity. 2012; 124548.

****** Tawara K. et al. Clinical significance of interleukin (IL)-6 in cancer metastasis to bone: potential of anti-IL-6 therapies. Cancer Management & Research. 2011; 3: 177-189.


ResearchBlogging.org Leigh, M., Nguyen, D., Mu, Y., Winarni, T., Schneider, A., Chechi, T., Polussa, J., Doucet, P., Tassone, F., Rivera, S., Hessl, D., & Hagerman, R. (2013). A Randomized Double-Blind, Placebo-Controlled Trial of Minocycline in Children and Adolescents with Fragile X Syndrome Journal of Developmental & Behavioral Pediatrics, 34 (3), 147-155 DOI: 10.1097/DBP.0b013e318287cd17

Wednesday 17 April 2013

Autism, the autisms or "developmental brain dysfunction"?

"If you've met one person with autism, you've met one person with autism" so the oft-cited phrase goes.

The implication is that whilst unified under the label of presenting with the triad/dyad characteristics of an autism spectrum condition, the heterogeneity present across the spectrum coupled with other comorbidity, allied to factors such as genes, personality, temperament, maturation, environment et al, mean that everyone is different and importantly everyone is dynamic.
Umbrella under an umbrella? @ Wikipedia  

Another term used by some people (including researchers) is that of 'neurotypical'  to somehow denote not-autism. For me however, that's always been a little too simplistic. It implied (a) that there is a definite line between autism and not-autism which kinda over-simplifies things including the broader autism phenotype (BAP), and (b) that there is such as thing as 'neurotypical' and indeed is counter to the phrase: 'if you've met one person, you've met one person' which should surely be as pertinent to not-autism as it is to autism; if you get me?

These concepts are relevant as today I'm talking about two papers: a paper by Whitehouse & Stanley* (open-access) questioning whether autism is one condition or multiple conditions, and a paper by Moreno-De-Luca and colleagues** which implies that we should even be doing away with behaviourally-defined labels such as autism and schizophrenia in favour of an altogether broader definition of 'developmental brain dysfunction' or DBD.

Regular readers might recognise the name Andrew Whitehouse as being one and the same researcher who has talked about various autism-related results from the Raine study (see here and here and here). His latest opinion piece builds on the fact that despite the 70 year anniversary since the first description of autism was published by Kanner (with appropriate consideration for Hans Asperger too), alongside huge amounts of time, money and research efforts, we are really still only scratching the research surface of the condition(s) known as autism. Certainly science hasn't yet come up with many defining 'universal' reasons to account for the appearance of the the clustering of symptoms and as for intervention options, well take a look at the recent draft guidance from NICE to see what I mean. One of the main stumbling blocks he and his colleague opine on is the "phenotypic variability" and how moves should be made towards defining smaller subgroups on the autism spectrum. In effect talking about the autisms over autism as per another very interesting paper by Poot*** (open-access).

To many people this is not new news. That the search for an 'autism gene' or 'autism genetic mutation' (sorry about the cold science term) or indeed 'autism environmental variable' has so far been underwhelming in terms of results coupled to the cost/benefit ratio of such research for example, is testament to the variability present in both autism and not-autism. This demonstrates also how complex a continuum the autism spectrum is. Indeed how complex a thing the human spectrum is****.

Likewise when it comes to intervention, I've talked before on this blog about how we should perhaps be re-assessing the way we look at proposed interventions and in particular focusing on subgroup responses rather than some almighty universal spectrum response to denote intervention success of not. Without equating autism with cancer or vice-versa, the recent opinion paper by Stewart & Kurzrock***** (open-access) might inform this methodological discussion somewhat further.

Whitehouse and Stanley also talk about the lessons learned from cerebral palsy (CP) and how where once CP was thought of as "a unitary disorder", the more contemporary view is somewhat more "umbrella" like. I've covered CP on this blog before so won't say much more about that; I think many people might agree that autism is similarly an umbrella term; even more so when the DSM-V comes into force in literally weeks time (Monday 20th May 2013 apparently).

The Moreno-De-Luca paper goes one stage further. As per the paper and some associated media attention (see here) the suggestion is that not only is there the autisms, but that because of the various overlapping genetic features between the autisms and conditions such as schizophrenia (the schizophrenias), we should be looking at using an even more over-arching concept to group these collected diagnoses together: developmental brain dysfunction (DBD). A sort of umbrella for the umbrella if you like. It's not a new suggestion by the way****** (open-access).

I can imagine that your view of autism - be that a personal perspective of autism, a parental perspective or just an observer looking in - is probably going to influence how you receive this suggestion to some degree. For a researcher looking at the possibility of shared genetics or even epigenetics between conditions which might overlap, there is some sense in looking at the bigger picture. My recent post on common ground (see here) based on the 'five psychiatric disorders linked' paper******* kinda reiterates this position alongside other papers including this one from Caamaño and colleagues******** on subclinical comorbid psychopathology. That and the fact that there might be some convergence when it comes to the autism and schizophrenia spectrums for example (see here) also makes a case. The authors sum it up well: "genes don't respect our diagnostic classification boundaries, but that really isn't surprising given the overlapping symptoms and frequent co-existence of neurodevelopmental disorders".

Other perspectives - and I am only speculating on such viewpoints - might not necessarily share the same sentiments. Aside from leaving out any important relationship that genes might have with little things like the environment, as in maternal immune activation during pregnancy, or all those correlations with other facets of modern living (see here and here), the implication of 'brain dysfunction' takes us back to the whole neurotypical 'us and them' scenario and the questions: what exactly is 'normal' brain function? and what factors can and do affect it? I might add that I can also see how some people might not necessarily be taken with the concept of autism being akin to 'brain dysfunction' in the same way that lumping autism and schizophrenia together might have other, more societal connotations.

I'm going to stop there with this post, save any charges of over-analysing the papers and potential implications. Accepting that a diagnosis is currently the best way for people to [theoretically] receive the help and support they may need, I'm not sure we are in a position to re-write the diagnostic manuals just yet with autism and schizophrenia in mind. That umbrella-ing (is that a word?) autism with other conditions might also impact on the autism awareness message that we've all just had with World Autism Awareness Day is another consideration to bear in mind.

That being said, I do think we have already started to see hints of this brave new world of links and threads coming together. The DSM-V diagnosis of autism seems to be quite explicitly spectral and whilst not yet knowing the consequences of removing diagnoses such as Asperger syndrome and how that Social Communication Disorder category will work, the idea behind the change is sub-type removal similar to that envisaged for schizophrenia (see here and here). I'm not altogether sure but I am also wondering how and whether there will be any exclusion criteria on for example a dual diagnosis of autism and schizophrenia in the new guidance and what effect this might have? We wait and see.

"OK stop already". And I will.


* Whitehouse AJO. & Stanley FJ. Is autism one or multiple disorders? Med J Aust 2013; 198: 302-303.

** Moreno-De-Luca A. et al. Developmental brain dysfunction: revival and expansion of old concepts based on new genetic evidence. The Lancet Neurology. 2013; 12: 406-414.

*** Poot M. Towards identification of individual etiologies by resolving genomic and biological conundrums in patients with autism spectrum disorders. Molecular Syndromology. February 2013.

**** Mitchell KJ. What is complex about complex disorders? Genome Biology. 2012; 13: 237.

***** Stewart DJ. & Kurzrock R. Fool's gold, lost treasures, and the randomized clinical trial. BMC Cancer 2013; 13: 193.

****** Hrdlicka M. & Dudova I. Controversies in autism: is a broader model of social disorders needed? Child & Adolescent Psychiatry and Mental Health 2013; 7: 9.

******* Cross-Disorder Group of the Psychiatric Genomics Consortium. Identification of risk loci with shared effects on five major psychiatric disorders: a genome-wide analysis The Lancet. February 2013.

******** Caamaño M. et al. Psychopathology in children and adolescents with ASD without mental retardation. JADD March 2013.


ResearchBlogging.org Whitehouse AJ, & Stanley FJ (2013). Is autism one or multiple disorders? The Medical journal of Australia, 198 (6), 302-3 PMID: 23545020

ResearchBlogging.org Moreno-De-Luca A, Myers SM, Challman TD, Moreno-De-Luca D, Evans DW, & Ledbetter DH (2013). Developmental brain dysfunction: revival and expansion of old concepts based on new genetic evidence. Lancet neurology, 12 (4), 406-14 PMID: 23518333

Sunday 14 April 2013

Fatigue severity and serum leptin levels in chronic fatigue syndrome

In the very complicated world of medical research and science, the days of one chemical, one metabolite, or one gene driving and sustaining ill-health and particular diseases or conditions seem to be all but long past. Sure, there are conditions which on the surface seem to be driven by only one factor, but more often than not is the realisation that we humans are very complicated creatures indeed.
Leptin @ Wikipedia  

I was therefore interested to read the paper by Elizabeth Stringer and colleagues* (open-access) describing the results from a small cohort of women diagnosed with chronic fatigue syndrome (CFS) looking at potential biological correlates which might accompany day-to-day changes in the severity of fatigue experienced by participants.

Yes, I'm back with CFS to add to my ramblings about gut bacteria, mitochondrial disorder, amino acids. Bear with me...

The paper is open-access but a few pointers might be useful:

  • It was an interesting methodology the authors adopted which saw 10 women diagnosed with CFS and 10 asymptomatic age- and BMI-matched controls asked to monitor their fatigue-related behaviours over the course of 25 days.
  • This self-report was accompanied by a professionally taken daily blood draw (yes, 25 days of giving a blood sample!) which were subsequently analysed for various cytokines - 51 in all.
  • The self-report data and pattern of cytokine levels were analysed, correlated and networked (using a machine learning algorithm).
  • Results: "Six participants with CFS and one healthy control demonstrated significant positive correlations between fatigue and leptin". Leptin by the way is a hormone normally implicated in the in-and-out process of energy expenditure, so potentially relevant to a condition like CFS which is characterised by fatigue.
  • Buoyed by their leptin results, the authors also report that with the help of that Weka’s LibLINEAR algorithm, they were able to use the suite of cytokine results to distinguish 'high' and 'low' fatigue days for the CFS group with 78.3% accuracy compared with just above chance level in the asymptomatic control group. "The CFS model correctly identified 77.8% of the low fatigue days and 78.9% of high fatigue days".
  • Ergo cytokines and inflammation seem to be not only tied into CFS pathology but might actually be overlap with the ebb and flow of clinical symptoms on a day-to-day basis.

You can perhaps see how this study might be an important one for CFS. Given the connection between leptin (energy) and CFS, you might be saying to yourself that this sounds all very logical so why did no-one look at the possible connection before? Well, they did, or rather Cleare and colleagues** did and concluded: "we found no evidence of alterations in leptin levels in CFS" despite some potential effects from low dose hydrocortisone therapy on leptin levels under placebo-controlled conditions.

This is not by any means the first time that immune function has cropped up on the CFS research radar (see this post) and probably won't be the last either. I don't however want to speculate too much more on these results without them being subject to appropriate replication with a larger patient set and that all-important diagnostic criteria being standardised. The XMRV story (see here) still lingers in the mind, as do other controversies on the CFS landscape such as Ampligen and Rituximab.

To close, a song about a dirty old town.


* Stringer EA. et al. Daily cytokine fluctuations, driven by leptin, are associated with fatigue severity
in chronic fatigue syndrome: evidence of inflammatory pathology. Journal of Translational Medicine. 2013; 11: 93.

** Cleare AJ. et al. Plasma leptin in chronic fatigue syndrome and a placebo-controlled study of the effects of low-dose hydrocortisone on leptin secretion. Clin Endocrinol (Oxf). 2001; 55: 113-119.


ResearchBlogging.org Stringer, E., Baker, K., Carroll, I., Montoya, J., Chu, L., Maecker, H., & Younger, J. (2013). Daily cytokine fluctuations, driven by leptin, are associated with fatigue severity in chronic fatigue syndrome: evidence of inflammatory pathology Journal of Translational Medicine, 11 (1) DOI: 10.1186/1479-5876-11-93

Friday 12 April 2013

ADHD and a sunny disposition

'Light it up blue' is probably a familiar phrase to many of those involved with autism as being the message championed by Autism Speaks on World Autism Awareness Day (2 April). The intention is noble enough: to bring autism to the attention of the world at large and importantly, keep their attention and resources focused on autism. I might add that awareness is one thing; actually 'doing something about autism' - whether that means improving prospects or modifying the course of autism or just levelling the playing field - is quite another thing.

Light it up @ Wikipedia  
By a funny twist of Internet fate, I stumbled upon a review of the study published by Arns and colleagues* looking at the possibility of a link between solar intensity (SI) and the prevalence of attention-deficit hyperactivity disorder (ADHD). The very tentative light it up blue connection was a sentence or two in the study write-up which suggested that the sleep problems which apparently come with a diagnosis of ADHD might result from "exposure to blue-light during the evening" and that strong sunlight during the day "might reset the biological clock and act as an antidote to the evening exposure to artificial blue-light causing sleep onset problems". Yes, I know it isn't a great blue light pun, sorry about that.

It should be noted that the Arns paper appears in a pretty good journal (Biological Psychiatry) so whilst you might be thinking, 'solar intensity... eh?' this is a correlation which has passed what one would expect to have been quite a rigorous peer-review battlefield. I could at this point offer you some more detailed description of the paper but it seems that the authors have already done that on their website (see here - no endorsement given or intended).

In effect, they mapped the prevalence figures for ADHD across various parts of the US and beyond and cross-referenced them with official figures relating to SI. Yes, prevalence of ADHD were partly based on "self-report of professional diagnoses" but this was to some degree countered by the use of more formal assessment data in other sites. They found a correlation (negative correlation) between ADHD prevalence and SI when controlling for various potential confounders: "a lower prevalence of ADHD in areas with high SI for both U.S. and non-U.S. data".

Bearing in mind the issue of correlation/causation (see here), one could construe this data several ways. If for example you work for the tourist boards of Arizona, Nevada or California you have a potentially interesting advert: 'Come live here, we've got lots of solar resource and potentially less risk of your children developing ADHD'. Or words to that effect. And indeed, the CDC figures do seem to suggest that those high SI states might have a lower prevalence of ADHD (assuming that this doesn't reflect other issues such as awareness, identification, etc). On a more serious note are the suggestions that (a) ADHD might be related to circadian clock disturbances, and (b) that exposure to the various new-fangled technologies we are surrounded by might be part and parcel of those circadian clock disturbances.

Just before you reach for the click away button, like I almost did, mumbling 'blame it all on technology', there are a few papers to bring to your attention. Yes, sleep issues are associated with ADHD** and indeed if the recent paper from Blesch and Breese McCoy*** is anything to go by, we might also assume that ADHD - some cases of ADHD - could be mistaken for things like sleep apnoea. True also that issues with circadian function seem also to be tied into cases of ADHD as per studies like this one from Gamble and colleagues****. On balance, sleep seems to show some connection with ADHD.

That the part of the light spectrum labelled blue emanating from various technology use is the primary cause or significant contributor to the sleep issues noted even in some cases of ADHD is the slightly more difficult proposition for me to whole-heartedly (hoof hearted!) accept from this work. I don't doubt that many children and adults with ADHD use this kind of technology. But I have to ask whether their use and exposure to the artificial blue light is really any more significant than that of everyone else? Indeed, without being an expert on the different ranges or wavelengths of light and their physiological effects, are we just talking blue or are we talking other parts of the light spectrum too?

There are details from this study which I would like to see further explored given the potential for a relationship between SI and ADHD prevalence. Readers for example, might know that I am more than a little intrigued by another sun related variable, vitamin D, and its various connections (or not) to conditions like autism or chronic fatigue syndrome among others. The question would have to be whether the sunshine vitamin / steroid hormone might also show some relationship to the latest findings? Are vitamin D levels likely to be greater / the same / reduced in cases of ADHD dependent on the specific geography and SI? Vitamin D receptors all in good working order*****? No significant drug interactions where medication is being used? Indeed, whether other correlates such as altitude - which also seem to map onto the SI exposure plots - might come into play?

There are questions which require some follow-up from this work but for now, and with all caveats in good working order when it comes to population studies of association - as with other recent results too, I'm intrigued by the Arns data and the suggested overlap. And also that ADHD might not be the only condition being looked at with a sun-related variable (see this study by Davis & Lowell******, full-text).

To close, after recently watching the quite brilliant film 'Rock of Ages' which satisfied all my 1980s rock needs, a taste of Sheffield's finest.


* Arns M. et al. Geographic Variation in the Prevalence of Attention-Deficit/Hyperactivity Disorder: The Sunny Perspective. Biol Psychiatry. March 2013.

** Yürümez E. & Kiliç BG. Relationship Between Sleep Problems and Quality of Life in Children With ADHD. J Atten Disord. March 2013.

*** Blesch L. & Breese McCoy SJ. Obstructive Sleep Apnea Mimics Attention Deficit Disorder. J Atten Disord. March 2013.

**** Gamble KL. et al. Delayed Sleep Timing and Symptoms in Adults With Attention-Deficit/Hyperactivity Disorder: A Controlled Actigraphy Study. Chronobiol Int. February 2013.

***** Malik S. et al. Common variants of the vitamin D binding protein gene and adverse health outcomes. Crit Rev Clin Lab Sci. 2013; 50: 1-22.

****** Davis GE. & Lowell WE. Variation in ultraviolet radiation and diabetes: evidence of an epigenetic effect that modulates diabetics' lifespan. Clinical Epigenetics. 2013; 5: 5.


ResearchBlogging.org Arns M, van der Heijden KB, Arnold LE, & Kenemans JL (2013). Geographic Variation in the Prevalence of Attention-Deficit/Hyperactivity Disorder: The Sunny Perspective. Biological psychiatry PMID: 23523340