Candida albicans triggering coeliac disease?

Will the bafflement around coeliac (celiac) disease ever stop?

I want you to cast your eye over the paper from Marion Corouge and colleagues [1] (open-access) and the interesting hypothesis that: "CI [Candida albicans infection] may trigger CeD [coeliac disease] onset in genetically-susceptible individuals."

Continuing a theme of 'bafflement' when it comes to the autoimmune condition known as coeliac disease (see here), Corouge et al reported that a protein, hyphal wall protein 1 (Hwp1) present in C. albicans, 'required for hyphal development and yeast adhesion to epithelial cells' "presents sequence analogy with the gluten protein gliadin and is also a substrate for transglutaminase." Further a: "suggestion that C. albicans infection (CI) may be a triggering factor for Celiac disease (CeD) onset."

Just in case you aren't au fait with all-things coeliac disease, my training post on the condition might come in useful (see here). Gliadin is a type of protein found in wheat and other cereal produce which together with the glutenins make up gluten. Gluten is the stuff that those with coeliac disease have to avoid as a consequence of the peptides that it eventually is metabolised into meeting a specific (geno)type of immune system. Transglutaminase reflects enzymatic alterations to said gluten peptides and a sort of 'super-charging' of them (deamidation) with reference to that 'coeliac immune system' and the processes it starts/continues.

There is quite a bit of chemistry included in the Corouge paper but the main results were:

• "using recombinant Hwp1" the authors reported "serological cross-reactivity in humans between this C. albicans antigen and gliadin." This translates into Hwp1 and gliadin - peptides from gliadin - potentially having something of a shared ability to invoke an immune response or be involved in immune processes pertinent to coeliac disease.
• Looking at serum samples from participants diagnosed with coeliac disease or presenting with "systemic CI" researchers also reported that: "CI and CeD patients had higher levels of anti-Hwp1... and anti-gliadin... antibodies" than asymptomatic control specimens. Interestingly, they couldn't [significantly] differentiate between the coeliac and CI samples on these parameters .
• When plotting Hwp1 levels and anti-gliadin antibodies "during the course of C. albicans infection" they found that the expected increase in anti-Hwp1 antibodies was also accompanied by an "increase in anti-gliadin antibodies that paralleled the anti-Hwp1 response."
• Finally: "The decrease in levels of anti-gliadin antibodies in GFD [gluten-free diet] -adherent compared to non-adherent CeD patients further validates the clinical classification used." That being said: "the relative independence of anti-Hwp1 antibodies from a GFD" hints that the gluten-free diet might do many things but not necessarily everything in this suggested relationship.

A final quote from the paper is worthwhile reproducing: "This study has revealed immune cross-recognition between two substrates of the potential auto-antigen transglutaminase, namely the fungal “invasive” protein Hwp1 and the dietary ‘innocuous” vegetal protein gliadin. Together our data, obtained from a translational comparative analysis of an infectious and an auto-immune disease, support the hypothesis... that the former may trigger the development of the latter."

Independent replication is the name of the game when it comes to the Corouge results before anyone gets too carried away with the possible implications. That being said, the idea that in those possessing the risk genotype of coeliac disease a bout of Candida albican infection might have the ability to set the biological wheels in motion in a journey towards the condition (or even perpetuating the condition) represents a potentially important finding [2]. One might also question whether similar cross reactivity (molecular mimicry?) might also be transferable to other autoimmune conditions and whether the agent of choice has to necessarily be just a fungus [3]?

Music: Kings Of Leon - The Bucket.

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[1] Corouge M. et al. Humoral Immunity Links Candida albicans Infection and Celiac Disease. PLoS One. 2015 Mar 20;10(3):e0121776.

[2] Nieuwenhuizen WF. et al. Is Candida albicans a trigger in the onset of coeliac disease? Lancet. 2003 Jun 21;361(9375):2152-4.

[3] Cabrera-Chávez F. et al. Maize prolamins resistant to peptic-tryptic digestion maintain immune-recognition by IgA from some celiac disease patients. Plant Foods Hum Nutr. 2012 Mar;67(1):24, 30.

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Corouge M, Loridant S, Fradin C, Salleron J, Damiens S, Moragues MD, Souplet V, Jouault T, Robert R, Dubucquoi S, Sendid B, Colombel JF, & Poulain D (2015). Humoral Immunity Links Candida albicans Infection and Celiac Disease. PloS one, 10 (3) PMID: 25793717

Assisted Reproductive Technology conception and autism

I noticed recently that the paper by Christine Fountain and colleagues [1] reporting that "incidence of diagnosed autism was twice as high for ART [assisted reproductive technology] as non-ART births" has been making some media headlines.

Based on an analysis of an impressive participant number "using linked records from the California Birth Master Files for 1997 through 2007, the California Department of Developmental Services autism caseload for 1997 through 2011, and the Centers for Disease Control and Prevention's National ART Surveillance System for live births in 1997 through 2007" authors looked at nearly 6 million births in California, USA. Including nearly 49,000 "ART-originated infants" and 33,000 "cases of autism diagnosed by the Department of Developmental Services", they set about looking at whether there was any difference between "births originated using ART with births originated without ART for incidence of autism."

They concluded that there was perhaps more to see when it came to ART births and autism albeit not necessarily a clear-cut relationship. Multiple births and "adverse prenatal and perinatal outcomes" seemed to play quite an important role in the 'association' reported, leading to quotes like this from others: "The results indicate that reducing multiple births during ART may be beneficial for decreasing the risk of autism."

This is not the first time that ART and some of the specific techniques linked to ART such as IVF (in vitro fertilisation) have been talked about with autism in mind. I have discussed the topic previously on this blog (see here) based on the findings reported by Venla Lehti and colleagues [2] for example. In that case, as in other instances [3], the results were less than impressive on any general association. These independent analyses did not rule out specific factors perhaps requiring further investigation, but overall the effect of ART on general autism risk was not particularly great.

The take-home message is that whilst ART might impact on autism risk, the techniques themselves included under the ART banner are probably not the primary source of any risk. Rather, as we've seen on quite a few other occasions, issues around gestation and birth (see here) might be the important variables which itself asks some interesting questions about autism research areas such as the use of twins (see here) among other things...

Music: Rihanna et al - Umbrella.

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[1] Fountain C. et al. Association Between Assisted Reproductive Technology Conception and Autism in California, 1997-2007. Am J Public Health. 2015 Mar 19:e1-e9.

[2] Lehti V. et al. Autism spectrum disorders in IVF children: a national case-control study in Finland. Hum Reprod. 2013 Mar;28(3):812-8.

[3] Sandin S. et al. Autism and mental retardation among offspring born after in vitro fertilization. JAMA. 2013 Jul 3;310(1):75-84.

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Fountain C, Zhang Y, Kissin DM, Schieve LA, Jamieson DJ, Rice C, & Bearman P (2015). Association Between Assisted Reproductive Technology Conception and Autism in California, 1997-2007. American journal of public health PMID: 25790396

No evidence for efficacy of omega-3 fatty acids on [autism] core symptom domains

To quote from the study by Deepali Mankad and colleagues [1] (open-access): "This study does not support high dose supplementation of omega-3 fatty acids in young children with ASD [autism spectrum disorder]."

Only yesterday I was discussing the results from Bos and colleagues [2] (see here) and the idea that inattention might be a target behaviour for supplementation with PUFAs [polyunsaturated fatty acids] with (and without) ADHD [attention deficit hyperactivity disorder] in mind. Then today, something completely opposite crops up on this blog...

Mankad and colleagues "conducted a 6-month, randomized, placebo controlled trial of omega-3 fatty acid supplements (1.5 g) vs placebo in children 2 to 5 years of age with ASD." The study entry at ClinicalTrials.gov can be seen here. The supplementation in question consisted of "0.75 g of EPA + DHA (1.875 ml once a day) of liquid formulation" rising to "1.5 g (3.5 ml) after 2 weeks" if well tolerated by participants.

Various measures were analysed over the course of the trial period beginning at baseline (no intervention). "Autism symptom severity was measured by the autism composite score of the Pervasive Developmental Disorder-Behavioral Inventory (PDDBI)." Further: "The effect of omega-3 fatty acids on externalizing behaviors was measured using the Behavior Assessment System for Children, Second Edition (BASC-2)." Blood draws were also included as part of the study protocol, not only to study EPA and DHA content in "the plasma phospholipid" but also looking at various immune markers such as cytokines too (see here).

Results: "There was no significant difference between groups on the 0- to 24-week change in PDDBI autism composite scores." So when it came to the core autism domains, fatty acid supplementation didn't seem to offer anything in excess of the placebo formulation of "refined olive oil and medium chain triglycerides."

But: "there was a statistically significant difference in externalizing behaviors, with participants in the placebo group experiencing slight improvements and children in the omega-3 group worsening over the course of the study." Curiously, those receiving the placebo showed some improvement in so-called externalising behaviours (outward behaviours such as hyperactivity, aggression and conduct problems) compared with a worsening of such parameters for those receiving the active intervention. The authors add: "This effect is peculiar in the context of previous studies, but is robust." One possible explanation may lie in the examination of gastrointestinal (GI) issues among the participant groups. So: "8/19 participants in the omega-3 group had GI distress at baseline, and only 1/19 in placebo group had GI distress at baseline. The possibility that preexisting GI distress predisposes to externalizing behaviors cannot be ruled out." Knowing what is known about GI issues in relation to autism and what areas of functioning they can impinge on (see here) I would support the authors' stance on this.

Going back to the Bos findings on ADHD and fatty acids, the authors also have some comment on the suggestion that ADHD might be an 'intervention target' for fatty acid supplementation. To quote again: "we explored the effect of this intervention on hyperactivity as measured by the BASC. There was no statistically significant difference between groups and the trend favored placebo." That and the lack of changes to the cytokine profile following intervention and we're just about done.

Accepting that there is some research out there that has suggested that fatty acid supplementation might be useful for some on the autism spectrum (see here) including the quite recent results reported by Ooi and colleagues [3] (albeit an open trial), in general the evidence base around this intervention with autism in mind, is perhaps not as favourable as that with something like ADHD in view (see here). I should point out that the dose of fatty acid used by Mankad et al was described as "high dose" and was, eventually, more than double that used in the Bos study but similar to that described by other researchers [4]. Whether there may be merit in looking at smaller doses combined with a greater focus on those presenting with an abnormal fatty acid profile (see here for example) remains to be seen. I might also suggest that lessons could be learned from the paper by Rapaport and colleagues [5] linking inflammatory molecules to best response to fatty acids in relation to depression...

Music: Beck - Where It's At.

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[1] Mankad D. et al. A randomized, placebo controlled trial of omega-3 fatty acids in the treatment of young children with autism. Molecular Autism 2015, 6:18.

[2] Bos DJ. et al. Reduced symptoms of inattention after Dietary Omega-3 Fatty Acid Supplementation in boys with and without Attention Deficit/Hyperactivity Disorder. Neuropsychopharmacology. 2015 Mar 19.

[3] Ooi YP. et al. Omega-3 fatty acids in the management of autism spectrum disorders: findings from an open-label pilot study in Singapore. Eur J Clin Nutr. 2015 Mar 25.

[4] Amminger GP. et al. Omega-3 fatty acids supplementation in children with autism: a double-blind randomized, placebo-controlled pilot study. Biol Psychiatry. 2007 Feb 15;61(4):551-3.

[5] Rapaport MH. et al. Inflammation as a predictive biomarker for response to omega-3 fatty acids in major depressive disorder: a proof-of-concept study. Molecular Psychiatry. 2015. March 24.

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Mankad, D., Dupuis, A., Smile, S., Roberts, W., Brian, J., Lui, T., Genore, L., Zaghloul, D., Iaboni, A., Marcon, P., & Anagnostou, E. (2015). A randomized, placebo controlled trial of omega-3 fatty acids in the treatment of young children with autism Molecular Autism, 6 (1) DOI: 10.1186/s13229-015-0010-7

Improving inattention in boys with and without ADHD

The [truncated] PubMed listing of the abstract by Dienke Bos and colleagues [1] does little justice to the results reported by this group looking at the effects of omega-3 fatty acid supplementation on the behaviour of boys both diagnosed with ADHD (attention-deficit hyperactivity disorder) and those who are described as 'typically developing'.

Luckily the paper is open-access (see here) and one can get a true flavour of what happened to this cohort of boys with and without a diagnosis of ADHD following consumption of "10 grams of margarine daily, enriched with either 650mg of EPA/DHA [Eicosapentaenoic Acid / Docosahexaenoic Acid] each or placebo." Indeed, the study is also listed on ClinicalTrials.gov too (see here) and has received some press attention too (see here).

So:

• Authors "set out to investigate the effects of omega-3 PUFA [polyunsaturated fatty acid] dietary supplementation on ADHD symptoms in young boys with and without ADHD in a randomized, placebo-controlled trial." Randomised [placebo-controlled] trials are sweet music to science ears.
• As mentioned, researchers did not however limit their analysis of any potential effects from fatty acid supplementation to just boys diagnosed with ADHD. No, instead they "included a typically developing reference group to investigate the specificity of treatment to subjects with ADHD."
• Over 16 weeks of supplementation (or not) and including measures at baseline (before intervention), researchers assessed the strength of any results based on both psychometric and other more physiological measures including buccal (cheek) swabs "for analysis of phospholipid fatty acid levels" and urine samples to "measure the HVA [homovanillic acid] to creatinine ratio, as a proxy for dopamine turnover." They also imaged the brain via fMRI.
• Results: "Omega-3 PUFA dietary supplementation improved symptoms of inattention in boys with and without ADHD in a double blind randomized controlled trial." This was based on scores on the Child Behavior Checklist (CBCL) and in particular, scores around attention. Inattention scores were not unexpectedly higher in boys diagnosed with ADHD but the authors are pretty adamant that "there was an effect of treatment on parent-rated symptoms of ADHD, regardless of diagnosis."
• "The dietary intervention affected omega-3 PUFA levels in cheek cell phospholipids." This gives us some idea that the behavioural changes reported also correlated with a physiological difference over placebo. It doesn't confirm the possible mechanism but is a good start linking behaviour and physiology. Other more physiological variables such as urinary HVA and the fMRI results did not show any specific effects following active intervention.
• The authors conclude: "this study provides new evidence that dietary supplementation using omega-3 PUFAs may be an effective augmentation of pharmacological treatments of ADHD."

These are interesting results which add to a growing body of work suggesting that PUFAs may have some important effects when it comes to behaviour. With ADHD specifically in mind, PUFAs have received a mixed response from science albeit with some more recent meta-analyses now starting to come down on the side of (possible) effect over no effect, at least for some (see here). Outside of just ADHD, there is also a bank of research suggesting that skills such as reading ability might also have some connection to PUFA status (see here) again, for some. I say this with the caveat that there is more research to do in these areas.

As per the discussions by Bos, their study was of a particularly high methodological standard so that must count in favour of strength of their results. They did note that "a small number of participants with ADHD had changes made to their medication during the intervention" but found similar results without including these participants in separate analysis. With those issues in mind, I'd be inclined to say that we should be paying a lot more attention to fatty acids and behaviour...

Music: Bobby Fuller Four - I Fought The Law.

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[1] Bos DJ. et al. Reduced symptoms of inattention after Dietary Omega-3 Fatty Acid Supplementation in boys with and without Attention Deficit/Hyperactivity Disorder. Neuropsychopharmacology. 2015 Mar 19.

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Bos DJ, Oranje B, Veerhoek ES, Van Diepen RM, Weusten JM, Demmelmair H, Koletzko B, de Sain-van der Velden MG, Eilander A, Hoeksma M, & Durston S (2015). Reduced symptoms of inattention after Dietary Omega-3 Fatty Acid Supplementation in boys with and without Attention Deficit/Hyperactivity Disorder. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology PMID: 25790022

Physical activity and sleep in autism

Sleep issues are not an uncommon feature for quite a few people on the autism spectrum (see here).

Autism research has provided some pretty strong evidence to support that last sentence and how sleep, or a lack of it in terms of quality and/or quantity, might not be optimal for people on the autism spectrum (as it isn't for those not on the spectrum).

The hows and whys of sleep affecting the behavioural presentation of autism are still a little in the air outside of what is known more generally about temperament and behaviour following poor sleeping patterns and routines. That being said, the relationship between sleep and behaviour specifically with the autism spectrum in mind has been the topic of some discussion [1] (open-access).

The findings reported by David Wachob & David Lorenzi [2] add to that literature with their suggestion that: "though over half of the children were identified as having at least one sleep-related problem, their activity levels were significantly related to their sleep patterns."

I was really quite interested in the idea that activity levels and sleep are sharing some research airtime when it comes to autism. Looking at a (very) small group of children/young adults (N=10) with autism who "were asked to wear accelerometer devices for 7 days in order to track objective measures of activity and sleep quality" researchers set about looking at any relationship. They concluded that over 7 days "the more physically active children had overall higher sleep quality."

I could quibble that the authors "included children who have a parent-reported diagnosis of ASD [autism spectrum disorder]" or that there were some gaps in the data as a result of breaks in the time that the "Actigraph GT3X+" were worn but I would be just quibbling. Particularly so following the tide of research on how accurate parent report can be when it comes to autism (see here for example). It's also worthwhile noting that other groups have also reported similar findings [3] to that of Wachob & Lorenzi.

Regular readers of this blog might have understood my specific interest in research on physical activity and autism as per posts on topics such as obesity (see here) and how movement issues might be one potential barrier to physical activity participation when it comes to autism (see here). I'm minded to suggest that there are various solutions to increasing a person's physical activity which might also have some interesting secondary effects too (see here) (although recognising that the martial arts are not for everyone).

The Wachob/Lorenzi results add an interesting dimension to the proposed benefits of physical activity when it comes to autism which requires some important follow-up. Their [objective] use of accelerometer devices also taps into increasing moves toward technology assisting in such research (see here). The paper from David Kennaway [4] advising some caution on one of the treatments of choice for sleep issues in relation to pediatric autism - melatonin - might also be dropped in at this point.

And just one more thing... one might also think about what physical activity might also do for parts of an important comorbidity in autism as per the preliminary findings from Silva and colleagues [5] on ADHD (attention-deficit hyperactivity disorder) and 'intense' physical activity...

Music: Madonna - Material Girl. (no capes).

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[1] Cohen S. et al. The relationship between sleep and behavior in autism spectrum disorder (ASD): a review. J Neurodev Disord. 2014;6(1):44.

[2] Wachob D. & Lorenzi DG. Brief Report: Influence of Physical Activity on Sleep Quality in Children with Autism. J Autism Dev Disord. 2015 Mar 20.

[3] Tatsumi Y. et al. Daytime physical activity and sleep in pre-schoolers with developmental disorders. J Paediatr Child Health. 2014 Sep 3.

[4] Kennaway DJ. et al. Potential safety issues in the use of the hormone melatonin in paediatrics. Journal of Pediatrics & Child Health. 2015. Feb 3.

[5] Silva AP. et al. Measurement of the Effect of Physical Exercise on the Concentration of Individuals with ADHD. PLoS One. 2015 Mar 24;10(3):e0122119.

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Wachob D, & Lorenzi DG (2015). Brief Report: Influence of Physical Activity on Sleep Quality in Children with Autism. Journal of autism and developmental disorders PMID: 25791123

Gulf War agents and delayed onset of symptoms in mice

I was recently intrigued by the findings reported by Zuchra Zakirova and colleagues [1] (open-access) on what happened to mice following 'acute' exposure to pyridostigmine bromide (PB) and the pesticide permethrin (PER) in the context of these compounds being "key contributors to the etiology of GWI [Gulf War Illness] post deployment to the Persian GW [Gulf War]."

I've covered the topic of Gulf War Syndrome (GWS) before on this blog (see here) and how, following one of the most toxic wars in history, quite a few service personnel (and local civilians) developed an array of symptoms which still confuse science and medicine today. There is no doubt that the conflict in 1990-1991 presented the military with a pretty hostile environment; not least because of the setting in the Persian Gulf. This was further compounded by burning oil fields, a variety of potential chemical exposures (including some rather nasty nerve agents) and issues like depleted urinanium tipped munitions to contend with. All-in-all, not a great place to be.

"We hypothesized that co-administration of PB and PER in our mouse model of GW agent exposure would recapitulate the late-onset symptom multiplicity and heterogeneity of symptoms observed in GW veterans, such as memory deficits and neurological deficits." That was the rationale behind the study bearing in mind that this was a study of mice for obvious ethical reasons.

Said mice - "Forty-eight male C57BL6/J mice" - were given either the PB/PER mix (via intraperitoneal injection) or 100% DMSO (as a control). As you may appreciate, direct injection of PB/PER is probably not the same kind of exposure that veterans would have come across in active theatre. PB as NAPS (nerve agent pre-treatment tablet set) was given in an oral dosage form. PER would probably have been delivered as a cream (or aerosol). One perhaps needs to keep this potentially important difference in mind when interpreting the Zakirova findings.

Dividing the mice groups up into a short-term cohort and a long-term cohort (18 days post exposure vs. 5 months post exposure respectively), various 'neurobehavioural' testing was undertaken on the cohorts. The mice participants were eventually euthanized so that any "neuropathological changes associated with GW agent exposure" could also be investigated.

There were some interesting results (and non-results) to be had from the amassed data. Short-term exposure to the PB/PER mix resulted in, well, not very much difference when compared to control animals: "No cognitive deficits were observed at the short-term time point, and only minor neuropathological changes were detected."

But longer-term, there were some potentially important differences noted between exposed and non-exposed animals. So for example: "Impairment for long-term memory formation was observed at day 106 days-post acute exposure to PB + PER." This was based on the results of a test of spatial memory. Further: "PB + PER exposure altered astrocytic activation in the hili of hippocampi and cerebral cortices of mice." Not being particularly au fait with all-things neuropathological, I can't readily put too much descriptive flesh on these experimental bones. I gather that "astroglial activation" might be something important when it comes to the destruction of neurons following injury or infection (but don't quote me on that). Potentially importantly too were the authors' findings that: "ACh [acetylcholine] levels were increased in the CNS [central nervous system] of exposed mice" and further "that exposure to GW agents may be attributed to the impaired cholinergic function observed in GWI and may in part contribute to deficits observed in long-term memory formation." I say this noting that permethrin is classified as a pyrethroid not an organophosphate (OP) which has a more classical relationship with acetylcholinesterase but PB has perhaps a more direct effect on acetylcholine.

Reiterating that the Zakirova study reports results based on mice and 'acute' exposure of said mice to potentially important agents, these are interesting results mirroring other studies from the authors [2]. I note that there may be more to see from this research group in future with the anticipation that "subsequent studies will provide us with a more lifetime picture regarding the long-lasting consequences of GW agent exposure." If this is indeed something that can be garnered from such a mouse model and given the significant suffering endured by many veterans, a little more scientific knowledge to illuminate the way would be very welcome.

Music: Tumbling Dice - The Rolling Stones.

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[1] Zakirova Z. et al. Gulf War Agent Exposure Causes Impairment of Long-Term Memory Formation and Neuropathological Changes in a Mouse Model of Gulf War Illness. PLoS One. 2015 Mar 18;10(3):e0119579.

[2] Ojo JO. et al. Exposure to an organophosphate pesticide, individually or in combination with other Gulf War agents, impairs synaptic integrity and neuronal differentiation, and is accompanied by subtle microvascular injury in a mouse model of Gulf War agent exposure. Neuropathology. 2014 Apr;34(2):109-27.

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Zakirova, Z., Tweed, M., Crynen, G., Reed, J., Abdullah, L., Nissanka, N., Mullan, M., Mullan, M., Mathura, V., Crawford, F., & Ait-Ghezala, G. (2015). Gulf War Agent Exposure Causes Impairment of Long-Term Memory Formation and Neuropathological Changes in a Mouse Model of Gulf War Illness PLOS ONE, 10 (3) DOI: 10.1371/journal.pone.0119579