Biomarkers in Autism : The Cholinergic system – In need of caffeine & nicotine or maybe just choline

Strange as it may sound, but if you have ASD a strong cup of coffee and a cigarette may actually do you some good.  Following on from my earlier post about Serotonin, showing that LSD was seen as an effective therapy in the 1960s, you might be wondering where my blog is taking us.  I just follow the science, wherever it takes us.

First of all what is the Cholinergeric system.

Cholinergic system (a summary from Wikipedia)

Cholinergic typically refers to acetylcholine in the neurological sense.  The parasympathetic nervous system, which uses acetylcholine almost exclusively to send its messages, is said to be almost entirely cholinergic. Neuromuscular junctions, preganglionic neurons of the sympathetic nervous system, the basal forebrain, and brain stem complexes are also cholinergic

In neuroscience and related fields, the term cholinergic is used in the following related contexts:

• A substance (or ligand) is cholinergic if it is capable of producing, altering, or releasing acetylcholine ("indirect-acting") or mimicking its behaviour at one or more of the body's acetylcholine receptor types ("direct-acting").
• A receptor is cholinergic if it uses acetylcholine as its neurotransmitter.^[2]
• A synapse is cholinergic if it uses acetylcholine as its neurotransmitter.

Acetylcholine is one of many neurotransmitters in the autonomic nervous system (ANS). It acts on both the peripheral nervous system (PNS) and central nervous system (CNS) and is the only neurotransmitter used in the motor division of the somatic nervous system.

In the central nervous system, acetylcholine and the associated neurons form a neurotransmitter system, the cholinergic system, which tends to cause anti-excitatory actions.

Damage to the cholinergic (acetylcholine-producing) system in the brain has been shown to be plausibly associated with the memory deficits associated with Alzheimer's disease.

Synthesis and degradation

Acetylcholine is synthesized in certain neurons by the enzyme choline acetyltransferase from the compounds choline and acetyl-CoA. Cholinergic neurons are capable of producing Ach.

Receptors

There are two main classes of acetylcholine receptor (AChR), nicotinic acetylcholine receptors (nAChR) and muscarinic acetylcholine receptors (mAChR). They are named for the ligands used to activate the receptors.

Nicotinic

Nicotinic AChRs are ionotropic receptors permeable to sodium, potassium, and calcium ions. They are stimulated by nicotine and acetylcholine. They are of two main types, muscle-type and neuronal-type. The former can be selectively blocked by curare and the latter by hexamethonium. The main location of nicotinic AChRs is on muscle end plates, on autonomic ganglia (both sympathetic and parasympathetic), and in the CNS.^[32]

Muscarinic

Muscarinic receptors are metabotropic, and affect neurons over a longer time frame. They are stimulated by muscarine and acetylcholine, and blocked by atropine. Muscarinic receptors are found in both the central nervous system and the peripheral nervous system, in heart, lungs, upper GI tract and sweat glands. Extracts from the plant Deadly night shade included this compound (atropine), and the blocking of the muscarinic AChRs increases pupil size as used for attractiveness in many European cultures in the past

--- end of wikipedia ---

 

The Research Showing Abnormality in ASD

The following study was carried out in the UK in 2002 on post mortem brain tissue from “Brain banks” in the US.  It is extensively referred to in the later research.

Nicotinicreceptor abnormalities in the cerebellar cortex in autism

 

An earlier paper on the same subject:-

Cholinergic Activity in Autism: Abnormalities in the Cerebral Cortex and Basal Forebrain

CONCLUSIONS: These neurochemical abnormalities implicate the cholinergic system in developmental disorders such as autism and suggest the potential for intervention based on cholinergic receptor modulation.

If the low level of cortical nicotinic receptors is consistently observed and clinically relevant, therapeutic strategies could include receptor agonists, such as nicotine, which has already been applied in Tourette’s disorder with amelioration of symptoms. Such treatment could also be disease modifying.

 

Other studies on autistic brain samples have shown diminished acetylcholine and nicotinic receptor activity.

Implications 10 years on remain the same

A recent study by neuroscientists at Ohio State University, concludes that neuronal nicotinic acetylcholine receptor (nAChR) alterations are biomarkers for ASD and that specific nAChRs subtypes are likely to be useful therapeutic targets for the treatment of core deficits. They claim a case can be made for the use of  α7 nAChRs to reduce neuroinflammation in the brain in those ASD individuals with such clinical pathology. The ultimate hope is that these agents, when administered early in development, by their presumed ability to modulate a number of different neurotransmitter systems and associated signaling pathways, could help correct core deficits associated with ASD.

Interventions

Just by spending 5 minutes on Wikipedia, you can find logical interventions that could have been tested since 2002.  Some have indeed been tested, others have not.  Here below is a copy-paste from Wikipedia, with interesting drugs highlighted.

 

Reversibel acetylcholinesterase inhibitor (often abbreviated AChEI)

Compounds which function as reversible competitive or noncompetitive inhibitors of cholinesterase are those most likely to have therapeutic uses. These include:

• Some organophosphates not listed under "Irreversible" below
• Delta9-tetrahydrocannabinol (THC)
• Carbamates
• Physostigmine
• Neostigmine
• Pyridostigmine
• Ambenonium
• Demarcarium
• Rivastigmine
• Phenanthrene derivatives
• Galantamine
• Caffeine – noncompetitive (also an Adenosine receptor antagonist)^[8]
• Piperidines
• Donepezil, also known as E2020
• Tacrine, also known as tetrahydroaminoacridine (THA')
• Edrophonium
• Huperzine A^[9][10]
• Ladostigil
• Ungeremine^[11]
• Lactucopicrin

Natural Compounds

• Huperzine A
• Galantamine
• Onchidal
• Coumarins
• Celastrus paniculatus

ACh receptor agonists/antagonists

Acetylcholine receptor agonists and antagonists can either have an effect directly on the receptors or exert their effects indirectly, e.g., by affecting the enzyme acetylcholinesterase, which degrades the receptor ligand. Agonists increase the level of receptor activation, antagonists reduce it.

Drugs acting on the cholinergic system

Blocking, hindering or mimicking the action of acetylcholine has many uses in medicine. Drugs acting on the acetylcholine system are either agonists to the receptors, stimulating the system, or antagonists, inhibiting it.

ACh and its receptors
Drug	Nm	Nn	M1	M2	M3
ACh, Charbacol, AChEi (Physostigmine, Galantamine, Neostigmine, Pyridostigmine)	+	+	+	+	+
Nicotine, Varenicline, Cotinine	+	+
Succinylcholine	+/-
Tubocurarine, Atracurium, Cisatracurium, Rocuronium, Vecuronium, Pancuronium	-
Epibatidine, DMPP, Decamethonium		+
Trimethaphan, Mecamylamine, Bupropion, Dextromethorphan, Hexamethonium		-
Muscarine, Methacholine, Oxotremorine, Bethanechol, Pilocarpine			+	+	+
Atropine, Tolterodine, Oxybutynin			-	-	-
Vedaclidine, Talsaclidine, Xanomeline, Ipratropium			+
Pirenzepine, Telenzepine			-
Methoctramin				-
Darifenacin, 4-DAMP, Darifenacin, Solifenacin					-

Direct acting

These are drugs that mimic acetylcholine on the receptor. In low doses, they stimulate the receptors, in high doses they numb them due to depolarisation block.

Acetyl l-carnitine[33] Acetylcholine itself Bethanechol Carbachol

Cevimeline Muscarine Nicotine

Pilocarpine Suberylcholine Suxamethonium

------- end of Wikipedia ---------

 

Evidence based approach

The web is full of commentators telling you to only pay attention to evidence-based treatments.  This sound great in principle, but it assumes there are copious amounts of well-constructed clinical trials.  Moreover, is assumes that there is just one type of autism, or that clinical trials are sophisticatedly constructed to test individual sub-types, one at a time (which they are not).

So, in reality, the evidence is generally poor quality and so applying a pure evidence-based approach will leave you exactly back where you started.

I have gathered together what I think is a remarkable amount of evidence from multiple imperfect trials and anecdotal case studies.

Use Of Donepzil

Following on two earlier trials, Chez et Al carried out a double-blind study  of Donepezil hydrochloride, an acetylcholinesterase inhibitor  to confirm those findings. 

 

Donepezil hydrochloride: a double-blind study in autistic children

 The trial concluded:-

Expressive and receptive speech gains, as well as decreases in severity of overall autistic behavior, were documented after 6-weeks for the treatment group. These improvements were statistically significant when compared to placebo, and were clinically meaningful as assessed over time. Donepezil hydrochloride appears to improve expressive and receptive language as well as overall autistic features, consistent with the hypothesis of acetylcholinergic enhancement

 Here is a more recent case study from India

Role of Donepezil in Autism: Its conduciveness in Psychopharmacotherapy

A woman consulted psychiatric Out-Patient Department (OPD) for her 5-year and 2-month-old son presenting with typical autistic symptoms like social, behavioural, and communicational ineptitudeness. Subsequent treatment with Donepezil resulted in marked improvement in the aforementioned symptomatology. Recent studies in autistic child have shown diminished acetylcholine and nicotinic receptor activity, thus an acetylcholinergic enhancer, Donepezil, likely accounts for improvement in autistic symptoms. Evidently, the case report consolidates Donepezil role as a potentially useful agent in the treatment of cognitive and behavioural symptoms observed in this disorder.

 Mecamylamine

There was a recent trial of Mecamylamine, with mixed results, but the researcher is already planning a follow trial of a similar drug called varenicline, that was previously suggested by other researchers.

Placebo-controlled pilot trial of mecamylamine for treatment of autism spectrum disorders.

RESULTS:

Eighteen participants (10 mecamylamine, 8 placebo) completed the study. All doses were well tolerated; the only side effect of note was constipation (50% compared with 25% of placebo group). Three children had clinically nonsignificant electrocardiographic QT prolongation. Both groups showed modest to moderate improvement, but differences between groups were negligible. On the primary outcome measure, the Ohio Autism Clinical Impressions Scale, 90% of the active treatment group showed improvement at some point (but only 40% sustained it), compared with 62% on placebo. Of the four in active treatment that sustained improvement, three had a maximum dose of 0.13-0.15 mg/kg/day, while those who regressed had doses ≥0.18 mg/kg/day. Graphed means suggested better outcome with lower mg/kg and longer medication duration. Four parents spontaneously reported reduced hyperactivity and irritability and better verbalization and continued mecamylamine at their own expense.

CONCLUSION:

Mecamylamine appeared to be safe, but not very effective in autism. The suggestion of better results at lower doses and longer exposure warrants consideration for future trials. The next step would be exploration of a more specific α4β2 nAChR agonist, such as varenicline.

Varenicline

Varenicline is a drug developed to help people to stop smoking.  It is widely used and looks set to be trialed in autism

Varenicline in Autistic Disorder: Hypothesis and Case Report of Single-Patient Crossover

Galantamine

Galantamine was successfully trialed and I am surprised we do not hear more about it.  In fact, it was developed in the Soviet Union in the 1950s and is now used for Alzheimer's.  It is based on snowdrop flowers.  It is available as a drug and as a supplement, depending on where you live.

A prospective, open-label trial of galantamine in autistic disorder.

RESULTS:

Patients showed a significant reduction in parent-rated irritability and social withdrawal on the ABC as well as significant improvements in emotional lability and inattention on the Conners' Parent Rating Scale--Revised. Similarly, clinician ratings showed reductions in the anger subscale of the Children's Psychiatric Rating Scale. Eight of 13 participants were rated as responders on the basis of their improvement scores on the Clinical Global Impressions scale. Overall, galantamine was well-tolerated, with no significant adverse effects apart from headaches in one patient.

CONCLUSION:

In this open trial, galantamine was well-tolerated and appeared to be beneficial for the treatment of interfering behaviors in children with autism, particularly aggression, behavioral dyscontrol, and inattention. Further controlled trials are warranted

The missing evidence

You will have noticed caffeine and nicotine in the title of this post.  You may have noted that back in 2001/2 the original researchers suggested the logical next step was to trial nicotine patches.

All I can find is one case report in ADHD, which to me is just ASD-lite.

Transdermal Nicotine in Adult ADHD With Depression and Anxiety

If you look in internet forums you will see that DAN doctors in the US are using nicotine patches.  You will also find people giving small doses of caffeine.

Having reviewed “the evidence” I think it is entirely logical to trial SMALL doses of nicotine and caffeine.  The research indeed tells us that only SMALL does may have the desired effect.

One report I read was a DAN Doctor giving her own child a quarter of 7mg nicotine patch.  By my research, that equals the nicotine of a single cigarette.

You will also see older kids with HFA (high functioning autism) writing on the web how they feel it easier to (pretend to) be more NT (neuro-typical) after drinking coffee and/or smoking. (Maybe they just look more NT, or maybe there is some truth in it).  They do not talk about alcohol.

The other “obvious” thing that has not been trialed is acetylcholine or choline itself.  It is known to be deficient in autism.  It is sometimes included in multivitamin pills in small amounts. Choline is widely available as a supplement.  It is also used for its nootropic properties and there are claims it reduces neuroinflammation.  It is used in depression, memory loss, Alzheimer’s and schizophrenia  It also lower cholesterol. Most surprisingly, choline is prescribed to control asthma, a comorbidity of ASD.  

Choline is used by people trying to boost their brainpower by combining it with other nootropic drugs.  Their favourite drug appear to be Piracetam, which is the same drug used for ASD in Ukraine and subject of a clinical trial in Iran, that I wrote about recently.

It is remarkable how many drugs I am writing about are either (ab)used by body builders or now IQ builders.

Conclusion

This post has really surprised me.  Firstly, there more drugs that look like they actually do work in autism (Donepezil and Galantamine).  There is an interesting phase 4 trial underway using Donepzil + Choline. Phase 4 is the final phase.

Nicotine may set alarm bells ringing, but if you check it out, you will see that very small amounts are apparently harmless.  Thanks to smokers, there exists a perfect transdermal delivery system.  Just why nobody trials it in autism (Glaxo produce Nicorette patches) is inexplicable.

Small amounts of coffee are given to even young children in many strong coffee drinking countries (like the Balkans). Coca Cola and even Ice Tea are caffeine-rich.

Choline is probably the simplest, cheapest and safest intervention;  but that does not mean it is will be effective.  Nobody has made a controlled trial with it, probably because there is no money in it.

For a change in my posts, it looks like there is something for everyone.

 

Biomarkers in Autism: Mercury – Science, Bad Science & GSH (again)

You do not need to have any particular view about vaccines and autism; but there are some very strange connections between mercury and autism.

I came back to look at this subject, having noticed that one of the more rational/objective researchers included a chelating agent in his patent for autism treatment.   Chelating agents remove heavy metals like mercury or lead from the body, but they also remove important elements like calcium.  Very high or low levels of electrolytes like Ca or K can kill you.

In 2006 clinical trials on chelation therapy in autism were halted by the US National Institute of Health on “safety reasons”.  But in 2012, a much bigger 5 year long, $30 million study called Trial to Assess ChelationTherapy (TACT) in coronary heart disease reported back that this “fringe” therapy did indeed work, though for reasons unknown.

Chelation Therapy: What To Do With Inconvenient Evidence

The autism trial was to use a chemical called DMSA,  while the coronary heart disease trial used a chemical called EDTA.  The 5 year trial appeared to show EDTA was safe.

Measuring Mercury

There are various ways of measuring for mercury; you can measure for it directly in urine, blood, hair and even teeth.  You can also measure for biomarkers of mercury and the popular one is called Porphyrin Testing.

The problem is that if you have been subject of some serious heavy metal contamination the metal may no longer be in your blood or urine in elevated levels.  This is why forensic science laboratories look at hair and teeth.

At this point the bad science and the science start to get mixed up.  There is a chemical called precoproporphyrin, an atypical porphyrin previously identified only in adult humans and animals with prolonged exposure to Mercury or compounds containing mercury.  It is often present in substantial concentrations in urine of younger children with autism.

This has created a nice business with laboratories charging $120 to measure porphyrin in the urine of autistic children.  A handful of researchers keep writing studies about mercury in autism, using porphyrin to “measure” them.

One of the labs used is surprisingly in France.  It seems many US citizens are mailing samples to Laboratoire Philippe Auguste in Paris.

But, at the same time, another group of scientists take the opposite approach and say that urinary porphyrins are biomarkers of autistic spectrum disorder, because a subset of people with ASD have disordered porphyrin excretion as a metabolic characteristic.  They have gone so far as to patent their idea as a test for autism.  By this logic paying $120 to test a kid known to have ASD would be pretty pointless.

Urinary porphyrins as biomarkers of autistic spectrum disorder risk  -  PATENT

The researcher suggests that the elevated Urinary porphyrins have nothing to do with mercury at all.

… Several possibilities might account for these differences. Not to be bound by theory, Hg exposure appears unlikely to play a role in this effect, because no significant differences were observed between NT and AUT subjects for indices of past exposure to Hg from dental or medical sources, as reported by parents/caregivers. Additionally, urinary Hg concentrations, measures of recent Hg exposure, were very low among all subjects in this study (Table 2), and no significant differences between diagnostic groups were observed …

… the present findings indicate that porphyrin metabolism, particularly in preadolescent children, may be too disordered or differently regulated to permit detection of the Hg-mediated changes in urinary porphyrin excretion that are apparent in adult subjects …

… another factor that may account for the differences in urinary porphyrin levels between AUT and NT children is mitochondrial dysfunction, a disorder commonly associated with autism …

Where is the Mercury coming from?

The sources put forward as to where the mercury is coming from include:-

·        Mother’s dental fillings containing mercury

·        Any amalgam fillings the child has

·        Mercury in the environment

·        Mercury in vaccines

If your body is unable remove mercury as fast as it is absorbing it, then the total amount of mercury in your body will increase.  So it is your cumulative past exposure, minus what you have removed, that is the key figure.

The body’s main antioxidant, glutathione (GSH), is its key resource to deal with disposing of heavy metals.  It has been established for years that GSH levels are reduced in almost all cases of autism.  Incidentally, GSH levels are also reduced in old age and so those subjects in the TACT clinical trial for chelation in heart disease that benefited, did do (according to Peter) because the chelator is an antioxidant.  It lowered their oxidative stress and raised their GSH level.

Mercury in Hair Samples

An interesting study measured the level of mercury in babies’ first haircuts.  This is about when the baby is 17 months old.

The study showed much lower levels of mercury in the ASD babies than in the control babies.  This is probably the opposite of what you might have expected.  There is also a nice chart correlating the level of mercury in the control babies with the number of amalgam fillings in the mother.

The authors proposed that the kids with ASD must have higher levels of mercury in their bodies, because they are unable to eliminate mercury like typical children.

“If reduced overall mercury elimination is related to hair elimination, then autistic infants will retain significantly higher levels of mercury in tissue, including the brain, than normal infants.”

Reduced Levels of Mercury in First Baby Haircuts of Autistic Children

  

A later study has some equally surprising findings.  The study in Poland, looked at kids aged 3-4 and also 7-9.  They found, as in the baby study, that the youngest kids had lower levels of mercury in their hair than the typical kids.  But the older kids had higher mercury levels in their hair than the kids in the control group. 

Age-dependent lower or higher levels of hair mercury in autisticchildren than in healthy controls.

The conclusion was that:-

The results suggest that autistic children differ from healthy children in metabolism of mercury, which seems to change with age.

Mercury in baby teeth

 So now we come to teeth.  If the ASD kids have low mercury, it will be claimed that this means they must have high internal levels since they have not eliminated it in their teeth.  If they have high mercury then they will say that this proves there is a high level of mercury in kids with ASD.  Read on and find out.

Well the study tells us that baby teeth are a good measure of cumulative exposure to toxic metals during fetal development and early infancy.  They found that 6 year old children with autism had twice as much mercury in their teeth as neurotypical children.

 Mercury, lead, and zinc in baby teeth of children withautism versus controls.

This study determined the level of mercury, lead, and zinc in baby teeth of children with autism spectrum disorder (n = 15, age 6.1 +/- 2.2 yr) and typically developing children (n = 11, age = 7 +/- 1.7 yr). Children with autism had significantly (2.1-fold) higher levels of mercury but similar levels of lead and similar levels of zinc. Children with autism also had significantly higher usage of oral antibiotics during their first 12 mo of life, and possibly higher usage of oral antibiotics during their first 36 mo of life. Baby teeth are a good measure of cumulative exposure to toxic metals during fetal development and early infancy, so this study suggests that children with autism had a higher body burden of mercury during fetal/infant development. Antibiotic use is known to almost completely inhibit excretion of mercury in rats due to alteration of gut flora. Thus, higher use of oral antibiotics in the children with autism may have reduced their ability to excrete mercury, and hence may partially explain the higher level in baby teeth. Higher usage of oral antibiotics in infancy may also partially explain the high incidence of chronic gastrointestinal problems in individuals with autism.

How much Mercury is bad for you?

Mercury is definitely not good for you, but just how much is actually bad for you?

Eating a lot of fish will raise maternal levels of mercury, so in the US women are advised to eat less fish during pregnancy.

In the Seychelles (islands in the Indian Ocean) the diet included 10 times as much fish and since they eat big fish, mercury consumption is 20 times higher.  The level of vaccination was near 100% and the vaccines contained thimerosal.

Autism Spectrum Disorder Phenotypes and Prenatal Exposure to Methyl mercury

Using linear and nonlinear regression analyses, the researchers found no consistent correlation between prenatal exposure to methyl mercury and scores on ASD screening instruments.

Parent feedback

If you look on the web, it is pretty clear that many parents think their chelation therapy had a positive impact.  There is even a very unscientific survey showing this somewhere; I cannot find it today.

Here is a typical chelation approach.

Since the chelation is like a big anti-oxidant infusion, I would expect to see a big positive improvement, regardless of whether mercury has anything at all to do with it.

Big Sceptics

There are some big sceptics about chelation.  Here is one site called chelation watch

and here is an interesting article by a Doctor who followed ”his dark side” into the world of alternative therapy and emerged a big sceptic.

James R. Laidler, MD    -  My Involvement with Autism Quackery

My personal journey through the looking glass has ended. I stepped into “alternative” medicine up to my neck and waded out again, poorer but wiser. I now realize that the thing the “alternative” practitioners are really selling is hope—usually false hope—and hope is a very seductive thing to those who have lost it.

Other research

There is plenty of other research on the subject of my post.  Normally you can tell by who funded the study or who worked on it, what the likely conclusion is to be.

Toxicological Status of Children with Autism vs. Neurotypical Children and the Association with Autism Severity

Mercury and autism: Accelerating Evidence?

This paper again shows that urinary porphyrins are a biomarker for autism, rather than mercury.

Disordered Porphyrin Metabolism: A Potential Biological Marker for Autism Risk Assessment

This paper repeats the story about urinary porphyrins indicating high mercury in autism  

Toxicity biomarkers in autism spectrum disorder: A blinded study of urinary porphyrins

Conclusion

If the US National Institute of Health removed its ban on the clinical trial of chelation in autism, then there would be some high quality facts to judge.  Sadly, this all seems to be linked to “big brother” trying to halt the debate about autism and vaccinations, all for the very sound reason of public health.

I think it is quite possible that the culprit is oxidative stress and low GSH and that the bizarre results of mercury levels in hair, teeth and urine are in fact no more than a consequence of low levels of GSH.  The oxidative stress is clearly damaging, perhaps the slightly elevated levels of heavy metals are themselves harmless.

Perhaps the best thing would be to measure the level of GSH (GSH redox) in babies, children and then again after middle age.  High levels of oxidative stress, whether linked to autism or other conditions could then be treated.

There is a cheap and effective antioxidant called NAC (N-acetyl cysteine), it is known to raise GSH.  If you want to call it a chelating agent, you would also be correct.

Since mercury is known to be a very harmful substance, we should of course try to minimize it in humans.