UA-45667900-1

Saturday 30 November 2013

Seasonal Autistic Mastocytosis



 The degranulation process in a Mast cell. 1 = antigen; 2 = IgE; 3 = FcεRI; 4 = preformed mediators (histamine, proteases, chemokines, heparin); 5 = granules; 6 - Mast cell; 7 - newly formed mediators  leukotrienes, platelet-activating factor)

Source: Wikipedia 



Some of the most popular posts on my blog refer to my investigation into the role of histamine in autism.  The investigation was productive and lead to a highly effective treatment for the wild summertime flare-ups in autistic behaviour exhibited by Monty, aged 10 with ASD. 

Since I have found a therapy it is only reasonable to give the condition a name. 

Seasonal Autistic Mastocytosis (SAM)

Seasonal Autistic Mastocytosis (SAM), sometimes known as Airborne Autistic Mastocytosis, occurs when airborne allergens like pollen, cause mast cells in the eyes, nose, mouth and lungs to degranulate.  These mast cells contain many granules, themselves containing histamine, serotonin and heparin, a naturally occurring anticoagulant.  This mast cell activation also releases inflammatory cytokines, leukotrienes and platelet activating factor (PAF).  Some of these pro-inflammatory agents enter the brain and stoke up the ever-present neuro-inflammation, starting a downward spiral with further localized cytokine release.  In behavioural terms, the result is that all the earlier bad behaviours will return, but in a magnified form.  The observer may notice swings to aggression and self-injurious behaviour (SIB).  If the subject is verbal, he may complain of unpleasant itching on arms and legs, typical of mastocytosis.  The autistic subject, not understanding the reason for the itching, is likely to react with some form of tantrum, aggression or hitting that part of his body.

SAM should be considered even when only very minor symptoms of an allergy are visible, like red eyes or runny nose.  

The most effective therapy is to use mast cell stabilizers, but even a standard OTC H1 antihistamine will provide some relief within 20 minutes.  The dosage required to have an effect, may be much higher than the recommended dose for allergic rhinitis (hay fever), but should still be within safe limits.
 
An alternative therapy is simply to move to somewhere that is pollen free, even just for a weekend and observe the effect.

Depending on where you live, SAM may be possible for about 5 months of the year.

Mast cells are particularly present in the digestive tract, the lungs, skin, eyes, mouth and nose.  They undoubtedly also play a major role is asthma.


Mastocytic enterocolitis is a related condition.  This condition is acknowledged in the medical community.  I am not a gastroenterologist, but I think Messrs Wakefield and Krigsman may have really stumbled upon cases of Mastocytic enterocolitis, when they came up with their diagnosis of Autistic enterocolitis.  Incidentally, Krigsman recently published an interesting paper on genes and colitis in ASD.

Some of the frequently reported cases of GI problems in autism may also be caused by mast cell degranulation.  Some of the DAN doctors treat GI problems with mast cell stabilizers and allergists routinely prescribe them.


Note on Serotonin

Approximately 30% of people with autism have high blood serotonin; perhaps a contributing factor is serotonin released by the degranulation of mast cells.  We have already seen that there often appears to be central hypo-function of serotonin in autism (i.e. low brain serotonin).  The endocrine system functions using feedback loops, so high blood serotonin sends a signal to lower serotonin; thus you could get low brain serotonin but high blood serotonin.  Remember that serotonin does not cross the blood brain barrier.



Wednesday 27 November 2013

Autism Clinical Trials, Arbaclofen (STX209), Curemark CM-AT and the Clever Chiropractor


 
In the world of clinical trials for drugs, judging success and failure can be highly subjective.  They try to make it as logical as possible and the method works pretty well for assessing things that you can measure objectively.




Primary and Secondary Endpoints
To quote Pfizer:

A trial endpoint of a clinical trial should fulfill three criteria: (1) be measurable and interpretable, (2) sensitive to the objective of the trial, and (3) clinically relevant. The endpoint can be either clinical or surrogate in nature.
If you are developing a drug to lower cholesterol or to increase survivability after a traumatic brain injury, it is pretty easy to define your endpoints.

When it comes to autism, one of the major hurdles is to define objective measurable endpoints.  As it stands today, none of the assessment tools are really fit for purpose, when Big Pharma is supposed to come along and invest hundreds of millions of dollars in some bright spark’s idea.

Arbaclofen, Seaside Pharma & Roche
The Swiss giant, Roche, recently had just such a problem.  They had partnered with a spinout company from MIT called Seaside Therapeutics.  One of the projects was to complete the trials of a fragile X targeted drug, called Arbaclofen (STX209).  During the 4+ years of trials Seaside had changed the primary endpoint.  Arbaclofen started out as drug to treat one aspect of behaviour, but by the time they got to phase 3  clinical trials this had been changed to lethargy and social withdrawal scores from the Autism Behavior Checklist (ABC).
Quite logically, Roche assessed the result of the stage 3 trial against its primary endpoint.  Based on the total cohort in the trial, Roche determined the drug to be a failure and pulled the plug on financing the drug further.
The owner and developer of the drug, Seaside, even though they have recently raised $90 million, said they could no longer continue to fund the trial and all those kids in the trial would have to be weaned of Arbaclofen ASAP.
It turns out that among the families involved in the trial there were many reports of wonderful improvements on Arbaclofen.  They even formed a group to lobby for a continuation of the trial.  There website is interesting.
It now appears that Seaside has had a rethink and will try again with a new trial with a new primary endpoint (mark 3).

Background on Arbaclofen
Some of the first studies of Arbaclofen were conducted in patients with Fragile X syndrome, a genetic condition caused by a change in a gene called FMR1, which normally is needed to make the brain grow properly. Fragile X is the most common form of inherited intellectual disability in boys and can be a cause of autism or related disorders. In those Phase 2 trials, Arbaclofen was shown to decrease social withdrawal and improve adaptive social function.

A  Phase 2a study conducted at 8 sites and involving 32 children showed significant positive behavioral outcomes, including improved scores on the Aberrant Behavior Checklist-Irritability Score (ABC-I) and on the ABC-Social Withdrawal Scale. The most common adverse events were agitation, irritability, fatigue, psychomotor hyperactivity, insomnia and diarrhea. Most resolved without dose changes, but one serious adverse effect did occur during down-titration of the medication.
In July 2011, Seaside Therapeutics, announced that 25 sites across the nation will be involved in a new clinical trial to involve approximately 150 ASD patients between the ages of 5 and 21.
STX209 is an orally-administered GABA-B agonist; the drug acts by stimulating the release of GABA, a neurotransmitter in the central nervous system. GABA inhibits the release of glutamate, an excitatory neurotransmitter, for which an overabundance negatively affects the ability of neurons to communicate with each other.

The GABA "A" receptor, is a chloride channel, while STX209 targets the GABA "B" receptor, which is a G-protein coupled receptor and regulates a different set of molecules from GABA "A".

The original basis for starting this blog was my success with bumetanide, which is affecting the GABA “A” receptor.  In the brain, bumetanide blocks the NKCC1 cation-chloride co-transporter and thus decreases internal chloride concentration in neurons.


Medicine as an art and a science
Mark Bear is a neuroscientist at MIT and he was the co-founder of Seaside Therapeutics.  He is clearly a very brainy guy.
There is a derivative of his Arbaclofen called Arbaclofen Placarbil.  I found it interesting that this substance was also being trialed as a therapy for Multiple Sclerosis and GERD.  GERD is the medical term for heartburn/indigestion.
Incidentally, Arbaclofen Placarbil failed both trials.


Now to the Clever Chiropractor and her Pancreatic Enzymes
People outside the US will find it very strange that in the US chiropractors and osteopaths have the same right to prescribe drugs as conventional medical doctors. 

Outside of the US, if you want to be a doctor you have to apply to medical school and in most countries the competition is very tough. There is no plan B if your exam grades slip.  In the US it is different, if your grades and resources are not taking you to the Harvard, you can opt to become an osteopathic physician or a chiropractic physician.
Rather than Harvard or MIT, Joan Fallon trained as a chiropractor at Palmer University.

Not surprisingly the scientific community is skeptical of her autism treatment, which is linked to pancreatic enzymes.  After all, how can a chiropractor know more than Ivy League neuroscientists?

Peter, on the other hand, thinks that Fallon is actually far more savvy than the very brainy people over at Seaside.  Her therapy may, or may not be effective, but her method of developing it is highly effective.
First she raised $6 million to start her company Curemark, then as trials progressed she very recently she raised another $18 million.
The reason I like what Fallon is doing is that she has figured out which sub-type of autism is helped by her therapy and she has identified a bio-marker for that subgroup.


Hallelujah, a street-smart autism researcher !
If you want to enroll in a clinical trial for Curemark’s CM-AT, first they will screen out the 50% that do not have the biomarker.  Fallon is making sure that her clinical trial results look as good as possible, by only including those subjects most likely to benefit.  This may sound like common sense, but in autism research this is a revolution.

CM-AT therapy and the biomarker
The reason the autism world are skeptical of Fallon, is that she is going on about Secretin and pancreatic enzymes.
Many years ago parents thought that Secretin was going to be the wonder cure for autism; it turned out not to be.  By reading her patents, it is clear that Fallon has some faith in the role of secretin, in addition to enzymes produced in the pancreas.

What impressed me was how she has screened the kids allowed into her clinical trials.


Eligibility
·         Inclusion criteria:
o    Child is 3-8 years old
o    Child has a diagnosis of autistic disorder
o    Child must have a low fecal chymotrypsin level (we will measure)

·         Exclusion criteria:
o    Child must have no dietary restrictions (other than for a nut allergy)
o    Child may not have an allergy to pork products
o    Child may not have a history of severe head trauma or stroke
o    Child may not have had a seizure within the past year
o    Child may not be diagnosed with: HIV, cerebral palsy, endocrine disorder or pancreatic disease
o    Child may not be taking any enzyme product, amino acids, secretin product or stimulant medication currently 

Low fecal chymotrypsin level” is a standard lab test available all around the world.  Over the years Fallon has found that it is a biomarker of the kids who benefit from her patented mix of enzymes sprinkled on their meals.
You actually can buy a very similar product called Creon, or Kreon, depending on which country you live in.  The reason why you cannot be in the trial if you have a pork allergy, is that they use the pancreas of dead pigs to make the enzymes.  This is bad news if you are Jewish, Muslim, a Seventh Day Adventist, or indeed the pig.

The active ingredient in Creon is Pancreatin. Pancreatin contains the pancreatic enzymes lipase, amylase and protease. These assist the digestion of fat, carbohydrates and proteins.

Update on trials of CM-AT
Here is a link to the always-helpful Simons Foundation, with the expected skeptical comments from experts:-

 https://sfari.org/news-and-opinion/news/2010/first-drug-for-autism-enters-final-stage-of-testing

Now Curemark have finished there phase 3 trial, and guess what? It met both primary and secondary endpoints and has been “fast-tracked” by the FDA.

Congratulations Joan !!!
One of the secrets of her success was to have the good sense to enroll herself in a course on clinical investigation run by Harvard/Massachusetts general hospital.
 
Curemark Begins NDA Submission for CM-AT Autism Treatment
CM-AT had previously been granted Fast Track status by the FDA, a designation given to drug candidates that treat serious or life-threatening conditions and demonstrate the potential to address unmet medical needs. The rolling submission process allows companies with a Fast Track designation to submit the NDA in sections to the FDA as they are completed.
“Initiating our ‘rolling NDA’ submission is a major step in the registration process for CM-AT,” said Dr. Joan Fallon, Curemark founder and CEO. “We have an extraordinary opportunity to help many children with autism improve the quality of their lives and we will continue to work closely with the FDA to make that happen.”
Curemark previously announced the successful completion of its Phase III multicenter clinical trial of CM-AT for autism. CM-AT met both primary and secondary endpoints in its double-blind, randomized, placebo-controlled study of children with autism at 3 to 8 years of age.



  
Conclusion

I would suggest those researchers who believe that diet can be an effective therapy in sub-types of ASD take good note of Joan Fallon's methods. You might indeed be right, but unless you can prove it, the skeptics will always hold sway.





 

Wednesday 20 November 2013

Catecholamines and Autism





 



 

 

 

 

 
Source: Wikipedia
 

As I mentioned a few posts back, it looks like endocrinology of the brain holds the key to treating autism and indeed most other psychiatric and neurological conditions.
Today’s post is about one group of hormones/neurotransmitters called  catecholamines.  Due to the inter-relationships between hormones, neurotransmitters and electrolytes it is helpful to group them together.  Catecholamines include three well known hormones: - epinephrine (adrenaline), norepinephrine (noradrenaline) and dopamine.
For those of you that did chemistry at school, the reason for the odd sounding name, catecholamines, is that these hormones contain a benzene ring with two OHs attached.
Catecholamines are very important hormones and also form the basis of several well-known drugs.  In chemistry when you take molecule like a hormone and make a tiny change to it, it then is referred to as an analogue (or an analog).   Some successful drugs are catecholamine analogs.
 
Dopamine

In the brain dopamine acts as a neurotransmitter; it appears to several distinct functions, some better known than others.

·        It controls the release of several hormones in the brain.  This may be the most important role in autism.

·        Motor control

·        Reward motivated behavior

Dysfunctions of the dopamine system are known to lead to:

Parkinson’s disease.  Loss of dopamine-secreting neurons in the midbrain disrupts motor control.
Schizophrenia involves altered levels of dopamine activity.
Attention deficit hyperactivity disorder(ADHD) and restless legs syndrome (RLS) are also believed to be associated with decreased dopamine activity.

Given that until recently autism was sometimes diagnosed as childhood schizophrenia and ADHD is evidently a case of autism-lite, it looks like dopamine plays a key role in Autism.
Dopamine does not cross the blood brain barrier (BBB) and its function outside the brain appears to be completely different.  Dopamine exerts its effects by binding to receptors on the surface of cells; so far 5 types of receptors have been identified.


Dopamine in ADHD
In ADHD it appears that genetic differences lead to altered dopaminergic neurotransmission. 


This part of science is only just emerging, but for many years some of the most effective therapeutic agents for ADHD have been psychostimulants such as methylphenidate (Ritalin) and amphetamine, drugs that increase both dopamine and norepinephrine levels in brain.
Very recently a study was published by Cambridge University, which would appear to contradict all this:-
Professor Barbara Sahakian who led the study at the BCNI said: “We feel these results are extremely important since they show that people who have poor concentration improve with methylphenidate(Ritalin) treatment whether they have a diagnosis of adult ADHD or not. These novel findings demonstrate that poor performers, including healthy volunteers, were helped by the treatment and this was related to increases in dopamine in the brain in an area of the striatum called the caudate nucleus.”
Professor Trevor Robbins, co-author and Director of the BCNI, said: “These findings question the previously accepted view of major abnormalities in dopamine function as the main cause of adult ADHD patients. While the results show that Ritalin has a 'therapeutic' effect to improve performance it does not appear to be related to fundamental underlying impairments in the dopamine system in ADHD.”

I find all this quite odd.  The researchers are surprised to find that Ritalin helps people without ADHD concentrate better.  Are they not aware that for many years students and “cognitive enhancers” have been taking Ritalin to improve their exam grades? These people do not have ADHD.  If the researchers spent half an hour on Google, they could have saved a lot of money. 
The study showed that Ritalin helps you concentrate and it also showed that using a combination of positron emission tomography (PET) and magnetic resonance imaging (MRI) to measure grey matter that in ADHD there are structural differences in the brain’s grey matter.  I wonder how this comes as a surprise to anyone.

It looks like the ADHD researchers in India are far more advanced than their Cambridge counterparts.

Affecting Dopamine Levels in the Brain
After synthesis, dopamine is transported from the cytosol into synaptic vesicles by the vesicular monoamine transporter 2 (VMAT2). Dopamine is stored in and remains in these vesicles until an action potential  occurs and causes the contents of the vesicles to be ejected into the synaptic cleft.

Once in the synapse, dopamine binds to and activates dopamine receptors.

After an action potential, the dopamine molecules quickly become unbound from their receptors. They are then absorbed back into the presynaptic cell, via reuptake mediated either by the high-affinity dopamine transporter (DAT) or by the low-affinity plasma membrane monoamine transporter (PMAT). Once back in the cytosol, dopamine is subsequently repackaged into vesicles by VMAT2, making it available for future release.

Dopamine is broken down into inactive metabolites by a set of enzymes, monoamine oxidase (MAO), aldehyde dehydrogenase (ALDH), and catechol-O-methyl transferase (COMT), acting in sequence. Both isoforms of MAO, MAO-A and MAO-B, are equally effective.
The level of dopamine circulating is there for a function of:-
·        How much is synthesized in the first place

·        How much is held in storage in the vesicles

·        How much is “recycled” via re-uptake

·        How much is degraded by MAOs

·        Presence of any Dopamine analog drugs acting as agonists
 
The release of Dopamine from the vesicles will be influenced by the factors maintaining central homeostasis; this includes hormones, electrolytes and other neurotransmitters.

Effect of Ritalin (Methylphenidate)
Recent research has shown that prolonged use of Ritalin increases dopamine transporter (DAT) levels and therefore amplifies the effect of amphetamines.

In the end this means that once on Ritalin, it will be very difficult to come off it, or in the words of the researchers:-
Upregulation of dopamine transporter availability during long-term treatment with methylphenidate may decrease treatment efficacy and exacerbate symptoms while not under the effects of the medication.

All in all, Ritalin does not look a good idea for children with ADHD or autism. 

Epinephrine
Epinephrine is a hormone and neurotransmitter that poorly crosses the blood brain barrier (BBB).

Regulation
The major physiologic triggers of adrenaline release centre upon stresses, such as physical threat, excitement, noise, bright lights, and high ambient temperature. All of these stimuli are processed in the CNS

Adrenocorticotropic hormone (ACTH) and the sympathetic nervous system stimulate the synthesis of adrenaline precursors by enhancing the activity of tyrosine hydroxylase and dopamine-β-hydroxylase, two key enzymes involved in catecholamine synthesis ACTH also stimulates the adrenal cortex to release cotisol, which increases the expression of PNMT in chromaffin cells, enhancing adrenaline synthesis. This is most often done in response to stress. The sympathetic nervous system, acting via splanchnic nerves to the adrenal medulla, stimulates the release of adrenaline. Acetylcholine released by preganglionic sympathetic fibers of these nerves acts on nicotinic acetylcholine receptors, causing cell depolarization and an influx of calcium through voltage-gated calcium channels. Calcium triggers the exocytosis of chromaffin granules and, thus, the release of adrenaline (and noradrenaline) into the bloodstream]

Unlike many other hormones, adrenaline and the other catecholamines do not exert negative feedback to down regulate their own synthesis. Their action is terminated with reuptake into nerve terminal endings, some minute dilution, and metabolism by MAO and catechol-O-methyl transferase. 

Norepinephrine
Norepinephrine is a hormone and neurotransmitter responsible for vigilant concentration.  As a stress hormone, norepinephrine affects parts of the brain, such as the amygdala, where attention and responses are controlled. Norepinephrine also underlies the fight-or-flight response, along with epinephrine, directly increasing heart, triggering the release of glucose from energy stores. It increases the brain's oxygen supply. Norepinephrine can also suppress neuroinflammation when released diffusely in the brain from the locus coeruleus.

Norepinephrine is synthesied from dopamine. It is released from the adrenal medulla into the blood as a hormone, and is also a neurotransmitter in the central nervous system (CNS).   The actions of norepinephrine are carried out via the binding to adrenergic receptors.
 
Clinical uses
Norepinephrine may be used for the indications attention deficit hyperactivity disorder (ADHD), depression, and hypotension. Norepinephrine, as with other catecholamines, cannot cross the blood–brain barrier, so drugs such as amphetamines are necessary to increase brain levels.

Attention-deficit/hyperactivity disorder

Norepinephrine, like dopamine, has come to be recognized as playing a large role in attention. For people with ADHD, psychostimulant medications such as amphetamines (Adderall, Desoxyn,) are prescribed to increase both levels of norepinephrine and dopamine.  Methylphenidate (Ritalin/Concerta), a dopamine reuptake inhibitor, and Atomoxetine (Strattera), a selective norepinephrine reuptake inhibitor (SNRI), increase both norepinephrine and dopamine in the prefrontal cortex equally but only dopamine and norepinephrine, respectively, elsewhere in other parts of the brain. Other SNRIs, currently approved as antidepressants, have also been used off-label for treatment of ADHD

Depression

Differences in the norepinephrine system are implicated in depression. Serotonin-norepinephrine reuptake inhibitors are antidepressants that treat depression by increasing the amount of serotonin and norepinephrine available to cells in the brain. There is some recent evidence implying that SNRIs may also increase dopamine transmission. This is because SNRIs work by inhibiting reuptake, i.e. inhibiting the serotonin and norepinephrine transporters from taking their respective neurotransmitters back to their storage vesicles for later use. If the norepinephrine normally recycles some dopamine too, then SNRIs will also enhance dopamine transmission. Therefore, the antidepressant effects associated with increasing norepinephrine levels may also be partly or largely due to the concurrent increase in dopamine.

Tricyclic antidepressants (TCAs) increase norepinephrine activity as well. Most of them also increase serotonin activity, but tend to produce unwanted side-effects due to the nonspecific inactivation of histamine, acetylcholine and alpha-1 adrenergic receptors. Common side-effects include sedation, dry mouth, constipation, sinus tachycardia, memory impairment, orthostatic hypotension, blurred vision, and weight gain.  For this reason, they have largely been replaced by newer selective reuptake drugs. These include the SSRIs, e.g. fluoxetine (Prozac), which however have little or no effect on norepinephrine, and the newer SNRIs, such as venlafaxine (Effexor) and duloxetine (Cymbalta).


Release modulators
 
Inhibitors of norepinephrine release
Substance
Receptor
norepinephrine (itself)/epinephrine

 

 
 
 

Anti-inflammatory agent role in Alzheimer’s disease

The norepinephrine from locus ceruleus cells in addition to its neurotransmitter role locally diffuses from "varicosities". As such, it provides an endogenous anti-inflammatory agent in the microenvironment around the neurons,  glial cells, and blood vessels in the neocortex and hippocampus. Up to 70% of norepinephrine projecting cells are lost in Alzheimer’s disease.


Timothy Syndrome
Timothy Syndrome is a rare genetic condition that is generally accompanied by autism.  Researchers at Stanford University found that this type of autism is caused by defective calcium channels in the  brain and that the defect could be reversed with  a drug.  Note that in this syndrome there is OVER-production of  dopamine and norepinephrine. 

In this study, the scientists suggest that the autism in Timothy syndrome patients is caused by a gene mutation that makes calcium channels in neuron membranes defective, interfering with how those neurons communicate and develop. The flow of calcium into neurons enables them to fire, and the way that the calcium flow is regulated is a pivotal factor in how our brains function.
The researchers also found brain cells grown from individuals with Timothy syndrome resulted in fewer of the kind of cells that connect both halves of the brain, as well as an overproduction of two of the brain’s chemical messengers, dopamine and norepinephrine. Furthermore, they found they could reverse these effects by chemically blocking the faulty channels.


Conclusion
This post was a short biology lesson.  Its relevance will become apparent in later posts as we look at the inter-relationships between hormones/neurotransmitters and ion channels/transporters. 

Then we can investigate therapeutic avenues.