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Wednesday, 12 March 2014

Single Dose of IL-6 Antibodies or TNF-ᾳ Inhibitor as Potential Disease-Changing Autism Therapies


 
We have noted in earlier posts that autism is a dynamic encephalopathy and this may help explain why a therapy that works in a child aged 10, may be of little help to another child aged 3.  Not only are there many sub-types of autism, but each sub-type is evolving, as the child matures.

None of the autism drug therapies I have implemented have permanent disease changing effects, they all seem to work, but the effect is lost once you stop taking them.  Today’s post is about drugs that you take just once.  For a parent trying to find a drug that works in the sub-type affecting their child, this has a big advantage.  No need to keep trying for months to see if the drug has any effect.
Perhaps the most important time to intervene with drug therapy is as soon as possible after the diagnosis; but with what?
In an earlier post on trying to get a non-verbal child to talk, I suggested the use of corticosteroids to arrest on-going neuroinflammation.  Drugs like prednisone are potent, but they these have nasty side-effects if used long term. In that post, Dr Michael Chez, an eminent neurologist from Sacramento, was upbeat on their potential as immunomodulators.  We will refer back to him in this post as well.
In this post I will give more background about the role of a cytokine called Interleukin 6, or just IL-6, in autism.  You will see how science can both create a mouse with autism using IL-6 and reverse it again using IL-6 antibodies.
We will also look at another cytokine called   TNF-ᾳ and see how a single dose of a TNF-ᾳ inhibitor can improve chronic neurological dysfunction following a stroke, TBI and indeed autism.  It is effective even a decade after the original traumatic event.
Both the IL-6 and TNF-ᾳ drugs are developed for arthritis and these drugs cost tens of thousands of dollars a year, but in the case of neurological conditions they may have a disease-changing effect when used just once. Remarkably, both drugs are already approved for long term use in very young children with Juvenile Idiopathic Arthritis.


Why am I interested in Cytokine inhibition?
My very first attempt to reduce neuroinflammation in Monty, aged 10 with ASD, was a very surprising, but resounding success.  That followed my research into cytokine storms and statins.  I know it works, because when I stop the statin, the very same behavioural improvement is lost in a day or so.
Are there randomized trials of atorvastatin in autism? Sadly, not; but it is a safe intervention that works in my mouse model.
Are there further potential benefits from such therapy? Quite possibly, but higher doses of statins have side effects.
We saw in recent posts that PEA, quercetin and luteolin also inhibit pro-inflammatory cytokines.  Is there a potential disease-changing therapy?  We will only find one, if we look.


The Cytokine IL-6 and Autism
Thanks to Dr Wei, we have some excellent research linking specifically the cytokine IL-6 to autism.  He suggests that elevated levels of IL-6 may cause much of the damage in autism and he went as far as to prove it in a mouse model.

A single injection of IL-6 into a pregnant mouse, produced a mouse pup with social deficits.  When the mother received a dose of IL-6 antibodies the resulting mouse pup has normal behaviour.  Humans are not mice, but we do already know from Ashwood and others that people with ASD have elevated levels of IL-6 and in particular those people with regressive autism.  
Abstract
Autism is a severe neurodevelopmental disorder characterized by impairments in social interaction, deficits in verbal and non-verbal communication, and repetitive behavior and restricted interests. Emerging evidence suggests that aberrant neuroimmune responses may contribute to phenotypic deficits and could be appropriate targets for pharmacologic intervention. Interleukin (IL)-6, one of the most important neuroimmune factors, has been shown to be involved in physiological brain development and in several neurological disorders. For instance, findings from postmortem and animal studies suggest that brain IL-6 is an important mediator of autism-like behaviors. In this review, a possible pathological mechanism behind autism is proposed, which suggests that IL-6 elevation in the brain, caused by the activated glia and/or maternal immune activation, could be an important inflammatory cytokine response involved in the mediation of autism-like behaviors through impairments of neuroanatomical structures and neuronal plasticity. Further studies to investigate whether IL-6 could be used for therapeutic interventions in autism would be of great significance


Abstract
 
Background: Although the cellular mechanisms responsible for the pathogenesis of autism are not understood, a growing number of studies have suggested that localized inflammation of the central nervous system (CNS) may contribute to the development of autism. Recent evidence shows that IL-6 has a crucial role in the development and plasticity of CNS. 

Methods: Immunohistochemistry studies were employed to detect the IL-6 expression in the cerebellum of study subjects. In vitro adenoviral gene delivery approach was used to over-express IL-6 in cultured cerebellar granule cells. Cell adhesion and migration assays, DiI labeling, TO-PRO-3 staining and immunofluorescence were used to examine cell adhesion and migration, dendritic spine morphology, cell apoptosis and synaptic protein expression respectively.

Results: In this study, we found that IL-6 was significantly increased in the cerebellum of autistic subjects. We investigated how IL-6 affects neural cell development and function by transfecting cultured mouse cerebellar granule cells with an IL-6 viral expression vector. We demonstrated that IL-6 over-expression in granule cells caused impairments in granule cell adhesion and migration but had little effect on the formation of dendritic spines or granule cell apoptosis. However, IL-6 over-expression stimulated the formation of granule cell excitatory synapses, without affecting inhibitory synapses.


Conclusions: Our results provide further evidence that aberrant IL-6 may be associated with autism. In addition, our results suggest that the elevated IL-6 in the autistic brain could alter neural cell adhesion, migration and also cause an imbalance of  excitatory and inhibitory circuits. Thus, increased IL-6 expression may be partially responsible for the pathogenesis of autism.  

Brain IL-6 elevation causes neuronal circuitry imbalances and mediates autism-like behaviors.
Abstract
Abnormal immune responses have been reported to be associated with autism. A number of studies showed that cytokines were increased in the blood, brain, and cerebrospinal fluid of autistic subjects. Elevated IL-6 in autistic brain has been a consistent finding. However, the mechanisms by which IL-6 may be involved in the pathogenesis of autism are not well understood. Here we show that mice with elevated IL-6 in the brain display many autistic features, including impaired cognitive abilities, deficits in learning, abnormal anxiety traits and habituations, as well as decreased social interactions. IL-6 elevation caused alterations in excitatory and inhibitory synaptic formations and disrupted the balance of excitatory/inhibitory synaptic transmissions. IL-6 elevation also resulted in an abnormal change in the shape, length and distributing pattern of dendritic spines. These findings suggest that IL-6 elevation in the brain could mediate autistic-like behaviors, possibly through the imbalances of neural circuitry and impairments of synaptic plasticity. 

Abstract


Schizophrenia and autism are thought to result from the interaction between a susceptibility genotype and environmental risk factors. The offspring of women who experience infection while pregnant have an increased risk for these disorders. Maternal immune activation (MIA) in pregnant rodents produces offspring with abnormalities in behavior, histology, and gene expression that are reminiscent of schizophrenia and autism, making MIA a useful model of the disorders. However, the mechanism by which MIA causes long-term behavioral deficits in the offspring is unknown. Here we show that the cytokine interleukin-6 (IL-6) is critical for mediating the behavioral and transcriptional changes in the offspring. A single maternal injection of IL-6 on day 12.5 of mouse pregnancy causes prepulse inhibition (PPI) and latent inhibition (LI) deficits in the adult offspring. Moreover, coadministration of an anti-IL-6 antibody in the poly(I:C) model of MIA prevents the PPI, LI, and exploratory and social deficits caused by poly(I:C) and normalizes the associated changes in gene expression in the brains of adult offspring. Finally, MIA in IL-6 knock-out mice does not result in several of the behavioral changes seen in the offspring of wild-type mice after MIA. The identification of IL-6 as a key intermediary should aid in the molecular dissection of the pathways whereby MIA alters fetal brain development, which can shed new light on the pathophysiological mechanisms that predispose to schizophrenia and autism.

Effects of exogenous cytokines

Our pilot studies indicated that maternal administration of IL-6, but not IL-1α, tumor necrosis factor α (TNFα), or IFNγ, causes PPI deficits in the adult offspring. PPI is the inhibition of a startle response when the startling stimulus is immediately preceded by a smaller, nonstartling stimulus of the same modality and is a measure of sensory-motor gating, attention, and distractibility. PPI deficits are observed in several mental disorders, including schizophrenia and autism. Furthermore, PPI deficits in the offspring elicited by maternal influenza infection respond to antipsychotic and psychomimetic drugs, and the PPI deficit resulting from poly(I:C) MIA is present in adult but not juvenile rats, mimicking the adult onset of schizophrenia. The changes seen in this very relevant behavior prompted further study of the effects of maternal IL-6 administration

Thus, a single injection of IL-6 on E12.5 causes deficits in two relevant behaviors (LI and PPI) in the adult offspring.
Abnormal behavior in MIA offspring is prevented by maternal treatment with anti-IL-6 antibody
f, In the social interaction test, control mice show a strong preference for the social chamber [defined as (percentage of time in social chamber) – (percentage of time in opposite chamber)], whereas the offspring of poly(I:C)-treated mice show no such preference. Again, the deficit is corrected by maternal administration of IL-6 antibody

Tocilizumab / Actemra
Wei has made a pretty solid case that IL-6 is implicated in autism and that IL-6 inhibition could be a very interesting therapy.  While we have a range of interventions that can do just that, the ultimate therapy would be IL-6 antibodies.
This therapy does actually exist as a recent option in treating arthritis. Tocilizumab, brand name Actemra, is an immunosuppressive drug made of humanized monoclonal antibodies  against the interleukin-6 receptor (IL-6R)  In 2013 Actemra was approved by the FDA for children as young as 2 years old, as an ongoing treatment for arthritis.

This drug is frighteningly expensive and in arthritis you need to keep taking it regularly.
Now let us look at another related very expensive drug. Etanercept (trade name Enbrel).  Enbrel is another immunosuppressive drug for arthritis , but this time it is not inhibiting IL-6 but rather tumor necrosis factor (TNF).
This drug also treats a condition called psoriasis.  There is a case of a 53 year old Italian lady only partially verbal and by the sound of it, autistic, living with her mother.  She had her psoriasis treated with Enbrel and suddenly she became social and her speech improved.  Now an example of one is definitely interesting, but it does not prove anything.
But, remember Dr Chez from Sacramento?  Tucked away in his excellent paper of immunomodulation in autism.
 

"A single case of repetitive regression, with bouts of inflammatory colitis in an 8-year-old with regressive autism after age 3, has shown elevated serum TN alpha levels and rapid colitis, as well as behavioral and language improvements after injections of etanercept (unpublished data, personal communication Y. Davies and M. Chez 2008)."

At the time, I did not pay much attention since who can afford an ongoing therapy costing tens of thousands of dollars a year?
But, there is more.
In the US, a controversial doctor has been treating various chronic neurological dysfunctions with single dose etanercept.  He was criticized both for his marketing and the lack of published research to back up his claims.  To his credit, he is now publishing his work and has patented his therapy.

Here is a press article.

Here is an abstract of the study:-

Selective TNF inhibition for chronic stroke and traumatic brain injury: an observational study involving 629 consecutive patients treated with perispinal etanercept.

Abstract

BACKGROUND:


Brain injury from stroke and traumatic brain injury (TBI) may result in a persistent neuroinflammatory response in the injury penumbra. This response may include microglial activation and excess levels of tumour necrosis factor (TNF). Previous experimental data suggest that etanercept, a selective TNF inhibitor, has the ability to ameliorate microglial activation and modulate the adverse synaptic effects of excess TNF. Perispinal administration may enhance etanercept delivery across the blood-CSF barrier.

OBJECTIVE:


The objective of this study was to systematically examine the clinical response following perispinal administration of etanercept in a cohort of patients with chronic neurological dysfunction after stroke and TBI.

METHODS:


After approval by an independent external institutional review board (IRB), a chart review of all patients with chronic neurological dysfunction following stroke or TBI who were treated open-label with perispinal etanercept (PSE) from November 1, 2010 to July 14, 2012 at a group medical practice was performed.

RESULTS:


The treated cohort included 629 consecutive patients. Charts of 617 patients following stroke and 12 patients following TBI were reviewed. The mean age of the stroke patients was 65.8 years ± 13.15 (range 13-97). The mean interval between treatment with PSE and stroke was 42.0 ± 57.84 months (range 0.5-419); for TBI the mean interval was 115.2 ± 160.22 months (range 4-537). Statistically significant improvements in motor impairment, spasticity, sensory impairment, cognition, psychological/behavioural function, aphasia and pain were noted in the stroke group, with a wide variety of additional clinical improvements noted in individuals, such as reductions in pseudobulbar affect and urinary incontinence. Improvements in multiple domains were typical. Significant improvement was noted irrespective of the length of time before treatment was initiated; there was evidence of a strong treatment effect even in the subgroup of patients treated more than 10 years after stroke and TBI. In the TBI cohort, motor impairment and spasticity were statistically significantly reduced.

DISCUSSION:


Irrespective of the methodological limitations, the present results provide clinical evidence that stroke and TBI may lead to a persistent and ongoing neuroinflammatory response in the brain that is amenable to therapeutic intervention by selective inhibition of TNF, even years after the acute injury.

CONCLUSION:


Excess TNF contributes to chronic neurological, neuropsychiatric and clinical impairment after stroke and TBI. Perispinal administration of etanercept produces clinical improvement in patients with chronic neurological dysfunction following stroke and TBI. The therapeutic window extends beyond a decade after stroke and TBI. Randomized clinical trials will be necessary to further quantify and characterize the clinical response.

Now I am fully aware that author, Dr Tobinick,  has got into trouble with the Medical Board of California for his marketing approach.  Here is a link for those interested.  This does not mean his off-label use of etanercept is without merit.
Etanercept (trade name Enbrel) is a biopharmaceutical that treats autoimmune diseases by interfering with tumor necrosis factor (TNF; a soluble inflammatory cytokine) by acting as a TNF inhibitor. It has U.S. F.D.A. approval to treat rheumatoid, juvenile rheumatoid and psoriatic arthritis, plaque psoriasis and ankylosing spondylitis. TNF-alpha is the "master regulator" of the inflammatory (immune) response in many organ systems. Autoimmune diseases are caused by an overactive immune response. Etanercept has the potential to treat these diseases by inhibiting TNF-alpha.
 
Other comorbidities

You might view arthritis and psoriasis as as being related rather than being comorbid with autism.  Are there other comorbid conditions where anti-cytokine therapy is used?

One example is Irritable Bowel Disease (IBD), where several anti-TNF-alpha drugs have been shown to be effective and are widely prescribed.  IBD includes ulcerative colitis (UC) and the more severe Crohn’s disease.  UC does appear to be comorbid with autism and indeed UC itself does seem to be associated with mild autistic behaviours.  You will find adults with UC debating whether or not they have Asperger’s.

Here is a short video on anti-TNF therapy in IBD.

 
 
 
  
The complete set of video on IBD can be found here:-

For those scientists among you here is a full paper on this subject:- 
Pro-Inflammatory Cytokines in the Pathogenesis of IBD
 

Conclusion

I am surprised that nobody has sought to do even a very small trial of Etanercept/Enbrel or Tocilizumab/Actemra in autism. These potent immunomodulatory drugs can have side effects with long term use, but the case reports suggest that a single dose can be disease changing in neurological conditions, like autism.
In all likelihood only a single dose would be needed, so you really would not need the usual years of delay to complete a trial.  There is a lot of interest in GH and IGF-1 therapy in autism, which both require ongoing injections. To trial Etanercept and Tocilizumab would be so easy, in comparison.
Because the mechanism of action is fully understood, and IL-6 and TNF-ᾳ are easy to measure, it would later be possible to identify the people most likely to benefit from the cytokine lowering therapy.  Quite possibly it would be people with regressive autism who would benefit most, since they have the highest level of inflammatory markers, as highlighted by Ashwood.
If indeed the therapy worked, it is not going to be cheap; but at least it would be a one-off cost of $1,000 to $2,000, rather than a monthly cost as in severe arthritis.
I think our new friend Dr Wei would favour Tocilizumab/Actemra. If you live in California, Dr Tobinick would be the one to ask about Etanercept/Enbrel, but it won’t be cheap.

If medicine was a true science, we would have longitudinal autism studies that showed the level of inflammatory cytokines over time.  Then we would be able to say, for example, when regression occurs there is acute neuroinflammation with a spike in IL-6,TNF-ᾳ and other cytokines. 
Perhaps this inflammation does some long term damage that might be halted with immediate immunomodulatory therapy.  If the data did show this, we could look for correlations between later behavioral improvement and falling level in inflammatory cytokines. 
In children with regressive autism and who do not improve much, do the inflammatory cytokines stay at high levels?  Are the behavioral problems caused by the current level of inflammatory cytokines, or is the problem caused by the long term damage the cytokines already caused?  With data, all these questions could be answered.  Without data it is just conjecture.
All you need to do this research are regular blood samples.  The tests themselves are cheap.  Then you could compare cheap immunomodulatory therapy using steroids versus the expensive arthritis injections used one-off.

3 comments:

  1. Dear Peter, Do you also think that in majority of the cases of ASD, there are structural defects at least in the microscopic level? Which may not be corrected with these agents.
    Maybe those with immunomoderation changes only involve a small portion of subjects. Yi

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  2. My understanding of autism is evolving over time and I treat only one case of it, albeit in extreme detail. It is definitely not static. I think it may be best viewed as multiple layers of disorder. In the perfect world you would optimally treat each layer and then be left just with the consequences of some degree of physical damage that was done to the brain during development. An example of that damage is Purkinje cell loss, you cannot bring them back; but you can protect the ones that are left.
    I think in each child with ASD the relative importance of each of those layers varies. For example, the problems of the immune system being over-active will connect to all kinds of allergies, but this is mainly unrelated to the issue of channelopathies. If you have a child with unresolved allergic/immune issues, treating the ion channel and transporter dysfunction will likely show minimal benefit. All the multiple layers need to be optimized, no small challenge.
    I think this is part of the reason autism is so hard to treat and why it is left un-treated.
    It is clear that even some children with severe autism and apparent MR can show dramatic improvement, when it is possible to address the critical issue. An example was the child treated by Herbert with the diet that was both ketogenic and gluten & casein free, who became near NT and normal IQ. Bumetanide would not have a major impact; in this child ion channel dysfunction was not the key issue, although it might help now.

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  3. A very informative article on IL6 antibodies.

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