Showing posts with label Cytokines. Show all posts
Showing posts with label Cytokines. Show all posts

Tuesday, 13 January 2015

Cytokines from the Eruption of Permanent Teeth causing Flare-ups in Autism

A recent post looked again at inflammation in autism and some possible therapies to try.  Over Christmas and New Year, Monty, aged 11 with ASD, had occasional outbursts, more typical of his summertime raging, which was later solved using allergy /mast cell therapies.

At least it did let me establish whether Verapamil was a universal “cure” for SIB.  It is not.  It works great for allergy-driven aggressive behaviors, but had no effect on these ones.

Christmas is often a stressful period for many people with, or without, autism; but Monty likes presents and he loves food.

Having pulled out a wobbly tooth on Boxing Day and noticed an apparent behavior change, I thought that perhaps the loss of milk teeth and development of permanent teeth might cause an effect similar to that of his mild pollen allergy.  Monty, in common with many people with autism, has a high pain threshold.  While teething causes well known problems in babies, most children have minimal problems when their milk teeth are replaced by their permanent ones.

I just wondered if perhaps the underlying biological mechanism might provide an inflammatory insult to the highly inflammation-sensitive autistic brain.

Just as histamine provokes a release of inflammatory cytokines like IL-6, perhaps losing your milk teeth does something similar.

Ibuprofen experiment

I decided that I would buy some Ibuprofen, the least problematic NSAID.   A day or two later, Monty declared that another tooth was wobbly and needed to be pulled out.  This tooth was, and remains, well and truly attached.

So I decided that in advance of another, potentially stressful, Christmas event, I would give 10 ml of Ibuprofen.  I did not give it in response to any comment about pain.

It did indeed seem to work.


A few days later we were in the Alps for skiing.

Monty can ski, but we always give him a 1:1 instructor.  On the first day, without Ibuprofen, he got agitated during the queuing at the bottom of the beginners’ ski lift.  The instructor thought it was the loud booming music.  It was clear that by the end of the lesson, it was no fun at all.

The following days, I gave 10 ml of Ibuprofen, 20 minutes before the lesson started.  He had a great time, going up by cable car to the top of the mountain and skiing along the blue/red slopes and coming down in a neighboring resort a couple of hours later.  Even a change of instructor on one day, passed without issue.

It might not be scientific proof of the effectiveness of Ibuprofen, but it was enough for me.

The Science

Since this is a scientific blog, arriving home I did some checking on the biology of what happens when you lose your milk teeth.

There is more written about “teething” when you first get your milk teeth, but there is information about “root resorption” of milk teeth and “eruption” of the permanent teeth.  The process is indeed modulated by inflammatory cytokines and transcription factors.

These cytokines will then circulate around the body and cross the blood brain barrier.


The aim of this study was to investigate whether there are increased levels of the inflammatory cytokines IL-1beta, IL-8, and TNF alpha in the gingival crevicular fluid (GCF) of erupting primary teeth. This increase could explain such clinical manifestations as fever, diarrhea, increased crying, and sleeping and eating disturbances that occur at this time.


Sixteen healthy children aged 5 to 14 months (mean=9.8 months) were examined twice a week over 5 months. Gingival crevicular fluid samples were taken from erupting teeth. As a control, GCF was collected from the same teeth 1 month later. Cytokine production was measured by ELISA. Signs and clinical symptoms were listed. Pearson correlation coefficients were used in the comparisons described below. A paired t test was used to analyze the same variable at different times.


Fifty teeth of the 16 children were studied. GCF samples were collected from 21 of these teeth. Statistically significant differences (P<.05) were found with regard to the occurrence of fever, behavioral problems, and coughing during the teething period and the control period. During the control period, 72% of the children did not exhibit any clinical manifestations, whereas during the teething period only 22% of the children did not exhibit any clinical manifestations. The study revealed high levels of inflammatory cytokines during the teething period, with a statistically significant difference in TNF alpha levels (P<.05) between the teething period and the control period. Correlations were found between cytokine levels and some of the clinical symptoms of teething: IL-1beta and TNF alpha were correlated with fever and sleep disturbances; IL-beta and IL-8 were correlated with gastrointestinal disturbances; IL-1beta was correlated with appetite disturbances.


Cytokines appear in the GCF of erupting primary teeth. The cytokine levels are correlated to some symptoms of teething.

Mechanism of Human Tooth Eruption: Review Article Including a New Theory for Future Studies on the Eruption Process

Physiologic root resorption in primary teeth: molecular and histological events

Root resorption is a physiologic event for the primary teeth. It is still unclear whether odontoclasts, the cells which resorb the dental hard tissue, are different from the osteoclasts, the cells that resorb bone. Root resorption seems to be initiated and regulated by the stellate reticulum and the dental follicle of the underlying permanent tooth via the secretion of stimulatory molecules, i.e. cytokines and transcription factors. The primary root resorption process is regulated in a manner similar to bone remodeling, involving the same receptor ligand system known as RANK/RANKL (receptor activator of nuclear factor-kappa B/ RANK Ligand). Primary teeth without a permanent successor eventually exfoliate as well, but our current understanding on the underlying mechanism is slim. The literature is also vague on how resorption of the pulp and periodontal ligament of the primary teeth occurs. Knowledge on the mechanisms involved in the physiologic root resorption process may enable us to delay or even inhibit exfoliation of primary teeth in those cases that the permanent successor teeth are not present and thus preservation of the primary teeth is desirable. (J. Oral Sci. 49, 1-12, 2007)

Nonsteroidal anti-inflammatory drugs (NSAIDS), such as ibuprofen, work by inhibiting the enzyme COX which converts arachidonic acid to prostaglandin H2 (PGH2). PGH2, in turn, is converted by other enzymes to several other prostaglandins ,which are mediators of pain, inflammation, and fever.

Prostaglandin E synthase

Prostaglandin E2 (PGE2) is generated from the action of prostaglandin E synthases on prostaglandin H2 (PGH2).

PGE2 has various known effects, but one known effect is to increase the pro-inflammatory cytokine IL-6.  The same one that is increased by histamine released from mast cells during allergic reactions.

Elevated interleukin 6 is induced by prostaglandin E2 in a murine model of inflammation: possible role of cyclooxygenase-2.


Injection of mineral oils such as pristane into the peritoneal cavities of BALB/c mice results in a chronic peritonitis associated with high tissue levels of interleukin 6 (IL-6). Here we show that increased prostaglandin E2 (PGE2) synthesis causes induction of IL-6 and that expression of an inducible cyclooxygenase, Cox-2, may mediate this process. Levels of both PGE2 and IL-6 are elevated in inflammatory exudates from pristane-treated mice compared with lavage samples from untreated mice. The Cox-2 gene is induced in the peritoneal macrophage fraction isolated from the mice. A cause and effect relationship between increased macrophage PGE2 and IL-6 production is shown in vitro. When peritoneal macrophages are activated with an inflammatory stimulus (polymerized albumin), the Cox-2 gene is induced and secretion of PGE2 and IL-6 increases, with elevated PGE2 appearing before IL-6. Cotreatment with 1 microM indomethacin inhibits PGE2 production by the cells and reduces the induction of IL-6 mRNA but has no effect on Cox-2 mRNA, consistent with the fact that the drug inhibits catalytic activity of the cyclooxygenase but does not affect expression of the gene. Addition of exogenous PGE2 to macrophages induces IL-6 protein and mRNA synthesis, indicating that the eicosanoid stimulates IL-6 production at the level of gene expression. PGE2-stimulated IL-6 production is unaffected by addition of indomethacin. Taken together with the earlier finding that indomethacin diminishes the elevation of IL-6 in pristane-treated mice, the results show that PGE2 can induce IL-6 production in vivo and implicate expression of the Cox-2 gene in the regulation of this cytokine

Indomethacin is another NSAID, like Ibuprofen.


If, as seems likely, many incidents of anxiety, aggression, explosive behavior, or "meltdowns" are made possible by elevated levels of the pro-inflammatory cytokine IL-6, then the occasional use of drugs known to inhibit IL-6 makes a lot of sense.

Ibuprofen is an NSAID and it is known that some people respond much better to certain NSAIDs and suffer side effects from others.   NSAID drugs work by affecting both COX-1 and COX-2.  It appears that desired effect of NSAIDs comes from their effect on COX-2, while the side effects come from changes made to COX-1.  So it is logical that some NSAIDs are better tolerated than others and for some people a different NSAID may be more appropriate.

Other common drugs also lower IL-6;  leukotriene receptor antagonists like Montelukast (Singulair)  being an example.  This drug is used in autism, but a known side-effect in typical people is to worsen behavior, sometimes severely.  There are plenty of reports of Singulair in autism, some good and some bad.  Since almost all drugs have multiple effects, this is not surprising.

Interestingly, one of the drugs in my Polypill, NAC, is also known to reduce IL-6; but it also reduces the “good” anti-inflammatory cytokines like IL-10.  Perhaps this is why NAC is not beneficial to some people with autism?

Occasional use of Ibuprofen at times anticipated to be stressful makes a lot of sense. 


While it is well known that Ibuprofen relieves pain from teething, low level pain is often completely ignored by people with ASD.  The cytokine release associated with the resorption of the milk teeth and the eruption of the permanent tooth appears to be much more problematic.

Ibuprofen, available OTC, limits the production of pain mediators, called prostaglandins, which in turn stimulate production of the inflammatory cytokine IL-6.

Ibuprofen will reduce both pain and the level of cytokines like IL-6.

In earlier extensive posts on mast cell degranulation in autism, I concluded that the resulting elevated levels of IL-6 likely produced behaviors ranging from anxiety, through aggression, all the way to self-injury.

Thursday, 17 October 2013

Cytokine Theory of Disease & the Vagus Nerve

If you are a regular reader of this blog you will know that the key to controlling autism is reducing oxidative stress and neuroinflammation.  One of the key drivers of the on-going neuroinflammation are signalling molecules called cytokines; if you can limit the release of harmful cytokines you can reduce neuroinflammation.  This appears to be easier said than done.  I learnt that some statins limit the release of pro-inflammatory cytokines and neuroscientists in the US are researching their use, but not yet in autism.  I did some home research and found a positive effect within 24 hours.
It turns out there is an entire field of neuroscience relating to cytokines as a mediator of disease and this is all channelled through the Vagus nerve.  There is an eminent  neuroscientist, Kevin Tracey, who dominates this field; he is credited with discovering that vagus nerve stimulation inhibits inflammation by suppressing pro-inflammatory cytokine production.   Tracey is also an inventor, he is seeking to apply the science and has an interesting start-up company.  So I have found a kindred spirit and if you read his papers, you will find that often missing element, a sense of humour.
Tracy has even written a book, which explains his discoveries.

Fatal Sequence: The Killer Within

For those scientists among you, a very readable paper is:- 

Physiology and immunology of the cholinergic  Anti-inflammatory pathway

For those in a hurry, here is summary
The cytokine theory of disease is a concept that cytokines produced by the immune system can cause the signs, symptoms, and damaging aftereffects of disease.

One example is the case of TNF, a cytokine implicated as a necessary and sufficient mediator of lethal septic shock. Administration of TNF to healthy humans reproduces the metabolic, immunological, and pathological manifestations of the disease and the gene knockout or pharmacological blockade of TNF activity prevents the development of lethal septic shock. Other pathophysiological activities ascribed to TNF are the capacity to cause fever and localized inflammation. Clinical successes in the 1990s using drugs that specifically inhibit TNF for patients with inflammatory bowel disease or rheumatoid arthritis directly implicated a pathogenic role of this cytokine in other diseases and validated in humans the fundamental premise of the cytokine theory of disease.


The cholinergic anti-inflammatory pathway

Tracey reasoned that, since the CNS coordinates major physiological responses via innervated circuits, it might also use neural input to control a potentially deadly cytokine response. In classical physiological systems, the sensory projections of the autonomic nervous system provide input to brain networks about essential bodily functions. These elicit a coordinated neural output from the CNS to maintain homeostasis for parameters as varied as heart rate, blood pressure, digestion, body temperature, organ perfusion, and blood glucose levels. Accordingly, it seemed possible to posit the existence of a comparable mechanism to control cytokine release that could, at least in theory, function as an extremely fast, reflex-like anti-inflammatory pathway controlled by brain networks.  Stimulation of vagus nerve signals was shown to significantly inhibit TNF release in animals receiving lethal amounts of endotoxin. Subsequent work established that vagus nerve signaling inhibits cytokine activities and improves disease endpoints in experimental models of sepsis, schemia/reperfusion, hemorrhagic shock, myocardial ischemia, ileus, experimental arthritis, and pancreatitis. The cellular molecular mechanism for inhibition of cytokine synthesis is attributable to acetylcholine (ACh), the major vagus nerve neurotransmitter. Macrophages and other cytokine-producing cells express acetylcholine receptors (AChRs), which transduce an intracellular signal that inhibits cytokine synthesis. The best characterized of these cholinergic receptors that suppress cytokines is the α7 subunit of the nicotinic AChR (α7 nAChR).


It takes nerve to restrain cytokines: anatomy of an innervated cytokine system

Recent studies of the physiology, functional anatomy, and cellular molecular mechanisms of the cholinergic anti-inflammatory pathway indicate that the principal components for cytokine suppression by the vagus nerve converge in the spleen. Endotoxin localizes to macrophages primarily in the spleen and liver, thereby activating an immediate early cytokine response. The spleen is the major source of both hepatic and systemic TNF during endotoxemia; it releases newly synthesized TNF into the splenic vein, which drains into the liver, and from there, TNF crosses into the systemic circulation.

 Vagus nerve stimulation, or administration of α7 nAChR agonists, inhibits not only TNF but also IL-1, IL-6, IL-8, and high mobility group box 1 (HMGB1)


Preclinical efficacy of experimental therapeutics
Preclinical studies are in progress to determine whether it may be possible to develop therapeutics based upon either devices that stimulate vagus nerve activity or drugs that activate the cholinergic anti-inflammatory pathway to suppress cytokine damage. A significant number of studies indicate that the cholinergic anti-inflammatory pathway is a robust regulator of cytokine-mediated damage in local and systemic experimental disease.

The role of exercise
Exercise reduces levels of TNF and other cytokines, confers protection against cardiovascular disease and type 2 diabetes, increases vagus nerve activity, and confers protection against the development of atherosclerosis. It is possible that the mechanism of these exercise effects is at least in part attributable to exercise-induced increases in cholinergic anti-inflammatory pathway activity. Obesity, on the other hand, is characterized by diminished vagus nerve output and elevated cytokine levels, which have been implicated in mediating insulin resistance and atherosclerosis. Since weight loss and exercise are each associated with increasing vagus nerve activity, one can consider whether enhanced activity in the cholinergic anti-inflammatory pathway might decrease cytokine production and reduce the damage and metabolic derangements mediated by chronic, low-grade systemic inflammation that is characteristic of the metabolic syndrome

His conclusion:-

“It is bemusing to think that one of the fundamental premises of the ancient Greeks was that dietary manipulation controlled humoral balances. This concept is now, at least in principle, supported by new evidence of a direct link between dietary composition and the regulation of cytokines by the cholinergic anti-inflammatory pathway. Modern clinical studies have advocated supplementing diet with fish oil, soy oil, olive oil, and other fats to significantly increase vagus nerve activity, reduce inflammatory markers, and improve disease severity in inflammatory bowel disease, rheumatoid arthritis, and cardiovascular disease. These clinical anti-inflammatory responses may be linked to the fat-induced stimulation of the cholinergic anti-inflammatory pathway, as is the case in rats. And now it appears that a major source of systemic TNF during lethal challenges is the spleen, the source of Galen’s black bile. One can’t help but wonder: How did the ancient Greeks know?”


Anti-inflammatory activities of vagus nerve stimulation

The discovery by Tracey that vagus nerve stimulation inhibits inflammation by suppressing pro-inflammatory cytokine production has led to significant interest in the potential to use this approach for treating inflammatory diseases ranging from arthritis to colitis, ischemia, myocardial infarction, and congestive heart failure. Action potentials transmitted in the vagus nerve activate the efferent arm of the Inflammatory Reflex, the neural circuit that converges on the spleen to inhibit the production of TNF and other pro-inflammatory cytokines by macrophages there. This efferent arc is also known as the Cholinergic anti-inflammatory pathway Because this strategy targets the release of TNF and other pro-inflammatory cytokines, it may be possible to use vagus nerve stimulation instead of anti-inflammatory antibodies (e.g., Remicade or Enbrel) to treat inflammation. SetPoint Medical, Inc. is an early-stage medical device company, set up by Tracey, developing an implantable  neurostimulation platform for the treatment of inflammatory diseases.

Remicade and Enbrel are ultra-expensive drugs, costing about $20,000 per year.  Not surprisingly, some US autism doctors are wondering what they would do in autism.

My Conclusion

I was wondering if Kevin Tracey might be related to Jeff Tracy, in which case, can Brains please make Monty, aged 10 with ASD,  a vagus nerve stimulation device, preferably with a built-in nuclear power pack.  (I refer to a cult British TV series from the 1960s called Thunderbirds, a favourite of both Monty and his big brother, Ted.)  


Saturday, 27 July 2013

More on anti-histamines in Autism and introducing H4

In my previous posts on histamine, you would have read that I found that Claritin appeared to reduce autistic behaviours.  Once I had got to the bottom of what was going on, I found out that histamine has a long record of stimulating challenging behaviour in all children.  It also became clear that typical anti-histamines (H1 antagonists) are all slightly different and one may be effective in one person and ineffective in another.  Each one tends to have additional secondary effects.

It now appears that the secondary effect of certain H1 antagonists may actually be more important than the primary intended effect of reducing itchy eyes and runny noses.
There are three generations of H1 drugs.  The fastest working and most potent is still the first generation, the second generation are non-drowsy derivatives of the first generation.  The third generation are the active metabolite of the second generation.  As you will see in today’s central paper, the third generation probably does not warrant the tittle.  For many users they may be just expensive versions of the second generation drug.

The excellent paper  New anti histamines: a critical view is from Brazil, but it has an English version.  It is highly readable.  It tells of the specific secondary effects of certain second generation  H1 antagonists.   (She omits to mention the secondary effects of the first generation. Some people say Ketotifen is 1st generation and other people say 2nd generation, anyway it appears not to be sold in Brazil).  I suggest you read the paper, if you have a child with an ASD. The key section is this:

Antiallergic/anti-inflammatory effects

Originally, studies of the relative potencies of H1 antihistamines were based on the capacity of different compounds to competitively inhibit the H1 receptor binding of histamine, i.e. on their blocking effect on the receptor.8 Nevertheless, it has already been known for some time that, in addition to acting on H1 receptors, many H1 antihistamines, at appropriate doses, are capable of inhibiting not only the release of histamine by mast cells,9,10 but also mast cell activation itself.11 Some of them can even regulate the expression and/or release of cytokines, chemokines, adhesion molecules and inflammatory mediators.5,8

Therefore, the antiallergic properties of H1 antihistamines are generally a reflection of their capacity to affect mast cell and basophil activity, inhibiting the release of preformed mediators such as histamine, tryptase, leukotrienes and others.8 Several second-generation H1 antihistamines have demonstrated antiallergic properties, irrespective of their interaction with the H1 receptor.5,8

Chronic allergic inflammation resulting from the late-phase reaction, exhibits components that are similar to other forms of inflammation, including chemotaxis of inflammatory cells followed by activation and proliferation, with subsequent production and release of many chemical mediators. Among cells involved in allergic inflammation are: antigen-presenting cells (for example, macrophages), mast cells, basophils, T lymphocytes, epithelial/endothelial cells and eosinophils - major effectors of chronic inflammation. Cytokines, chemokines, inflammatory mediators and adhesion molecules also contribute to this process which ultimately leads to dysfunction of the affected organ.8

Many second-generation H1 antihistamines (particularly cetirizine) are capable of inhibiting the influx of eosinophils to the site of allergen challenge in sensitized individuals.5,8 Studies have demonstrated that some of them can also alter adhesion molecules expression on epithelium and eosinophils, and reduce in vitro survival of eosinophils. Finally, some second-generation H1 antihistamines are capable, in vitro and in vivo, of altering the production of inflammatory cytokines (for example, TNF-a, IL-1b and IL-6) and the Th1/Th2 balance regulation cytokines (for example, IL-4 and IL-13).5,8

Therefore, it is well established that, in addition to their effects on H1 receptors, many second-generation H1 antihistamines also manifest antiallergic and anti-inflammatory properties which differ depending upon their molecules and the experiments used for their evaluation.5

From my own experience, I have already replaced Claritine (Loratadine) with Cetirizine to see if it will remain active for longer.  Rather than working for 24 hours, Claritine is working for about 5 hours.
I thought Cetirizine might remain active for longer, but the main difference seems to be in how it works, rather than for how long it works.  With Cetirizine autistic behaviour has pretty much returned to where it was at the start of summer, before the allergy season.  With Claritine things improved greatly, but not all the way back to "normal".

Reading the paper and one of its references -
makes me think that the expensive new  version of Cetirizine, called Levocetirizine, might be even better.  It happens to be available locally, but it is seven times as expensive.

The Brazilian paper does rather contradict some of what Dr Theoharides says about stabilizing mast cells.  You can choose who you think has got it right.  The good thing is that both Dr Inês Cristina Camelo-Nunes and Dr Theoharides seem very serious, objective people, which cannot be said about all the people offering their advice on the internet.

In fact, I found an interesting paper on the anti-inflammatory effects of the new version of Claritin, called Aerius/Clarinex (Desloratadine).

It really seems to be the case of trying several antihistamines and selecting the one that works best for you.
The H4 Histamine Receptor and Inflammation
You may recall that there is a fourth histamine receptor, naturally called H4.

It was only recently discovered, as you might guess from the short entry in Wikipedia.  It seems that the H4 receptor plays a substantial role in the inflammatory response.  It is seen as playing a key role in conditions ranging from arthritis to asthma.
Here is a full text paper for those interested in the science:-

The role of histamine H4 receptor in immune and inflammatory disorders

 Here is a graphic from that paper:-

I wonder if that H4 is a ticking bomb in autism as well ?

Those more peaceful people among you will be less aware of what C4 is, and hence the sticks of H4 dynamite.



Saturday, 25 May 2013

A Cytokine Storm? Mr Spock

I have recently started learning the workings of the human immune system, while 12 year old Ted (“normal” except for a Star Wars obsession) has been discovering Star Trek.  Last weekend we went to the cinema with Adrian “Mole” to see the latest release.  Mr Spock made one interesting observation, regarding what can happen when the interests of the many outweigh the interests of the few; this will be the tittle of a forthcoming post about the fate of Dr Wakefield and his vaccine theory.


Cytokines really do exist, even though they sound like something from science fiction.  They are signalling molecules associated with inflammation.  Several inflammatory cytokines are induced by oxidative stress.  The fact that cytokines themselves trigger the release of other cytokines and also lead to increased oxidant stress, makes them important in chronic inflammation.  In extreme cases, there is a downward spiral of inflammation making it worse and worse.  The Spanish Flue in 1918 and SARS in 2003 are given as examples of such deadly cytokine storms.

The Research

There is a vast amount of research about the role of cytokines in autism and some very good work has been done by Paul Ashwood.  Finally, I have found an Englishman, even though he has gone to live in California, publishing some really high quality and useful research.  It turns out he is a colleague of Dr Wakefield.  Much of Paul Ashwood’s research is not available for free.  This one is:-  The role of immune dysfunction in the pathophysiology of autism

This paper is very readable and shows how a dysfunction of the immune system is without doubt a major part of the autism story. In typical post-Wakefield fashion, nobody wants to stick their necks out and draw usable, if only hypothetical, conclusions; it is easier to just suggest further research.

All the research shows high levels of cytokines in autistic subjects in the brain, spinal fluid, blood and in the gut.  Recent research also shows high levels of cytokines in the siblings of autistic people:- Plasma cytokine profiling insibling pairs discordant for autism spectrum disorder

The researchers comment:-

Thus, the lack of significant differences between sibling pairs discordant for ASD found in our study is in line with the results of previous studies. It is possible that a common immunogenetic background shared by siblings might eventually lead to different clinical outcomes when an environmental stress (for example, prenatal exposure to environmental toxins, viral and bacterial infections, parental microchimerism, etc.) occurs during development.

This last finding was deftly understood by 12 year old Ted, who commented, “Well Dad, you nearly had two autistic children”

Well isn’t he a chip off the old block.

Peter Interpretation

So combining this knowledge with my other readings, drew me to the logical conclusion that the inherited immune dysfunction, combined with the oxidative shock, so well described by Chauhan et al,(in the 400 page book) most likely resulted in a cytokine storm that damaged the brain, and autism resulted.  Due to the feedback loop of the cytokines, the neuroinflammation continues for life.

This then led me to research cytokine storms, to see how the cycle could be stopped and some kind of homeostasis reinstated.  I did not expect to find an answer, but I did.   

First we have to introduce new terms, TNF and TNFR.

Tumor necrosis factors (or the TNF family) refer to a group of cytokines whose family can cause cell death or apoptosis.  19 members of the TNF family have so far been identified; the one that caught my eye was OX40L, a cytokine that co-stimulates T cell proliferation and cytokine production.

A tumor necrosis factor receptor (TNFR), or death receptor, is a cytokine receptor that binds TNFs.  The matching TNFR for the TNF OX40L is called OX40 (also known as CD134).
OX40 binds to receptors on T-cells, preventing them from dying and subsequently increasing cytokine production. OX40 has a critical role in the maintenance of an immune response beyond the first few days and onwards to a memory response due to its ability to enhance survival. OX40 also plays a crucial role in both Th1 and Th2 mediated reactions in vivo. T helper cells (type 1 and 2) are white blood cells that play a major role in the immune system
OX40 has been implicated in cytokine storms.

Cause of the Cytokine Storm

When the immune system is fighting pathogens, cytokines signal immune cells such as T-cells and macrophages to travel to the site of infection. In addition, cytokines activate those cells, stimulating them to produce more cytokines.  Normally, this feedback loop is kept in check by the body. However, in some instances, the reaction becomes uncontrolled, and too many immune cells are activated in a single place. The precise reason for this is not entirely understood but may be caused by an exaggerated response when the immune system encounters a new and highly pathogenic invader. Cytokine storms have potential to do significant damage to body tissues and organs.

TNF inhibitors and Cytokine Storms

The cytokine storm is kept going by the TNF cytokines.  So if these cytokines could be inhibited the storm might abate. An existing medication developed for arthritis called a TNF-alpha blocker was proposed as a possible drug. Corticosteroids and NSAIDS (Non-steroidal anti-inflammatory drugs) have been found ineffective.

In 2003 researchers at Imperial College demonstrated the possibility of preventing a cytokine storm by inhibiting or disabling T-cell response. A few days after T cells are activated, they produce OX40, a "survival signal" that keeps activated T-cells working at the site of inflammation during infection with influenza or other pathogens. OX40 binds to receptors on T-cells, preventing them from dying and subsequently increasing cytokine production. A combined protein, OX40- immunoglobulin (OX40-Ig), a human-made fusion protein, prevents OX40 from reaching the T-cell receptors, thus reducing the T-cell response. Experiments in mice have demonstrated that OX40-Ig can reduce the symptoms associated with an immune overreaction while allowing the immune system to fight off the virus successfully. By blocking the OX40 receptor on T-cells, researchers were able to prevent the development of the most serious flu symptoms in these experimental mice.  Sadly, it appears this discovery has been abandoned by the small company that tried to develop it.

And now for the shock …

In 2009 researchers in China found that a statin induced down-regulation of OX40 and OX40L in a concentration-dependent manner.

"These findings improve our understanding of the anti-inflammatory and immunomodulatory properties of simvastatin"

Antioxidants have been successfully trialled in cases of Acute Respiratory Distress Syndrome (ARDS), which is another example of cytokine storm.  Organ damage was reduced and there was an improved survival rate.


It would seem that the combination of antioxidant and statin is about as good a combination as is currently possible, to dampen down the remaining effects of a cytokine storm, which is the extreme case of neuroinflammation.

By skill, or luck, this combination is exactly what I am trialling with Monty.