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.
Skiing
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.
Abstract
PURPOSE:
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.
METHODS:
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.
RESULTS:
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.
CONCLUSIONS:
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
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.
Abstract
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
Implications
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.
Conclusion
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.