The Open Question of Autoimmunity

So far, I've stuck rather close to the evidence (although the evidence is often new) that medical research provides, although sometimes I have certainly drawn inferences that haven't appeared yet in the scientific literature, from that evidence. The question of autoimmunity, and in particular the cause of autoimmunity, is still very much an open in medical science. There are interesting hints in the literature, but no direct answers. Autoimmune and inflammatory diseases make up a very large chunk of chronic illness, including asthma, eczema, multiple sclerosis (at least in part), rheumatoid arthritis, and much more. I believe we can now sketch out a very reasonable guess about the cause of autoimmunity, too, since this is something we might very well expect, given the known consequences of the Photoperiod Effect (long hours under light.)

We know that a great deal is done during darkness to clean us up, inside and outside our cells, removing all sorts of garbage; including but by no means limited to free radicals. During this time, our activities are minimal, and far less detritus such as bits and pieces of broken proteins from mechanical stress, dead cells, or unusual molecules introduced from food are introduced. Therefore, late in the night after long exposure to melatonin and other cleaning molecules and processes; when our bodies and bloodstreams and cells are relatively clean and contain the fewest number of foreign particles, is the most convenient time to schedule the normal process of self-recognition which informs T-cells about what to kill and what not to kill. Why then? Because at this time, late during the period of darkness and after so much garbage collection has already taken place, invaders will be most obvious. Truly threatening pathogens will now stick out because they have continued to reproduce while all sorts of other garbage, protein fragments, and other stray garbage was being removed. Therefore, the end of our nightly immune cycle (or possibly the contrast between the rates of particles at the beginning and nearer the end of this nightly cycle) is the time at which our bodies can most easily distinguish and specifically recognize foreign invaders (as opposed to unusual molecules from food, pollen, or bits of our own cells.) Antibodies can then be made to counter them. Mistakes in this identification of foes are least likely at this time, provided we are experiencing a natural, long night, because there's less “noise” in the system, so fewer opportunities for things to go wrong. By the same token, identification of enemies will be most certain then – if we have been experiencing full, natural periods of darkness.

However, if our nights, the consistent periods of darkness we experience, are constantly being cut short, interrupted, or juggled; truly thorough cleaning and garbage collection and excretion never quite happens for us. A condition that is likely to be particularly consequential during childhood while our immune systems are developing. This process of identification of friend and foe may become confused if we grow up in unnaturally short nights. It should not be too surprising then, if our bodies may start to tag bits of ourselves, of our own proteins, or stray pollen, etc, as viral or bacterial enemies to be attacked, or become sufficiently erratic at the task of identifying enemies that our bodies fall back on natural killer T-cells (NTKs) that are much less targeted, and tend to attack indiscriminately. (NTKs have now been implicated in asthma, for example.)

Our immune system doesn't shut down during the day. It continues, but at a much different pace, performing somewhat different tasks. A front-line defence is maintained, especially in local areas such as the nose. Even a continuous process of pathogen identification throughout the day could then be expected to become increasingly difficult, and erratic. The more litter is left in the bloodstream (and perhaps elsewhere) the harder it will be to recognize real enemies (principally viruses and bacteria.) One would certainly expect that pathogens stand a better chance to gain a foothold before they are recognized if our bodies aren't getting the housecleaning nature intended. Atopy, or autoimmunity (together with inappropriate immune responses to pollen, etc) is all too predictable in such a circumstance as well. Asthma, hayfever, eczema, multiple sclerosis, rheumatoid arthritis may then result or be exacerbated, all as a result of the Photoperiod effect.

Specifically, very recent research (October, 2006) suggests that rheumatoid arthritis may result from one particular clean-up task not being properly performed by the immune system. The DNase II enzyme in macrophages (a garbage-collecting white cell) snips apart and thus digests waste DNA in the bloodstream from dead cells. Mice that are prevented from producing this enzyme, by deleting that gene “develop a chronic polyarthritis resembling human rheumatoid arthritis.” [17066036] [http://www.newscientist.com/article/dn10379-is-arthritis-caused-by-a-buildup-of-surplus-dna.html]

Now granted, there isn't good research aimed directly to show the effect of photoperiod on the identification of pathogens or self-identification. The possibility hasn't been considered by medical science, even though the evidence is mounting steadily. Certainly, I haven't been able to find much research relevant to this point. Research into the bodies daily cycle (chronobiology) is making great strides, but it has not extended into many practical directions, as yet. I hope that explicitly raising and arguing for the Photoperiod Effect or if you like Photoperiod Hypothesis will encourage just such research.

So questions about the daily immune cycle quickly take us beyond exact research. Nonetheless, it's already clear within medical science that our immune system is cyclic – circadian – in many respects. Therefore, we should expect modern long days and short nights to have an effect, and probably many effects, on our immune system. Just one of the effects we might expect is that if we have insufficient melatonin circulating each night to do a proper cleaning job, then no matter when the process of identification of friend and foe happens, day or night, it's surely more likely to become confused and result in autoimmunity. More opportunities for such mistake occur, when our bloodstreams are cluttered with fragments of ourselves, pollen, etc.

Another possible cause of autoimmunity is metabolic syndrome itself. If our mitochondria can't produce sufficient energy then the body goes on a budget. There is good indication that at least some autoimmune reactions result from fallback immune reactions – very broad spectrum immune responses that evolved earlier than more specifically targeted pathogen killing mechanisms. This could possibly be a result of “budgetary constraints” on ATP energy usage preventing more sophisticated, safer, methods from being employed. Or, less likely perhaps, it may be that when our immune systems are allowed only limited resources, checks and balances that ensure we aren't about to attack our own tissues can't be performed. This seems less likely because it would imply that autoimmune disease might result from starvation, but if anything, the reverse seems to be true.

(Remember, the purpose here is to show that there is at least one possible explanation showing how excess light could cause or help cause autoimmunity, so extra possibilities are more confirmatory than disconfirming.)