Is It Possible to be TOO Clean Living? Random Thoughts on Autoimmune Disease and Infectious Diseases

[McCamy Taylor]

Sometimes, I like to pull up Ovid and just start skimming journal articles and see where they take me. Here is where they took me today:

1. Do We Have Autoimmune Diseases Because We Evolved an Automatic Defense System Against Tuberculosis that Reacts Against Other Tissue if We Do NOt Get Tb?

About the effect of Tb on human evolution---one in four of us that did not die of something else, died prematurely from Tb before the modern era with antibiotics. That is probably true for the entire history of humanity, not just the last few hundred years. Recently, they discovered that the human HLA genes were picked up as moderns left Africa and bred with Neanderthals. The HLAs encode built in immunity and resistance to disease----as opposed to the strictly learned kind that you get when you are exposed to a new antigen and your B cells make an antibody (IgM then IgG for lasting immunity). The HLA genes gave moderns built in immunity to lots of things that they would encounter as they spread out across the world including, presumably the various types of mycobacteria which include Tb and leprosy (note that only a small portion of people can even get leprosy). HLAs also influence autoimmune disease, like rheumatoid arthritis, Crohns disease, reiter's syndrome. Some people think that we have so many autoimmune diseases in industrialized countries because the HLA portions of our genes that are supposed to be fighting Tb and other mycobacteria have nothing to do so they start attacking our own tissues instead. Which raises the question---are there less food allergies and allergies and asthma in third world countries because people there get the Tb. And, if they do not get Tb, they get the BCG vaccine (a bovine mycobacterium vaccine designed to prevent Tb infections)? We do not take it in the US for public health surveillance reasons, because Tb is so rare that it is easier just to test for Tb exposure with a Tb skin test and if you test positive you treat. The BCG gives you a positive Tb skin test whether you have Tb or not, so if you take the vaccine, you can not take a Tb skin test. However, there is a new blood test, the Tb spot that can be used instead of the Tb skin test and which is reliable even if you have had the BCG vaccine. So, should we be vaccinating with BCG both to reduce the incidence of Tb and to calm down our HLA genes so that they have something to do besides give us allergies and autoimmune diseases? And then use the Tb spot blood test to screen for Tb infection? It is worth considering.

2. Did Running Around Barefoot as Children Help Prevent MS?

Second random medical thought of the day. You know how they always used to say that no one who grew up in the South would ever get Multiple Sclerosis? This is back in the 70s and early 80s. And how it is no longer true. People from the south now get MS. They can give rats MS and if they give them a dose of BCG, their MS gets better---as if the immune system stops attacking the nervous system because it finds something better to fight. Here is my theory. What did people used to do in the South back before 1970? We used to run around barefoot all summer. We got chiggers, ticks. We got hookworms. Some of us had outhouses. We were exposed to all kinds of infections that people up north who wore their shoes and clothes when they went out to play did not get exposed to. I am wondering if all those infections that southern children were exposed to kept their immune systems so busy that they did not have time to start attacking normal body tissue. Now that kids in the south stay indoors and play video games and wear shoes if they go out and use bug spray--maybe now they are so sterile that they do not get enough infections to keep their inherited immunity busy.

[TexasProgresive]

1. Don't know about barefoot/MS but I think so.

Our immune systems are not challenged enough and so in a way gets bored and starts seeing enemies that aren't there. Hmmm that sounds like a metaphor for modern society in the US.

[NightWatcher]

2. Autoimmune diseases are a mystery (being polite). I've got a couple and tried to do some research

(Lupus in the kidneys and liver, dermatomyositis, rheumatory arthritis, and some other related shit)

There's no telling where they come from, why they are triggered for some at certain times, nor how to treat them.

Lupus for example, affects women way more than men, African Americans way more than Caucasians, Native Americans way more than Caucasians too. It doesn't always pass directly from one generation to the next.

I'm a Creek/ Caucasian mix and mine was passed to me by my father and acquired soon after a trauma triggered it at the same age my dad was when his popped up.

There are those who tried to send me articles about healthy living and cutting entire groups out of my diet. Guess what, only made me feel worse. My immune system is way too strong. I take chemotherapy pills to knock me down a notch. I feel better when I'm a little hung over. It's a life of constantly monitoring certain levels in my blood. If I start to lean one way, they knock me back the other way.

[NaturalHigh]

3. "Is It Possible to be TOO Clean Living?"

According to some doctors, yes, pretty much for the reasons you listed.

[SheilaT]

4. Yep. And this is not exactly breaking news.

I read several decades ago that polio, the scourge of the 20th century, had gotten traction in first world countries precisely because of first world cleanliness standards.

Auto-immune diseases are somewhat different, as they involve the immune system over-reacting to something. The trigger hear does not appear to be over-cleanliness, but a pre-disposition to the specific auto-immune disorder, and then some sort of trigger, possibly a viral infection. It's simply not clear at this point.

I speak as the mother of two sons with alopecia areata, considered to be an auto-immune disorder.

[dflprincess]

5. I remember hearing the same thing about polio - I think on an episode of "Nova"

The polio germ lives in dirt and, once upon a time, most people were not only exposed to it but it is thought that many had very mild cases of polio that left them without permanent damage. Often these mild cases were misdiagnosed as something else.

[McCamy Taylor]

8. Triggers are also a factor.

But there is a whole body of research that involves giving something mildly antigenic (like the BCG) to an animal with an autoimmune disease and then demonstrating that the autoimmune disease gets better. I did not realize how many experiments like these have been done until today. Since no one has a patent on BCG, we probably will not see it go anywhere. Drug companies will want something they can sell.

[elias49]

6. You lean towards an environmental cause for auto-immune diseases

while others talk about hereditary causes. I wonder if it could be a little of both. I'm living with RA and scleroderma..a 62 year old male. Scleroderma is seen much more often in women than man, so that's confusing.
And to the best of my knowledge, neither of my parents suffered an auto-immune disease. Either that or it just wasn't diagnosed.
A mysterious and, frankly, miserable disease.

[McCamy Taylor]

7. Pregnancy is also thought to rev up women's immune systems.

Because they get exposed to foreign DNA. That can then cross react.

[SheilaT]

10. I'm sure that some auto-immune diseases

were not diagnosed, or not properly diagnosed, in the past.

Also keep in mind that the RA and the scleroderma, while both auto-immune, are probably not at all connected with each other. You just have the singularly bad luck to have gotten both.

My two sons both have alopecia areata. Older son is also Asperger's, and they are certainly not connected, although as you are already thinking, "But only the alopecia is auto-immune". Of course you're right, and you have two auto-immune disorders, which does bring up the possibility they are connected.

Anyway, my guess is that they are not, you just happened to have gotten those two things with the roll of the genetic dice. In any case, I know those are both miserable diseases to have, so I do extend sympathy and hope they are both being controlled as well as they can be.

[alp227]

9. Personally I would avoid excessive use of disinfectant, instead

opting to vacuum and dust my home weekly.

[magical thyme]

11. antibodies, proteins, etc. don't get bored

They either have something to bind to, or they don't.

Autoimmune diseases most likely are caused when the antibodies that were originally produced to match the peptide that a specific HLA presented for recognition and destruction happens to fit the surface protein of a specific organ, causing a cross-reaction.

HLAs are hereditary and the exact combination of genes is unique per individual. Certain HLAs are linked to autoimmune disease, so if you inherit one or more of them, then you will be predisposed to that disease given the appropriate trigger.

For example, many people can get Strep A and recover without problems. However, some people will develop the sequelae Rheumatic Fever, which is an autoimmune disease where your Strep A antibodies attack your heart lining tissue. (I am fortunately in the first group since when I got strep as a kid, she didn't bother to take me to the doctor).

Per the NIH, the HLA- autoimmune disease relationship appears to be triggered by exposure to specific bacteria and viruses.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2647156/
"These results provide further evidence of a possible role for bacterial or viral infection and CD8+ T cells in AID (autoimmune disease) onset."

Likewise there are other protein sources in nature that stimulate antibody production. For example, a person who is blood type A will develop, within their first couple years, antibodies to blood type B without ever having been exposed to blood type B. The reverse also happens: blood type Bs develop antibodies to blood type A. And blood type O develops antibodies to A and to B. All without exposure to the other types.

Given that at the molecular level, all interactions are based on the 3-d shape of the molecules and attraction weak electrical forces, I lean toward the HLAs in question happening to interact with peptides of a particular shape, which lead to developing antibodies that happen to fit both the invading peptides and surface antigen on specific tissue cells, causing them to bind, subsequently fitting with the circulating T-cells, and so on.

If you don't make that specific HLA, then when your WBC phagocytizes the invader, the specific peptide/HLA combination doesn't happen and the cross-reactivity doesn't happen.

Also, kids up north also go barefoot, just not generally in winter. However, there are things that people in the south are exposed to that northerners are not, and vice versa.