What leads you to believe that autoimmune disease is not real?
So I am skeptical that the body simply randomly attacks itself. I suspect it's attacking something that's actually wrong, we just aren't seeing it...yet.
One explanation could be that our living conditions have changed sufficiently to trigger the erroneous behavior more frequently. There are various proposals for factors, ranging from mundane (e.g. dirt) to crazy, of course.
Another one could be that the immune system attacks things that are no longer there, either because the system gets stuck, or because those things looked too much like our own tissues.
Or indeed, we're overlooking something. The latter is a difficult one, and won't get much attention, because the risk of not finding anything publishable is too high.
The way I usually phrase it is "Wherever you see firefighters, you see burning buildings. So get rid of the fire department and problem solved."
Nope, that's not how that works.
Your skin is a first line of defense against invaders.
The mucus in your respiratory tract and gut is a first line of defense.
Your bone marrow is where white blood cells get produced.
Etc.
The antigens we produce are not the entirety of the immune system. It's like saying the alarm is all that's involved in securing a building and hand waving off the walls, doors, locks, etc.
There are myriad ways to trick the white blood cells and the body also has ways of killing stuff other than the white blood cells.
For my example, no, it's not pertinent.
People with cystic fibrosis are prone to being too acid. Everyone in the CF community knows this but it's not deemed medically significant and goes largely untreated.
The body will strip the bones of calcium to mitigate excess acidity in the blood and people with CF are prone to very early onset osteoporosis. But it's also known that high levels of calcium inside a cell are associated with cell death.
Instead of drawing the conclusion that calcium is being used to buffer the cell against chemical derangement, some people with CF try to limit consumption of calcium because they they the calcium causes cell death rather than thinking the calcium signifies a desperate attempt to mitigate extreme acidity.
It's 3am. This no doubt rambles.
But even if we go with the fire fighter analogy, how is it any different from say, liver disease? Usually the trigger is something else, like drinking too much, and your liver is like a firefighter, trying to fix the issue, but it's still called liver disease. In fact it's more apt because the liver won't directly attack other tissues when it fails, unlike the immune system.
Yes, sort of. In a way, it’s just one manifestation of entropy. Systems breaking down is the default and the norm, against which life constantly fights.