The thing with all these autoimmune diseases: they have the same foundational problem. Their is something in the blood that doesn’t belong there and it resembles some part/cell of our body. Our body builds white blood cells to destroy this thing and inadvertently destroys part of the body. The important questions: what is it and how is it getting into the blood?

The most likely way it gets into the blood is through the digestive track. Some possible mechanisms: 1. Some detergent or similar chemical (e.g. PFAS is a solvent) dissolves the food (or the oil carrying the food) into water. The stomach pulls water back into the blood stream, bringing dissolved things with it. 2. There is some damage to the stomach or intestinal lining, stemming from physical injury, things getting stuck (lack of fiber), acid damage, some other chemical destroying mucus lining, etc. 3. You also have some autoimmune damage on your intestines. 4. You eat certain foods that require a symbiotic digestion with gut bacteria, but lack that bacteria or have killed it with eating preservatives or pesticides or artificial sweeteners, etc. The undigested food makes it to the larger absorption holes at the end of the intestinal run.

It’s also possible that a brain injury caused some brain cells to end up in the blood stream. Normally, though, the body has a mechanism to avoid attacking its own cells, the CD47 mechanism. Maybe that can become damaged or malnourished in some way. I’m sure that there’s a host of other things that can go wrong with that.