Does the negative energy of spirit attachments attacking their host, trigger autoimmune diseases? If so, what percentage is caused in this way, and do certain diseases more than others have this origin?

The insight is a brilliant one. You have seen this association with allergies developing in a person, as well as food intolerance. When you think about the immune system becoming triggered by the presence of some kind of threat present energetically in the body, this opens the door to even more serious long-term consequences, and this is the case, that autoimmune disease can be triggered by onboard spirit meddler attachments stirring up energetic discord that is perceived by the immune system as an invasion by outside organisms, and then will attempt to counterattack and destroy the invaders. The problem becomes it may well be that the sign of invaders is an inappropriate nervous system response that is affecting local cell clusters and tissues and will be misinterpreted as the onset of an invasion by infectious organisms or parasites, and then a general attack will be launched. The end result can be an autoimmune reaction to the tissues at the site of the energetic discord, and those components become an antigenic target for a chronic assault. This can be quite precise, as you have seen with destruction of Beta cells in the pancreas causing type I diabetes, but can also occur with other organs and tissue types, and can be generalized as well. One of the more common outcomes is Lupus Erythematosus. In general, 10% of autoimmune disease is an interaction of the nervous system inappropriately because of spirit meddler induced inner discord within the body.