There has been a lot of debate between scientists whether Endo should be classified as an autoimmune disease. If you do a little research you can find many articles about it. Basically if you don't care to do the search, the argument is because of the presence of autoantibodies in women with Endo and the association with other autoimmune diseases, among other things, it technically could be considered an autoimmune disease and that's why your ANA levels are so high. However, because "reduced cell-mediated natural immunity is observed during the disease", it is argued that although Endo is linked to other autoimmune diseases, it is only considered an immune disease and a chronic inflammatory disease.
Long story short, if you tested negative for autoimmune diseases but you have high ANA levels, it's possible Endo could cause it and I would get it checked out. I also had high ANA and they found a large amount of Endo that was burned during my laparoscopic surgery a year ago. I will be going to a specialist for excision surgery next because the pain came back about 3 months later, but at least knowing what it is means you can take the first steps towards treating it. Good luck!

Had a positive ANA for Lupus since i could remember. My 'flares' occurred every 2 years or so where id have a full panel of bloodwork drawn & multiple referrals hitting deadends. Id give up after 6 months & await my next flare. from pcp, rheumatologist, cardiologist, & GI, etc every single round.. My numbers this lap around at the rheumatologist were finally high enough for him to consider starting treatment with immunosuppressants. Had to see a cardiologist who sent me to a GYN who sent me to GI when i finally got my surgery to confirm endometriosis, which i now call the special female kind of Lupus. lol

They kept saying the same thing to me and kept testing me for all kinds of autoimmune disorders and all the blood work came back fine then I let them do the exploratory surgery and that's when they found the Endo don't give up you know ur body and know when something is wrong I still can't find a good Dr that knows about endo

Mine was negative :/

I had a positive Ana then saw a rhumatologist and he found nothing then had surgery and they found endometriosis