I thonk @Jonathan Edwards is the right person to answer this question... autoantibodies might show that you have some kind of autoimune response, but you don´t need them to diagnose ME and I think that there are no treatments based on what kind of autoantibodies you have.
Maybe they can help in ruling out other diseases if you have some atypical clinical features.
I have a ANA 1;160 but this information doesn´t help much.
Thats the thing I'm wondering, since I only 'scrape in' on ME diagnosis (4 criteria 'met') but I don't seem to have anywhere near the supplementary issues that many others have.
I think I am atypical ME, so to speak.
The biggest issue I have is the symptom of post-exertional malaise - how can you identify PEM, if you're tired all the time anyway!!!!!
ME can be an "I don't know what it is, so I'll just call it ME" diagnosis. Make them do a through check for other possibilities. And no, I don't know what all tests that requires.