I can also attest to the fact that ANA levels can change. Mine have been different each time they were tested in the past 2.5 years. They have gone from 1:160 to 1:320, and this last time they were 1:1280. I have not been diagnosed with anything, since my other bloodwork has come back normal in the past, and my symptoms have been minor. I have occasional minor joint pain, frequent tingling in my hands and feet, and occasional numbness in spots on my legs. In cold weather, my hands and feet get very cold and I have a hard time warming them up, but I don't get the red, white and blue of Raynauds, so I'm not sure about that. I've had a few rashes on my face around my eyes, but not the distintive butterfly rash.
Have you received a diagnosis of lupus? I am going back to the rhuemy on Tuesday, my GP wants me to go b/c the ANA was so high this time. Yesterday I was told by my ENT that my CT scan showed normal sinuses but I have arthritis in my jaw (TMJ). I don't know if this is related or not, I just wish I could get some kind of diagnosis!
Good luck with everything,