Rheumatoid Arthritis

Hi all.... this is my first post. I'm hoping somebody knows what it means to have a very very high RA Factor. I know the test is a diagnostic tool, but since the initial one was done 7years ago, my doc has repeated it about every 12-18months due to results. She also has checked me for liver disease etc several times just to rule out other reasons. Of course, I also have symptoms of RA that support the diagnosis, some of which improved from typical meds. My lab's RA Factor range of normal-neg is 0-13. My results have never been under 1,250 and in recent years it's over 1,600. I'm just one of those people that likes to have explanations. My doc doesn't have one.
Cathy -California