How high were your positive ANA levels (usually reported in titers)?
Drug induced lupus usually has high ANA titers, plus positive anti-histone antibodies.
Systemic lupus (not drug-induced) usually has high ANA titers plus it often has positive anti-dsDNA antibodies.
But keep in mind that up to half of people who are on anti-TNFs can have positive ANA results, so those results alone don't mean you have lupus or drug-induced lupus.
Positive ANAs can also come from viruses, cancers, other medications, and other autoimmune diseases (rheumatoid arthritis, sjogren's, undifferentiated connective tissue disease, mixed connective tissue disease, scleroderma, and a few others).
Or they can be false positives, or just positive due to your use of an anti-TNF with no clinical significance.
You need to have the Remicade antibodies checked, then work with your gastro and a rheumatologist to figure this all out.
I meet with my Dr this week with the plan of testing for antibodies. I did have a test about
3 years ago for RA and that was negative. I go to the Mayo Clinic in Eau Claire WI-- I would think/hope they would know what test. I am however very frustrated that it took them this long to take me seriously. This has been a big issue for me since this last March. They put me on Methotrexate with seeing if it was something else. Prednisone up to this point has been the only thing that has helped.