HCV and Autoimmune hepatitis (AIH)

I am 42, female.  Diagnosed with Non-A, Non-B Hepatitis in '82 following patient contact.  No known problems with the hepatitis for yrs--abstained from alcohol, tylenol, meds of any kind.  Last yr, I had a bout of multiple medical problems including, cholecystitis, bacterial endocarditis, and liver problems.  Initially, it was believed that my liver difficulties were related to Trovan, which was taken off of the market a week after I was started on it.  Subsequent tests revealed that I was HCV+.  The hepatologist biopsied my liver due to my long hx of hepatitis and current problems.  The biopsy was fairly benign--chronic Hep C with mild-moderate activity; no appreciable fibrosis or steatosis.  I opted not to take treatment.  My annual follow-up is in 2 months.  Now, the new problem.  I have had low grade fever (100-101), weight loss, fatigue, arthralgias for several months.  Repeated blood cultures neg.  Rheumatology work-up negative except, ANA+ 1:160 with a homogenous pattern.  All the liver immunological markers (LKM, ASM, etc) were negative.  My liver enzymes are elevated (300 range), along with my bili and globulin.  My PCP believes that I have AIH and wants to start at least some prednisone therapy.  Are there any additional lab tests that might indicate AIH?  Would it be prudent to try steroids, at least short-term to see if it would have a + effect on decreasing my enzymes?  Could the Trovan have triggered an autoimmune process or would it have shown up on my biopsy that was done about 2 months after I received the Trovan?  Is another liver biopsy the only definitive way to determine if I have AIH?  Thanking you in advance for your time and energy in responding to my post.