Autoimmune liver disease is also associated with celiac disease, which you may already know. I think you should reconsider celiac testing, remembering the testing is not perfect, but might be worth doing in case you could get any 'easy' diagnosis. However, even if your blood testing falls short.... a gluten free diet is still worth trying.

However, don't start making dietary changes until after the blood testing is done because it is essential to be consuming gluten for accurate testing.

A gluten free diet requires eliminating all forms of gluten, which is found in wheat, barley, and rye. There are many processed foods that are gluten free, but the simplest way to start a gluten free diet is by sticking to a diet of whole foods consisting of minimally processed meats, fruits, vegetables, rice, potatoes, nuts, eggs. Then, you can slowly back in other processed foods that are deemed safe. Here is an overview article which covers allowed and not allowed foods, at a very basic level:
http://digestive.niddk.nih.gov/ddise...liac/index.htm

Here are some of the safe food lists available, that get into much more detail.

Safe Food Lists
Celiac.com Safe & Forbidden Food Lists
GF Products- Mainstream- Wheaton Gluten Free Support Group
Delphi Celiac Forum Safe Product List
Delphi Celiac Forum Cross Contamination Checklist
GF/CF DIET


There are also many good books that can be purchased. You can search amazon.com for other titles, but two are:

Wheat Free Worry Free by Danna Korn
Gluten Free for Dummies

Here are a few mores studies on liver disease associated with celiac disease:

Liver disease

The results of this study showed a high prevalence of CD in patients with AIH. For this reason, early serological screening testing for CD is strongly recommended for all AIH patients
High prevalence of celiac disease in autoimmune hepatitis detected by anti-tissue tranglutaminase autoantibodies. PMID: 15645466

The possible presence of celiac disease should be investigated in patients with severe liver disease. Dietary treatment may prevent progression to hepatic failure, even in cases in which liver transplantation is considered.
Celiac disease in patients with severe liver disease: gluten-free diet may reverse hepatic failure. PMID: 11910339

Autoimmune hepatitis, cryoglobulinaemia and untreated coeliac disease: a case report. PMID: 12655265

Celiac disease-associated autoimmune cholangitis. PMID: 12492211

Elevated transaminases were the most frequently reported abnormality. A gluten-free diet produced resolution of elevated transaminases in 115 of 130 patients. ...Mildly abnormal liver biochemistry is frequent in untreated coeliac disease and may provide a key to the diagnosis. Routine investigations for undiagnosed liver disease should include tissue transglutaminase testing. Left untreated, coeliac-induced hepatitis may rarely progress to end-stage liver disease. Primary biliary cirrhosis is clearly linked to coeliac disease.
Systematic review: the liver in coeliac disease. PMID: 15740533 Mar 2005


Hope this helps~

Cara