Serum alkaline phosphatase is derived predominantly from the liver and bones, although other sources may contribute to serum levels in some settings. If all the liver tests are normal (i.e. normal GGT as well as the normal liver enzymes you have reported), then you may want to inquire about bone diseases (i.e. obtaining a bone scan).
Initial liver testing should include a right upper quadrant ultrasound (which can assess the hepatic anatomy and bile ducts) and an antimitochondrial antibody (AMA), which is highly suggestive of PBC (primary biliary cirrhosis).
A positive AMA test should be followed up with a liver biopsy. I would discuss this workup with your personal physician or gastroenterologist.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.
Bibliography:
Pratt. Approach to the patient with abnormal liver function tests. UptoDate, 2004.