Hello! I have been through your question. Related your concern I think that you should know that the elevated levels of ALT/AST is moderate and usually fatty liver is the most common cause of unexplained persistent elevation of liver enzyme levels after hepatitis and other chronic liver diseases have been excluded. The good news is that fatty liver is a reversible condition that can be resolved with changed behaviors and often has no symptoms and typically does not cause permanent damage. But when fatty liver is caused by an underlying condition, it can become harmful to the liver if the cause is not recognized and treated.The most common cause of fatty liver is alcoholism and other common causes obesity,hyperlipidemia, diabetes some medications. You should know that potential causes of liver transaminase elevations include viral hepatitis, alcohol use, medication use, steatosis , and cirrhosis. So what I suggest for your wife in this situation is doing a physical examination by a hepatologist, exclude viral hepatitis (lab test HBsAg and anti HCV), abdominal ultrasound to see the local situation of your fatty liver and to exclude cirrhosis and lipidograme. Furthermore, a liver biopsy definitively allows to exclude alternate causes of elevated liver enzymes, and it is the only method to distinguish (in certainty) non alcoholic fatty liver from non alcoholic steatohepatitis, and it provides information on the stage of the disease. But it belongs the hepatologist, based on your data to decide to do or not a liver biopsy because as all invasive procedures exist some risks. I hope my answer help you.