The ENT's office finally called me back with the results from the test. Everything is in the normal range but the ALP (alkaline phosphatase), but this is often elevated in growing children. Four months ago, the AST and ALP were elevated, so it appears the AST has come down into the "normal" range.
It is interesting how the test ranges can vary. Nolan's first AST value was something in the neighborhood of 45, but the lab in Jamestown uses a reference range with an upper limit of 30 or so. The lab in Buffalo uses an upper limit of 62, so even though his AST value is 51, he is within the "new" normal limits.
We can take liver function off the "worry list" and focus on his eating issues. My blood pressure just came down a few notches!