Hi,
The normal values for liver enzymes are as follows:-
BILIRUBIN 3 - 20 umol/l
ALKALINE PHOSPHATE 42 - 141 IU/l
ALKALINE TRANSFERASE (ALT) 5 - 35 IU/l
GAMMA GLUTAMYL TRANSFERASE (GTP) 5 - 29 IU/l
I hope this helps, but remember, if your tests were ok before, then it could always be a false result. If you are concerned, why not go and see your doc and get him to take bloods for you?
Good luck
Sarah