Hi. i had an ast and alt test . the alt came back normal 41 u/l but the ast said haemolysed sample.my question is how was only the ast haemolysed and not the alt when it was only one blood sample? surely that would have an effect on the alt?thanks?

Result of ALT is only affected when specimen is heavily hemolyzed but AST result is affected even with very mild to moderately hemolyzed specimen. That is the reason AST result can't be reported due to error. In general, for annual physical exam if ALT is normal most common acute liver conditions are ruled out.

You are correct, that would be an unusual circumstance. I would recommend that you wait for 2 to 3 months and have repeat blood tests drawn, including a complete liver profile. If your AST or ALT are elevated, you should see a hepatologist to have the cause of the abnormal liver tests evaluated. Do not ignore this. Good luck.

Red cells contain AST but not ALT. Therefore, in a hemolyzed specimen, AST would be falsely elevated but not ALT. For information: https://pubmed.ncbi.nlm.nih.gov/22141211/