QuestionQUESTION: I'm confused. I had a liver function panel done through LabCorp and my ALT was high- 80 on a 7-41 'range.' I had it taken again (omitting my meds) at Quest Lab and their scale is 9-60 scale (my ALT with them was 27). I know different labs may have different ranges, but by that much? I'd like to know what the 27 ALT value I got from Quest would be on Labcorp's scale, is there any way to get just an approximation? Thanks
ANSWER: Hi Lee. When different labs have different reference ranges, it doesn't necessarily mean that your value would be different. Reference ranges will be different at each lab because their "normal" patient population (which is established when they start performing that specific test) is different. Your value may be so different because you stopped taking your medication, hence the much lower and normal ALT that you got with Quest. I'm not sure which medications you take, but some can cause an elevation in ALT (a liver enzyme), which might be why you got the ALT of 80 at Labcorp. You also have to look at the units each lab reported for ALT (such as mg/dL). If they are different, then you can't really compare your results because their testing method is different.
Samantha
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QUESTION: Hi Samantha,
I still don't get it, I guess I'm talking more about the difference in 'reference range' more than my results. I'm sure my ALT went down after no meds, but one lab's range is 7-41 while the other is 9-60 and they both use "U/L" whatever that is. So a person could have a 50 value on one and be considered too high, yet normal on the other scale.
I just wonder how different my '27' ALT on the 9-60 scale would be using the 7-41 scale. I wish now I would have used the same lab for both tests!
AnswerHi again, Lee. I'm sorry I wasn't clear enough on my response! But I'll try again. You can't really look at one result and compare it to another lab's reference range. The results are different because of their testing methods. A simgle chemistry test can have many different ways of being tested (i.e. There are many brands of chemistry analyzers [machines] out there.). Because of the differences in one brand compared to another, that's why you get different numbers. Your 80 at Labcorp could've been a 95 at Quest because they use a different analyzer. But you have to look at that 80 with the 7-41 and that reference range ONLY. Does this make sense? I hope so!
Samantha
