"..........................but what else can be done when laboratories don't use standardised methods?"
So, a question -
If someone (and let's not get hung up on who) pronounced for example -
"In the UK all ALT measurements must be done by IFCC method with PP" (assuming that all manufacturers had that method available for their analysers)
How many labs would decide they knew better? It's a serious question
DJ
-----Original Message-----
From: Clinical biochemistry discussion list [mailto:[log in to unmask]] On Behalf Of Jonathan Kay
Sent: 15 October 2015 10:27
To: [log in to unmask]
Subject: Re: ALT reference intervals
IMHO it's generally better not to bring "healthy" or "normal" into this. The question is whether you can distinguish the two populations of interest. The unaffected population may not be healthy.
Recommended reading, as ever: Galen and Gambino, and the NORDKEM reports from the mid 80s.
And "Yes", those mentions of twice the upper limit are an attempt to get round inter-laboratory variation. A third-rate attempt, but what else can be done when laboratories don't use standardised methods?
Jonathan
On 14 Oct 2015, at 12:00, Alan <[log in to unmask]> wrote:
> ALT is an interesting example of the choice of "what is a true healthy reference interval" versus "what feels right from our population's results". The "pragmatic" or the in-house derived ranges I've seen seem to be about double the NICE guidance concentrations you quote (note NICE are consistent with some published a priori intervals with aggressive exclusion criteria). I wonder if it's a coincidence that a lot of decision cutoffs for ALT are stated as twice the reference interval.
>
> I guess it depends what message we should send to our users... Is a lower cutoff falsely reassuring in the presence of mild or chronic disease, or does it reduce GP concern for the vast majority of patients who are just overindulging a bit and may(?) not require intervention? What's more important?
>
> On Tue, 13 Oct 2015 12:27:37 +0000, Jordaan Marieke <[log in to unmask]> wrote:
>
>> Dear colleagues
>>
>> It would be interesting to get an impression of the ALT reference range used in other laboratories.
>>
>> NICE CG165 on Diagnosis and Management of Chronic Hepatitis B,
>> published in June 2013
>> (http://www.nice.org.uk/guidance/cg165/evidence/cg165-hepatitis-b-chr
>> onic-full-guideline3) makes reference to ALT a number of times, and
>> bases important clinical decisions on "normal", "abnormal" and
>> "normalized" ALT levels, which they define as greater than or equal
>> to 30 IU/L for males and greater than or equal to 19 IU/L for females
>>
>> There is some explanation of why these cutoffs were chosen on page 159:
>> [cid:image003.jpg@01D105BB.0FBF3EF0]
>>
>> With alcohol use and obesity now so common the impact of using these ALT reference ranges on diagnostic investigations could be very significant.
>>
>> Harmony does not appear to have agreed a cutoff for ALT, unlike other LFT.
>>
>> If you want to reply with your cutoff only, I will collate the responses for the mailbase.
>>
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