Uric Acid Test Result Range and its impact on UA results

[Utubelite]

Hi GP / Zip / All others

There are different ranges of acceptable Uric Acid Test values followed by different labs. I know of the following –

1. 2.0 to 8.5 mg/dL

2. 2.4 to 8.2 mg/dL

3. 3.5 to 7.2 mg/dL

4. 3.4 to 7.0 mg/dL

I assume that the machines that analyze the sample would calibrte against these ranges and plot the results accordingly.

Does it mean that the same sample calibrated against these ranges separately would give different results? I mean the same sample may give a value of say 6.0 against the range 2.0 to 8.5 while 5.0 against the range 3.4 to 7.0.

All the drug information I have seen refers to range of 3.5 to 7.2 or 3.4 to 7.0 and accordingly talk about 6.0.

What would be this value if the reference range is 2.0 to 8.5, still 6.0 or higher?

It is something which is confusing me and I am not getting any clear picture on it.

[Keith Taylor (GoutPal Admin)]

I realize that, whilst I've made references to this sort of thing several times before, I've yet to do a comprehensive review of the issues around uric acid testing. Your figures would make a good starting point, but do you have the sources? I need contact details so I can investigate more thoroughly.

The essence of the problem is that labs have assessment ranges based on statistical averages. These high/normal low assessments are from a population that includes gouties. It is nothing to do, as far as I am aware, with machine calibration, though I need to confirm this.

Once you have had a gout attack, the assessment ranges are meaningless. The only ranges that matter are good, danger, and bad uric acid numbers.

There are too many issues to ever get a completely clear picture. Uric acid simply does not work like that. Fluctuations occur at different body sites, during the day, and from day to day. Fluctuations occur from the age and storage conditions of samples. There may be other  factors, and you need to  avoid micro-managing from single test results, and looking at trends. More about seeing the big picture rather than a clear one.

The golden rule for gouties is always seek a uric acid level below 6mg/dL. If you have undissolved urate deposits, aim for something lower until you get rid of the crystals. 3 is very good.

[Utubelite]

The reference of 2.0 to 8.5 is what I get from my hospital lab while the 2.4 to 8.2 is from the Personalabs.

The range of 3.5 to 7.2 is listed in the booklet provided with the UASure home test kit. The range of 3.4 to 7.0 is listed on the website when I check about uric acid testing( I do not recall the exact website though).

I tested  with the home test kit yesterday and got value of 4.3. At the same time( 30 minutes apart), I gave the sample to Personalabs and got the value of 4.4, which are alomst same.

I have seen when I test at my hospital lab, the value is .2 to .3 higher than the personalabs.

I will compare it with my Home test kit when I get the sample tested at the hospital(sometime next week).

[zip2play]

I think the VALUE of the test is an absolute, of course subject to error. Mg/dL is a physical measurable quantity…it is NOT relative. 

The RANGE given by any lab is an interpretation gleaned by opinion.  Thus in the labs of the original original post a 7.3 mg/dL urate concentration would be the same number in all 4 labs if the tests were done perfectly but  would be flagged in only the last two as “HIGH.”

It would be good if there was a proviso for two ranges: one for those with proven gout and one for those without gout. Actually there are two ranges commonly used for UA: a low range for womenn and a higher range for men.

[Author]

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