Sweat Test Results

[chipper28]

After posting a couple of weeks ago about some CF speculations, I
got in contact with my local CF center (through the help of a board
member) who recommended that I get a second sweat test.  The
results came back a 139.  Isn't this really high??  They
said my previous lower value was likely in part due to the fact
that they collected insufficient sweat.  <br>
<br>
I had thought that higher sweat values were associated with more
significant symptoms, but as someone who's getting diagnosed at age
25, this seems like a bit of a shock to get such a high value. .
.<br>
<br>
Not completely sure what I'm asking here--still kind of processing,
but I guess I'm wondering if anyone has noticed any sort of
correlation between their sweat test value and the severity of
their symptoms?

 

[JazzysMom]

The # does not have an indication of the severity. They havent even completely confirmed that mutations do yet. There are possibilities, but nothing that they can put across the board. A false negative happens alot. It can be caused by many things. One good thing about a high # is there is not borderline issues!

 

[amber682]

Melissa's right. Just because you have a higher number does not
have anything to do with how severe the cf is.

 

[chipper28]

Thanks for the reality check that nothing has changed with a
diagnosis with the exception of possibly better coordinated and
more educated care.<br>
<br>
A name in itself means nothing and in fact will probably make life
seem a lot easier. . .<br>
<br>
Thanks all

 

[NoExcuses]

why are sweat tests even done now-a-days? with most CF genes identified, why aren't genetic tests standard?????

 

[chipper28]

I was told they wanted the sweat test because it was
"faster" (not sure of the relevance when I'm already in
my twenties... but the medical folks seemed to think that
days/weeks mattered.... which I guess is a good thing) and that
there are a lot of mutations and they only check for twenty... I
was told that particularly with older diagnoses with less symptoms
they really wanted to check both genetic and sweat tests and a
positive on either is sufficient because older presentations are
typically not double F508 (i think that's the right mutation
name...)

 

[chipper28]

To clarify (i realized i wasn't very clear, and while this is
partially because I'm just not very clear, I thought I could
improve a bit): the reason they want to do both is that there are
mutations which do not result in sufficiently elevated chloride
levels which are identifiable mutations while there are individuals
who have sufficiently elevated chloride levels to be positive on a
sweat test but do not have mutations which are typically
identifiable.<br>
<br>
Feel free to clarify, correct, or add to this if you are able...
I'm very new to the whole discussion.<br>

 

[Alyssa]

As others have already said, no as of yet there has been no evidence of higher sweat test numbers correlating to more severe symptoms.

The thing you do have to watch for with higher numbers is the risk of dehydration -- be sure to always stay hydrated with something with electrolytes, like Gatorade. Some people take salt tables to replace the salt on hot days. Most CF docs recommend salting your food as much as you like and eating salty snacks all you want too.

So did you have the genetic tests too? Yes, it is possible that a "screening" contains looking for 20 mutations but since there are over 1300 known mutations it seems like a waste of time to me - I always recommend getting the full testing - all 1300, yes it costs more. I think it's a good idea to test using both sweat test and genetic, most doctors like to know if they are in the ball park with the sweat test numbers and then a great follow through is the "real" results with the genetic tests. The possible problems are that many people fall in the "normal" range still in the 30's (I really feel the number scale should be moved down) and although the genetic test is great, it's not fullproof as it's possible you still have 1 or even 2 unidentified genes.

 

[imondeck]

My son has had 2 positive sweat tests (different times, at accredited CF centers), he has had 2 different DNA tests (Genzyme first for the 80 most common mutations, and than Ambry's amplified test), no mutations have been found. His Pulmo diagnosed him with CF and is not concerned about finding the mutations. He said that in several years we can do the gene testing again. I am finding that CF presents itself in so many different and variable ways....

 

[jjflash]

Welcome. I think that's the important thing for you to hear. I think you should see this diagnosis as a truly positive thing. The diagnosis doesn't give you the disease, you already had that, but hopefully it will give you the health care to maximize your health. I'm mostly a reader of these forums, but they can be a great source of support even as a reader.

Welcome.