Hi Jabug. Hopefully you are well on your way to a definitive opinion from a CF Center. I do want to try to clarify a few things for you and hopefully give you some helpful references. First of all, although the ideal is a sweat test from a CF Center, there are apparently other labs doing sweat tests, but I believe they need to be accredited to do them. If you are at an unaccredited lab, your results may be all over the board. It is also apparently possible to use different equipment to perform the test, but the acceptable variations are also designated under the accreditation guidelines. Here is a document provided by the CFF with the Guidelines.
http://www.cff.org/UploadedFiles/tr...-Testing-CFF-Guidelines-J-Pediatrics-2007.pdf Is the next sweat test being done at a lab suggested by the CF Center? I also hope the genetic testing is being done either at the CF Center or by a lab recommended by them.
I mention all this because I read some things that I found odd when you described your testing. Specifically, you indicated they told you to dress your child in heavy clothing - presumably to produce sweat? The sweat collected for the sweat test is chemically generated. They put a substance called pilocarpine on her skin, which (with a mild electrical stimulation) causes her to sweat in that location. Not all over. But obviously if this was suggested by the CF Center, I suspect they have their reasons - perhaps they have found this helpful with children who haven't previously produced enough sweat. There's a video on YouTube by the Cystic Fibrosis Foundation that will show you how it's done.
http://www.youtube.com/watch?v=8UCWoz6gUp8.
I am also unfamiliar with a "quantive" test. I am not a Sweat Test Guru so it may refer to something with which I am not familiar. But I wonder if what they were trying to explain is that there must be a certain quantity of sweat for the test results to be accurate and reliable. If your child did not produce enough sweat on the first test, or really any of them, the results would not be helpful either way. In fact, I don't believe they are supposed to even determine the concentration of salt in the sweat collected unless they first establish that there is enough sweat under the guidelines, or the results will be misleading and confusing. The Cystic Fibrosis Foundation, again, has links that will explain the recommended steps for testing and diagnosis which you will find helpful.
http://www.cff.org/AboutCF/Testing/SweatTest/
It sounds as though your CF Center was saying that the test they did relied on the quantitative approach - meaning first ensuring there was sufficient sweat. That would be the reliable approach! And because they are having you run in effect a THIRD sweat test, it again suggests to me that the first one was not reliable. Usually two borderline tests are enough to move to the next step - an evaluation by the CF Center potentially including gene testing. As you may realize by now, CF is usually diagnosed by sweat testing in conjunction with symptoms, or genetic testing. Not necessarily just the sweat testing alone. Sweat Testing is of course known as "the gold standard" and is therefore a critical piece. But a diagnosis does not necessarily end there, especially in circumstances where the results are borderline.
Perhaps I have gone into too much detail. But I really want to echo the sentiments so many others have expressed so well here. You are doing a remarkable job advocating for your child. Many parents would have justifiably accepted their pulmonologists recommendation and left this alone. Your daughter is lucky to have you! Do let us know how things progressed. I'm thinking about you and your daughter.
