Sweat test

Question

Hello, a sweat test has been done to my daughter. The result was 61 borderline. What does that mean?

Answer

Hello,
A sweat test has probably been performed on your daughter because Cystic Fibrosis was suspected. The result of a chloride concentration of 61 mmol/l underlines this suspicion, however, this fact alone does not prove the diagnosis for sure. Assumed that the test was done correctly – probably the test has been done twice to be on the safe side – in a next step a genetic analysis could be done in your child, to look for possible mutations in the CF-gene of your daughter, especially for those mutations, which are associated with a negative/borderline sweat test. Probably this could already clarify the situation. In case this result does not lead to a clear assessment of the situation (as the genetic analysis can not include all (100%) possible mutations), there are some more diagnostic tools (so-called potential difference of the nasal mucosa or a rectum biopsy, analysis of the function of the pancreas (stool-fat, elastase in the stool), microbiological investigation of the airways, clinical symptoms...), which could probably be used in the diagnostic procedure of your daughter. You should talk about this complicated situation with the physicians of a CF-centre nearby your home. The specialists there can help you for sure quickly to clarify the situation definitely. In case you need a list of addresses, you can find it on the homepage of “Mukoviszidose e.V. (Germany)”.
Yours sincerely
Dr. H.-G. Posselt

07.12.2007