Reference Intervals
A sweat chloride concentration less than 30 mmol/L makes cystic fibrosis unlikely, although cases have been described. The likelihood of cystic fibrosis decreases with decreasing sweat chloride levels so that a sweat chloride less than 20 mmol/L makes cystic fibrosis extremely unlikely.
A sweat chloride concentration between 30 and 59 mmol/L is suggestive of the diagnosis of cystic fibrosis. Recommend CFTR mutation analysis to confirm or clarify the diagnosis.
A sweat chloride concentration greater than 60 mmol/L strongly supports the diagnosis of cystic fibrosis. Recommend CFTR mutation analysis to confirm or clarify the diagnosis.
Test Method
Chloride - mercuric thiocyanate
