The page below is a sample from the LabCE course Laboratory Diagnosis of Cystic Fibrosis. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about Laboratory Diagnosis of Cystic Fibrosis (online CE course) »
How to Subscribe
MLS & MLT Comprehensive CE Package
Includes 97 CE courses, most popular
$95 Add to cart
Pick Your Courses
Up to 8 CE hours
$50 Add to cart
Individual course$20 Add to cart

Reference Intervals for Sweat Chloride

Sweat chloride concentrations can increase slightly with age so there are age-related reference intervals. Sweat chloride concentrations should always be interpreted with regards to the clinical situation and the knowledge that some rare CF causing mutations of CFTR can be associated with chloride values in the normal and intermediate ranges.

Diagnostic interpretations for infants up to and including 6 months of age

Chloride Concentration
Diagnostic Interpretation
< 29 mmol/L
CF unlikely
30-59 mmol/L
Intermediate (CF is possible)
> 60 mmol/L
Indicative of CF

Diagnostic interpretations for patients over 6 months of age

Chloride Concentration
Diagnostic Interpretation
< 39 mmol/L
CF unlikely
40-59 mmol/L
Intermediate (CF is possible)
> 60 mmol/L
Indicative of CF