Sweat test (sweat chloride)

Test investigation

Sweat test (sweat chloride)

Laboratory offering test

NNUH

Units

mmol/L

Comments precautions

Please contact laboratory (NNUH)

Sample type

Sweat collection arranged by the Respiratory Paediatrics Team

Turnaround times (TAT) Urgent/Routine/GP or OPD

Test performed on Wednesdays only, unless by prior arrangement

Reference intervals

As per 2014 guidelines 'Performance of the Sweat Test for the Investigation of Cystic Fibrosis': A sweat chloride concentration of > 60 mmol/L supports the diagnosis of CF. A chloride concentration of 40 – 60 mmol/L, or if less than 6 months of age 30 – 60 mmol/L, is an intermediate result which requires further cystic fibrosis assessment such as a repeat test and/or further investigations. A sweat chloride of < 40 mmol/L (or < 30 mmol/L in patients less than 6 months of age) makes CF unlikely but requires genetic and clinical correlation.

If ukas accredited

Y NNUH