Sweat test (sweat chloride)

Test/Investigation

Sweat test (sweat chloride)

Site(s) or Laboratory offering Test/Investigation

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 (adult unless stated)

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 Test indicate at which site

Y NNUH

Source

Guidelines for the performance of the Sweat Test for the Investigation of Cystic Fibrosis in the UK v.2 (2014). http://www.acb.org.uk/docs/default‐source/committees/scientific/guidelines/acb/sweat‐guideline‐v2‐1.pdf (accessed 05/05/2022)