Sweat testing

 

Alternative names, keywords

 

Samples required

Pilocarpine-stimulated Wescor coil, one sample from each arm.

Please inform laboratory on ext. 64151 before taking samples, and do not take samples on Friday afternoons.

Samples must be collected in accordance with the manufacturer's instructions (Wescor Macroduct® Sweat Collection System Model 3700 SYS instruction/service manual download here). A copy is held by Children's Outpatients at RACH, and in the laboratory document control system.

Test indications

Click here to download Guidelines for the Performance of the Sweat Test for the Investigation of Cystic Fibrosis in the UK.

Reference range

Weight of sample: 20 - 80 mg

Chloride (mmol/L):

< 40*

normal, low probability of CF

* <30 for babies under 6 months old.  
40 - 60**

suggestive but not diagnostic of CF. Suggest genetics.

** 30 - 60 for babies under 6 months old. 
> 60

supports diagnosis of CF

 

Slight increases may be noted in ?heterozygotes.

Turnaround time

24h on routine working weekdays (Monday – Friday).

Enquiries

Biochemistry (Special Chemistry)

 

Details