sweat test

Question

My son was tested for chloride in sweat twice at different places. The values are borderline: 38,86(Kyjov), 34,46(Brno). Should we be concerned that our son suffers from CF?

Answer

Hello,
The values for chloride in sweat stated by you are truly borderline. It is very important that this test is conducted correctly in a laboratory which has enough experiences with this test. If the first two tests were done correctly and the boarderline results are confirmed again, then the molecular genetic tests should be done. Only finding two CF gene mutations could confirm the diagnosis. It is highly probable that one of the mutations would belong to a group of so called mild mutations due to the fact that the stated results are borderline and do not exceed the value of 60 mmol/l. Higher levels of chloride in sweat confirm that there are so called severe type of CFTR gene mutations usually with pancreatic insufficiency. It is very important to consider all the symptoms and problems your son has and perform additional testing accordingly. There are other diseases and also some drugs which may increase the level of chlorides in sweat.
Best regards, Jitka Brazova

23.04.2009