What is the significance of a Sweat Chloride Test result greater than 60?

A Sweat Chloride Test result greater than 60 millimoles per liter is significant because it suggests possible Cystic Fibrosis (CF). Cystic Fibrosis is a genetic disorder that affects the respiratory, digestive, and reproductive systems, primarily caused by mutations in the CFTR gene, which leads to the production of thick and sticky mucus.

In individuals with CF, the sweat glands excrete an abnormally high level of salt, specifically chloride. Therefore, a result over 60 indicates that the patient's sweat is hypertonic, which is consistent with CF pathology. While higher levels can support a diagnosis of CF, confirmatory genetic testing is often needed to identify specific mutations and definitively diagnose the condition. This test is particularly important in children presenting with respiratory issues or failure to thrive.

The other response options do not align with the test's purpose or results. Normal lung function is not indicated by such a high chloride level; rather, it suggests an underlying issue. Confirmation of a genetic mutation requires additional genetic testing and cannot be determined solely by this sweat test. An allergic reaction would not be evaluated with a sweat test, as it's not related to chloride levels in sweat. Thus, option B is the most appropriate interpretation of a Sweat Chlor