Diagnosis of Cystic Fibrosis by Sweat Testing: Age-Specific Reference Intervals

Abstract

OBJECTIVE: To develop reference intervals (RIs) for sweat chloride and sodium in healthy children, adolescents, and adults. STUDY DESIGN: Healthy, unrelated subjects aged from 5 to >50 years and subjects who were pancreatic insufficient with cystic fibrosis (CF) were recruited. Sweat collection was performed on all subjects with the Wescor Macroduct system. Sweat electrolytes were analyzed with direct ion selective electrodes. DeltaF508 mutation analysis was performed on the healthy subjects >/=15 years old. RESULTS: A total of 282 healthy and 40 subjects with CF were included for analysis. There was no overlap of sweat chloride between the group with CF and the group without CF, but there w..