<prompt> Which of the following is seen in cystic fibrosis?Low sweat chloride levelsElevated sweat chloride levelsLow sweat sodium levelsElevated sweat potassium levels  <response>: b. Elevated sweat chloride levelsRef: Nelsons 20e p 2100Because the function of sweat gland duct cells is to absorb rather than secrete chloride, salt is not retrieved from the isotonic primary sweat as it is transported to the skin surface; chloride and sodium levels are consequently elevated. So sweat chloride is usually 60mEqL in cystic fibrosis. 