Urinary acid mucopolysaccharides in cystic fibrosis

Total urinary acid mucopolysaccharides (AMPS) were slightly, but not significantly, elevated in 8 out of 17 patients with cystic fibrosis. By complete analyses, paper electrophoresis, and distribution of molecular weights of the separated urinary AMPS, the patterns were normal in 9 of the 11 patients studied in greater detail. In the 2 others there were consistent abnormalities. Although these findings do not rule out a primary disturbance of AMPS metabolism in cystic fibrosis they do not support it. In 5 of the patients, when receiving gentamicin, the urinary AMPS exhibited abnormal patterns which disappeared after discontinuance of the drug. This finding emphasizes that caution is needed to avoid misinterpretation and generalization.