Excretion of urinary collagen metabolites correlates to severity of pulmonary disease in cystic fibrosis.

The urinary excretion of collagen metabolites (hydroxylysine, hydroxyproline and proline) was significantly increased in 10 patients with cystic fibrosis and chronic broncho-pulmonary Pseudomonas aeruginosa infection as compared with 14 age matched controls. The increase was significantly correlated to impaired pulmonary function (FVC and FEV1). The results indicate that urinary collagen metabolites reflect degradation of lung connective tissue and may be an indicator of the severity of pulmonary disease in cystic fibrosis. Parts of the excreted hydroxyproline may be degradation products of elastin.