Cathepsin K expression is diminished in infants with bronchopulmonary dysplasia.

UNLABELLED: The expression of a potent collagenolytic enzyme, cathepsin K, was measured in repeated tracheal aspirate samples from premature infants with and without a chronic lung disorder, bronchopulmonary dysplasia (BPD). At 9--13 d, but not before, cathepsin K expression was significantly lower in the lungs of premature infants developing BPD.
CONCLUSION: Insufficient pulmonary cathepsin K in BPD may predispose premature lungs to pulmonary fibrosis.