Markers of
collagen metabolism may possibly be used in the assessment of pulmonary involvement in
asbestosis-related
pulmonary diseases. In this study the levels of the carboxyterminal propeptide of
type I procollagen (
PICP) and the aminoterminal propeptide of
type III procollagen (
PIIINP) were evaluated in bronchoalveolar lavage fluid (BALF), epithelial lining fluid (ELF) and serum from patients with
asbestos related pulmonary and pleural involvement. Forty-two consecutive patients with occupational exposure to
asbestos fibres, who underwent bronchoscopy and bronchoalveolar lavage (BAL) at the time of the diagnosis were investigated. Five patients were diagnosed as having
asbestosis, while 37 showed no parenchymal involvement. Of the latter group, 25 had pleural plaques, while 12 had no detectable changes in chest radiographs. The patients were followed-up for an average of 7 yrs. The
PICP in BALF and ELF was detectable in all patients with
asbestosis and in 8/37 subjects without parenchymal involvement. The levels of
PICP in BALF and ELF were significantly higher in the
asbestosis group compared to the patients without
asbestosis (9.8+/-1.8 microg x L(-1) versus 0.6+/-1.3 microg x L(-1), p<0.001 and 488.9+/-208.8 microg x L(-1) versus 22.6+/-50.6 microg x L(-1), p<0.001, respectively). Only 1 patient with
asbestosis and 3 patients without parenchymal involvement had detectable levels of
PIIINP in BALF. The serum levels of
PICP and
PIIINP did not differ between the patients with
asbestosis and those with exposure to
asbestos fibres without
asbestosis and were within the normal range. None of the 37 patients exposed to
asbestos fibres without parenchymal involvement at the baseline developed
asbestosis during the follow-up period of 7 yrs. In conclusion, the data show that the carboxyterminal propeptide of
procollagen type I, but not the aminoterminal propeptide of
type III procollagen is highly elevated in bronchoalveolar lavage fluid and epithelial lining fluid in patients with
asbestosis, but not in those without parenchymal involvement. This suggests that the determination of carboxyterminal propeptide of
procollagen type I in bronchoalveolar lavage fluid could be used as a marker of parenchymal involvement in patients exposed to
asbestos fibres.