SerumtypeIIIprocollagen peptide inasbestos workers: anearly indicator ofpulmonary fibrosis

SerumtypeIIIprocollagen peptide (PIIIP) concentrations were determined in36male workers exposed toasbestos fibres intheproduction ofasbestos cementitems andin13healthy male controls. Mean(SD)PIIIP serumconcentrations were93(1. 5)ng/ml (range 7-12) inthecontrols and 13-7 (3-5)ng/ml (range 75-20) intheasbestos workers; thedifference was statistically significant (p< 001). Theexposed workers weresubdivided according topresenceorabsence ofradiological signs ofasbestosis andintensity andduration ofexposure.PIIIP serum values ofworkers with asbestos related interstitial fibrosis werethehighest ofthe groups at14-6 (23)ng/ml. Inworkers with heavy exposurethePIIIPvalues were significantly related toduration ofexposure (r= 095; p < 001). PIIIP serum values may bea useful index fortheearly diagnosis ofasbestos induced pulmonary fibrosis andits useshould beconsidered aspartofthebiological monitoring ofexposed workers. Exposure toasbestos mayinduce several non-malig- nantandmalignant lung diseases.' Amongtheformer, hyaline plaques ofparietal pleura andasbestosis are themostimportant. Thediagnosis ofasbestos induced nonmalignant lung disease isbased onthepresence of abnormal physical signs, impairment oflung function, andradiographic abnormalities. Suchsymptoms and signs, however, arenotlikely todetect early pulmon- aryeffects25 andother methods mayberequired to detect these andprevent progression toamoresevere stage ofinterstitial fibrosis.6 Techniques suchasbronchoalveolar lavage (BAL) and67-gallium scintigraphy havebeenreported tobe useful indetecting pulmonary effects before the appearance ofradiological orfunctional changes,78 butarenotsuitable foruseinlarge groups of occupationally exposed workers; moreovertheir specificity hasstill tobeassessed. Recent studies suggest thatthepathogenesis of pulmonary fibrosis mayberelated tochanges inthe structure andfunction ofpulmonary collagen rather thantoanincrease initsabsolute amount.9 Atleast fivecollagen isotypes arepresent inthehuman lung,'0" themostabundant aretypeIandtypeIII collagen andtheir normal ratio is66:33.12 An increase intypeIIIcollagen wasrecently