OBJECTIVETo evaluate the role of transbronchial lung biopsy (TBLB) pathology in pneumoconiosis diagnosis.

METHODSDuring Jan 2003 to Jun 2010 in our hospital. 418 patients exposed to dusts were examined with TBLB. The chest radiographs of all subjects showed the pneumoconiosis-like opacities. Because the dust property or accumulated doses didn't match with abnormality on chest radiographs or there were no a series of chest radiographs, it was required for subjects to perform the TBLB for diagnosis. Three hundred seventy nine cases with satisfying samples served as the study subjects. The dust deposition, fibrosis and birefringent particles were found in TBLB pathological examinations. From May 2005, the Prussian blue iron reaction test was conducted on the TBLB samples. A panel made pneumoconiosis diagnosis according to GBZ 70-2002 and GBZ 70-2009 Pneumoconiosis Diagnostic Criteria, consulting subjects' accounts and pathologic results.

RESULTSAmong 379 subjects, 376 cases (99.2%) showed the lung interstitial fibrosis, 228 cases (60.2%) demonstrated the dust deposition, 111 cases (29.3%) expressed the birefringent particles by polarized light microscopy. Birefringent particles positive rate was 37.8% (62/164) in 164 patients exposed to either silica or potter dusts or cement dusts or coal-silica dusts or foundry dusts, which was much higher than that (22.7%, 49/215) in patients exposed to other dusts (welding fume or asbestos or aluminum dusts) (P < 0.05). The positive rate of Prussian blue iron reaction in 177 patients exposed to welding fume or burnishing dusts was 53.1% (94/177), which was significantly higher than that (23.2%, 13/56) in patients exposed to other dusts (cement dusts, casting dusts or silica) (P < 0.001). There were no significantly differences in rates of lung fibrosis, dust deposition and birefringent particles between pneumoconiosis and none-pneumoconiosis subjects. The rate of lung fibrosis in pneumoconiosis cases was significantly higher than that in non- pneumoconiosis cases (P < 0.05).

CONCLUSIONTBLB could provide the evidence of exposure to dusts and pathological changes, which may be useful to the pneumoconiosis diagnosis.