title: Semi-quantitative X-ray microanalysis of bronchoalveolar lavage samples from silica-exposed and nonexposed subjects.
abstract: To evaluate the possibility of quantifying alveolar dust burden in conditions of exposure to silica, four groups of subjects were submitted to bronchoalveolar lavage (BAL): 10 healthy control subjects and 39 patients affected by diffuse interstitial lung disease (DILD) never exposed to dust, 23 silicotic patients and 12 chronic bronchitis patients with a history of occupational exposure to silica dust. Five to ten million BAL recovered cells were analysed with an energy-dispersive X-ray microanalysis (EDXA) system to determine the silicon content, expressed in a semi-quantitative way as silicon to sulphur (Si/S) ratio. The results were independent of smoking habit. The Si/S median values (interquartile range in brackets) for the four groups were 0.53 (0.5-0.65), 0.60 (0.41-0.8), 1.23 (1.06-1.39), 1.31 (1.11-1.97), respectively. Silicotics and simply exposed individuals did not show a significant discrepancy, but they were both significantly different in comparison with normal and DILD patients without history of exposure (p less than 0.001). 14.3% false negative cases were found, and 4.1% false positive cases (none among normal subjects). We did not see any significant relationships between the amount of silicon and the duration of exposure or the degree of chest X-ray involvement. A study of cytocentrifuge slides from the same subjects by polarizing light microscopy revealed a lower sensitivity (34% false negative cases).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Clinica del Lavoro Foundation, Medical Center of Rehabilitation, Veruno, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Lusuardi
authors.forename: A
authors.initials: A
authors.lastname: Capelli
authors.forename: C F
authors.initials: CF
authors.lastname: Donner
authors.forename: O
authors.initials: O
authors.lastname: Capelli
authors.forename: G
authors.initials: G
authors.lastname: Velluti
mesh_terms: D001991:Bronchitis / Q000175:diagnosis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D004577:Electron Probe Microanalysis; D005260:Female; D006801:Humans; D008297:Male; D008859:Microscopy, Polarization; D008875:Middle Aged; D016273:Occupational Exposure; D011658:Pulmonary Fibrosis / Q000175:diagnosis; D012825:Silicon / Q000032:analysis*; D012829:Silicosis / Q000175:diagnosis*; D012907:Smoking / Q000503:physiopathology; D013997:Time Factors
chemical_list: D012825:Silicon