Comparative analysis of induced sputum and bronchoalveolar lavage fluid (BALF) profile in asbestos exposed workers

Our plain-English summary of Comparative analysis of induced sputum and bronchoalveolar lavage fluid (BALF) profile in asbestos exposed workers, by E.C. Alexopoulos, D. Bouros, M. Dimadi, et al (Journal of Occupational Medicine and Toxicology, 2011).

The study

• Authors: E.C. Alexopoulos, D. Bouros, M. Dimadi, A. Serbescu, G. Bakoyannis, F.P. Kokkinis
• Journal: Journal of Occupational Medicine and Toxicology
• Published: 2011;6:23
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Biological monitoring of healthy workers exposed to hazardous dusts lack validated screening tools. Induced sputum (IS) cellular profile was compared with bronchoalveolar lavage fluid (BALF) profile in asbestos exposed workers in order to assess its usefulness in monitoring workers exposed to asbestos for a long period of time.

Methods: IS and BALF analysis was performed in 39 workers of a car brakes and clutches factory that uses chrysotile asbestos. Selection criteria were an employment history of > 15 years and the absence of a diagnosis of pneumonoconiosis. The type of cells, the existence of dust cells, of iron laden macrophages and of asbestos bodies were assessed and compared between IS and BALF samples.

Results: 35 IS samples (90%) had dust cells, 34 (87%) iron laden macrophages and in 8 samples (21%) asbestos bodies were found. In most samples neutrophils were dominated. Samples with asbestos bodies (ABs) had significantly higher lymphocytes and lower neutrophils count compared with the samples without ABs. Macrophages and neutrophils in IS and BALF exhibited significant inter-relations (Spearman's rho: 0.26-0.29, p < 0.05) while IS lymphocytes count showed an inverse relation with BALF neutrophils (Spearman's rho: -0.36). Neutrophils and dust cells were highly correlated between the samples (Spearman's rho: 0.35, p < 0.05) while IS dust cells and lymphocytes were inversely related (Spearman's rho: -0.36, p < 0.05). More years of employment in the company was related with more neutrophils (Spearman's rho: 0.26) and less lymphocytes (Spearman's rho: -0.33) count. In multivariate analysis the presence of AB in IS samples was strongly related to the presence of asbestos bodies and lymphocytes count in BALF samples.

Conclusions: IS and BALF analysis showed a similar cellular profile indicating that IS sampling in exposed workers to asbestos as a less invasive and expensive method may be useful in providing an insight both for inhalation of dusts and inflammatory processes in the lung.

In plain English

This cross-sectional study, done in Romania, compared two ways of collecting cells from the lungs of 39 long-term workers at a factory making car brakes and clutches, where chrysotile asbestos had been used until December 1999. Workers had spent at least 15 years at worksites with medium to high asbestos exposure and had no diagnosis of pneumoconiosis. Each gave an induced sputum sample (coughed up after inhaling a salt-water mist) and also had bronchoalveolar lavage, a lung washing done during bronchoscopy. Of the 39 sputum samples, 35 (90%) contained dust cells, 34 (87%) iron-laden macrophages and 8 (20.5%) asbestos bodies. Several cell counts in sputum were related to counts in lavage fluid, some only at borderline significance. In multivariate analysis, asbestos bodies in sputum were very strongly related to asbestos bodies in lavage fluid. The authors concluded that induced sputum, a less invasive method, may give insight into dust inhalation and lung inflammation, but that its usefulness for screening workers needs further evaluation. They noted the small sample, the lack of control subjects and the lack of detailed exposure data.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cross-sectional study comparing induced sputum with bronchoalveolar lavage fluid (BALF) in the same workers
• Who was studied: 39 workers out of 200, mainly blue-collar, at a Romanian factory making brakes and clutches for cars, interviewed by the end of 2000. They were selected for long employment and no diagnosis of pneumoconiosis.
• Exposure: Chrysotile asbestos used in the factory from its foundation until December 1999. Workers had at least 15 years at worksites with medium to high asbestos exposure intensity; detailed exposure measurements were not available.
• Main results:
  • Of the 39 induced sputum samples, 35 (90%) had dust cells and 34 (87%) had iron-laden macrophages.
  • Asbestos bodies were found in 8 sputum samples (20.5%). These were 7 of the 14 workers who had asbestos bodies in BALF.
  • Sputum samples with asbestos bodies had significantly higher lymphocyte counts and lower neutrophil counts than sputum samples without them.
  • Macrophage and neutrophil counts in BALF and sputum were related at borderline significance (Spearman's rho 0.26 to 0.29).
  • Neutrophils and dust cells were correlated between sputum and BALF samples (Spearman's rho 0.35).
  • Sputum macrophages predicted high BALF macrophage counts with an area under the ROC curve of 0.663 (95% CI 0.497 to 0.829).
  • Sputum neutrophils predicted high BALF neutrophil counts with an area under the ROC curve of 0.683 (95% CI 0.515 to 0.852).
  • In multivariate analysis, asbestos bodies in sputum were very strongly related to asbestos bodies in BALF.
  • More years of employment in the company appeared related to more neutrophils (Spearman's rho 0.26) and fewer lymphocytes (Spearman's rho -0.33).
• The authors' conclusion: The authors concluded that asbestos bodies and iron-laden macrophages in induced sputum are strongly related to the BALF cell profile in chrysotile-exposed workers, and that induced sputum may give insight into dust inhalation and lung inflammation. They added that its usefulness for screening workers should be further evaluated.
• Limitations the authors state:
  • The cross-sectional design does not allow conclusions about cause.
  • The study population was relatively small.
  • Detailed exposure data were not available.
  • No control subjects were studied.
  • The inflammatory response seen was not specific; it may have been caused by asbestos, other dust or smoking.

Topics

Medical terms in this study, explained in our Lexicon: Sputum, Bronchoalveolar Lavage (BAL), Chrysotile, Macrophage, Asbestos Bodies, Multivariate Analysis.

Related studies

• Bronchoalveolar lavage fluid cellular profile in workers exposed to chrysotile asbestos — F.P. Kokkinis, D. Bouros, et al. (2011)
• Erionite bodies and fibres in bronchoalveolar lavage fluid (BALF) of residents from Tuzköy, Cappadocia, Turkey — P. Dumortier, L. Coplü, et al. (2001)
• Bronchoalveolar lavage cell and lymphocyte phenotype profiles in healthy asbestos-exposed shipyard workers — J.M. Wallace, J.S. Oishi, et al. (1989)
• Asbestos bodies in bronchoalveolar lavage fluids of brake lining and asbestos cement workers — P. Dumortier, P. De Vuyst, et al. (1990)
• Lymphocyte subpopulations in bronchoalveolar lavage fluid in asbestos workers — A.R. Gellert, M.G. Macey, et al. (1985)
• Cytological analysis of bronchoalveolar lavage fluid in asbestos-exposed workers — P. Sartorelli, S. Indini, et al. (2020)

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