Bronchoalveolar lavage fluid cellular profile in workers exposed to chrysotile asbestos

Our plain-English summary of Bronchoalveolar lavage fluid cellular profile in workers exposed to chrysotile asbestos, by F.P. Kokkinis, D. Bouros, K. Hadjistavrou, et al (Toxicology and Industrial Health, 2011).

The study

• Authors: F.P. Kokkinis, D. Bouros, K. Hadjistavrou, R. Ulmeanu, A. Serbescu, E.C. Alexopoulos
• Journal: Toxicology and Industrial Health
• Published: 2011;27(9):849-56
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The cellular profile of bronchoalveolar lavage fluid (BALF) in asbestos-exposed population remains controversial. We, therefore, aimed to investigate BALF in apparently healthy individuals that were exposed in asbestos-related work for a long period of time. Participants were selected among employees of a car brakes and clutches factory that used chrysotile asbestos. Selection criteria were an employment history of ≥ 15 years and the absence of severe respiratory disease. The total number and type of BALF cells, the existence of dust cells, iron-laden macrophages and asbestos bodies were assessed. Thirty-nine workers (25 men), with a mean age of 46.2 ± 4.2 years and a mean employment time of 23.5 ± 4 years, participated. Asbestos bodies were observed in 14 out of 39 (36%) specimens, dust cells in 37 and iron-laden macrophages in all. Those with asbestos bodies had at least 3 times higher probability to have lymphocytosis (lymphocytes > 11%: 64% vs 28%, p = 0.027) and had an increased percentage of iron-laden macrophages compared to those without asbestos bodies (median values: 42% vs 13%, p = 0.08). Smokers (36%) had less lymphocytes compared to non and ex-smokers (median values: 6% vs. 13%, p = 0.002), and iron-laden macrophages count had a positive relation (r = 0.31, p = 0.05) to lymphocyte count. Asbestos-exposed asymptomatic individuals with the presence of asbestos bodies in the BALF are more likely to have lymphocytic alveolitis while concurrent dust exposure and smoking habits hold a significant role.

In plain English

This cross-sectional study examined fluid washed from the lungs (bronchoalveolar lavage) of 39 apparently healthy workers at a Romanian factory that made car brakes and clutches using chrysotile asbestos until December 1999. Workers had spent at least 15 years at worksites with medium to high asbestos exposure. There was no comparison group. Asbestos bodies were found in 14 of the 39 workers (36%): in 13 of 28 workers rated highly exposed and in 1 of 11 rated moderately exposed (p = 0.06). Iron-laden macrophages were found in every sample. Workers with asbestos bodies more often had a raised share of lymphocytes, a type of white blood cell (above 11%: 64% vs 28%, p = 0.027). This link was statistically significant only at the 11% or 12% cut-off, and not in the multivariate analysis (p = 0.286). Smokers had fewer lymphocytes. The authors concluded that asbestos bodies after long chrysotile exposure trigger a lymphocyte-type inflammatory response. They noted that the cross-sectional design does not permit causal inference, the group was small, and exposure was not assessed in detail.

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 of bronchoalveolar lavage fluid in exposed workers, without a control group
• Who was studied: 39 apparently healthy workers at a Romanian factory making car brakes and clutches. The Methods give 25 men and 14 women; the Results and Table 1 give 24 men and 15 women. They were described as those, out of a total of 200, who met the selection criteria and agreed to take part. Workers were interviewed by the end of 2000 and were aged 37 to 53.
• 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 exposure intensity (atmospheric levels above 5 fibres per mL). Median cumulative exposure was roughly estimated as possibly exceeding 150 fibre/mL-years, with no exposure measurements available. 28 workers were rated highly exposed and 11 moderately exposed.
• Main results:
  • Asbestos bodies were identified in the lavage fluid of 14 of the 39 workers (36%).
  • Asbestos bodies were found in 46% of highly exposed workers (13 of 28) and in 9% of moderately exposed workers (1 of 11), p = 0.06.
  • Iron-laden macrophages were found in all samples.
  • Workers with asbestos bodies more often had lymphocytes above 11% than workers without (64% vs 28%, p = 0.027).
  • In the analysis across several lymphocyte cut-off points, the association between asbestos bodies and lymphocytosis reached statistical significance only at the 11% or 12% cut-off.
  • In the multivariate analysis, the association between asbestos bodies and lymphocytes (OR 3.19, p = 0.286) was not statistically significant.
  • Samples from smokers had a higher total number of cells (p < 0.001) and fewer lymphocytes (p = 0.020).
  • On bronchoscopy, chronic bronchitis was seen in the bronchial lining of all but one participant.
• The authors' conclusion: The authors concluded that the appearance of asbestos bodies in the lavage fluid after long-lasting chrysotile exposure triggers an inflammatory response of the lymphocyte type in the lung.
• Limitations the authors state:
  • The cross-sectional design does not permit causal inference.
  • Possible selection bias: workers with severe respiratory problems may have moved to other jobs (the healthy worker effect).
  • Clinical assessment did not include more sensitive methods such as high-resolution CT scans.
  • The study group was small and there was no control group.
  • Asbestos exposure was not assessed in detail.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile.

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

Related studies

• Comparative analysis of induced sputum and bronchoalveolar lavage fluid (BALF) profile in asbestos exposed workers — E.C. Alexopoulos, D. Bouros, et al. (2011)
• Asbestos bodies in bronchoalveolar lavage fluids of brake lining and asbestos cement workers — P. Dumortier, P. De Vuyst, et al. (1990)
• Bronchoalveolar lavage cell and lymphocyte phenotype profiles in healthy asbestos-exposed shipyard workers — J.M. Wallace, J.S. Oishi, et al. (1989)
• Association between neutrophil concentration in bronchoalveolar lavage fluid and recent losses in diffusing capacity in men formerly exposed to asbestos — M.R. Cullen, W.W. Merrill (1992)
• Asbestos fibers in bronchoalveolar lavage and lung tissue of former asbestos workers — H. Teschler, K.H. Friedrichs, et al. (1994)
• Fibres and asbestos bodies in bronchoalveolar lavage fluids of asbestos sprayers — T. Tuomi, P. Oksa, et al. (1992)

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