Bronchoalveolar lavage cell and lymphocyte phenotype profiles in healthy asbestos-exposed shipyard workers

Our plain-English summary of Bronchoalveolar lavage cell and lymphocyte phenotype profiles in healthy asbestos-exposed shipyard workers, by J.M. Wallace, J.S. Oishi, R.G. Barbers, et al (The American Review of Respiratory Disease, 1989).

The study

• Authors: J.M. Wallace, J.S. Oishi, R.G. Barbers, P. Batra, D.R. Aberle
• Journal: The American Review of Respiratory Disease
• Published: 1989;139(1):33-8
• Cited by: 30 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 004773).

Abstract

The cellular and lymphocyte phenotypic composition of bronchoalveolar lavage (BAL) fluid and peripheral blood (PB) from 15 healthy, nonsmoking, asbestos-exposed shipyard workers (AEW) and 10 nonsmoking, age-matched unexposed workers (UEW) were compared. None of the AEW had clinical, radiographic, or physiologic evidence of asbestosis, but six had radiographic evidence of pleural plaques and/or thickening. The mean duration of asbestos exposure was 16.3 +/- 2.3 yr, and the mean period since exposure was 10.8 +/- 0.5 yr. All but three of the AEW and none of the UEW had asbestos bodies detected in the first 20 ml of BAL fluid recovered (0.1 to 35 asbestos bodies/ml). The AEW had a significantly higher mean percentage (19.1 +/- 2.8% versus 9.7 +/- 1.6%) and concentration (31.6 +/- 5.2 x 10(3) cells/ml versus 14.7 +/- 2.5 x 10(3) cells/ml) of BAL lymphocytes compared with that in the UEW, with an increased mean concentration of each phenotype measured. In PB, the mean lymphocyte concentration was also higher in the AEW than in the UEW (2.0 +/- 0.3 x 10(3) cells/ml versus 1.5 +/- 0.3 x 10(3) cells/ml), but the difference was not statistically significant, and there was no increase of any phenotype measured. BAL lymphocytosis did not correlate with exposure history or BAL asbestos body count, but was greater in AEW with pleural abnormality (30.1 +/- 2.9% versus 11.8 +/- 1.6%). BAL concentrations of CD-20, CD-3, and CD-4, but not of CD-8 cells were significantly increased compared with those in the AEW without pleural abnormality. Further longitudinal studies are needed to determine the prognostic significance of these findings.

In plain English

The authors compared cells in lung-washing fluid (bronchoalveolar lavage) and blood from 15 healthy, nonsmoking men with past heavy asbestos exposure from ship refitting at the Long Beach Naval Shipyard and 10 nonsmoking, age-matched workers with no known asbestos exposure. None of the exposed workers had signs of asbestosis, but six had pleural abnormalities on chest X-ray. Asbestos bodies were found in the lavage fluid of all but three exposed workers and of none of the unexposed workers. Lymphocytes, a type of immune cell, made up a mean 19.1% of lavage cells in exposed workers versus 9.7% in unexposed workers. In blood, the difference in lymphocyte levels was not statistically significant. Among exposed workers, lavage lymphocyte levels did not correlate with length of exposure, time since exposure, or asbestos body count. They were higher in the six with pleural abnormalities than in the nine without (30.1% versus 11.8%). The authors concluded that this increase occurs in some previously exposed workers without lung disease and may correlate with pleural disease. They said long-term follow-up is needed.

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 comparison of bronchoalveolar lavage fluid and peripheral blood between asbestos-exposed and unexposed workers
• Who was studied: 15 male asbestos-exposed workers (mean age 57.3) from a U.S. Department of Labor evaluation program for Long Beach Naval Shipyard employees, and 10 unexposed workers (mean age 50.9) recruited by public notice. All were nonsmokers or ex-smokers. No study dates are given.
• Exposure: Heavy asbestos exposure during ship refitting work, in jobs such as boilermaker, welder, pipe fitter and machinist. Mean duration of exposure was 16.3 years (range 3 to 32), and the mean time since the most recent exposure was 10.8 years. The fiber type is not specified.
• Main results:
  • Asbestos bodies were detected in the first aliquot of lavage fluid in all but three of the 15 exposed workers and in none of the 10 unexposed workers.
  • Exposed workers had a significantly higher mean percentage of lavage lymphocytes (19.1 ± 2.8% versus 9.7 ± 1.6%) and concentration (31.6 ± 5.2 versus 14.7 ± 2.5 x 10^3 cells/ml) than unexposed workers.
  • The mean lavage concentration of each lymphocyte type measured was significantly higher in exposed workers.
  • In blood, the mean lymphocyte concentration was 2.01 ± 0.15 x 10^3/mm3 in exposed workers versus 1.53 ± 0.18 x 10^3/mm3 in unexposed workers. The difference was not statistically significant.
  • Among exposed workers, lavage lymphocyte concentration did not correlate with duration of exposure, years since most recent exposure, or asbestos body count.
  • Exposed workers with pleural abnormalities (n = 6) had a significantly higher mean lavage lymphocyte concentration than those without (n = 9): 47.7 ± 8.3 versus 20.9 ± 3.7 x 10^3/ml. The lymphocyte percentages were 30.1 ± 2.9% versus 11.8 ± 1.6%.
  • In exposed workers with pleural disease, mean lavage concentrations of CD-20, CD-3 and CD-4 cells, but not CD-8 cells, were significantly higher than in exposed workers without pleural disease.
  • When exposed workers with pleural abnormalities were excluded, lavage lymphocyte concentration did not differ significantly between exposed and unexposed workers.
• The authors' conclusion: The authors concluded that lower respiratory tract lymphocytosis occurs in some workers previously exposed to asbestos who have no clinical, radiologic or physiologic evidence of lung disease, and that it may correlate with pleural disease. They said long-term follow-up is needed to judge its prognostic significance.
• Limitations the authors state:
  • Asbestos bodies were measured only in the first aliquot of lavage fluid, which may underestimate concentrations in the lung tissue.
  • Computed tomography was not performed systematically, so subtle pleural abnormalities could have been missed on plain chest films.

Topics

Medical terms in this study, explained in our Lexicon: Bronchoalveolar Lavage (BAL), Pleural Plaques, Asbestos Exposure, Asbestos Bodies, BAL Fluid, Exposure History, Asbestos Body Formation.

Related studies

• Lymphocyte subpopulations in bronchoalveolar lavage fluid in asbestos workers — A.R. Gellert, M.G. Macey, et al. (1985)
• Bronchoalveolar lavage fluid cellular profile in workers exposed to chrysotile asbestos — F.P. Kokkinis, D. Bouros, et al. (2011)
• Brief inhalation of asbestos compromises superoxide production in cells from bronchoalveolar lavage — J.M. Petruska, J. Marsh, et al. (1990)
• Bronchoalveolar lavage and 99mTc-DTPA clearance as prognostic factors in asbestos workers with and without asbestosis — N. al Jarad, A.R. Gellert, et al. (1993)
• Influence of cigarette smoking on bronchoalveolar lavage cellularity in asbestos-induced lung disease — D.A. Schwartz, J.R. Galvin, et al. (1992)
• Asbestos bodies in bronchoalveolar lavage fluids of brake lining and asbestos cement workers — P. Dumortier, P. De Vuyst, et al. (1990)

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