Asbestosis: assessment by bronchoalveolar lavage and measurement of pulmonary epithelial permeability

Our plain-English summary of Asbestosis: assessment by bronchoalveolar lavage and measurement of pulmonary epithelial permeability, by A.R. Gellert, J.A. Langford, R.J. Winter, et al (Thorax, 1985).

The study

• Authors: A.R. Gellert, J.A. Langford, R.J. Winter, S. Uthayakumar, G. Sinha, R.M. Rudd
• Journal: Thorax
• Published: 1985;40(7):508-14
• Cited by: 48 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Thirty two patients with asbestosis were assessed by means of bronchoalveolar lavage (27 patients) and the half time clearance from lungs to blood (T1/2LB) of an inhaled aerosol of diethylenetriamine pentacetate (DTPA) labelled with technetium 99m (32 patients). T1/2LB was also measured in 20 non-smoking normal individuals and 17 smokers without a history of exposure to asbestos. Thirteen patients (46%) showed an increase in the percentage of neutrophils with or without an increase in the percentage of eosinophils and eight (29%) showed an increased percentage of lymphocytes. The number of neutrophils plus eosinophils expressed as a percentage of the total count was positively correlated with the length of the history of disease (r = 0.53, p less than 0.025) and greater percentages were associated with more severe impairment of lung function. Smokers had lower percentages of lymphocytes than non-smokers (p less than 0.002) and showed increased proportions of neutrophils and eosinophils more often than non-smokers (p less than 0.05). In 18 non-smokers with asbestosis the mean T1/2LB was 33.8 (range 10.0-62.0) minutes, significantly less than 57.2 (30.5-109) minutes in 20 non-smoking normal subjects (p less than 0.002). In non-smokers shorter T1/2LB correlated with a longer time since first exposure to asbestos (r = -0.65, p less than 0.005), longer duration of exposure (r = -0.70, p less than 0.001), and a shorter time since last exposure (r = 0.59, p less than 0.01). Shorter T1/2LB was also associated with increased inflammatory activity as shown by higher bronchoalveolar lavage cell counts (r = -0.53, p less than 0.025) and higher combined percentages of neutrophils, eosinophils, and lymphocytes (r = -0.47, p less than 0.05). The techniques of bronchoalveolar lavage and measurement of inhaled solute clearance may be useful in assessing inflammatory activity in asbestosis.

In plain English

This London Chest Hospital study examined 32 asbestosis patients (31 men, one woman). Twenty had worked in lagging, 12 in asbestos cutting, milling and spinning. In 27, the authors rinsed cells out of the lungs (bronchoalveolar lavage). In all 32, and in 20 normal non-smokers and 17 smokers without known asbestos exposure, they measured how fast an inhaled radioactive tracer passed into the blood, thought to reflect lung lining leakiness. On lavage, 13 patients had raised neutrophils and eight raised lymphocytes (printed as 46% and 29%, fitting 28 patients, not 27). More neutrophils plus eosinophils went with a longer disease history (r = 0.53). In 18 non-smokers with asbestosis, half the tracer cleared in a mean of 33.8 minutes, versus 57.2 minutes in 20 non-smoking controls (p less than 0.002). Smokers with asbestosis showed no significant clearance difference from smoking controls. Among non-smokers, faster clearance went with longer exposure, longer time since first exposure, and more inflammatory cells. The authors concluded that lavage findings related to clinical features and lung lining permeability; longitudinal studies would show whether these tests help judge prognosis.

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: Clinical study of patients with asbestosis using bronchoalveolar lavage and a lung-to-blood tracer clearance test. Tracer clearance was also measured in 20 normal non-smoking men and in 17 current smokers without known exposure to asbestos.
• Who was studied: 32 patients with asbestosis (31 men, one woman; mean age 57, range 32-74 years) attending an asbestos screening clinic at the London Chest Hospital. Of these, 14 were current smokers and 18 were non-smokers. There were two comparison groups. The first was 20 non-smoking men described as normal individuals (12 had never smoked and 8 had stopped at least five years earlier; mean age 54). The second was 17 current smokers (11 men, six women; mean age 42). The article describes the comparison subjects as without known exposure to asbestos.
• Exposure: Occupational asbestos exposure. Twenty patients had worked in the lagging industry and 12 in asbestos cutting, milling and spinning. Mean time since first exposure was 34 years (range 18-53), and mean duration of exposure was 19 years (range 1-43). For most patients, exposure had been heavy and without protection. Fiber types were not reported.
• Main results:
  • In lavage fluid, 13 patients showed increased neutrophils, printed as 46%. Six of these also had increased eosinophils. The 46% fits a denominator of 28, not the 27 patients reported to have had lavage.
  • In lavage fluid, eight patients showed an increased proportion of lymphocytes, printed as 29%. The Discussion gives this as eight of 28 cases. Six of the eight had no increase in neutrophils or eosinophils.
  • Among patients with asbestosis, smokers had lower lymphocyte percentages (mean 5, range 1-14) than non-smokers (mean 18, range 2-47), p less than 0.002.
  • In the whole patient group, a longer history of disease was associated with higher percentages of neutrophils plus eosinophils (r = 0.53, p less than 0.025).
  • In the whole patient group, higher percentages of inflammatory cells other than macrophages were associated with faster decline in forced vital capacity (FVC) over the previous 12 months (r = 0.45, p less than 0.025).
  • Asbestos bodies were counted in 23 patients, with a mean of 141 bodies per ml of lavage fluid (range 15-642). Fewer bodies were associated with a longer time since first exposure (r = -0.46, p less than 0.025).
  • In 18 non-smokers with asbestosis, the mean clearance half time was 33.8 minutes (range 10.0-62.0). This was significantly shorter than 57.2 minutes (30.5-109) in 20 non-smoking controls (p less than 0.002).
  • In 14 current smokers with asbestosis, the mean clearance half time was 21.2 minutes (9.5-57.0). This was not significantly different from 21.8 minutes (11.5-68) in 17 smoking controls.
  • In non-smokers with asbestosis, a shorter clearance half time correlated with a longer time since first exposure (r = -0.65, p less than 0.005) and a longer duration of exposure (r = -0.70, p less than 0.001).
  • In non-smokers with asbestosis, clearance half time correlated positively with time since last exposure (r = 0.59, p less than 0.01).
  • In non-smokers with asbestosis, a shorter clearance half time correlated with a higher percentage of non-macrophage inflammatory cells (r = -0.47, p less than 0.05) and with a higher total lavage cell count (r = -0.53, p less than 0.025).
  • In non-smokers with asbestosis, transfer factor correlated positively with lymphocyte percentage (r = 0.66, p less than 0.01) and negatively with neutrophil plus eosinophil percentage (r = -0.59, p less than 0.025). No relationships were seen in smokers.
• The authors' conclusion: The authors concluded that in asbestosis, lavage findings were related to clinical features and to abnormalities in lung epithelial permeability. They stated that longitudinal studies would show whether these techniques are useful for assessing prognosis and for selecting patients for treatment trials.
• Limitations the authors state:
  • Because of a delay in perfecting the counting method, asbestos bodies were counted in only 23 cases.
  • Retrospective clinical data, including spirometry and chest radiographs, were very limited for some patients.
  • Whether lavage cell profiles predict outcome in asbestosis had not yet been shown and would depend on follow-up.

Topics

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

Medical terms in this study, explained in our Lexicon: Bronchoalveolar Lavage (BAL).

Related studies

• Assessment of progression of asbestosis in the sheep model by bronchoalveolar lavage and pulmonary function tests — R. Bégin, M. Rola-Pleszczynski, et al. (1983)
• Alveolitis of pulmonary asbestosis. Bronchoalveolar lavage studies in crocidolite- and chrysotile-exposed individuals — B.W. Robinson, A.H. Rose, et al. (1986)
• Influence of cigarette smoking on bronchoalveolar lavage cellularity in asbestos-induced lung disease — D.A. Schwartz, J.R. Galvin, et al. (1992)
• Bronchoalveolar lavage in pulmonary fibrosis: comparison of cells obtained with lung biopsy and clinical features — P.L. Haslam, C.W. Turton, et al. (1980)
• Lymphocyte subpopulations in bronchoalveolar lavage fluid in asbestos workers — A.R. Gellert, M.G. Macey, et al. (1985)
• 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)

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