Clinical correlation of asbestos bodies in BAL fluid

Our plain-English summary of Clinical correlation of asbestos bodies in BAL fluid, by P. Vathesatogkit, T.J. Harkin, D.J. Addrizzo-Harris, et al (Chest, 2004).

The study

• Authors: P. Vathesatogkit, T.J. Harkin, D.J. Addrizzo-Harris, M. Bodkin, M. Crane, W.N. Rom
• Journal: Chest
• Published: 2004;126(3):966-71
• Cited by: 19 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Asbestos bodies (AB) in BAL cells are specific markers of asbestos exposure.

Methods: We retrospectively reviewed BAL cytocentrifuge slides of 30 utility workers with a history of asbestos exposure and 30 normal volunteers. BAL cytocentrifuge slides were blinded and scanned under 40 x light microscope.

Results: AB were found more frequently in subjects with a history of asbestos exposure compared to normal volunteers (10 of 30 subjects, 33%, vs 0 of 30 subjects). The mean number of AB seen in the AB-positive group was 2.7 per slide. Demographic data were comparable including age, gender, and smoking. Exposure histories were also similar: duration > 20 years, onset > 30 years ago, and time since last exposure > 7 years. More AB-positive patients reported respiratory symptoms (70% vs 26%, p < 0.05). High-resolution CT scans of AB-positive patients revealed a higher prevalence of parenchymal disease (70% vs 26%, p < 0.05). AB-positive subjects had reduced pulmonary function compared to AB-negative subjects: FVC (86% vs 97% predicted), FEV(1) (77% vs 92% predicted, p < 0.05), and diffusion capacity of the lung for carbon monoxide (76% vs 104% predicted, p < 0.01).

Conclusion: In individuals with a history of asbestos exposure, the presence of AB in BAL cells is associated with higher prevalence of parenchymal abnormalities, respiratory symptoms, and reduced pulmonary function.

In plain English

This retrospective study examined stored lung-wash (bronchoalveolar lavage, BAL) slides for asbestos bodies, inhaled asbestos fibers coated by lung cells. The slides came from 30 New York City electric utility workers with a history of asbestos exposure and 30 normal volunteers; readers did not know whose slides they were reading. Asbestos bodies were found in 10 of 30 workers and in none of the 30 volunteers, averaging 2.7 per slide among workers who had them. The 10 workers with asbestos bodies and the 19 without (one lacked data) had similar age, smoking and exposure histories. Workers with asbestos bodies more often reported respiratory symptoms (70% vs 26%). On high-resolution CT, they more often showed lung-tissue (parenchymal) disease (70% vs 26%), including fibrosis (40% vs 0%). They also had significantly lower FEV1 (77% vs 92% predicted) and carbon monoxide diffusion capacity (76% vs 104% predicted). Pleural plaques did not differ significantly (60% vs 58% on CT). The authors concluded that asbestos bodies in BAL were associated with these abnormalities. They noted their slide method is less sensitive at low levels.

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: Retrospective review of BAL cytocentrifuge slides, read blind, with comparison of clinical findings between exposed workers with and without asbestos bodies
• Who was studied: 30 asbestos-exposed workers from Consolidated Edison, an electric utility in New York City (all male, average age 55), and 30 normal volunteers (nonsmokers with normal chest radiographs and spirometry, average age 34, 25 of 30 male). Data were unavailable for one worker, leaving 29 workers: 10 with asbestos bodies and 19 without.
• Exposure: Occupational asbestos exposure, mostly as asbestos insulators, boiler makers, pipe fitters and construction workers, with some shipyard workers and mechanics. Average duration was about 21 to 23 years, onset 32 to 35 years earlier, and last exposure about 8 years earlier. Ongoing exposure was reported by 70% of workers with asbestos bodies and 53% of those without. Fiber types were not specified.
• Main results:
  • Asbestos bodies were found on BAL slides of 10 of 30 asbestos-exposed workers (33%) and 0 of 30 normal volunteers.
  • Among workers with asbestos bodies, the mean was 2.7 per slide (range 1 to 11).
  • Workers with and without asbestos bodies had comparable age, sex and smoking. Their asbestos exposure histories (duration, time since onset, time since last exposure) were not significantly different.
  • Respiratory symptoms were reported by 70% (7 of 10) of workers with asbestos bodies versus 26% (5 of 19) of those without, especially cough and sputum production. Dyspnea was reported equally in both groups.
  • Parenchymal disease on high-resolution CT was seen in 70% of workers with asbestos bodies versus 26% of those without.
  • Pulmonary fibrosis on high-resolution CT was seen in 40% of workers with asbestos bodies versus 0% of those without (Table 4 p value 0.002).
  • Workers with asbestos bodies had lower FEV1 (77% vs 92% predicted, p less than 0.05) and diffusion capacity for carbon monoxide (76% vs 104% predicted, p less than 0.01) than workers without. FVC was 86% vs 97% predicted, and no p value was given for FVC.
  • BAL fluid of workers with asbestos bodies showed a significant increase in neutrophils (3.5 vs 2.2, p 0.029) and eosinophils (1.1 vs 0.3, p 0.018), which the authors interpreted as more alveolitis.
  • Pleural plaques and diffuse pleural thickening did not differ significantly between the groups. On high-resolution CT, pleural plaques were seen in 6 of 10 workers with asbestos bodies (60%) and 11 of 19 without (58%), p 0.92.
• The authors' conclusion: The authors concluded that, in people with a history of asbestos exposure, asbestos bodies in BAL cells are associated with a higher prevalence of parenchymal abnormalities, respiratory symptoms and reduced pulmonary function. They wrote that their findings support the clinical utility of asbestos bodies on BAL cytospin slides as an indicator of asbestos-related lung disease in a high-risk population.
• Limitations the authors state:
  • The cytocentrifuge slide method used here has lower sensitivity at low asbestos body concentrations than the recommended membrane filter technique, because a slide contains far fewer cells.
  • Most subjects had a smoking history, and the high percentage of smokers might contribute to the numbers with COPD.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Bodies, BAL Fluid, Asbestos Exposure, High-Resolution CT (HRCT).

Related studies

• The clinical utility and reliability of asbestos bodies in bronchoalveolar fluid — D.A. Schwartz, J.R. Galvin, et al. (1991)
• Asbestos bodies in bronchoalveolar lavage fluid in relation to occupational history — A. Karjalainen, S. Anttila, et al. (1994)
• 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)
• Diagnostic value of asbestos bodies in bronchoalveolar lavage fluid — P. De Vuyst, P. Dumortier, et al. (1987)
• Asbestos bodies in bronchoalveolar lavage fluids of brake lining and asbestos cement workers — P. Dumortier, P. De Vuyst, et al. (1990)
• Erionite bodies and fibres in bronchoalveolar lavage fluid (BALF) of residents from Tuzköy, Cappadocia, Turkey — P. Dumortier, L. Coplü, et al. (2001)

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