Cytopathology of asbestos-associated pulmonary disease

Our plain-English summary of Cytopathology of asbestos-associated pulmonary disease, by S.D. Greenberg (Diagnostic Cytopathology, 1985).

The study

• Author: S.D. Greenberg
• Journal: Diagnostic Cytopathology
• Published: 1985;1(3):177-82
• Cited by: 2 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. 000474).

Abstract

The goal of this investigation was to determine the practical role of cytopathology in the clinical and laboratory diagnosis of asbestos-related pulmonary diseases. For this purpose, sputum, bronchial washings, lung tissues, and pleural fluids were obtained from asbestos workers and controls. The asbestos-associated pulmonary diseases studied were: (1) asbestosis, (2) carcinoma, and (3) mesothelioma. The cytology smears were prepared with both Papanicolaou and iron stains. Lung tissues were digested by the Chlorox (5.25% sodium hypochlorite solution) technique for quantitation of asbestos bodies. Asbestos bodies within the sputum were found to be highly specific markers for past asbestos exposure, indicating a heavy residual pulmonary asbestos load (greater than 900 asbestos bodies/g wet lung weight). Asbestos bodies in sputum were also found to have a highly significant relationship (P less than 0.001) with the degree of accompanying atypia of bronchial epithelial cells. Bronchial washings appeared to be more sensitive than sputum for the detection of asbestos bodies. Asbestos bodies were not found within the pleural fluids of malignant mesotheliomas. It is concluded that sputum cytology screening represents a practical, noninvasive, and inexpensive approach to the diagnosis and study of asbestos exposure.

In plain English

This article was the author's critical review of the author's own earlier and ongoing studies. They asked whether cytology (examining cells in sputum, bronchial washings and pleural fluid) can detect asbestos exposure and asbestos-related lung disease. The studies included a cohort of 890 former amosite asbestos workers in Tyler, Texas (1974 to 1979), reviews of hospital sputum specimens in Houston, and lung tissue digests that counted asbestos bodies. Among 11,000 Harris County hospital and clinic patients, asbestos bodies were found in the sputum of 5 patients, each of whom had occupational asbestos exposure. Asbestos bodies in sputum corresponded to lung digests with 900 or more asbestos bodies per gram of wet lung. Twelve Methodist Hospital cases had both kinds of specimen: 6 had asbestos bodies in sputum and all 12 had them in bronchial washings. Sputum with asbestos bodies was likely to contain atypical cells (p less than 0.001). No asbestos bodies were reported in pleural fluids from mesothelioma cases. The author concluded that asbestos bodies in sputum are highly specific markers of past exposure, but do not necessarily imply asbestosis.

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: Review by the author of the author's own previous and ongoing studies: a worker cohort with repeated sputum cytology, retrospective reviews of hospital sputum and bronchial washing specimens, and lung tissue digests with asbestos body counts
• Who was studied: 890 former amosite asbestos workers in the Tyler Asbestos Workers Program, Tyler, Texas, 1974 to 1979 (13,000 sputum specimens). Also reviewed: 27,000 sputum specimens from 11,000 Harris County Hospital District patients; six cohorts of asbestos workers (30 to 80 each) at Baylor College of Medicine, 1979 to 1981; 13,600 sputum specimens and 5,700 bronchial washings at Methodist Hospital, Houston, 1973 to 1984; lung digests from 6 former asbestos workers and 19 pleural mesothelioma cases, with 50 consecutive adult autopsy lungs as controls
• Exposure: Occupational asbestos exposure. In the Tyler cohort this was amosite used for pipe insulation, at work levels the author describes as over 100 fibers/cc
• Main results:
  • Tyler cohort: significant correlations were found between the number of asbestos bodies in sputum, irregular small opacities on chest x-rays, and restrictive defects on pulmonary function tests
  • Tyler cohort: sputum specimens from 15% of the men showed no asbestos bodies
  • Lung digests: about 1000 asbestos bodies per gram in mild asbestosis, and more than 10,000 per gram in severe asbestosis
  • Asbestos bodies in sputum corresponded to lung digests of 900 or more asbestos bodies per gram wet weight. A significant correlation (p less than 0.02) was reported between lung asbestos body content and sputum specimens positive for asbestos bodies
  • Lung digests averaged 460 asbestos bodies per gram wet weight in the lung carcinoma cases and 440 in the malignant mesothelioma cases
  • Controls (50 consecutive adult autopsies): 92% of wet lung digests showed a mean of 2 asbestos bodies per gram. Counts above 100 per gram were treated as evidence of occupational exposure
  • Counts in the malignant mesothelioma cases varied: 3 cases had more than 20,000 per gram wet weight. The figure for the other 16 cases is cut off in the text
  • Harris County patients: asbestos bodies were found in the sputum of 5 of 11,000 patients, and each had occupational asbestos exposure
  • Baylor study: 80 workers (24% of the cohort) had asbestos bodies in sputum, ranging from 1 to 14 per specimen, with a mean of 4
  • Methodist Hospital: of 12 cases with both specimen types, 6 had asbestos bodies in sputum and all 12 had them in bronchial washings
  • In heavily exposed amosite workers, sputum specimens with asbestos bodies were likely to contain atypical bronchial epithelial cells (p less than 0.001)
  • No asbestos bodies were found in pleural fluid from 19 pleural mesothelioma cases or from 10 additional consultation cases (29 malignant mesothelioma cases in all)
• The authors' conclusion: The author concluded that asbestos bodies in sputum are highly specific markers of past asbestos exposure, reflecting a significant asbestos load in the lungs. Sputum with asbestos bodies is also likely to contain atypical bronchial cells, and sputum cytology screening is a practical, noninvasive and inexpensive approach to studying asbestos exposure
• Limitations the authors state:
  • The greater sensitivity of bronchial washings comes from preliminary studies, and its clinical significance depends on future investigations
  • Sputum cytology for detecting exposure is best applied to the commercial amphiboles (amosite and crocidolite). Chrysotile forms asbestos bodies less readily
  • Finding asbestos bodies in sputum does not necessarily mean the person has asbestosis

Topics

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

Medical terms in this study, explained in our Lexicon: Cytopathology, Sputum, Carcinoma, Mesothelioma, Cytology, Iron Stain (Prussian Blue), Asbestos Bodies, Asbestos Exposure.

Related studies

• Recent advances in pulmonary cytopathology — S.D. Greenberg (1983)
• Pulmonary cytopathology of former asbestos workers. Report of the first year — S.D. Greenberg, G.A. Hurst, et al. (1976)
• An update on pleuro-pulmonary cytopathology: Part i: Cytological diagnosis of mesothelioma and molecular cytology of lung cancer with an historical perspective — C.W. Bedrossian (2015)
• Crackles (rales) in the interstitial pulmonary diseases — G.R. Epler, C.B. Carrington, et al. (1978)
• Relative release of interleukin-1 beta and interleukin-1 receptor antagonist by alveolar macrophages. A study in asbestos-induced lung disease, sarcoidosis, and idiopathic pulmonary fibrosis — J.N. Kline, D.A. Schwartz, et al. (1993)
• Environmental fiber-induced pleuro-pulmonary diseases in an Anatolian village: an epidemiologic study — M. Artvinli, Y.I. Baris (1982)

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