Lymphocyte subpopulations in bronchoalveolar lavage fluid in asbestos workers

Our plain-English summary of Lymphocyte subpopulations in bronchoalveolar lavage fluid in asbestos workers, by A.R. Gellert, M.G. Macey, S. Uthayakumar, et al (The American Review of Respiratory Disease, 1985).

The study

• Authors: A.R. Gellert, M.G. Macey, S. Uthayakumar, A.C. Newland, R.M. Rudd
• Journal: The American Review of Respiratory Disease
• Published: 1985;132(4):824-8
• Cited by: 29 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We examined peripheral blood and bronchoalveolar lavage (BAL) fluid lymphocyte subpopulations in 29 asbestos workers, 10 with and 19 without clinical or radiologic evidence of asbestosis. Peripheral blood lymphocyte subpopulations were also measured in 13 control subjects. The mean OKT4:OKT8 (T-helper/inducer:T-suppressor/cytotoxic lymphocyte) ratio in BAL fluid in the 29 asbestos workers was 0.96 (range, not detected to 3.33), significantly less than 1.76 (1.33 to 2.67) in peripheral blood (p less than 0.001). There were no significant differences in OKT4:OKT8 ratios in peripheral blood between the 10 patients with asbestosis, the 19 asbestos workers without asbestosis, and the 13 normal control subjects or in the OKT4:OKT8 ratios in BAL fluid between patients with asbestosis and asbestos workers without asbestosis. In the group as a whole, 83% of those who had suffered more than 5 yr of exposure to asbestos showed OKT4:OKT8 ratios less than 1.2, whereas in those who had suffered fewer than 5 yr of exposure, 80% showed ratios greater than 1.2 (p less than 0.02). No other relationships between OKT4:OKT8 ratios and clinical, radiographic, or physiologic variables were observed.

In plain English

This study examined lymphocytes (a type of white blood cell) in lung-wash fluid (bronchoalveolar lavage) and in blood from 29 male asbestos workers who had heavy, unprotected exposure, mostly in the lagging industry. Ten had clinical and radiologic evidence of asbestosis; 19 had neither clinical nor radiologic evidence of it. Blood was also tested in 13 healthy hospital laboratory staff. The authors measured the OKT4:OKT8 ratio, which compares helper/inducer T cells with suppressor/cytotoxic T cells. In all 29 workers, the mean ratio was 0.96 in lung fluid, significantly lower than 1.76 in their blood (p less than 0.001). Blood ratios did not differ significantly between the two worker groups and the controls. Lung-fluid ratios did not differ significantly between the two worker groups. Among workers exposed more than 5 years, 83% had ratios below 1.2. Among those exposed under 5 years, 80% had ratios above 1.2 (p less than 0.02). The authors lacked their own lung-fluid data from healthy people. They concluded that asbestos workers often show depressed lung-fluid ratios compared with their own blood and with published data on normal subjects.

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 clinical study comparing lymphocyte subpopulations in bronchoalveolar lavage fluid and peripheral blood of asbestos workers with and without asbestosis, plus blood from normal controls
• Who was studied: 29 male asbestos workers seen at an asbestos screening clinic (authors based at the London Chest Hospital and The London Hospital, England). 10 had clinical and radiologic evidence of asbestosis (mean age 53, range 32 to 68). 19 were asymptomatic, had no clinical or radiologic evidence of asbestosis, and were all current nonsmokers (mean age 49, range 36 to 68). Blood controls were 13 normal, nonsmoking hospital laboratory staff (6 men and 7 women, mean age 28). Lavage light-microscopy counts were compared with 20 patients without asbestos exposure. Study dates are not given.
• Exposure: Heavy, unprotected occupational asbestos exposure, probably involving both amphibole and serpentine fibers, most commonly in the lagging industry. Mean exposure duration was 18 yr (range 1 to 36) in the asbestosis group and 13 yr (range 3 to 30) in the group without evidence of asbestosis.
• Main results:
  • In all 29 asbestos workers, the mean OKT4:OKT8 ratio in peripheral blood was 1.76 (range 1.33 to 2.67). This was significantly greater than the 0.96 (range 0 to 3.33) in BAL fluid (p less than 0.001).
  • In the 10 patients with asbestosis, the mean blood OKT4:OKT8 ratio was 1.67 (range 1.45 to 1.96). This was not significantly different from 1.80 (range 1.33 to 2.67) in the 19 workers without evidence of asbestosis, or from 1.72 (range 1.12 to 2.80) in the 13 normal controls. The values 1.80 and 2.80 correct the OCR readings '1.S0' and '2.S0'; Tables 2 and 4 confirm the corrections.
  • In patients with asbestosis, the mean BAL OKT4:OKT8 ratio was 0.80 (range, not detected to 3.33).
  • In asbestos workers without evidence of asbestosis, the mean BAL OKT4:OKT8 ratio was 1.00 (range, not detected to 2.0).
  • BAL lymphocyte subset percentages and BAL OKT4:OKT8 ratios did not differ significantly between patients with asbestosis and workers without asbestosis.
  • In the group as a whole, 83% of those with more than 5 yr of exposure had OKT4:OKT8 ratios less than 1.2. Of those with fewer than 5 yr of exposure, 80% had ratios greater than 1.2 (p less than 0.02). The article does not give group sizes for this comparison.
  • BAL ratios were repeated in a random sample of 16 subjects. The mean differences from the first examination were not significant.
• The authors' conclusion: The authors concluded that asbestos workers often show depressed OKT4:OKT8 ratios in BAL fluid compared with ratios in their own blood and with published data on BAL ratios in normal subjects.
• Limitations the authors state:
  • The authors had no BAL OKT4:OKT8 control data of their own from normal persons. They relied on published reports, citing ethical doubts in the UK about performing lavage in normal volunteers.
  • Ratios from subjects with few BAL lymphocytes are more susceptible to observer error.
  • Numbers were small for comparing smokers and nonsmokers.

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), BAL Fluid.

Related studies

• Bronchoalveolar lavage cell and lymphocyte phenotype profiles in healthy asbestos-exposed shipyard workers — J.M. Wallace, J.S. Oishi, et al. (1989)
• The effects of chrysotile and crocidolite asbestos on the lower respiratory tract: analysis of bronchoalveolar lavage constituents — E. Kagan, Y. Oghiso, et al. (1983)
• Biochemical components of bronchoalveolar lavage in early experimental asbestosis of the sheep: phospholipase A2 activity, prostaglandin E2 and proteins — P. Sirois, G. Drapeau, et al. (1983)
• Mineralogical analysis of bronchoalveolar lavage fluid as an aid to diagnosis of "imported" pleural asbestosis — P. De Vuyst, M. Mairesse, et al. (1983)
• Characterization of the bronchoalveolar cellular response in experimental asbestosis. Different reactions depending on the fibrogenic potential — I. Lemaire (1985)
• Asbestosis: assessment by bronchoalveolar lavage and measurement of pulmonary epithelial permeability — A.R. Gellert, J.A. Langford, et al. (1985)

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