Immunological monitoring in workers occupationally exposed to asbestos

Our plain-English summary of Immunological monitoring in workers occupationally exposed to asbestos, by S. Ilavská, E. Jahnová, J. Tulinská, et al (Toxicology, 2005).

The study

• Authors: S. Ilavská, E. Jahnová, J. Tulinská, M. Horváthová, M. Dusinská, L. Wsolová, S.A. Kyrtopoulos, L. Fuortes
• Journal: Toxicology
• Published: 2005;206(2):299-308
• Cited by: 22 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Occupational exposure to asbestos is strongly associated with pulmonary diseases, cancer and immunotoxic effects. Both systemic and local immunity may play an important role in the pathogenesis of these events. Immune cells appear to be influenced by asbestos exposure, either through direct effects or as a result of the host's protective response to exposure. In this study several immune system parameters were assessed in workers (n = 61) with at least 5 years' exposure to asbestos at an industrial plant. Workers exposed to asbestos fibres had significantly increased levels of immunoglobulin E and concentrations of interleukin-6 and -8 in comparison with two sets of controls (in-plant and town control groups). The levels of soluble adhesion molecule ICAM-1 were higher in the exposed group compared to the town control group. Significantly increased levels of IgA were found in asbestos-exposed group in comparison to the town control. Evaluation of the expression of adhesion molecules on lymphocytes, monocytes and granulocytes by flow cytometry showed significant increases in the class of selectins CD62L on monocytes and granulocytes. Moreover, significantly increased expression of markers CD69 and CD66b on eosinophils was found among workers exposed to asbestos. In conclusion, exposure to asbestos fibres was found to have several effects on immune system. Alterations of these immune parameters may indicate hypersensitivity (increased levels of IgE, increased expression of activation markers CD66b and CD69 on eosinophils) and an elevated inflammatory status (increased levels of interleukins--IL-6, IL-8) in exposed workers.

In plain English

This study compared blood immune markers in 61 workers at an asbestos cement plant with 48 unexposed people from the town and 21 unexposed workers from the same factory. The workers, exposed to chrysotile with added crocidolite, had been employed at the factory for 5 to 39 years (mean 23.9). The factory had stopped using asbestos 9 months before the study. On X-rays, 32 exposed workers showed at least one of pulmonary fibrosis or pleural fibrosis, and 29 showed no changes. Compared with both control groups, exposed workers had higher average levels of immunoglobulin E and of the inflammatory signals interleukin-6 and interleukin-8. Interleukin-8 was also higher in exposed workers with normal X-rays. IgA and soluble ICAM-1 were higher than in town controls. Exposed workers also showed more CD62L on monocytes and granulocytes, and more of the activation markers CD69 and CD66b on eosinophils. Interleukin-1, two other soluble adhesion molecules and lymphocyte subsets showed no significant differences. The authors concluded that asbestos exposure had several effects on the immune system. In their view, the changes suggest the injury mechanism in asbestosis shares features with hypersensitivity.

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 immune markers in asbestos-exposed workers versus two unexposed control groups (town controls and in-factory controls)
• Who was studied: 61 workers at an asbestos cement plant (16 women, 45 men), employed at the factory 5 to 39 years (mean 23.9 years); 48 unexposed town controls (30 women, 18 men) and 21 unexposed in-factory controls (10 women, 11 men). Plant air sampling was done in 2001.
• Exposure: Occupational exposure to chrysotile with added crocidolite in an asbestos cement plant. Asbestos use had stopped 9 months before the study, and current concentrations were below the Slovak occupational limit. Plant records show fibre concentrations of 2 to 11 fibres/cm3 in 1978 to 1990, falling to 0.2 to 1 fibres/cm3 in 1994 to 1998.
• Main results:
  • Historical plant measurements: asbestos fibre concentrations ranged from 2 to 11 fibres/cm3 during 1978 to 1990.
  • Among the 61 exposed workers, 32 had X-ray evidence of pulmonary fibrosis, pleural fibrosis or both, and 29 had no pathological changes.
  • IgA was higher in exposed workers (mean 2.5 g/L, S.D. 1.1, p less than 0.01) than in town controls (1.96 g/L, S.D. 0.7).
  • Total IgE was higher in exposed workers (mean 549, S.D. 1202, p less than 0.01) than in town controls (mean 247.6, S.D. 335) and in-factory controls (mean 236.2, S.D. 306). The unit is printed as g/L.
  • Soluble ICAM-1 was higher in exposed workers (mean 322.4 ng/ml, S.D. 78) than in town controls (mean 271.7 ng/ml, S.D. 70.6), p less than 0.01. Factory controls averaged 305.3 ng/mL.
  • Soluble VCAM-1 and E-selectin showed no significant differences between groups.
  • Interleukin-6 was higher in exposed workers (3.62 ng/mL, S.D. 1.8) than in town controls (2.86 ng/mL, S.D. 1.1) and factory controls (2.7 ng/mL, S.D. 0.6); p less than 0.01 for both comparisons.
  • Interleukin-8 was higher in exposed workers (19.2 ng/mL, S.D. 4.3) than in town controls (14.8 ng/mL, S.D. 8.9) and factory controls (13.4 ng/mL, S.D. 2.7); p less than 0.001.
  • Interleukin-8 was significantly higher in exposed workers with asbestosis and also in exposed workers with normal X-rays, compared with both control groups.
  • Interleukin-1 showed no significant differences compared with controls.
  • T-lymphocyte, B-lymphocyte, natural killer cell and activated T-cell percentages were in the normal range, with no significant differences from controls.
  • CD62L (L-selectin) on monocytes was higher in exposed workers (31.3%, S.D. 18.6) than in town controls (21.2%) and factory controls (18.6%), p less than 0.001.
  • CD62L on granulocytes was higher in exposed workers (41%, S.D. 22.8) than in town controls (27%) and factory controls (25%), p less than 0.001.
  • On eosinophils, CD69 was higher in exposed workers (1.39%) than in town controls (1.1%) and factory controls (0.8%), p less than 0.001. CD66b was also higher in exposed workers (2%) than in town controls (1.27%) and factory controls (1.28%), p less than 0.001.
  • No significant differences were found between smokers and non-smokers in any of the measured parameters.
• The authors' conclusion: The authors concluded that asbestos exposure had several effects on the immune system. In their view, the changes indicate that the injury mechanism in asbestosis shares features with the hypersensitivity process.
• Limitations the authors state:
  • The authors suggested that finding no smoking effect was probably due to the low number of smokers, and possibly to differing genetic predispositions.

Topics

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

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Asbestos Exposure, Interleukins.

Related studies

• Immunomodulatory effects of mineral fibres in occupationally exposed workers — J. Tulinska, E. Jahnova, et al. (2004)
• An epidemiological survey of immunological abnormalities in asbestos workers. I. Nonorgan and organ-specific autoantibodies — A. Lange (1980)
• An epidemiological survey of immunological abnormalities in asbestos workers. II. Serum immunoglobulin levels — A. Lange (1980)
• Sequential immunological studies on an asbestos-exposed population. I. Factors affecting peripheral blood leucocytes and T lymphocytes — M.M. Wagner, M.J. Campbell, et al. (1979)
• Lung cancer risk in male workers occupationally exposed to diesel motor emissions in Germany — I. Brüske-Hohlfeld, M. Möhner, et al. (1999)
• Increased incidence of DNA double-strand breaks and anti-ds DNA antibodies in blood of workers occupationally exposed to asbestos — B. Marczynski, A.B. Czuppon, et al. (1994)

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