Immunological studies of patients with asbestosis. I. Studies of cell-mediated immunity

Our plain-English summary of Immunological studies of patients with asbestosis. I. Studies of cell-mediated immunity, by E. Kagan, A. Solomon, J.C. Cochrane, et al (Clinical and Experimental Immunology, 1977).

The study

• Authors: E. Kagan, A. Solomon, J.C. Cochrane, E.I. Beissner, J. Gluckman, P.H. Rocks, I. Webster
• Journal: Clinical and Experimental Immunology
• Published: 1977;28(2):261-7
• Cited by: 97 articles, as counted by NIH iCite
• Read it: PubMed · Free full text

Abstract

A variety of cancers have been documented in patients exposed to asbestos dust. Since a deranged immune system may play a rôle in cancer development, the general level of immunocompetence was studied in a group of twenty-six patients with radiographically defined asbestosis, who might be at risk of developing asbestos-related neoplasms. Statistical comparisons were made with a comparable control group. A disproportionate number of the patients displayed cutaneous energy to certain recall antigens and to 2,4-dinitrochlorobenzene. In vitro studies of cellular immunity, as evaluated by phytohaemagglutinin-induced proliferative and cytotoxicity assays, showed significantly lower values amongst the patient group. Serum inhibitors of mitogen-induced lymphocyte transformation were also detected in several of the patients. The possible significance of these findings is discussed.

In plain English

This study, from South Africa's National Research Institute for Occupational Diseases in Johannesburg, compared immune function in 26 men whose chest X-rays showed asbestosis with men who had no history of asbestos exposure: 30 had skin tests and 45 had blood tests. Most patients had worked in the asbestos cement industry, with mixed exposure to chrysotile, Cape crocidolite and amosite. On skin tests, reactions to tuberculin did not differ significantly between the groups. Five of 26 patients and no controls failed to react to Candida extract. Fourteen of 26 patients and 6 of 30 controls failed to react to streptokinase-streptodornase. Seventeen of 26 patients failed to react to the chemical DNCB, while all controls reacted strongly. In blood tests, patients' lymphocytes showed significantly lower responses to the stimulant PHA and significantly lower cell-killing activity. Serum inhibitors were found in 5 of 26 patients and 1 of 45 controls, a difference that was not statistically significant. The authors suggested a possible T-cell defect, said the findings may be relevant to cancer development, and said immunological tests may prove useful for screening selected populations at risk of developing cancer in certain situations.

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: comparison of patients with asbestosis and unexposed control subjects, using skin tests and laboratory blood tests of cell-mediated immunity
• Who was studied: 26 male patients with asbestosis seen on X-rays, referred to the Department of Occupational Medicine of the National Research Institute for Occupational Diseases, Johannesburg, South Africa. They were aged 36 to 75 years (mean 49.8 years), with 9 to 39 years of asbestos exposure (mean 21.9 years). Controls were professional, scientific, clerical and maintenance workers of the institute and neighbouring institutions with no asbestos exposure history: 30 men had skin tests (aged 29 to 65) and 45 men gave blood for laboratory tests (aged 28 to 68).
• Exposure: Most patients worked in the asbestos cement industry, with mixed exposure to chrysotile, Cape crocidolite and amosite. One was a welder who worked with asbestos lagging and one was a carpenter who cut asbestos sheeting. Two had mined asbestos: one Cape crocidolite, and one chrysotile and Cape crocidolite.
• Main results:
  • Tuberculin (PPD) skin test: no significant difference between patients and controls; one subject in each group did not react.
  • Candida albicans skin test: 5 of 26 patients did not react, while all 30 controls reacted (P less than 0.05).
  • Streptokinase-streptodornase skin test: no reaction in 14 of 26 patients versus 6 of 30 controls (P less than 0.05).
  • DNCB skin test: 17 of 26 patients did not react and 2 more reacted only weakly, while all controls reacted strongly (P less than 0.01).
  • PHA-stimulated lymphocyte proliferation: stimulation indices were significantly lower in patients than controls, both in the patients' own serum (P less than 0.001) and in allogeneic AB serum (P less than 0.001).
  • Serum inhibitors of PHA-induced lymphocyte transformation were found in 5 of 26 patients and 1 of 45 controls; the difference was not statistically significant.
  • PHA-induced cell-mediated cytotoxicity was significantly lower in the patient group than in the control group (P less than 0.01).
• The authors' conclusion: The authors suggested that a qualitative T-cell defect may be present in patients with asbestosis and that multiple factors may be involved. They said the findings may have relevance to later cancer development and that immunological procedures may prove useful for screening selected populations at risk of developing cancer in certain situations.
• Limitations the authors state:
  • The authors did not attempt to relate the extent of X-ray changes to the immune test results, because most patients had advanced changes and only four had slight changes.
  • Macrophage function was not specifically investigated.

Topics

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

Medical terms in this study, explained in our Lexicon: Neoplasm.

Related studies

• Assessment of cell-mediated immunity to malignant mesothelioma by microcytotoxicity tests — M.J. Embleton, J.C. Wagner, et al. (1976)
• Analysis of depressed cell-mediated immunity in asbestos workers — R.D. deShazo, J. Nordberg, et al. (1983)
• Identification of environmental carcinogens utilizing T-cell mediated immunity — R.H. Stevens, D.A. Cole, et al. (1986)
• Identification of carcinogens by measurement of cell-mediated immunity. III. Immunity to asbestos-induced rat peritoneal mesothelioma — D.A. Cole, R.H. Stevens, et al. (1982)
• Diminished suppressor cell function in patients with asbestosis — H.R. Gaumer, N.J. Doll, et al. (1981)
• The Effects of Asbestos Fibers on Human T Cells — N. Kumagai-Takei, S. Lee, et al. (2020)

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