Asbestos exposure correlates with alterations in circulating T cell subsets

Our plain-English summary of Asbestos exposure correlates with alterations in circulating T cell subsets, by L.G. Miller, D. Sparrow, L.C. Ginns (Clinical and Experimental Immunology, 1983).

The study

• Authors: L.G. Miller, D. Sparrow, L.C. Ginns
• Journal: Clinical and Experimental Immunology
• Published: 1983;51(1):110-6
• Cited by: 31 articles, as counted by NIH iCite
• Read it: PubMed · Free full text

Abstract

Peripheral blood lymphocytes were analysed from 40 subjects with occupational asbestos exposure and 40 controls matched for age and smoking habits. Patients were classified by duration of exposure as short or long, and by chest radiograph as normal, pleural plaques or interstitial changes. As a group, subjects with asbestos exposure had decreased percentages of OKT3+ and OKT8+ cells and increased OKT4+/OKT8+ ratio compared to controls. Correcting for age and smoking, those with short exposure were similar to controls, while those with long exposure had decreased percentages OKT3+ and OKT8+ cells and an increased OKT4+/OKT8+ ratio. Among radiographic subgroups, those with normal radiographs were similar to controls, but those with plaques had increased circulating OKT4+ cells, and those with interstitial changes had decreased percentages OKT3+ and OKT8+ cells and OKT8+ cells/mm3, with an increased OKT4+/OKT8+ ratio. There were no differences between subjects and controls in OKT10+ cells and OKIa+ cells. There appears to be a progressive decrease in percentage OKT8+ cells and increase in OKT4+/OKT8+ ratio with increasing exposure to asbestos, as determined by length of exposure and by radiographic abnormalities.

In plain English

This study compared blood immune cells in 40 men who had worked as pipefitters, boilermakers or insulation workers, jobs associated with asbestos inhalation, with 40 men without known asbestos exposure. The two groups were matched for age, sex and smoking. All were evaluated at Massachusetts General Hospital. The article did not name a fiber type. The authors counted subsets of T cells, a kind of white blood cell. As a group, the exposed men had lower percentages of OKT3+ and OKT8+ cells and a higher OKT4+ to OKT8+ ratio than controls. Men exposed for less than 5 years tended to have lower OKT3+ and OKT8+ percentages. These trends reached statistical significance in men exposed for more than 5 years. Men with normal chest X-rays resembled controls. Those with pleural plaques had more OKT4+ cells per cubic millimetre of blood. Those with interstitial lung changes had lower OKT3+ and OKT8+ percentages and a lower total count of OKT8+ cells. Adjusting for age and smoking did not change these results. The authors concluded that the balance of T cell subsets appeared altered in relation to the amount of asbestos exposure.

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 asbestos-exposed workers with matched unexposed controls (blood T cell subsets measured with monoclonal antibodies and flow cytometry)
• Who was studied: 80 men evaluated at Massachusetts General Hospital, Boston: 40 with occupational asbestos exposure and 40 controls matched for age, sex, current smoking and total smoking history. Of the exposed men, 12 had short and 28 had long exposure. By chest X-ray, 8 were normal, 19 had pleural plaques and 13 had interstitial changes. Study dates are not given.
• Exposure: Work as pipefitters, boilermakers or insulation workers. Duration was classified as short (less than 5 years) or long (greater than 5 years). Eight subjects had not worked with asbestos for 30-40 years; the others continued in jobs requiring exposure. No fiber type was specified.
• Main results:
  • As a group, the 40 asbestos-exposed subjects had decreased percentages of OKT3+ and OKT8+ cells compared with controls.
  • As a group, asbestos-exposed subjects had a high ratio of OKT4+ to OKT8+ cells (4/8 ratio).
  • Subjects with short exposure tended to have decreased percentages of OKT3+ and OKT8+ cells. These trends reached significance in subjects with long exposure.
  • Subjects with normal chest radiographs were similar to controls. Those with pleural plaques had increased OKT4+ cells per cubic millimetre.
  • Subjects with interstitial changes had decreased percentages of OKT3+ and OKT8+ cells and decreased total OKT8+ cells per cubic millimetre. Correction for age and smoking did not affect these results.
  • The 4/8 ratio tended to increase progressively from subjects with normal radiographs to those with plaques to those with interstitial changes.
  • There were no differences between subjects exposed to asbestos long ago and those with ongoing exposure.
  • In 28 exposed subjects and 28 controls tested with the OKT11A antibody, the percentage of OKT11A+ cells was decreased in asbestos subjects (printed as 56 2 vs 63 1, read as 56.2 vs 63.1 percent).
  • In 16 exposed subjects and 16 controls, there were no differences in percentages of OKIa+ or OKT10+ cells.
  • Subjects with interstitial changes had a decreased percentage of lymphocytes and a decreased total lymphocyte count compared with those with normal radiographs.
• The authors' conclusion: The authors concluded that their findings support the idea that the balance of T cell subsets is altered in relation to the amount of asbestos exposure. They suggested that a threshold exposure appears necessary for immune alterations, since subjects with short exposure had normal T cell profiles.
• Limitations the authors state:
  • The study examined only circulating blood T cells. The authors state that studies of lung cells are also needed to assess local lung immunity.
  • The authors state that further studies of lymphocyte function are needed to clarify effects on cell-mediated immunity.

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Habit, Chest X-Ray, Pleural Plaques, Interstitial.

Related studies

• Lymphocyte subsets in subjects exposed to asbestos: changes in circulating natural killer cells — N. al Jarad, M. Macey, et al. (1992)
• Inflammatory Alteration of Human T Cells Exposed Continuously to Asbestos — N. Kumagai-Takei, S. Yamamoto, et al. (2018)
• Lymphocyte subsets in subjects exposed to asbestos: changes in circulating natural killer cells — P.J. Borm, P.F. Schins (1993)
• Malignant Mesothelioma Effusions Are Infiltrated by CD3+ T Cells Highly Expressing PD-L1 and the PD-L1+ Tumor Cells within These Effusions Are Susceptible to ADCC by the Anti-PD-L1 Antibody Avelumab — S. Khanna, A. Thomas, et al. (2016)
• 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)
• Immune response in shipyard workers with x ray abnormalities consistent with asbestos exposure — H. Anton-Culver, B.D. Culver, et al. (1988)

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