Molecular basis for differences in susceptibility to coal workers' pneumoconiosis

Our plain-English summary of Molecular basis for differences in susceptibility to coal workers' pneumoconiosis, by P.J. Borm, R. Schins, Y.M. Janssen, et al (Toxicology Letters, 1992).

The study

• Authors: P.J. Borm, R. Schins, Y.M. Janssen, L. Lenaerts
• Journal: Toxicology Letters
• Published: 1992;64-65 Spec No:767-72
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

It is generally accepted that there are differences among workers in susceptibility towards the effects of mineral dusts such as silica, coal dust and asbestos. Basic research continues to find new factors involved in the process of pulmonary fibrosis caused by these minerals. In this paper, two hypotheses implicitly generated by recent findings were tested in two case-control studies among coal miners: generation of tumour necrosis factor (TNF) by blood monocytes of miners with coal workers' pneumoconiosis (CWP) and serum type III procollagen peptide (PIIIP) in CWP. Our data indicate that both parameters can be used as biological markers for early diagnosis of CWP. A follow-up study is described in which the predictive power of increased TNF release and serum PIIIP as risk factor to develop lung fibrosis will be assessed.

In plain English

This short paper concerned coal mine dust, not asbestos. The authors summarized two 1987 case-control studies among underground workers of Belgian coal mines and described a planned five-year follow-up. Blood was taken from 139 miners, all heavily exposed to coal dust for at least 12 years, and 31 unexposed blood donors. Cases were miners with coal workers' pneumoconiosis (CWP) on chest X-ray; the methods describe one case matched to two controls, but the two studies reported 27 cases each, with 39 and 46 controls. Blood cells from control miners released more tumour necrosis factor (TNF), an inflammatory signal, than cells from unexposed donors. Dust-induced TNF release tended to fall as the disease advanced. A collagen-related blood marker, type III procollagen peptide (PIIIP), was significantly raised in about 37% of miners without X-ray signs of CWP. It was not significantly different from unexposed donors in miners with CWP beyond ILO category 1/0. The authors concluded that both measures could serve as markers for early diagnosis of CWP. They planned repeat X-rays to test whether high values predict later disease.

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: Summary of two previously reported case-control studies (baseline, 1987), described as matched triplets of one case and two controls, plus a description of a planned five-year follow-up study
• Who was studied: 139 underground coal miners from Belgian coal mines (Kempische Steenkolenmijnen): TNF study 27 cases and 39 controls; PIIIP study 27 cases and 46 controls. Also 31 non-dust-exposed controls randomly selected from healthy blood donors at a university hospital blood bank. The methods state that triplets were matched on age, starting year of employment, duration of exposure, smoking and medication.
• Exposure: Coal mine dust. All miners had been heavily exposed for at least 12 years and were still working in mining. CWP was diagnosed and staged from chest radiographs using ILO criteria.
• Main results:
  • Blood monocytes from dust-exposed control miners released more TNF than monocytes from non-dust-exposed controls.
  • Among miners, TNF release in response to coal mine dust showed a trend of decreasing as CWP progressed. The authors suggested this probably reflects a feedback mechanism. The trend was absent or not statistically significant for spontaneous TNF release, or for release induced by other stimulants or concentrations.
  • TNF release induced by coal mine dust or by endotoxin (3 ng/ml) was highest in cases with a small number of opacities (ILO 0/1).
  • Control miners could be tentatively divided into low and high TNF secretors in response to coal mine dust. High secretors made up 56% of the control miners.
  • Serum PIIIP was significantly elevated, compared with non-dust-exposed controls, in about 37% of miners without radiological signs of CWP.
  • In miners with CWP beyond ILO classification 1/0, PIIIP levels were not significantly different from those of non-dust-exposed controls. Trend analysis within the miners showed PIIIP decreasing as fibrosis progressed.
• The authors' conclusion: The authors concluded that both TNF release and serum PIIIP can be used as biological markers for early diagnosis of CWP. They suggested that, in early lung fibrosis, measuring serum PIIIP may be more sensitive than radiological diagnosis.
• Limitations the authors state:
  • The authors stated that the idea that miners with high TNF or PIIIP values are at higher risk was a hypothesis that needed proof from a follow-up study.
  • The authors stated only that the biochemical assays were 'preferably' done without knowledge of disease status, not that this was done in every case.

Topics

Medical terms in this study, explained in our Lexicon: Pneumoconiosis, Pulmonary Fibrosis, Necrosis, Fibrosis.

Related studies

• Investigative techniques in the laboratory study of coal workers' pneumoconiosis: recent advances at the cellular level — J.S. Harington (1972)
• Ventilatory function after exposure to various respirable hazards in a population of former coal miners — G.M. Calvert, M. Moore, et al. (1991)
• A battle for compensation for Welsh coal miners: JS Haldane v "Sericite" Jones, 1932-1934 — M. Greenberg (1997)
• Respiratory symptoms and functional status in workers exposed to silica, asbestos, and coal mine dusts — X.R. Wang, D.C. Christiani (2000)
• Respiratory impairments due to dust exposure: a comparative study among workers exposed to silica, asbestos, and coalmine dust — X. Wang, E. Yano, et al. (1997)
• Some observations of the dust content and composition in lungs with asbestosis, made during work on coal miners pneumoconiosis — G. Nagelschmidt (1965)

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