Frequency of HLA antigen in asbestos workers with and without pulmonary fibrosis

Our plain-English summary of Frequency of HLA antigen in asbestos workers with and without pulmonary fibrosis, by C.C. Evans, H.C. Lewinsöhn, J.M. Evans (British Medical Journal, 1977).

The study

• Authors: C.C. Evans, H.C. Lewinsöhn, J.M. Evans
• Journal: British Medical Journal
• Published: 1977;1(6061):603-5
• Cited by: 34 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 004846).

Abstract

HLA antigens were determined in 37 patients with asbestosis and 37 matched controls with equivalent asbestos exposure but no pulmonary fibrosis. All had worked in the same textile factory. No significant differences in the prevalence of antigens were found between the two groups or between either group and controls who had not been exposed to asbestos. When the data were combined with findings from other pilot studies the previously suggested association between asbestosis and HLA-B27 was not confirmed. Subjects who were positive for HLA-B12 tended also to have advanced radiographic fibrosis. Asbestos workers without pulmonary fibrosis had an unexpectedly high frequency of HLA-BW5, which might indicate that this antigen protects against the development of pulmonary fibrosis.

In plain English

This study compared HLA antigens, which are inherited tissue-type markers, among workers from a single asbestos textile factory. Of 44 workers certified as having asbestosis, the authors confirmed lung fibrosis from asbestos dust in 37 using strict criteria. They compared these 37 with 37 workers who had comparable exposure but no fibrosis, 40 white-collar workers from the same factory, and 616 blood donors from Merseyside. The workers were mainly exposed to chrysotile, and small amounts of crocidolite may once have been present. HLA-B12 was found in 18 of the 37 asbestosis patients. The relative risk of asbestosis in people with HLA-B12, compared with healthy volunteers, was 2.37. After correcting for the number of antigens tested, this was not statistically significant, and the authors said further data should be obtained. HLA-BW5 was more common in workers without fibrosis. No differences were seen for HLA-B27. Combining this study with two earlier ones gave a relative risk of 1.87 for B27, which was not statistically significant. The authors concluded that BW5 might protect against fibrosis.

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 HLA antigen frequencies in exposed workers with asbestosis versus matched exposed workers without fibrosis, plus two unexposed control groups
• Who was studied: 37 asbestos textile workers with confirmed asbestosis and 37 matched exposed workers without fibrosis, all from the same factory. The 37 came from 44 workers certified by the pneumoconiosis panel, most of them retired. The study also included 40 white-collar workers from the factory and 616 blood donors from Merseyside.
• Exposure: Work in an asbestos textile factory (carding, spinning, twisting, handling, supervising), predominantly chrysotile asbestos; small quantities of crocidolite may also have been present in the past
• Main results:
  • HLA-B12 was found in 18 of the 37 workers with asbestosis (49%)
  • The relative risk of asbestosis in people with HLA-B12, compared with healthy volunteers, was 2.37. The authors stated the probability was no more than that expected by chance when P was multiplied by the number of specificities tested.
  • HLA-BW5 was more common in exposed workers without fibrosis (group 2) than in the blood donors (group 4) and the asbestosis patients (group 1)
  • No differences were seen in HLA-B27. Combining all three series (this study and two earlier ones) gave a relative risk of 1.87 for B27, with P greater than 0.05.
  • There was a definite but not statistically significant association of HLA-B12 with radiographically severe disease, and of BW5 with clear radiographs
  • No significant differences were found for any other antigens between any of the groups
• The authors' conclusion: The authors found no association between HLA-B27 and asbestosis. They suggested that the high prevalence of HLA-BW5 in exposed workers without asbestosis raises the possibility that this antigen protects against pulmonary fibrosis.
• Limitations the authors state:
  • None of the reported associations between HLA antigens and asbestosis reached significance after correcting for the number of antigens tested
  • The authors cautioned that ignoring the trend may obscure an association and said further data should be obtained
  • Family studies, which could confirm HLA findings, are unlikely to be possible in asbestos workers

Topics

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

Medical terms in this study, explained in our Lexicon: Pulmonary Fibrosis, Asbestos Exposure, Fibrosis.

Related studies

• HLA-A and B antigen frequencies in an asbestos exposed population with normal and abnormal chest radiographs — C. Darke, M.M. Wagner, et al. (1979)
• HLA-A and B antigen frequencies and mesothelioma in relation to asbestos exposure — M.M. Wagner, C. Darke, et al. (1983)
• Combined pulmonary fibrosis and emphysema alters physiology but has similar mortality to pulmonary fibrosis without emphysema — M.D. Jankowich, S. Rounds (2010)
• Failure to demonstrate tumour-associated transplantation antigens on asbestos-induced mesotheliomas in rats — D.G. Brown, J.C. Wagner, et al. (1980)
• Pulmonary fibrosis in asbestos insulation workers with lung cancer: a radiological and histopathological evaluation — H.M. Kipen, R. Lilis, et al. (1987)
• Asbestosis: interstitial pulmonary fibrosis and pleural fibrosis in a cohort of asbestos insulation workers: influence of cigarette smoking — R. Lilis, I.J. Selikoff, et al. (1986)

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