Autoimmune antibodies and asbestos exposure: Evidence from Wittenoom, Western Australia

Our plain-English summary of Autoimmune antibodies and asbestos exposure: Evidence from Wittenoom, Western Australia, by A. Reid, P. Franklin, N. de Klerk, et al (American Journal of Industrial Medicine, 2018).

The study

• Authors: A. Reid, P. Franklin, N. de Klerk, J. Creaney, F. Brims, B. Musk, J. Pfau
• Journal: American Journal of Industrial Medicine
• Published: 2018;61(7):615-620
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Studies comparing different forms of asbestos are rare, and limited by the failure to compare results with unexposed populations. We compare autoimmune responses among former workers and residents of the crocidolite mining and milling town of Wittenoom, Western Australia, with an unexposed population.

Methods: ANA testing using indirect immunofluorescence was performed on randomly selected serum samples from Wittenoom workers or residents and compared with those from participants of another unexposed cohort study.

Results: ANA scores were higher in the Wittenoom participants compared with Busselton and the odds of being ANA positive was fivefold greater among Wittenoom participants than Busselton (OR 5.5, 95%CI 2.3-13.0).

Conclusions: This study is the first to report increased ANA positivity among persons exposed exclusively to crocidolite. This finding of a high frequency of positive ANA tests among crocidolite-exposed subjects may be an indicator for an increased risk of systemic autoimmune diseases and needs further scrutiny.

© 2018 Wiley Periodicals, Inc.

In plain English

This brief report compared antinuclear antibodies (ANA) in people exposed to crocidolite (blue asbestos) at Wittenoom, Western Australia, with people from Busselton, a town the authors treated as unexposed. ANA is a blood marker that can appear before or alongside autoimmune diseases. Stored blood from 49 Wittenoom cancer prevention program participants was tested: 17 former workers, 16 residents and 16 people first exposed as children. These results were compared with existing results for 147 Busselton participants. In this preliminary analysis, 53% of Wittenoom participants were ANA negative, compared with 85% of Busselton participants. After adjusting for age, sex and smoking, Wittenoom participants had about five times the odds of a positive test (OR 5.48, 95% CI 2.32-12.97). The difference remained when former workers, who may also have breathed silica, were left out (unadjusted OR 4.42, 95% CI 1.92-10.2). The study measured antibodies, not diagnosed disease. The authors concluded that the finding may indicate an increased risk of systemic autoimmune diseases and needs further scrutiny.

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: Brief report; preliminary comparison of ANA test results in stored serum from an asbestos-exposed group and an unexposed comparison cohort, with logistic and ordinal logistic regression
• Who was studied: 49 Wittenoom cancer prevention program participants chosen randomly from each cohort (17 former workers, 16 former residents, 16 first exposed as children under 15), samples analysed in 2015; compared with 147 Busselton Health Study participants of similar age range whose 1994 serum was tested in 2012
• Exposure: Crocidolite (blue asbestos) from mining and milling at Wittenoom, 1943 to 1966, as workers, residents, or children; the authors describe this as exclusive exposure to the amphibole crocidolite
• Main results:
  • 85% of the Busselton group were ANA negative, compared with 53% of the Wittenoom group (26 of 49 Wittenoom participants negative; 125 of 147 Busselton participants negative)
  • Odds of ANA positivity, Wittenoom vs Busselton: unadjusted OR 5.03 (95% CI 2.44-10.3); fully adjusted logistic model (Model A) OR 5.48 (2.32-12.97); adjusted ordinal model for higher ANA score (Model B) OR 5.00 (2.15-11.6)
  • Within Wittenoom, there was no significant difference in ANA titre between workers and residents (P = 0.669)
  • With the 17 Wittenoom workers excluded (residents and children only), the unadjusted OR was 4.42 (95% CI 1.92-10.2), Model A 4.60 (1.82-11.63) and Model B 4.34 (1.74-10.81)
  • Model A run separately by sex: OR 2.81 (95% CI 0.87-9.09) for males and 11.0 (95% CI 2.94-41.2) for females
  • Across both groups combined, females had higher odds than males of being ANA positive (unadjusted OR 2.30, 95% CI 1.16-4.56)
• The authors' conclusion: The authors concluded that the high frequency of positive ANA tests among crocidolite-exposed subjects may be an indicator for an increased risk of systemic autoimmune diseases and needs further epidemiological and biological study.
• Limitations the authors state:
  • Wittenoom workers, especially miners, were probably also exposed to silica, a known cause of autoimmunity, and silica was never measured
  • Some Busselton participants may have been exposed to asbestos, mostly chrysotile, through construction materials
  • Little information was available on actual autoimmune diseases in either group
  • The two groups' samples were tested by different laboratories, and ANA positivity was scored slightly differently in each

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Wittenoom, Crocidolite, Cohort Study.

Related studies

• Cancer incidence among women and girls environmentally and occupationally exposed to blue asbestos at Wittenoom, Western Australia — A. Reid, J. Heyworth, et al. (2008)
• Malignant mesotheliomas in former miners and millers of crocidolite at Wittenoom (Western Australia) after more than 50 years follow-up — G. Berry, A. Reid, et al. (2012)
• Malignant pleural and peritoneal mesotheliomas in former miners and millers of crocidolite at Wittenoom, Western Australia — G. Berry, N.H. de Klerk, et al. (2004)
• Asbestos-related mortality among Italian migrants to Western Australia — E. Merler, D. Balzi, et al. (1996)
• Retinol supplementation and mesothelioma incidence in workers earlier exposed to blue asbestos (Crocidolite) at Wittenoom, Western Australia — H.S. Alfonso, A. Reid, et al. (2010)
• Familial aggregation of malignant mesothelioma in former workers and residents of Wittenoom, Western Australia — N. de Klerk, H. Alfonso, et al. (2013)

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