Prevalence of anti-nuclear autoantibodies in subjects exposed to natural asbestiform fibers: a cross-sectional study

Our plain-English summary of Prevalence of anti-nuclear autoantibodies in subjects exposed to natural asbestiform fibers: a cross-sectional study, by C. Ledda, R. Caltabiano, C. Loreto, et al (Journal of Immunotoxicology, 2018).

The study

• Authors: C. Ledda, R. Caltabiano, C. Loreto, D. Cinà, P. Senia, A. Musumeci, V. Ricceri, C. Pomara, V. Rapisarda
• Journal: Journal of Immunotoxicology
• Published: 2018;15(1):24-28
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Fluoro-edenite (FE) is an asbestiform mineral fiber spotted in the lava rocks excavated from a stone quarry in Biancavilla (Italy). The derived material had been employed locally for building purposes. Previous studies found evidence that exposure to asbestos may induce autoimmunity, with frequency of anti-nuclear autoantibodies (ANA). The aim of this study was to explore the relationship between FE exposure and autoimmune responses in an exposed population. For the study, 60 subjects living in the area of Biancavilla and 60 subjects as control group were randomly invited to participate. A free medical check, including spirometry and a high-resolution computer tomography chest scan, was given to all participants. ANA were determined by indirect immunofluorescence. On medical check, no subject showed any sign and/or symptoms of illness. Prevalence for samples positive to ANA were 70% (n = 42) and 25% (n = 15), respectively, for exposed and non-exposed subjects (p < 0.05). The presence of pleural plaques (PP) was found in 21 (30%) of the exposed subjects and in 2 (3%) of the non-exposed participants. PP subjects were always ANAs positive. In conclusion, as already it was observed with exposure to asbestos fibers, levels of ANA seemed to significantly increase in subjects who had been exposed to FE. Furthermore, all subjects showing PP were also ANA-positive. This first finding in subjects exposed to FE should encourage researchers to further investigate associations between autoimmune unbalance and environmental exposure to asbestiform fibers.

In plain English

This cross-sectional study from Sicily, Italy, asked whether living in Biancavilla was linked to anti-nuclear autoantibodies (ANA), blood markers associated with autoimmune disease. In Biancavilla, an asbestiform mineral fiber called fluoro-edenite occurs in lava rock from a local quarry that was used for building. The authors compared 60 Biancavilla residents with 60 people living and working at least 40 km away. Exposure was defined by where people lived and was not measured. No participant had signs or symptoms of illness, and lung function and blood test values were within normal ranges. ANA were found in 70% (42/60) of exposed and 25% (15/60) of non-exposed people (odds ratio 7.00, 95% CI 3.13–15.64). CT scans showed pleural plaques in 21 of 60 exposed people and 2 of 60 non-exposed people. Plaques were statistically associated with ANA positivity. The authors concluded that their data support a hypothesis that fibers like fluoro-edenite are likely to be associated with autoimmune responses. They also stated that the meaning of raised ANA is unknown and that the amount and length of exposure could not be determined.

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: cross-sectional study comparing exposed residents with a non-exposed control group
• Who was studied: 120 people born 1950–1980, chosen within periodic occupational surveillance. 60 lived in Biancavilla (Sicily, Italy) and 60 controls lived and worked at least 40 km away. The groups were reported as similar in age, smoking and BMI, and half of each group was male.
• Exposure: Environmental exposure to fluoro-edenite, an asbestiform fiber in lava rock from a local stone quarry used for building. Exposure was defined by residence in Biancavilla rather than by measurement. People with previous asbestos exposure were excluded.
• Main results:
  • ANA-positive: 70% (42/60) of exposed vs 25% (15/60) of non-exposed, p less than 0.05
  • Odds ratio for ANA positivity, exposed vs non-exposed: 7.00 (95% CI 3.13–15.64)
  • The predominant ANA staining pattern in the exposed group was speckled (29 cases)
  • Pleural plaques on HRCT: 21 of 60 exposed (printed as 30%) vs 2 of 60 non-exposed (3%)
  • Odds ratio for pleural plaques, exposed vs non-exposed: 15.62 (95% CI 3.46–70.41)
  • In binary logistic regression, pleural plaque frequency and ANA-positive status were significantly associated (p less than 0.05). The article's abstract states that subjects with plaques were always ANA-positive.
  • No subject showed signs or symptoms of illness. Spirometry and laboratory values were within normal ranges in both groups.
• The authors' conclusion: The authors concluded that their data support a hypothesis that exposure to asbestiform fibers like fluoro-edenite is likely to be associated with autoimmune responses. They called this the first study showing increased ANA prevalence in people exposed to fluoro-edenite, while stating that the significance of elevated ANA is unknown.
• Limitations the authors state:
  • It was impossible to determine how much and how long the population had been exposed to fluoro-edenite fibers.
  • Few studies have explored asbestos exposure and autoimmune-like disorders, so results could not be compared in depth with other studies.
  • The meaning of elevated ANA levels in fiber-exposed people is unknown.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Asbestiform, fluoro-edenite, Mineral Fiber, Biancavilla, Spirometry, Pleural Plaques, Environmental Exposure.

Related studies

• Occupational exposure to fluoro-edenite and prevalence of anti-nuclear autoantibodies — V. Rapisarda, C. Loreto, et al. (2018)
• Mesothelial cell and anti-nuclear autoantibodies associated with pleural abnormalities in an asbestos exposed population of Libby MT — L.S. Marchand, S. St-Hilaire, et al. (2012)
• Modelling prevalence and incidence of fibrosis and pleural plaques in asbestos-exposed populations for screening and follow-up: a cross-sectional study — C. Paris, A. Martin, et al. (2008)
• Defense and protection mechanisms in lung exposed to asbestiform fiber: the role of macrophage migration inhibitory factor and heme oxygenase-1 — C. Loreto, R. Caltabiano, et al. (2020)
• Nonmalignant pleural lesions due to environmental exposure to asbestos: a field-based, cross-sectional study — M. Metintas, S. Metintas, et al. (2005)
• Is living close to ophiolites related to asbestos related diseases? Cross-sectional study — I. Döngel, M. Bayram, et al. (2013)

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