Exposure to asbestos: correlation between blood levels of mesothelin and frequency of micronuclei in peripheral blood lymphocytes

Our plain-English summary of Exposure to asbestos: correlation between blood levels of mesothelin and frequency of micronuclei in peripheral blood lymphocytes, by V. Marini, L. Michelazzi, A. Cioé, et al (Mutation Research, 2011).

The study

• Authors: V. Marini, L. Michelazzi, A. Cioé, C. Fucile, F. Spigno, L. Robbiano
• Journal: Mutation Research
• Published: 2011;721(1):114-7
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Inhalation of asbestos, a mineral extensively used in a variety of applications, is strongly associated with malignant mesothelioma (MM), a fatal cancer of the pleura. Soluble mesothelin-related peptides (SMRP) are a promising biomarker suggested for the screening of MM in healthy asbestos-exposed subjects. In the present study a comparison of micronucleus (Mn) frequencies in peripheral blood lymphocytes (PBL) between 44 asbestos-exposed and 22 control individuals has been performed, and the correlation with serum SMRP has been examined. SMRP levels were found to be significantly higher in subjects exposed to asbestos and in their various subgroups than in controls. Concerning micronucleated lymphocytes, a statistically significant difference from controls was seen in the percentages of both micronucleated mononucleated lymphocytes (MnMNL) and micronucleated binucleated lymphocytes (MnBNL), but the difference was markedly higher for the percentage of micronucleated polynucleated lymphocytes (MnPNL). With respect to the correlation between the frequency of the three types of micronucleated lymphocytes and serum-SMRP values of asbestos-exposed subjects, it was statistically significant for MnMNL, but not for MnBNL and MnPNL.

Copyright © 2011 Elsevier B.V. All rights reserved.

In plain English

This short communication from Genoa, Italy, compared 44 people with past occupational asbestos exposure, described as still healthy, with 22 age-matched people not exposed to asbestos. The exposed workers were identified with help from the Italian Workers Compensation Agency (INAIL) and grouped by estimated fiber exposure. The article does not name fiber types. The researchers measured blood levels of soluble mesothelin-related peptides (SMRP), a proposed marker for mesothelioma. They also counted micronuclei, a sign of DNA damage, in cultured blood lymphocytes. Mean SMRP was 0.93 in the exposed group and 0.54 in controls, a statistically significant difference, though the article gives the unit inconsistently. Micronuclei were significantly more frequent in exposed subjects in all three lymphocyte types counted. In cells with more than two nuclei the rate was 44.59 per thousand, against 9.31 in controls. The authors called this a 4.8-fold difference and attributed it to asbestos exposure. Across all exposed subjects, SMRP correlated significantly with micronuclei in single-nucleus lymphocytes (r = 0.5037), but not in the other two cell types.

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 comparison of asbestos-exposed and unexposed people (published as a short communication)
• Who was studied: 44 people with past occupational asbestos exposure, identified with help from INAIL, and 22 age-matched controls not exposed to asbestos, in Genoa, Italy. Study dates are not given.
• Exposure: Past occupational asbestos exposure. Fiber types are not named. Exposed subjects were classified by a German method adopted by INAIL that estimates a "fibers-day" concentration from workplace fiber concentration and hours of exposure.
• Main results:
  • Mean SMRP was 0.93 ± 0.49 in the 44 exposed subjects and 0.54 ± 0.28 in the 22 controls. The tables print no unit, and the text gives the unit inconsistently: nanomoles per millilitre in the methods, nanomoles per litre in the results. SMRP was significantly higher in the exposed group and in its subgroups than in controls.
  • Micronucleated polynucleated lymphocytes (cells with more than two nuclei) were 44.59 ± 32.60 per thousand in exposed subjects and 9.31 ± 17.54 in controls (p less than 0.001). The authors described this as a 4.8-fold higher frequency, which they considered due to the exposure.
  • Micronucleated mononucleated lymphocytes were 1.32 ± 0.84 per thousand in exposed subjects and 0.46 ± 0.30 in controls. Micronucleated binucleated lymphocytes were 9.94 ± 3.92 and 4.84 ± 2.73. Both differences were statistically significant (p less than 0.001).
  • In all 44 exposed subjects, SMRP correlated significantly with micronucleated mononucleated lymphocytes (r = 0.5037, p = 0.0005). This correlation was also significant in smokers, ex-smokers, non-smokers and fiber classes 2F and 4F.
  • SMRP did not correlate significantly with micronucleated binucleated lymphocytes (r = 0.2164, p = 0.150) or with micronucleated polynucleated lymphocytes (r = 0.2604, p = 0.090) in all exposed subjects.
• The authors' conclusion: The authors concluded that a statistically significant correlation with SMRP was present only for micronucleated mononucleated lymphocytes, and that in exposed subjects micronuclei were markedly more frequent in polynucleated lymphocytes than in the other two cell types. They tentatively suggested that a persistent irritating stimulus from asbestos fibers might explain the findings.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelin, Micronuclei, Malignant Mesothelioma, Pleura, Soluble Mesothelin-Related Peptides (SMRP), Biomarker.

Related studies

• Factors affecting soluble mesothelin related protein levels in an asbestos-exposed population — E.K. Park, P.S. Thomas, et al. (2010)
• Soluble mesothelin-related protein--a blood test for mesothelioma — B.W. Robinson, J. Creaney, et al. (2005)
• Soluble mesothelin-related peptide level elevation in mesothelioma serum and pleural effusions — H.I. Pass, A. Wali, et al. (2008)
• Combined CA125 and mesothelin levels for the diagnosis of malignant mesothelioma — J. Creaney, I. van Bruggen, et al. (2007)
• Serum levels of soluble mesothelin-related peptides in malignant and nonmalignant asbestos-related pleural disease: relation with past asbestos exposure — J.A. Rodríguez Portal, E. Rodríguez Becerra, et al. (2009)
• Soluble mesothelin related peptides (SMRP) and osteopontin as protein biomarkers for malignant mesothelioma: analytical validation of ELISA based assays and characterization at mRNA and protein levels — A.J. Rai, R.M. Flores, et al. (2010)

Browse more research in Mutation Research, or return to medical research.