Elemental analysis of histological specimens: a method to unmask nano asbestos fibers

Our plain-English summary of Elemental analysis of histological specimens: a method to unmask nano asbestos fibers, by M. Scimeca, A. Pietroiusti, F. Milano, et al (European Journal of Histochemistry, 2016).

The study

• Authors: M. Scimeca, A. Pietroiusti, F. Milano, L. Anemona, A. Orlandi, L.T. Marsella, E. Bonanno
• Journal: European Journal of Histochemistry
• Published: 2016;60(1):2573
• Type of article: Randomized trial
• Cited by: 30 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

There is recent mounting evidence that nanoparticles may have enhanced toxicological potential in comparison to the same material in the bulk form. The aim of this study was to develop a new method for unmask asbestos nanofibers from Formalin-Fixed, Paraffin-Embedded tissue. There is an increasing amount of evidence that nanoparticles may enhance toxicological potential in comparison to the same material in the bulk form. The aim of this study was to develop a new method to unmask asbestos nanofibers from Formalin-Fixed Paraffin-Embedded (FFPE) tissue. For the first time, in this study we applied Energy Dispersive X-ray (EDX) microanalysis through transmission electron microscopy to demonstrate the presence of asbestos nanofibers in histological specimens of patients with possible occupational exposure to asbestos. The diagnostic protocol was applied to 10 randomly selected lung cancer patients with no history of previous asbestos exposure. We detected asbestos nanofibers in close contact with lung cancer cells in two lung cancer patients with previous possible occupational exposure to asbestos. We were also able to identify the specific asbestos iso-type, which in one of the cases was the same rare variety used in the workplace of the affected patient. By contrast, asbestos nanofibers were not detected in lung cancer patients with no history of occupational asbestos exposure. The proposed technique can represent a potential useful tool for linking the disease to previous workplace exposure in uncertain cases. Furthermore, Formalin-Fixed Paraffin-Embedded (FFPE) tissues stored in the pathology departments might be re-evaluated for possible etiological attribution to asbestos in the case of plausible exposure. Since diseases acquired through occupational exposure to asbestos are generally covered by workers' insurance in most countries, the application of the protocol used in this study may have also relevant social and economic implications.

In plain English

This technical note described a method for finding very thin asbestos fibers (nanofibers) in archived lung tissue preserved in formalin and paraffin. The authors used transmission electron microscopy and EDX microanalysis, which identifies the chemical elements in fibers. In this retrospective study, they re-examined lung biopsies from 10 lung cancer patients with a history of possible asbestos exposure and 10 randomly selected lung cancer patients with no such history. All tumors were adenocarcinomas. Ordinary light microscopy did not identify asbestos fibers. Electron microscopy showed several fibers 0.1 to 0.6 micrometers long and under 0.1 micrometers wide in the tumor tissue of two patients with possible exposure. The article does not say what was found in the other eight patients in that group. No fibers or nanofibers were detected by electron microscopy in the tumor tissue of the 10 patients with no exposure history. The fibers were mainly silicon and iron. The authors judged them compatible with gedrite, which they described as an asbestiform variety of amosite. The authors concluded that the method can reveal nanofibers missed by conventional methods. They noted that further data are needed.

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: Retrospective study presented as a technical note. It developed a laboratory method for archived tissue: flat slice embedding followed by transmission electron microscopy and EDX microanalysis.
• Who was studied: Archived lung biopsies from 20 lung cancer patients: 10 with a history of possible asbestos exposure and 10 randomly selected patients with no history of asbestos exposure. The work was done at the University of Rome Tor Vergata, Italy. No dates are given.
• Exposure: Possible occupational asbestos exposure. Jobs, products and doses are not described. Fibers found in the tissue were identified as gedrite, described as an asbestiform variety of amosite. The discussion calls it anthophyllite-gedrite.
• Main results:
  • All 20 lung biopsies were classified as lung adenocarcinomas.
  • Light microscopy did not identify asbestos fibers in the tissues.
  • In the tumor tissue of two patients with possible asbestos exposure, electron microscopy showed several fibers 0.1 to 0.6 micrometers long and less than 0.1 micrometers in diameter.
  • In the tumor tissues of the 10 patients with no history of asbestos exposure, no fibers or nanofibers were detected by electron microscopy (TEM).
  • In the two patients with possible exposure, EDX microanalysis showed the nanofibers were mainly silicon and iron. Together with the fibers' shape and size, this led the authors to identify them as asbestos.
  • The authors stated that identifying the specific asbestos type allowed them to link the fibers to the patient's actual occupational exposure.
• The authors' conclusion: The authors concluded that, using archived lung tissue, the method can reveal exposure to asbestos nanofibers that conventional methods do not detect.
• Limitations the authors state:
  • The processing method loses fine structural detail in paraffin-embedded tissue, so magnification cannot go above 10,000 times.
  • The authors said further data are needed on whether the association is specific.

Topics

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

Medical terms in this study, explained in our Lexicon: Elemental Analysis, Transmission Electron Microscopy (TEM), Occupational Exposure, Lung Cancer, Asbestos Exposure, Pathology, Attribution.

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