Morphological features of pulmonary fibrosis in workers occupationally exposed to alpha radiation

Abstract

Purpose: The article reports on a comparative analysis of biological specimens of lung tissues collected from workers with pulmonary fibrosis induced by internal exposure to plutonium alpha-particles (plutonium-induced pulmonary fibrosis [PuPF]) and with etiologically different pulmonary fibrosis (non-PuPF) that developed as an outcome of a chronic obstructive pulmonary disease (COPD).

Materials and methods: To perform histological examinations, lung tissues were sampled during autopsy. Six samples of various lung regions (the apical region, the lingula of the left lung and the inferior lobe) were collected from each donor. The resected tissue samples were fixed in 10% neutral-buffered formalin during 24 h and embedded into paraffin blocks (FFPE). FFPE blocks with lung tissue specimens collected from 56 workers with PuPF, 34 workers with non-PuPF and 35 workers without any lung disease were used in the study. To perform microscopic examination, lung tissue specimens were hematoxylin and eosin stained. To examine the connective-tissue scaffold of lung stroma and identify foci of pulmonary fibrosis, the cut sections of paraffin blocks were stained by Van Gizon’s method (to assess the total volume of fibrosis-affected tissues), Gomori’s technique (to define the reticular scaffold of lung stroma) and Weigert’s technique (to examine elastic fibers). Morphological patterns of all biological specimens were studied using immunohistochemistry. To fit the empirical data, the Weibull’s model was used.

Results and conclusions: The study found qualitative and quantitative morphological features specific for PuPF compared to non-PuPF. The study demonstrated that hyper-production of collagen type V plays a key role in PuPF. The collagen type V content in fibrotic foci in lung tissue specimens from workers with PuPF was found to be increased.

Keywords:

• Occupational radiation exposure
• internal alpha radiation
• Mayak PA workers
• pulmonary fibrosis
• collagen content

Acknowledgments

T.A. is the guarantor of this work and, as such, has full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Gleb Sychugov

Dr. Gleb Sychugov, PhD, MD (anatomic pathology), is a senior researcher of the clinical department of the Southern Urals Biophysics Institute of the Federal Medical Biological Agency, Ozyorsk, Chelyabinsk region, Russia; adjunct professor (docent) of the anatomic pathology and forensic medicine department of the State Educational Institution of Higher Professional Education South Ural State Medical University at the Ministry of Health of the Russian Federation, Chelyabinsk, Russia.

Tamara Azizova

Dr. Tamara Azizova, PhD, MD (neurology), is the head and the leading researcher of the clinical department, science deputy director at the Southern Urals Biophysics Institute of the Federal Medical Biological Agency, Ozyorsk, Chelyabinsk region, Russia.

Sergey Osovets

Dr. Sergey Osovets, PhD, is a senior researcher (mathematical biology and statistics) of the clinical department of the Southern Urals Biophysics Institute of the Federal Medical Biological Agency, Ozyorsk, Chelyabinsk region, Russia.

Evgeny Kazachkov

Professor Evgeny Kazachkov, PhD, MD (anatomic pathology), is a senior researcher of the clinical department of the Southern Urals Biophysics Institute of the Federal Medical Biological Agency, Ozyorsk, Chelyabinsk region, Russia; the chairperson of the anatomic pathology and forensic medicine department of the State Educational Institution of Higher Professional Education South Ural State Medical University at the Ministry of Health of the Russian Federation, Chelyabinsk, Russia.

Valentina Revina

Dr. Valentina Revina, PhD, is a senior researcher (pathohistologist) of the clinical department of the Southern Urals Biophysics Institute of the Federal Medical Biological Agency, Ozyorsk, Chelyabinsk region, Russia.

Evgeniya Grigoryeva

Mrs. Evgeniya Grigoryeva, is a researcher (epidemiological statistics) of the clinical department of the Southern Urals Biophysics Institute of the Federal Medical Biological Agency, Ozyorsk, Chelyabinsk region, Russia.