Silico-asbestosis that responded to steroid therapy

Our plain-English summary of Silico-asbestosis that responded to steroid therapy, by S. Hoshi, Y. Tamai, A. Tamura, et al (Internal Medicine, 2006).

The study

• Authors: S. Hoshi, Y. Tamai, A. Tamura, H. Ishida, N. Yoshida, C. Ogawa, N. Suzuki, Y. Sano, Y. Kawabata
• Journal: Internal Medicine
• Published: 2006;45(15):917-21
• Type of article: Case report
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

A 73-year-old man with silico-asbestosis responded to steroid therapy. Chest CT scans showed diffuse micronodular opacities and ground glass opacities bilaterally throughout the entire lung fields, as well as progressive massive fibrosis in the bilateral upper lung fields. Diagnostic thoracoscopic biopsy revealed mixed dust pneumoconiosis with silicotic nodules, as well as fibrosis similar to that of Usual Interstitial Pneumonia (UIP) with many fibroblastic foci and alveolitis. Many asbestos bodies were also detected by iron staining.

In plain English

This case report described one 73-year-old man who had worked for 32 years as a craftsman using firebrick and had also used mortar containing asbestos, talc and mica. He had smoked 10 cigarettes a day for 50 years and was admitted with shortness of breath on exertion. Chest X-ray and CT scans showed nodular and reticular changes in the upper lungs, small nodules and hazy 'ground glass' areas in the middle and lower lungs, and a few honeycomb areas in the lower lungs. Lung function tests suggested restricted breathing. A surgical lung biopsy showed mixed dust pneumoconiosis with silicotic nodules and many asbestos bodies. It also showed scarring resembling usual interstitial pneumonia (UIP), with many fibroblastic foci and inflammation. The authors diagnosed silico-asbestosis and could not determine whether silicosis or asbestosis caused the UIP-like changes. After steroid treatment, the hazy areas improved on X-ray and CT, and the six-minute walk distance rose from 306 to 370 m. While on a low maintenance dose, the patient had no fatigue or exertional shortness of breath. The authors described the steroid therapy as partly effective.

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: case report (single patient) with a review of the literature
• Who was studied: one 73-year-old man with shortness of breath on exertion, a smoker of 10 cigarettes per day for 50 years
• Exposure: 32 years of work as a craftsman using firebrick, from 1961, plus use of mortar containing asbestos, talc and mica; asbestos fiber type not specified
• Main results:
  • Chest CT on admission showed nodular and reticular changes in the upper lung fields, and ground glass opacities plus small nodules in the middle and lower fields
  • Lung function in this patient: %VC of 77.4% and FEV1.0% of 90.5%, suggesting restrictive impairment
  • Surgical (VATS) biopsy showed mixed dust pneumoconiosis with silicotic nodules
  • Many asbestos bodies were found in the biopsy tissue by iron staining
  • Because the authors could not determine whether the UIP-like changes were related to asbestosis or silicosis, they diagnosed silico-asbestosis with UIP-like features
  • Treatment was methylprednisolone 250 mg/day for 3 days, followed by tapering prednisolone maintenance therapy
  • After steroid therapy, the ground glass opacities improved on chest X-ray and CT
  • Six-minute walk distance improved from 306 to 370 m and KL-6 fell from 653 to 415 U/ml
  • On 5 mg prednisolone every other day since April 4, 2005, the patient had no fatigue or exertional shortness of breath
• The authors' conclusion: The authors concluded that steroid therapy was partly effective in this case of subacute-onset silico-asbestosis with UIP-like features, and that they could not define whether silicosis or asbestosis caused the UIP-like changes
• Limitations the authors state:
  • The authors stated that deciding when steroid therapy is indicated is difficult because of a lack of evidence
  • The authors noted that acute exacerbation remains possible in this patient, who needs careful follow-up

Topics

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

Medical terms in this study, explained in our Lexicon: CT Scan, Fibrosis, Bilateral, Thoracoscopic Biopsy, Pneumoconiosis, Interstitial, Asbestos Bodies.

Related studies

• Asbestosis and silicosis — G.R. Wagner (1997)
• TruCutR needle biopsy in asbestosis and silicosis: correlation of histological changes with radiographic changes and pulmonary function in 41 patients — P. Tukiainen, E. Taskinen, et al. (1978)
• Radiographic readings for asbestosis: misuse of science--validation of the ILO classification — A. Miller (2007)
• Asymmetric rapidly progressive lung fibrosis: a cause of pseudotumour in asbestosis — W.O. Cookson, J.J. Glancy, et al. (1985)
• Can "steroid switching" improve steroid-induced musical hallucinations in a patient with terminal cancer? — S. Kanemura, H. Tanimukai, et al. (2010)
• Mechanisms in the pathogenesis of asbestosis and silicosis — B.T. Mossman, A. Churg (1998)

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