A method for extracting ferruginous bodies from sputum and pulmonary tissue

Our plain-English summary of A method for extracting ferruginous bodies from sputum and pulmonary tissue, by M.J. Smith, B. Naylor (American Journal of Clinical Pathology, 1972).

The study

• Authors: M.J. Smith, B. Naylor
• Journal: American Journal of Clinical Pathology
• Published: 1972;58(3):250-4
• Cited by: 141 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

A method for extracting ferruginous bodies from sputum and fixed or unfixed lung is described. The principle is to digest the sputum or tissue completely in domestic laundry bleach (5.25% sodium hypochlorite) and to collect the solid residue on a membrane filter. This method allows one to extract from a specimen virtually every ferruginous body that is visible with the light microscope. With this method, ferruginous bodies were found in pulmonary tissue from each of 100 consecutive necropsies of patients 16 years old and over. In one case, ferruginous bodies were found in a concentration of about 750,000 per Gm. of wet fixed pulmonary tissue.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This 1972 methods paper from the University of Michigan described how to recover ferruginous bodies (inhaled fibers coated with an iron-protein complex) from sputum and lung tissue. Each sample was dissolved in household laundry bleach (5.25% sodium hypochlorite), and the whole residue was collected on a membrane filter for light microscopy. The authors applied the method to formalin-fixed lung from 100 necropsies of Michigan residents aged 16 to 88. Ferruginous bodies were found in all 100, at 1 per 20 Gm. to 750 per Gm. of wet fixed tissue. Earlier scrape and tissue-section examinations of the same lungs had found them in 4% and 18%. Dried lung yielded mostly fractured bodies. In a separate case, a 50-year-old bulldozer operator who died of bronchogenic squamous cell carcinoma had about 750,000 per Gm. of wet fixed lung. The bodies looked like asbestos bodies, but the authors noted that special analysis is needed to prove an asbestos core. Some tissue samples weighed under 0.5 Gm. The authors concluded the method was efficient and simple, and suggested using 5 Gm. of uninflated, formalin-fixed lung.

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: Laboratory methods study: description of a bleach-digestion and membrane-filter technique, applied to autopsy (necropsy) lung tissue
• Who was studied: Portions of wet, formalin-fixed lung from 100 necropsies (as far as possible consecutive) of patients aged 16 to 88 years, 66 male and 34 female, all Michigan residents at death. None had clinical evidence of pulmonary fibrosis, and six died of bronchogenic carcinoma. The article does not give dates for the necropsies. One additional case, a 50-year-old bulldozer operator, was described separately.
• Exposure: No exposure histories were reported for the 100 cases. The study counted ferruginous bodies (inhaled fibers coated with an iron-protein complex) in lung tissue. These bodies had the light-microscopic appearance of asbestos bodies, but their fiber cores were not analyzed. The one separately described case was a bulldozer operator.
• Main results:
  • Ferruginous bodies were found in lung tissue from all 100 necropsies, at concentrations from 1 per 20 Gm. to 750 per Gm. of wet fixed tissue.
  • Earlier examinations of the same lungs by the scrape method and by tissue sections had found ferruginous bodies in only 4% and 18% of them, respectively.
  • In formalin-fixed lung that had been allowed to dry, most ferruginous bodies were fractured. The authors stated that dried lung should not be used.
  • A separate case, not one of the 100, was a 50-year-old bulldozer operator who died of bronchogenic squamous cell carcinoma. No more than seven ferruginous bodies were found in any one of his sputum specimens. His lung contained about 750,000 per Gm. of wet fixed lung, calculated from a 1:10,000 dilution of a digest of 3 Gm.
• The authors' conclusion: The authors concluded that the digestion method was efficient, simple, reliable and reproducible, and allowed reasonably accurate quantification. They judged it suitable for comparative studies. For comparability, they suggested using 5 Gm. of uninflated, formalin-fixed lung.
• Limitations the authors state:
  • The amount of tissue digested varied widely, from 0.1 to 20.0 Gm. In some cases less than 0.5 Gm. was available, because the need for extra tissue had not been anticipated.
  • The bodies looked like asbestos bodies, but the authors stated that light-microscopic appearance cannot show the core is asbestos. For that reason they used the general term ferruginous body.

Topics

Medical terms in this study, explained in our Lexicon: Ferruginous Bodies, Sputum, Ferruginous body.

Related studies

• A procedure for the isolation of amosite asbestos and ferruginous bodies from lung tissue and sputum — M.G. Williams, R.F. Dodson, et al. (1982)
• A rapid and simple method of extracting asbestos bodies from lung tissue by cytocentrifugation — A. Ehrlich, Y. Suzuki (1987)
• Perls' Prussian Blue Stains of Lung Tissue, Bronchoalveolar Lavage, and Sputum — A.J. Ghio, V.L. Roggli (2021)
• Techniques for microscopic detection of asbestos bodies in lung tissue — P. Bradbury (2005)
• Sputum asbestos bodies and radiographic changes in residents of Wittenoom, Western Australia — A.W. Musk, J.E. Baker, et al. (1983)
• Fibrous dust particles and ferruginous bodies. Methods for quantitating them and some results from the lungs of city dwellers — P. Gross, J. Tuma, et al. (1970)

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