Clinical and radiological criteria for the differential diagnosis between asbestosis and idiopathic pulmonary fibrosis: Application in two cases

Our plain-English summary of Clinical and radiological criteria for the differential diagnosis between asbestosis and idiopathic pulmonary fibrosis: Application in two cases, by A. Stufano, A. Scardapane, M.P. Foschino Barbaro, et al (La Medicina del Lavoro, 2021).

The study

• Authors: A. Stufano, A. Scardapane, M.P. Foschino Barbaro, L. Soleo, M. Corradi, P. Lovreglio
• Journal: La Medicina del Lavoro
• Published: 2021;112(2):115-122
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: Idiopathic pulmonary fibrosis (IPF) and asbestosis are pulmonary interstitial diseases that may present overlapping clinical aspects in the full-blown phase of the disease. For both clinical entities the gold standard for diagnosis is histological examination, but its execution poses ethical problems, especially when performed for preventive or forensic purposes.

Objective: To evaluate the application of internationally accepted clinical, anamnestic and radiological criteria for differential diagnosis between asbestosis and IPF, and to assess the ability to discriminate between the two diseases. Even if clinically similar, the two diseases present extremely different prognostic and therapeutic perspectives.

Methods: Two clinical cases of IPF are reported, in which the differential diagnosis was made by studying occupational exposure to asbestos, the onset and progression of clinical symptoms, and the identification of specific radiological elements by means of chest High Resolution Computed Tomography (HRCT).

Results: The diagnosis of IPF could be made on the basis of the absence of significant exposure to asbestos, the early onset and rapid progression of dyspnea and restrictive ventilatory defects, in association with a pulmonary radiological pattern characterized by peculiar elements such as honeycombing.

Discussion: The diagnostic procedure adopted to make a differential diagnosis with asbestosis provides practical clinical elements facilitating the differentiation between the two forms of pulmonary fibrosis, a fundamental aspect of the activity of the occupational physician.

In plain English

This article is a report of two cases. The authors described two men who had worked at a steelwork plant, mainly as repairmen, and whose claims to have their lung fibrosis recognized as an occupational disease caused by asbestos exposure went to a labor court. Using the court files, the authors applied published clinical and radiological criteria to tell asbestosis apart from idiopathic pulmonary fibrosis (IPF), a lung-scarring disease of unknown cause. They assumed constant exposure at 0.1 ff/ml, the level recognized by the Italian compensation authority. On that basis they calculated cumulative asbestos exposure of 2.1 ff/ml/year for Case I and 2.2 ff/ml/year for Case II, with risk indexes of 1.08 and 1.09. Neither man had pleural plaques or diffuse thickening of the visceral pleura on CT scans. Both had honeycombing in the lower lungs. No asbestos fibers or asbestos bodies were found in Case I's lung washings. Breathlessness progressed to full-blown disease in 3 years in Case I and 4 years in Case II. The authors concluded that these findings allowed them to confirm IPF and exclude asbestosis in both men.

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 of two cases, assessed for a forensic (court) diagnosis of asbestosis
• Who was studied: Two men who worked at a steelwork plant in Italy. Case I worked as a mechanic repairman (1971-1996), then in water and sludge treatment (1996-2000); he died in 2012 at age 64. Case II worked as a machine repairman (1970-2000) and was aged 72. Information came from court files.
• Exposure: Occupational asbestos exposure at a steelwork plant up to 1992. The plant estimated 0.001 to 0.092 ff/ml for Case I and no quantifiable exposure for Case II. The compensation authority (INAIL) recognized exposure of 0.1 ff/ml for both workers.
• Main results:
  • Assuming constant exposure, the calculated cumulative asbestos exposure was 2.1 ff/ml/year for Case I and 2.2 ff/ml/year for Case II.
  • The resulting risk index was 1.08 for Case I and 1.09 for Case II.
  • No asbestos fibers or asbestos bodies were found in Case I's broncho-alveolar lavage.
  • Neither worker showed pleural plaques or diffuse thickening of the visceral pleura on chest HRCT.
  • Both workers showed honeycombing in the posterior basal segments on HRCT.
  • The time from onset of breathlessness to full-blown IPF was 3 years in Case I and 4 years in Case II.
  • DLCO (a measure of how well the lungs transfer gas) was reduced: 81.6% and then 86% in Case I, and 55% and then 65% in Case II.
  • Both workers were described as heavy smokers: 40 packs/year for Case I and 39 packs/year for Case II.
• The authors' conclusion: The authors concluded that the absence of moderate to high asbestos exposure, the absence of pleural plaques or thickening, and the rapid progression of disease with honeycombing allowed them to confirm IPF and exclude asbestosis in the two cases. They suggested the methodology can help occupational physicians.

Topics

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

Medical terms in this study, explained in our Lexicon: Differential Diagnosis, Idiopathic, Pulmonary Fibrosis, Interstitial, Occupational Exposure, High-Resolution CT (HRCT), Dyspnea, Honeycombing.

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