Pleural plaques and asbestosis: dose- and time-response relationships based on HRCT data

Abstract

Most studies on asbestos-related diseases are based on chest radiographs, and dose-response relationships are still controversial. The aim of this study was to describe the most relevant parameters of asbestos exposure linked to pleural plaques and asbestosis diagnosed by high-resolution computed tomography (HRCT).A large screening programme including systematic HRCT examinations was organised from 2003 to 2005 in France for formerly asbestos-exposed workers. The time since first exposure (TSFE), level, duration and cumulative exposure to asbestos were used in adjusted unconditional logistic regression to model the relationships of the two diseases.Analysis of a population of 5,545 subjects demonstrated that TSFE (p,0.0001) and cumulative exposure (p50.02) (or level, depending on the models used), were independently associated with the frequency of pleural plaques. Only cumulative exposure (p,0.0001) or level of exposure (p50.02) were significantly associated with asbestosis. All trend tests were significant for these parameters.To date and to our knowledge, this study is the largest programme based on HRCT for the screening of asbestos-exposed subjects. Both time-response and dose-response relationships were demonstrated for pleural plaques, while only dose-response relationships were demonstrated for asbestosis. These parameters must be included in the definition of high-risk populations for HRCT-based screening programmes.

Are pleural plaques an appropriate endpoint for risk analyses?

“…For example, in one series of analyses TSFE, mean fiber concentration and cumulative exposure were found to be significant (Paris et al, 2008(Paris et al, , 2009. Various mathematical models have been suggested to describe the relationship between exposure and the prevalence of pleural plaques (Finkelstein & Vingilis, 1984;Järvholm, 1992;McDonald et al, 1986;Paris et al, 2008Paris et al, , 2009). …”

“…Numerous studies have examined the dose-or exposureresponse relation for pleural plaques (Bar-Shai et al, 2012;Boffetta, 1998;Clin et al, 2011;Eisenhawer et al, 2014;Ehrlich et al, 1992;Finkelstein & Vingilis, 1984;Hosoda et al, 2008;Jakobsson et al, 1995;Järvholm, 1992;Karjalainen et al, 1994;Lockey et al, 2015;Mastrangelo et al, 2009;McDonald et al, 1986;Moolgavkar et al, 2014;Paris et al, 2008Paris et al, , 2009Rohs et al, 2008;Sandén & Järvholm, 1986;Shepherd et al, 1997;Soulat et al, 1999;Van Cleemput et al, 2001). Results differ among these studies, 6 but exposure variables found relevant in one or more studies include time since first exposure (TSFE), age at first exposure (Jones, 1997), type (Hillerdal, 1997;Jones, 1997;Sandén & Järvholm, 1986) and dimensions of fiber (Hillerdal, 1997;Jones, 1997), lung fiber burden (Karjalainen et al, 1994;Roberts, 1971), duration of exposure, intensity of estimated asbestos exposure and cumulative exposure (measured in various ways).…”

Asbestos-Related Diseases in Automobile Mechanics

“…In the absence of a control group, demonstration of a significant relationship between pleural plaques and duration of exposure (used as a surrogate of cumulative exposure to asbestos) is an argument in favor of the causal role of asbestos (Paris et al, 2009).…”

“…Furthermore, only automobile mechanics with no other known occupational exposure to asbestos and with a sufficiently long latency (.20 years in 99% of cases, .30 years in 89% of cases) to allow evaluation of asbestos-related diseases, especially pleural plaques, were included in the study (Schwartz, 1991;Paris et al, 2009).…”

A first step against idiopathic pulmonary fibrosis

“…For example, connective tissue diseases-associated lung fibrosis is very common and sometimes leads the prognosis, such as in patients with systemic sclerosis or rheumatoid arthritis [13]. Asbestosis and chronic hypersensitivity pneumonitis are environmentinduced lung fibrotic diseases with a poor prognosis and limited therapeutic possibilities [14,15]. Idiopathic fibrotic nonspecific interstitial pneumonia is also a progressive fibrotic lung disease with a significant mortality, although it has a better prognosis than IPF [16].…”