Sarcoidosis: An Occupational Disease?
Sarcoidosis is an important member of the family of granulomatous lung diseases. Since its recognition in the late 19th century, sarcoidosis has been thought of as a disease of unknown cause. Over the past 20 years this paradigm has been shifting, more rapidly in the past 10 years. Epidemiologic studies, bolstered by case reports, have provided evidence of causal associations between occupational exposure to specific agents and sarcoidosis. Pathogenesis has been more clearly defined, including the role of genetic-exposure interactions. The use of in vitro lymphocyte proliferation testing (LPT) to detect sensitization to inorganic antigens is being examined in sarcoidosis patients. These antigens include silica and certain metals. Results of studies to date show differences in immunoreactivity of occupationally-exposed sarcoidosis cases compared to controls, suggesting that LPT may prove useful in diagnosing work-related disease. Our review discusses recently published findings with regard to associations between occupational exposure to silica and silicates, World Trade Center (WTC) dust, and metals and risk for sarcoidosis, as well as advances in the development of diagnostic tools. Not all cases of sarcoidosis have an identified cause, but some do. Where the cause is occupational, its recognition is critical to enable effective treatment through removal of the affected worker from exposure and to inform intervention aimed at primary prevention.
Authors: L Christine Oliver, Andrew M Zarnke