Journal of Occupational & Environmental Medicine:
Letters to the Editor
Earle A Chiles Research Institute, Portland, Ore
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To the Editor:
Several findings weaken the authors’ conclusion that a causal relationship exists between World Trade Center Disaster (WTC) exposure and the development of sarcoidosis.1
1. Dose-response: Assuming causation, one would expect inhalation of airborne, pulverized material from the disaster explosions, the highest systemic dose, to generate the greatest likelihood of developing sarcoidosis. The authors reported a sarcoidosis odds ratio of 1 between those exposed and unexposed to the dust cloud (Table 4).
2. Exposure-disease interval: The interval between immunogenic exposure and inception of granulomatous diseases, for example, tuberculosis and histoplasmosis, is measured in weeks to a few months. A similar interval is occasionally identified in persons in whom inception is definable (acute onset sarcoidosis), who, fortuitously, have had a recent, normal, presymptomatic chest radiograph. Evolution of a positive Kveim response requires 6 to 8 weeks. Ascribing the evolution of sarcoidosis up to 5-year postexposure (Table 2) implies a latency of immunological response inconsistent with the natural history of infectious granulomatous disorders and our circumscribed knowledge of the time course of sarcoidosis. In addition, were WTC exposure a cause of sarcoidosis, one would expect a secular incidence decline over time-since-exposure. Constant incidence for years following the exposure (Table 2) renders a causal connection less plausible. Might it not represent the background incidence of radiographically detectable sarcoidosis (the majority of screen-identified cases are clinically inevident) in the surveilled, working-age cohort?
Jerome Mark Reich, MD
Earle A Chiles Research Institute
1. Jordan HT, Stellman SD, Prezant D, Teirstein A, Osahan SS, Cone JE. Sarcoidosis diagnosed after September 11, 2001 among adults exposed to the World Trade Center disaster. J Occup Environ Med. 2011;53:963–974.