BACKGROUND: Autoimmune diseases are a potentially emerging condition among persons exposed to the September 11, 2001 terrorist attack on the World Trade Center (WTC). Exposure to silica, a component of the dust cloud resulting from the collapse of the WTC towers, has been associated with autoimmune diseases. There is also evidence that posttraumatic stress disorder (PTSD), one of the most common 9/11-related mental health conditions, may be linked with autoimmune diseases. Among New York City firefighters, a dose-response relationship has been identified between length of time worked at the WTC site and increased odds of autoimmune disease. Currently, there are no studies that have examined autoimmune diseases other than sarcoidosis among other populations who were exposed to the WTC attack.
METHODS: The WTC Health Registry (“the Registry”) comprises 71,430 persons who were exposed to the 9/11 attack on the WTC and/or were involved in the subsequent recovery and cleanup effort. All enrollees completed a baseline survey in 2003-2004, providing information on exposure and current and past health status. A total of 2,786 enrollees who reported a post-9/11 diagnosis of an autoimmune disease on a follow-up survey (2011-2012) were sent an in-depth survey which included questions about their autoimmune diagnoses, symptoms, and medication history (response rate= 73%.) As multiple studies have found that only 20-40% of self-reported diagnoses of autoimmune disease are true cases, medical verification of cases is necessary. Of the survey participants, 1,043 (51%) consented to having their medical records released to us for verification. Currently, the Registry has obtained medical records for 643 enrollees (62%), though this study is still ongoing. Bivariate analyses were conducted using chi square and p<.05 as criteria for statistical significance.
RESULTS: We identified medically verified cases of the following autoimmune diseases diagnosed in 2002 or later: rheumatoid arthritis-60; lupus-23; Sjögren’s Syndrome-17; mixed connective tissue disease (MCTD)-11; myositis-11; scleroderma-6; as well as 62 enrollees with other autoimmune diseases. A higher proportion of these diagnoses occurred among female enrollees. Rheumatoid arthritis, lupus, and MCTD occurred more frequently among enrollees with PTSD at enrollment. Exposure to the dust cloud and having been a rescue /recovery worker were not associated with an autoimmune disease diagnosis. Among rescue/recovery workers, longer work duration was not significantly associated with a confirmed diagnosis.
CONCLUSIONS: Though this study is ongoing, the preliminary results suggest that PTSD may be associated with autoimmune diseases among persons who were exposed to the WTC disaster.