The African American Gullah population of the Sea Islands of South Carolina and Georgia are a unique community for defining environmental factors for autoimmune diseases due to their low genetic admixture, environmental homogeneity, and a high prevalence of anti-nuclear antibody (ANA) positivity and families with multiple affecteds with systemic lupus erythematosus (SLE). With local seafood consumption being a dietary staple, potential pollutant contamination of the seafood is of high concern to the community. The basis for this concern is twofold. First, high levels of certain highly persistent organic pollutants (POPs), specifically polybrominated diphenyl ethers (PBDEs) and perfluoroalkyl acids (PFAAs), are found in local bottlenose dolphins and red drum, both sentinel wildlife species that serve as surrogates of human health effects. Second, links were recently established between these bioaccumulating, ubiquitous compounds and multiple deleterious health effects in humans, including immune system dysfunction and autoimmunity. As part of this proposal, we will study the immunological consequences associated with exposure to these specific environmental contaminants over time in first-degree relatives (FDRs) of patients with SLE, who are known to exhibit an increased risk of developing autoimmune disease themselves. The information gathered as part of this investigation will be used to support sound environmental public health action. The overall hypothesis of this proposal is that PBDEs and PFAAs play a pathogenic role as environmental triggers of autoimmunity in genetically at-risk individuals. We will test this hypothesis by accomplishing the following Specific Aims: 1) To test the hypothesis that residential, occupational and food frequency questionnaires are valid for assessing the burden of exposure to PBDEs and PFAAs among the African American Gullah community living in the Sea Island areas of South Carolina. 2) To test the hypothesis that serum levels of PBDEs and PFAAs will correlate with the presence of autoimmunity among first-degree relatives of patients with SLE and that levels of these bioaccumulating compounds increase over time within individuals exposed and that the rate of increase will correlate with the presence of autoimmunity. 3) To develop an algorithm to identify community members at high-risk for PBDE and PFAA exposure and test the hypothesis that cumulative exposure directly correlates with development and progression of autoimmunity. 4) To perform community outreach and education through a Steering Committee and public forums. 5) To evaluate the participatory process in reaching the educational and research objectives.
The proposed studies address concerns of the Sea Island African American community regarding bioaccumulating persistent organic pollutants found in local dietary staples such as fish. This study will provide important, not currently available information regarding the role of PBDEs and PFAAs as potential environmental triggers for the development and progression of autoimmune disease. The ultimate goal is to improve the quality of and community participation in multidisciplinary research on the human health effects of environmental exposures and develop effective strategies for exposure reduction and autoimmune disease prevention.
