The etiology of rheumatoid arthritis (RA) is currently unknown, including where and how autoimmunity initially develops. Multiple lines of evidence support that there is a pre-clinical period of autoimmunity prior to the onset of joint disease in RA, and this autoimmunity in RA likely originates at a mucosal surface. My research is focused on identifying the mucosal site and key mechanisms involved in the initial generation of autoimmunity in RA, with a specific focus on sex differences in this process. Specifically, my research projects test for RA-related autoantibodies in the lung using induced sputum testing and the female genital tract using cervicovaginal fluid samples. In cross-section and longitudinally, we study elevations of RA-related autoantibodies at these sites in individuals who are in the pre-clinical period of RA as well as those who have already developed established RA in order to understand the origins of these autoantibodies. In addition, we study the presence of these mucosal RA-related autoantibodies and associations with potential mechanisms that could trigger their generation such as mucosal microbiota, neutrophil extracellular traps (NETs) and cytokine elevations.