Exposure to occupational inhalable agents is associated with an increased risk for anti-citrullinated protein antibodies (ACPA)-
positive RA, according to a study published in the Annals of the Rheumatic Diseases. Bowen Tang and colleagues used data from
4,033 incident RA cases and 6,485 matched controls to examine the effects of occupational inhalable exposures on RA development. Exposure to 32 inhalable agents was estimated based on retrieval of occupational histories, combined with a national job-exposure matrix. The risk for ACPA-positive RA was increased in association with exposure to any occupational inhalable agents (OR, 1.25). As the number of exposed agents increased, or duration of exposure elongated, the risk increased. When jointly considering exposure to any occupational inhalable agents, smoking, and high genetic risk score, those who were  triple-exposed had a markedly elevated risk for ACPA-positive RA compared with those with no exposures (OR, 18.22). In ACPA-positive RA, significant interactions were identified between occupational inhalable agents and smoking/genetic factors.