Occupational Exposition to Pesticides Increases the Risk of Autoimmunity and Autoimmune Diseases: A Systematic Review and Meta-Analysis

Studies have suggested the existence of a relationship between exposure to pesticides and autoimmunity as well as autoimmune diseases. Parallel to this, the increase in exposure to pesticides in recent decades and in the identification of autoimmunity such as autoimmune diseases throughout the world is a reality. Given this scenario, more in-depth investigations are increasingly necessary to determine this relationship. Thus, we performed a comprehensive meta-analysis from published studies to answer the question: "Is there a higher risk for autoimmunity in farmers/rural workers exposed to pesticides?". The databases: Pubmed, Embase, Lilacs, Scopus, CAF-e and BVS were searched to identify qualified literatures. The meta-analysis was based on the calculation via Multivariate/Multilevel Linear (Mixed-Effects) Model and a total of 259 parameters in nine articles were included in the study. The results showed that the random effect for all analyses was 0.36 (0.33- 0.39; p<.0001) and the meta-analysis showed a significant heterogeneity among the studies. All together, these results are a consequence of the variation in the immune parameters evaluated by each selected study and in the different groups of individuals evaluated among the included studies. The bias analysis was complemented by the sensibility analysis, which showed that withdrawing one study, the overall effect remains positive, and the heterogeneity does not change significantly. These findings indicated that exposure to pesticides might increase the risk of autoimmunity in farmers and rural workers. Further studies are needed to better understand the underlying mechanisms of immune alterations compatible with autoimmunity due to occupational exposure to pesticides.