Influence of polychlorinated biphenyls and organochlorine pesticides on the inflammatory milieu. A systematic review of in vitro, in vivo and epidemiological studies

Abstract Background Organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB) are relevant families of persistent organic pollutants, which have been linked to several long-term adverse health effects. The mechanisms of action of these pollutants are still poorly understood. However, there are some evidences suggesting that inflammation might play a key role on their effects. Aim To systematically synthesize the published in vitro, in vivo and epidemiological data assessing the potential influence of exposure to OCP and PCB on the development of an inflammatory milieu. Methods A systematic review of peer-reviewed original research papers published until 1st May 2019 was conducted, by using Medline, Web of Science and Scopus databases. A total of 39 articles met the inclusion criteria and were evaluated in this review. Results The majority of the studies showedsignificant associations of PCB and OCP exposure with all inflammatory markers measured (n = 30). Some studies showed positive and negative associations (n = 7) and only two studies evidenced negative associations (n = 2). Most of the available evidences came from in vitro and in vivo studies (n = 31), with few epidemiological studies (n = 8). Conclusions We found consistent positive associations between exposure to PCB and OCP and the development of a pro-inflammatory milieu, with only few discrepancies. However, given the limited epidemiological evidence found, our results warrant further research in order to elucidate the real contribution of OCP and PCB on the inflammatory processes and subsequent diseases.