Mechanisms of Immune Dysregulation Induced by Pesticide Exposure and their Implications for Cancer: A Systematic Review

Abstract

The inappropriate use of pesticides contaminates natural resources and has consequences for human health. Evidence of immune dysregulation caused by pesticides has been presented, but studies linking exposure to these substances with immune dysregulation and its relationship to cancer are scarce. This study systematically reviews the published literature that addresses the topic of immune dysregulation and cancer and its relationship to pesticide exposure. Studies developed in vitro cell culture and in vivo experimental animals and human exposure data were included. The results show that pesticide exposure has a relevant impact on immune dysfunction, negatively affecting immune system cells and cytokine production in innate and adaptive responses. The main consequences reported were suppression of the Th1 response, induction of the Th2 response, cellular balance dysregulation, and cytokine production changes. All reported events are related to the occurrence of immunosuppression. This dysregulation is paramount for cancer progression and may lead to a worse prognosis in chronically exposed populations. These findings also point to the need for further studies, primarily focused on human exposure.