A Systematic Review of Tumor Necrosis Factor-α in Post-Traumatic Stress Disorder: Evidence from Human and Animal Studies.

Abstract

Growing evidence suggests a pathophysiological role of cytokines in post-traumatic stress disorder (PTSD). Tumor necrosis factor (TNF)-α is a key cytokine. Therefore, we performed a systematic review to examine the findings regarding TNF-α derived from both animal and human studies of PTSD. Using PRISMA guidelines, we reviewed relevant articles in PubMed from inception until 11th April 2017. Human studies that reported group comparisons and/or longitudinal investigations of TNF-α production/concentration were included. Research reporting on TNF-α levels in animal models of PTSD were also included. Twenty-seven articles were identified. Data from human cross-sectional studies suggests that plasma/serum levels of TNF-α are elevated in those with PTSD, as compared to healthy controls. Longitudinal assessments of TNF-α are limited and data are mixed. Limited data from animal studies suggest an increased TNF-α production in the hippocampus of rats following stress, which can be reversed by immunomodulatory drugs. Our findings suggest TNF-α may be a potential biomarker and treatment target for PTSD. Findings need to be considered in light of heterogeneous methods for measurement and analysis of TNF-α concentration. Longitudinal research is needed to understand the role of TNF-α in the development and/or maintenance of PTSD.