Genetic and serum biomarker evidence for a relationship between TNFα and PTSD in Vietnam war combat veterans

Background: Posttraumatic stress disorder (PTSD) is associated with increased inflammation and comorbid medical. conditions. However, study findings for individual inflammatory marker levels have been inconsistent. Some research suggests that resilience may play a role in decreased inflammation. A polymorphism in the promoter region of the tumor necrosis factor alpha gene (TNF alpha), TNFA-308 (rs1800629) is associated with psychiatric illness but its role in PTSD is yet to be elucidated. Objective: This study investigates a key inflammatory marker, TNF alpha, for its role in PTSD severity. Method: In a cohort of trauma-exposed Vietnam War veterans (n = 299; 159 cases, 140 controls) TNF alpha serum levels and TNF alpha polymorphism rsl800629 were correlated with PTSD severity and resilience scores. Results: The polymorphism was associated with PTSD severity (p = 0.045). There were significant group differences between cases and controls with regards to serum TNF alpha levels (p = 0.036). Significant correlations were found between PTSD severity and elevated TNF alpha levels (r = 0.153; p = 0.009), and between resilience and decreased TNF alpha levels at a trend level (p = 0.08) across the entire cohort. These relationships were non-significant after controlling for covariates. In the PTSD diagnostic group, a correlation of TNF alpha and PTSD severity was observed on a trend level (p = 0.06), the relationship between TNFa and resilience remained non-significant. Conclusions: To our knowledge, this is the first time rsl 800629 has been investigated in PTSD contributing to a growing body of literature that identifies the GG as a risk genotype for psychiatric disorders in Caucasian cohorts. However, more research is needed to replicate our results in larger, equally well-characterized cohorts. The relationship between serum TNF alpha levels and PTSD severity and resilience requires further investigation. Crown Copyright (C) 2017 Published by Elsevier Inc. All rights reserved.