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

• Published in: Comprehensive psychiatry 2017-04, Vol.74, p.125-133
• Main Authors: Bruenig, Dagmar, Mehta, Divya, Morris, Charles P, Harvey, Wendy, Lawford, Bruce, Young, Ross McD, Voisey, Joanne
• Format: Article
• Language: English
• Subjects: Aged; Australia - epidemiology; Biomarkers - blood; Case-Control Studies; Cohort Studies; Combat Disorders - blood; Combat Disorders - epidemiology; Combat Disorders - genetics; Genetic Markers - genetics; Humans; Male; Middle Aged; Polymorphism, Genetic - genetics; Psychiatry; Severity of Illness Index; Stress Disorders, Post-Traumatic - blood; Stress Disorders, Post-Traumatic - epidemiology; Stress Disorders, Post-Traumatic - genetics; Tumor Necrosis Factor-alpha - blood; Tumor Necrosis Factor-alpha - genetics; Veterans - psychology; Vietnam Conflict
• ISSN: 0010-440X; 1532-8384
• DOI: 10.1016/j.comppsych.2017.01.015

Abstract 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 tumour necrosis factor α gene ( TNFα ), 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, TNFα, for its role in PTSD severity. Method In a cohort of trauma-exposed Vietnam War veterans ( n = 299; 159 cases, 140 controls) TNF α serum levels and TNFα polymorphism rs1800629 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 TNFα levels ( p = 0.036). Significant correlations were found between PTSD severity and elevated TNFα levels ( r = 0.153; p = 0.009), and between resilience and decreased TNFα 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 TNFα and PTSD severity was observed on a trend level ( p = 0.06), the relationship between TNFα and resilience remained non-significant. Conclusions To our knowledge, this is the first time rs1800629 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-characterised cohorts. The relationship between serum TNFα levels and PTSD severity and resilience requires further investigation.