Gene expression analysis in combat veterans with and without post‑traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a common, debilitating and complex disorder. Numerous genetic and environmental factors are important in the genesis and maintenance of PTSD. Thus, gene expression analysis (GEA) is a critical technology for PTSD research since it detects essential genetic output affected by gene-environment interactions. Quality control methods are rarely reported in gene expression studies. The present study aimed to identify reliably expressed genes in whole blood samples from subjects with combat-induced PTSD (n=6) and, secondly, to investigate the expression of genes that may be differentially expressed in PTSD compared with an appropriate control group (n=11). Strict quality control methods were used. From a theoretically driven set of 42 genes, 17 were reliably detected using quantitative PCR on samples from 17 combat-exposed veterans. Four of these 17 genes were consistently and modestly correlated with clinical phenotypes and had significant expression effects on phenotypes. These genes regulate inflammatory systems and are regulated by the adrenergic system, consistent with peripheral markers important in PTSD. Inflammatory disinhibition may be involved in combat-induced PTSD, and may be responsible for the increased prevalence of inflammatory‑related illnesses observed in PTSD. This is a preliminary study with a small sample size. A number of genes are not reliably detected by the current methodology. Improved detection methods are important to extend the current study and to further understand mechanisms in PTSD.