title: Blood-based gene-expression biomarkers of post-traumatic stress disorder among deployed marines: A pilot study.
abstract: The etiology of post-traumatic stress disorder (PTSD) likely involves the interaction of numerous genes and environmental factors. Similarly, gene-expression levels in peripheral blood are influenced by both genes and environment, and expression levels of many genes show good correspondence between peripheral blood and brain tissues. In that context, this pilot study sought to test the following hypotheses: (1) post-trauma expression levels of a gene subset in peripheral blood would differ between Marines with and without PTSD; (2) a diagnostic biomarker panel of PTSD among high-risk individuals could be developed based on gene-expression in readily assessable peripheral blood cells; and (3) a diagnostic panel based on expression of individual exons would surpass the accuracy of a model based on expression of full-length gene transcripts. Gene-expression levels in peripheral blood samples from 50 U.S. Marines (25 PTSD cases and 25 non-PTSD comparison subjects) were determined by microarray following their return from deployment to war-zones in Iraq or Afghanistan. The original sample was carved into training and test subsets for construction of support vector machine classifiers. The panel of peripheral blood biomarkers achieved 80% prediction accuracy in the test subset based on the expression of just two full-length transcripts (GSTM1 and GSTM2). A biomarker panel based on 20 exons attained an improved 90% accuracy in the test subset. Though further refinement and replication of these biomarker profiles are required, these preliminary results provide proof-of-principle for the diagnostic utility of blood-based mRNA-expression in PTSD among trauma-exposed individuals.
authors.affiliation: Psychiatric Genetic Epidemiology & Neurobiology Laboratory (PsychGENe Lab), Departments of Psychiatry and Behavioral Sciences & Neuroscience and Physiology, Medical Genetics Research Center, SUNY Upstate Medical University, Syracuse, NY, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Tylee
authors.affiliation: Center for Behavioral Genomics, Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA.
authors.forename: Sharon D
authors.initials: SD
authors.lastname: Chandler
authors.affiliation: VA Center of Excellence for Stress and Mental Health, San Diego, CA, USA; Veterans Affairs San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Nievergelt
authors.affiliation: Center for Behavioral Genomics, Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA; Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Liu
authors.affiliation: Center for Behavioral Genomics, Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Pazol
authors.affiliation: Veterans Affairs San Diego Healthcare System, San Diego, CA, USA; Department of Medicine, University of California, La Jolla, San Diego, CA, USA.
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Woelk
authors.affiliation: VA Center of Excellence for Stress and Mental Health, San Diego, CA, USA; Veterans Affairs San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA.
authors.forename: James B
authors.initials: JB
authors.lastname: Lohr
authors.affiliation: Center for Behavioral Genomics, Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA; VA Center of Excellence for Stress and Mental Health, San Diego, CA, USA; Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA.
authors.forename: William S
authors.initials: WS
authors.lastname: Kremen
authors.affiliation: VA Center of Excellence for Stress and Mental Health, San Diego, CA, USA; Veterans Affairs San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA.
authors.forename: Dewleen G
authors.initials: DG
authors.lastname: Baker
authors.affiliation: Psychiatric Genetic Epidemiology & Neurobiology Laboratory (PsychGENe Lab), Departments of Psychiatry and Behavioral Sciences & Neuroscience and Physiology, Medical Genetics Research Center, SUNY Upstate Medical University, Syracuse, NY, USA. Electronic address: glatts@upstate.edu.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Glatt
authors.affiliation: Center for Behavioral Genomics, Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA; VA Center of Excellence for Stress and Mental Health, San Diego, CA, USA; Veterans Affairs San Diego Healthcare System, San Diego, CA, USA; Department of Psychiatry, University of California, La Jolla, San Diego, CA, USA; Institute of Genomic Medicine, University of California, La Jolla, San Diego, CA, USA; Harvard Institute of Psychiatric Epidemiology and Genetics, Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Ming T
authors.initials: MT
authors.lastname: Tsuang
mesh_terms: D000293:Adolescent; D000328:Adult; D055826:Afghan Campaign 2001-; D015415:Biomarkers / Q000097:blood; D003130:Combat Disorders / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D054542:Iraq War, 2003-2011; D008016:Life Change Events; D008297:Male; D008889:Military Personnel; D010865:Pilot Projects; D013313:Stress Disorders, Post-Traumatic / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Alternative splicing; Antioxidant; Biomarker; Diagnosis; Microarray; Oxidative stress; Peripheral blood mononuclear cells; Transcriptome; Trauma; mRNA