biostudies-literatureBhatt SNCATS NIH HHSVA National Center for PTSDGustavus and Louise Pfeiffer Research FoundationNIMH NIH HHSNIAAA NIH HHSU.S. Department of Health & Human Services | NIH | National Institute of Mental HealthNIGMS NIH HHS2360https://www.ebi.ac.uk/biostudies/studies/S-EPMC7217830biostudies-literatureUnknown11(1)Despite well-known peripheral immune activation in posttraumatic stress disorder (PTSD), there are no studies of brain immunologic regulation in individuals with PTSD. [¹¹C]PBR28 Positron Emission Tomography brain imaging of the 18-kDa translocator protein (TSPO), a microglial biomarker, was conducted in 23 individuals with PTSD and 26 healthy individuals-with or without trauma exposure. Prefrontal-limbic TSPO availability in the PTSD group was negatively associated with PTSD symptom severity and was significantly lower than in controls. Higher C-reactive protein levels were also associated with lower prefrontal-limbic TSPO availability and PTSD severity. An independent postmortem study found no differential gene expression in 22 PTSD vs. 22 controls, but showed lower relative expression of TSPO and microglia-associated genes TNFRSF14 and TSPOAP1 in a female PTSD subgroup. These findings suggest that peripheral immune activation in PTSD is associated with deficient brain microglial activation, challenging prevailing hypotheses positing neuroimmune activation as central to stress-related pathophysiology.Nature communicationsPTSD is associated with neuroimmune suppression: evidence from PET imaging and postmortem transcriptomic studies.PMC7217830R01MH110674K01 AA024788F30 MH116607F30MH116607T32 GM007205UL1 TR001863R01 MH110674Davis MTFriedman MJTraumatic Stress Brain Study GroupPietrzak RHHillmer ATRusowicz ADuman RSBhatt SMatuskey DAngarita GAKrystal JHGirgenti MJHuang YSouthwick SMKapinos MNabulsi NCarson REEsterlis ICosgrove KPfalsePTSD is associated with neuroimmune suppression: evidence from PET imaging and postmortem transcriptomic studies.Despite well-known peripheral immune activation in posttraumatic stress disorder (PTSD), there are no studies of brain immunologic regulation in individuals with PTSD. [¹¹C]PBR28 Positron Emission Tomography brain imaging of the 18-kDa translocator protein (TSPO), a microglial biomarker, was conducted in 23 individuals with PTSD and 26 healthy individuals-with or without trauma exposure. Prefrontal-limbic TSPO availability in the PTSD group was negatively associated with PTSD symptom severity and was significantly lower than in controls. Higher C-reactive protein levels were also associated with lower prefrontal-limbic TSPO availability and PTSD severity. An independent postmortem study found no differential gene expression in 22 PTSD vs. 22 controls, but showed lower relative expression of TSPO and microglia-associated genes TNFRSF14 and TSPOAP1 in a female PTSD subgroup. These findings suggest that peripheral immune activation in PTSD is associated with deficient brain microglial activation, challenging prevailing hypotheses positing neuroimmune activation as central to stress-related pathophysiology.2020-01-01T00:00:00Z2020 May2026-05-02T00:19:03.557Z2020-05-22T20:19:52ZS-EPMC72178303239867710.1038/s41467-020-15930-5