Characteristics of pro- and anti-inflammatory cytokines alteration in PTSD patients exposed to a deadly earthquake

The (neuro)inflammatory system in anxiety disorders and PTSD: Potential treatment targets

Targeting the immune system has recently garnered attention in the treatment of stress- associated psychiatric disorders resistant to existing pharmacotherapeutics. While such approaches have been studied in considerable detail in depression, the role of (neuro)inflammation in anxiety-related disorders, or in anxiety as an important transdiagnostic symptom, is much less clear. In this review we first critically review clinical and in part preclinical evidence of central and peripheral immune dysregulation in anxiety disorders and post-traumatic stress disorder (PTSD) and briefly discuss proposed mechanisms of how inflammation can affect anxiety-related symptoms. We then give an overview of existing and potential future targets in inflammation-associated signal transduction pathways and discuss effects of different immune-modulatory drugs in anxiety-related disorders. Finally, we discuss key gaps in current clinical trials such as the lack of prospective studies involving anxiety patient stratification strategies based on inflammatory biomarkers. Overall, although evidence is rather limited so far, there is data to indicate that increased (neuro)inflammation is present in subgroups of anxiety disorder patients. Although exact identification of such immune subtypes of anxiety disorders and PTSD is still challenging, these patients will likely particularly benefit from therapeutic targeting of aspects of the inflammatory system. Different anti-inflammatory treatment approaches (microglia-directed treatments, pro-inflammatory cytokine inhibitors, COX-inhibitors, phytochemicals and a number of novel anti-inflammatory agents) have indeed shown some efficacy even in non-stratified anxiety patient groups and appear promising as novel alternative or complimentary therapeutic options in specific ("inflammatory") subtypes of anxiety disorder and PTSD patients.

Chlorogenic acid improves SPS-induced PTSD-like behaviors in rats by regulating the crosstalk between Nrf2 and NF-κB signaling pathway

Post-traumatic stress disorder (PTSD) is a long-term delayed mental disorder caused by sudden, threatening or catastrophic life events. Chlorogenic acid (CGA) is a polyphenolic acid rich in Eucommia ulmoides and other plants with potential neuroprotective effects, effectively enhances learning and memory, and exerts a beneficial impact on improving mood and attention. However, the effects and mechanisms of CGA on PTSD-like behaviors remain uncertain. This study is to explore the effects and mechanisms of CGA on PTSD by using network pharmacology analysis, molecular docking and experimental validation, and try to provide new strategies for the treatment of PTSD. The results indicated that 9 core targets with a strong binding affinity with CGA were screened out, and they were mainly enriched in apoptosis, inflammation, and oxidative stress. The followed vivo experiments indicated that CGA could alleviate single prolonged stress (SPS)-induced PTSD-like behaviors, and improve hippocampal pathological damage, apoptosis and synaptic plasticity through antioxidant and anti-inflammatory effects by regulating Nrf2 and NF-κB pathways. Thus, CGA may inhibit hippocampal neuronal apoptosis, reduce neuroinflammatory and oxdiative stress response, and enhance hippocampal synaptic plasticity through regulating the crosstalk between Nrf2 and NF-κB signaling pathway, thereby improving SPS-induced PTSD-like behaviors.

Evaluation of fear of falling, balance, and kinesiophobia in earthquake survivors: A comparative study between older and young adults

Objectives

This study aims to evaluate fear of falling, balance, and kinesiophobia among survivors of the earthquake that occurred in Türkiye on February 6th, 2023 and to identify potential predictors of fear of falling and impaired balance.

Patients and methods

In this single-center, cross-sectional study, a total of 260 Kahramanmaraş earthquake survivors (105 males, 155 females; median age: 44.0 years; range, 18 to 91 years) between May 08, 2024 and July 08, 2024 were included. The sociodemographic data including age, sex, body mass index (BMI), marital status (single, married, widow), education status (years), monthly income (Turkish Lira [TL]), smoking status (never smoked, smoking before the earthquake or started smoking after the earthquake), alcohol intake (never, regular use of alcohol before the earthquake, or started alcohol consumption after the earthquake) of the participants were recorded. Comorbidities were evaluated using the modified Charlson Comorbidity Index (CCI), anxiety and depression using the Hospital Anxiety and Depression Scale (HADS), post-traumatic stress disorder (PTSD) using the National Stressful Events Survey for PTSD-Short Scale (NSESSS-PTSD), sleep disorders using the Jenkins Sleep Evaluation Scale (JSS), fear of falling using the Falls Efficacy Scale (FES), functional balance using the Berg Balance Scale (BBS), and kinesiophobia using the Tampa Scale for Kinesiophobia (TSK).

Results

Of the survivors (n=260), 4.6% and 33.8% experienced loss of first-degree relatives and house damage, respectively. The FES and TSK scores were higher, while the BBS score was lower in older adults (n=56) compared to younger counterparts (n=204) (p<0.001). Multivariate linear regression analysis revealed that increased age affected the BBS (β=-0.124; 95% CI: -0.263 - -0.185; p<0.001) and FES scores (β=0.404; 95% CI: 0.255 - 0.451; p<0.001). The PTSD-SS score had a significant effect on the FES score (β=0.915; 95% CI: 0.734 - 1.110; p<0.001).

Conclusion

The Kahramanmaraş earthquake caused detrimental effects. Older people were more affected in terms of balance, fear of falling, and kinesiophobia. Increased age and post-traumatic stress are significantly associated with fear of falling following the earthquake. As a potential risk factor for fear of falling, post-traumatic stress should be managed properly in survivors of such disasters, particularly in those at older age.

Circulating biomarkers and neuroanatomical brain structures differ in older adults with and without post-traumatic stress disorder

The aim of this study was to advance post-traumatic stress disorder (PTSD) understanding in older adults (48-77 years) by determining if circulating cytokines (IL-1β, IL-2, IL-4, IL-6, IL-12p70, IL17A and TNFα), brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF-A) and neuroanatomical brain volumes (grey and white matter, hippocampus, and amygdala) significantly differed in those with versus without PTSD. While none of the tested cytokines showed a significant difference, serum BDNF and VEGF-A levels were found to be significantly higher in the PTSD cohort. The assay used for BDNF quantification was important, with differences in general BDNF detected, but not when pro- and mature BDNF were measured specifically. Additionally, BDNF genotyping revealed a significant difference in Val66Met genotype distribution by PTSD diagnosis, with Val66Met carriers generally having lower circulating levels of BDNF compared to their Val66Val counterparts, regardless of PTSD diagnosis. Neuroanatomically, an all-female subset was examined to find total grey and white matter volumes and left and right hippocampal volumes were significantly smaller in those with PTSD. Collectively, these results show that both novel (VEGF-A) and established targets (BDNF and neuroimaging) may serve as useful biomarkers for older adults with PTSD.

Neutrophil-to-lymphocyte, platelet-to-lymphocyte ratios and systemic immune-inflammation index in patients with post-traumatic stress disorder

BACKGROUND

Low-grade systemic inflammation has been reported in many psychiatric diseases and is described as a non-severe state of the inflammatory response. Post-traumatic stress disorder (PTSD) is a chronic psychiatric disorder characterized by symptoms of avoidance, re-experiencing and hyperarousal that develop secondary to a serious traumatic event. The trauma itself creates psychological and biological changes in the individual, apart from PTSD. This complex situation has still not been clarified and researchers have tended to research on inflammatory processes. Systemic immune inflammation index (SII), as a new index related to inflammation, is a comprehensive value based on peripheral lymphocyte, neutrophil and platelet counts. SII has been used as a marker of subclinical inflammation and prognosis in various studies. Although the presence of inflammation in PTSD was tried to be demonstrated through cytokines, inflammatory variables such as neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and SII, which are low-cost and easily shown in routine examinations, have not been studied before.

METHOD

We compared PTSD patients with healthy controls. 160 subjects (80 PTSD and 80 controls) were enrolled for study. All patients were evaluated with Structured clinical study form for DSM-V Axis 1 disorders. Exclusion criteria were as follows: presence of PTSD symptoms shorter than one month, presence of psychiatric comorbidity, being diagnosed with psychotic disorder, bipolar disorder, autism spectrum disorder, presence of mental retardation, being under psychotropic drug treatment, presence of a neurological disease that may cause serious disability (epilepsy, cerebrovascular disease), migraine, presence of organic brain damage, smoking, alcohol and substance use disorder, presence of a chronic disease such as diabetes mellitus, hypertension, hyperlipidemia, chronic lung diseases, being in pregnancy and breastfeeding, presence of heart disease were determined as exclusion criteria. Additionally, patients with diseases that could affect the leukocyte count (hematopoietic disease, malignancy, acute infection, acute or chronic renal failure, liver failure) and medication use (chemotherapy, history of glucocorticoid use in the last three months) were not included in the study. Patients who smoked more than fifteen cigarettes per day and had a body mass index > 30 were also excluded. SII is calculated as follows; SII = platelet count x neutrophil count / lymphocyte count.

RESULTS

Sociodemographic data were comparable among groups. Neutrophil and platelet levels of PTSD patients were significantly higher than controls although both groups' values were in normal range. Moreover, NLR, PLR and SII were significantly higher in PTSD group.

CONCLUSION

We found that NLR, PLR and SII values, which are easily calculable and cost-effective markers of systemic inflammation, were significantly higher in PTSD patients than in the control group. These values may be considered to identify patients who may benefit from adjuvant anti-inflammatory pharmacological treatment on top of psychotherapeutic treatment.

Memantine Alleviates PTSD-like Symptoms and Improves Dendritic Arborization through Modulation of the HPA Axis and Neuroinflammation in Rats

Post-traumatic stress disorder (PTSD) poses significant neurological and psychiatric challenges. Investigations into the glutamatergic system, particularly the N-methyl-D-aspartate (NMDA) receptor, are crucial for understanding PTSD mechanisms. This study aimed to evaluate the therapeutic potential of the non-competitive NMDA receptor antagonist memantine in mitigating PTSD symptoms and to explore its underlying cellular and molecular impacts. Male Sprague Dawley rats were subjected to inescapable foot shock stress (FS-stress) to model PTSD. Following stress exposure, memantine was administered at doses of 5 mg/kg and 10 mg/kg six hours post-stress. Behavioural assessments, including fear conditioning and sucrose preference tests, were conducted. Golgi-Cox staining was used to assess neuroanatomical changes related to synaptic plasticity. Western blotting was used to analyse molecular markers associated with synaptic plasticity, while immunoassays measured proinflammatory cytokines and cortisol levels. Memantine treatment improved behavioral outcomes, restoring sucrose preference and reducing freezing behavior. Morphological analysis demonstrated that memantine enhanced dendritic spine structure, particularly increasing the proportion of mature mushroom spines, which are critical for synaptic stability. Additionally, memantine normalized cortisol levels, suggesting a regulatory effect on the hypothalamic-pituitary-adrenal (HPA) axis. Additionally, memantine treatment improved the inflammatory cytokine profile, reducing IL-6 and TNF-α levels. These results suggest that memantine has potential as a therapeutic intervention for PTSD by targeting critical pathways involved in stress responses.The findings indicate that memantine, an NMDA receptor antagonist, can counteract behavioral and functional disturbances induced by FS-stress.

Learning from Hindsight: Examining Autonomic, Inflammatory, and Endocrine Stress Biomarkers and Mental Health in Healthy Terrorism Survivors Many Years Later

INTRODUCTION

Terrorism and trauma survivors often experience changes in biomarkers of autonomic, inflammatory and hypothalamic-pituitary-adrenal (HPA) axis assessed at various times. Research suggests interactions of these systems in chronic stress.

STUDY OBJECTIVE

This unprecedented retrospective study explores long-term stress biomarkers in three systems in terrorism survivors.

METHODS

Sixty healthy, direct terrorism survivors were compared to non-exposed community members for cardiovascular reactivity to a trauma script, morning salivary cortisol, interleukin 1-β (IL-1β), and interleukin 2-R (IL-2R). Survivors' biomarkers were correlated with psychiatric symptoms and diagnoses and reported functioning and well-being seven years after the Oklahoma City (OKC) bombing.Main outcome measures were the Diagnostic Interview Schedule (DIS) Disaster Supplement for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) diagnoses, Impact of Events Scale-Revised (IES-R), Beck Depression Inventory-II (BDI-II), Distress and Functioning Scale (DAF), and General Physical Well-Being Scale.

RESULTS

Survivors had higher inflammatory IL-1β, lower anti-inflammatory IL-2R, lower cortisol, higher resting diastolic blood pressure (BP), and less cardiovascular reactivity to a trauma script than comparisons. Survivors' mean posttraumatic stress (PTS) symptom levels did not differ from comparisons, but survivors reported worse well-being. None of survivors' biomarkers correlated with PTS or depressive symptoms or diagnoses or reported functioning.

CONCLUSIONS

Alterations of biological stress measures in cardiovascular, inflammatory, and cortisol systems coexisted as an apparent generalized long-term response to terrorism rather than related to specific gauges of mental health. Potential interactions of biomarkers long after trauma exposure is discussed considering relevant research. Longer-term follow-up could determine whether biomarkers continue to differ or correlate with subjective measures, or if they accompany health problems over time. Given recent international terrorism, understanding long-term sequelae among direct survivors is increasingly relevant.

Causal Relationship Between Post-Traumatic Stress Disorder and Immune Cell Traits: A Mendelian Randomization Study

INTRODUCTION

Post-traumatic stress disorder (PTSD) is a debilitating psychological disorder that occurs after exposure to catastrophic-level experiences. Although alterations in immune function have been identified in individuals with PTSD, the causal relationship between the two remains unclear.

METHODS

To investigate the causal relationship between PTSD and immune function, we conducted the forward and backward two-sample Mendelian randomization (MR) analyses, based on summary-level genome-wide association studies (GWAS) data on PTSD and immune cell traits.

RESULTS

For the forward MR analysis, PTSD was found to reduce the levels of CD62L- dendritic cell (DC) (beta = -0.254, FDR = 0.01), CD86+ myeloid DC (beta = -0.238, FDR = 0.014), CD62L- myeloid DC (beta = -0.26, FDR = 0.01), CD62L- CD86+ myeloid DC absolute count (beta = -0.264, FDR = 0.024), and CD62L- CD86+ myeloid DC (beta = -0.328, FDR = 0.002). In contrast, PTSD was observed to increase the level of CD28- CD8dim T-cell absolute count (beta = 0.27, FDR = 0.029). For the backward MR analysis, the odds ratio (OR) for CD33 on CD33dim HLA DR+ CD11b- in relation to PTSD risk was found to be 1.045 (95% CI = 1.021-1.069, FDR = 0.008). The OR for FSC-A on HLA DR+ CD8br was 1.048 (95% CI = 1.018-1.079, FDR = 0.039) and for CCR2 on CD14- CD16+ monocyte was 1.059 (95% CI = 1.027-1.092, FDR = 0.008). No significant pleiotropy was detected in both forward and backward MR analyses.

CONCLUSION

The bidirectional MR study shed light on the intricate interplay between immune function and PTSD. The identification of a bidirectional causal relationship between T cells and PTSD opens new avenues for considering innovative approaches to the prevention and early intervention of PTSD.

Effects and mechanisms of salidroside on the behavior of SPS-induced PTSD rats

Post-traumatic stress disorder (PTSD) is a complex mental disorder, closely associated with stress and traumatic events. Salidroside (Sal) has been reported to possess neuroprotective effects. However, the behavioral effects and mechanisms of Sal on PTSD remain unknown. In this study, we utilized a rat model of PTSD induced by single prolonged stress (SPS) and administered Sal intraperitoneally (25, 50, 75 mg/kg/d) for 14 days. We then examined the behavioral effects and underlying mechanisms of Sal on SPS-induced PTSD rats. Our findings demonstrated that Sal alleviated anxiety-like behavior and spatial learning and memory impairment in SPS-induced PTSD rats. Furthermore, Sal treatment preserved the histomorphology of the hippocampal region. It was observed that Sal protected against hippocampal neuronal apoptosis in PTSD rats by reducing the number of TUNEL-positive cells and modulating apoptosis-related proteins (Bcl-2 and Bax). Additionally, Sal inhibited the activation of the NF-κB/iNOS/COX-2 signaling pathway in the hippocampus of PTSD rats, thereby suppressing the release of inflammatory factors (TNF-α and IL-1β) and the activation of microglia. Notably, Sal increased the expression of synapse-associated proteins PSD95 and Synapsin I in the hippocampus, while also enhancing dendritic density in the region. In conclusion, our results demonstrated that Sal could attenuate SPS-induced PTSD-like behaviors by inhibiting hippocampal neuronal apoptosis, enhancing hippocampal synaptic plasticity, and reducing neuroinflammatory responses. These findings may provide a foundation for the potential clinical application of Sal in the treatment of PTSD.

Correlation analysis of salivary cytokines and hormones with resiliency

BACKGROUND

Frequent exposure to acute stress increases risk of suicide, posttraumatic stress disorder, and other stress-related disorders. Neuroendocrine and immunologic dysregulation associated with stress may underlie predispositions to psychological disorders and inflammatory disease processes in individuals, such as first-responders and other healthcare professionals, who function in high stress situations. The Hardiness Resilience Gauge (HRG) can be used to psychometrically measure resilience, a psychological modifier of the stress response. Using the HRG alongside salivary biomarker profiling, may help to identify low resilience phenotypes and allow mitigation and early therapeutic interventions. There is a paucity of knowledge regarding biomarkers of resilience. This study aims to evaluate the relationship between factors of resilience with salivary biomarker levels and fluctuations during and following acute stress.

METHODS

Sixty-three first responders underwent a standardized stress-inducing training exercise, providing salivary samples before (prestress), immediately after (post-stress), and 1 hour after the event (recovery). The HRG was administered before (initial) and after (final) the event. Multiplex ELISA panels quantified 42 cytokines and 6 hormones from the samples, which were analyzed for relationships to psychometric factors of resilience measured by the HRG.

RESULTS

Several biomarkers correlated with psychological resilience following the acute stress event. The HRG scores correlated ( p < 0.05) with a select set of biomarkers with moderate-to-strong correlations (|r| > 0.3). These included EGF, GROα, PDGFAA, TGFα, VEGFA, interleukin (IL)1Ra, TNFα, IL18, cortisol, FGF2, IL13, IL15, and IL6. Interestingly, fluctuations of EGF, GROα, and PDGFAA in post-stress compared with recovery were positively correlated with factors of resilience, which were negatively correlated from the pre-stress to post-stress period.

CONCLUSION

This exploratory analysis discovered a small subset of salivary biomarkers that are significantly correlated with acute stress and resilience. Further investigation of their specific roles in acute stress and associations with resiliency phenotypes is warranted.

The Role of the Adrenal-Gut-Brain Axis on Comorbid Depressive Disorder Development in Diabetes

Diabetic patients are more affected by depression than non-diabetics, and this is related to greater treatment resistance and associated with poorer outcomes. This increase in the prevalence of depression in diabetics is also related to hyperglycemia and hypercortisolism. In diabetics, the hyperactivity of the HPA axis occurs in parallel to gut dysbiosis, weakness of the intestinal permeability barrier, and high bacterial-product translocation into the bloodstream. Diabetes also induces an increase in the permeability of the blood-brain barrier (BBB) and Toll-like receptor 4 (TLR4) expression in the hippocampus. Furthermore, lipopolysaccharide (LPS)-induced depression behaviors and neuroinflammation are exacerbated in diabetic mice. In this context, we propose here that hypercortisolism, in association with gut dysbiosis, leads to an exacerbation of hippocampal neuroinflammation, glutamatergic transmission, and neuronal apoptosis, leading to the development and aggravation of depression and to resistance to treatment of this mood disorder in diabetic patients.

Molecular Toxicology and Pathophysiology of Comorbid Alcohol Use Disorder and Post-Traumatic Stress Disorder Associated with Traumatic Brain Injury

The increasing comorbidity of alcohol use disorder (AUD) and post-traumatic stress disorder (PTSD) associated with traumatic brain injury (TBI) is a serious medical, economic, and social issue. However, the molecular toxicology and pathophysiological mechanisms of comorbid AUD and PTSD are not well understood and the identification of the comorbidity state markers is significantly challenging. This review summarizes the main characteristics of comorbidity between AUD and PTSD (AUD/PTSD) and highlights the significance of a comprehensive understanding of the molecular toxicology and pathophysiological mechanisms of AUD/PTSD, particularly following TBI, with a focus on the role of metabolomics, inflammation, neuroendocrine, signal transduction pathways, and genetic regulation. Instead of a separate disease state, a comprehensive examination of comorbid AUD and PTSD is emphasized by considering additive and synergistic interactions between the two diseases. Finally, we propose several hypotheses of molecular mechanisms for AUD/PTSD and discuss potential future research directions that may provide new insights and translational application opportunities.

Purinergic P2X7 receptor-mediated inflammation precedes PTSD-related behaviors in rats

Clinical evidence has linked increased peripheral pro-inflammatory cytokines with post-traumatic stress disorder (PTSD) symptoms. However, whether inflammation contributes to or is a consequence of PTSD is still unclear. Previous research shows that stress can activate purinergic P2X7 receptors (P2X7Rs) on microglia to induce inflammation and behavioral changes. In this investigation, we examined whether P2X7Rs contribute to the development of PTSD-like behaviors induced by single prolonged stress (SPS) exposure in rats. Consistent with the literature, exposing adult male and female rats to SPS produced a PTSD-like phenotype of impaired fear extinction and extinction of cue-induced center avoidance one week after exposure. Next, we examined if inflammation precedes the behavioral manifestations. Three days after SPS exposure, increased inflammatory cytokines were found in the blood and hippocampal microglia showed increased expression of the P2X7R, IL-1β, and TNF-α, suggesting increased peripheral and central inflammation before the onset of impaired fear extinction. In addition, SPS-exposed animals with impaired fear extinction recall also had more Iba1-positive microglia expressing the P2X7R in the ventral hippocampus. To determine whether P2X7Rs contribute to the PTSD-related behaviors induced by SPS exposure, we gave ICV infusions of the P2X7R antagonist, A-438079, for one week starting the day of SPS exposure. Blocking P2X7Rs prevented the SPS-induced impaired fear extinction and extinction of cue-induced center avoidance in male and female rats, suggesting that SPS activates P2X7Rs which increase inflammation to produce a PTSD-like phenotype.

Neuroinflammation is a susceptibility factor in developing a PTSD-like phenotype

Introduction

Post-Traumatic Stress Disorder (PTSD) is a psychological disorder that occurs after a traumatic event in a subset of exposed individuals. This implies the existence of susceptibility factors that foster the development of PTSD. Susceptibility factors are present before trauma and can contribute to the development and maintenance of PTSD after trauma. Manipulation of susceptibility factors may decrease the probability of developing PTSD. A putative susceptibility factor is inflammation. Patients with PTSD have been documented to have a higher pro-inflammatory profile compared to non-PTSD subjects. In addition, they are more likely to develop and die from cardiovascular disease which has a strong inflammation component. It is not known, however, whether inflammation plays a role in developing PTSD or whether reducing inflammation can prevent PTSD.

Methods

We used the Revealing Individual Susceptibility to a PTSD-like phenotype (RISP) model to behaviorally classify male rats as resilient or susceptible before trauma and tested their serum and prefrontal cortical (mPFC) levels of IL-1β, IL-6, TNFα, IL-10, IFN IFNγ, and KC/GRO to determine whether inflammation represents a putative susceptibility factor for PTSD.

Results

We found elevated IL-6 levels in the mPFC, but not serum, of susceptible rats compared to resilient animals before trauma. Serum and mPFC levels were not correlated in any of the cytokines/chemokines. Rats with high anxiety-like behavior had elevated IL-6 and IL-10 mPFC levels. Acoustic startle responses were not associated with cytokine/chemokine levels.

Discussion

Neuroinflammation, rather than systemic inflammation exists in susceptible male rats before trauma and is thus a putative susceptibility factor for PTSD. Thus, susceptibility appears neurogenic in its pathogenesis. The lack of differences between susceptible and resilient rats in serum cytokine/chemokine levels infers that peripheral markers will not be useful in determining susceptibility. Chronic neuroinflammation appears more broadly associated with anxiety rather than startle responses.

Metabolic and Inflammatory Response in Post-Traumatic Stress Disorder (PTSD): A Systematic Review on Peripheral Neuroimmune Biomarkers

Several heterogeneous pathophysiology pathways have been hypothesized for being involved in the onset and course of Post-Traumatic Stress Disorder (PTSD). This systematic review aims to summarize the current evidence on the role of inflammation and immunological dysregulations in PTSD, investigating possible peripheral biomarkers linked to the neuroimmune response to stress. A total of 44 studies on the dysregulated inflammatory and metabolic response in subjects with PTSD with respect to controls were included. Eligibility criteria included full-text publications in the English language, human adult samples, studies involving both subjects with a clinical diagnosis of PTSD and a healthy control group. The research was focused on specific blood neuroimmune biomarkers, namely IL-1β, TNF-α, IL-6 and INF-γ, as well as on the potential harmful role of reduced antioxidant activity (involving catalase, superoxide dismutase and glutathione peroxidase). The possible role of the inflammatory-altered tryptophan metabolism was also explored. The results showed conflicting data on the role of pro-inflammatory cytokines in individuals with PTSD, and a lack of study regarding the other mediators investigated. The present research suggests the need for further studies in human samples to clarify the role of inflammation in the pathogenesis of PTSD, to define potential peripheral biomarkers.

Association of pro-inflammatory cytokines with trauma and post-traumatic stress disorder visiting a tertiary care hospital in Kathmandu

Post-traumatic stress disorder (PTSD) is a mental disorder that can occur after trauma. Although inflammatory markers such as cytokines are found altered in trauma and PTSD, there is no consensus regarding which can be considered as biomarkers. Studies from South Asia region is also rare. We studied cytokines among trauma affected patients and matched healthy controls. Fifty patients (cases) with trauma, visiting the University hospital in Kathmandu and thirty-nine healthy controls were selected, and the levels of cytokines were determined using a Luminex IS 200. We compared the levels of the cytokines in thirty-four age and gender matched pairs of case and control among three groups: healthy volunteers, cases diagnosed as PTSD, and cases without PTSD. Among the 34 pair-matched cases and controls, IL-6 was significantly higher in both PTSD positive cases [2.43 (0.00-14.54) pg/ml; p = 0.004] and PTSD negative cases [3.00 (0.92-3.86) pg/ml; p = 0.005], than in controls [0.39 (0.00-11.38) pg/ml]. IL-1β was significantly higher in PTSD positive cases [0.17 (0.00-5.27) pg/ml; p = 0.011] than in controls 0.00 (0.00-0.12) pg/ml. Other cytokines did not show significant differences. IL-6 was higher in both the trauma affected groups and IL-1β was higher in the trauma affected group with PTSD when compared to healthy controls. This supports the immune system activation hypothesis after trauma.

Sex-dependent effects of microglial reduction on impaired fear extinction induced by single prolonged stress

Single prolonged stress (SPS) is a preclinical rodent model for studying post-traumatic stress disorder (PTSD)-like behaviors. Previously we found that increased expression of the microglial marker Iba-1 in the ventral hippocampus after SPS exposure was associated with impaired fear extinction, suggesting that microglial activity contributed to the SPS-induced behavioral changes. To test this, we examined whether reducing microglia with the colony-stimulating factor 1 receptor blocker, PLX3397, in the diet would prevent the SPS-induced extinction impairment. Male rats exposed to SPS showed enhanced fear acquisition and impaired fear extinction memory. Adding PLX3397 to the diet prevented these behavioral changes. In contrast, PLX3397 did not prevent SPS from impairing fear extinction memory in the female rats. Despite the sex-dependent behavioral effects, we found a reduced number and area fraction of Iba-1+ microglia in both male and female rats suggesting that PLX3397 had similar effects on microglia in both sexes. Altogether, these results suggest that microglia contribute to the behavioral changes induced by SPS in male but not female rats.

Stress- and drug-induced neuroimmune signaling as a therapeutic target for comorbid anxiety and substance use disorders

Stress and substance use disorders remain two of the most highly prevalent psychiatric conditions and are often comorbid. While individually these conditions have a debilitating impact on the patient and a high cost to society, the symptomology and treatment outcomes are further exacerbated when they occur together. As such, there are few effective treatment options for these patients, and recent investigation has sought to determine the neural processes underlying the co-occurrence of these disorders to identify novel treatment targets. One such mechanism that has been linked to stress- and addiction-related conditions is neuroimmune signaling. Increases in inflammatory factors across the brain have been heavily implicated in the etiology of these disorders, and this review seeks to determine the nature of this relationship. According to the "dual-hit" hypothesis, also referred to as neuroimmune priming, prior exposure to either stress or drugs of abuse can sensitize the neuroimmune system to be hyperresponsive when exposed to these insults in the future. This review completes an examination of the literature surrounding stress-induced increases in inflammation across clinical and preclinical studies along with a summarization of the evidence regarding drug-induced alterations in inflammatory factors. These changes in neuroimmune profiles are also discussed within the context of their impact on the neural circuitry responsible for stress responsiveness and addictive behaviors. Further, this review explores the connection between neuroimmune signaling and susceptibility to these conditions and highlights the anti-inflammatory pharmacotherapies that may be used for the treatment of stress and substance use disorders.

Systemic interleukin-6 inhibition ameliorates acute neuropsychiatric phenotypes in a murine model of acute lung injury

Acute neuropsychiatric impairments occur in over 70% of patients with acute lung injury. Mechanical ventilation is a well-known precipitant of acute lung injury and is strongly associated with the development of acute delirium and anxiety phenotypes. In prior studies, we demonstrated that IL-6 mediates neuropathological changes in the frontal cortex and hippocampus of animals with mechanical ventilation-induced brain injury; however, the effect of systemic IL-6 inhibition on structural and functional acute neuropsychiatric phenotypes is not known. We hypothesized that a murine model of mechanical ventilation-induced acute lung injury (VILI) would induce neural injury to the amygdala and hippocampus, brain regions that are implicated in diverse neuropsychiatric conditions, and corresponding delirium- and anxiety-like functional impairments. Furthermore, we hypothesized that these structural and functional changes would reverse with systemic IL-6 inhibition. VILI was induced using high tidal volume (35 cc/kg) mechanical ventilation. Cleaved caspase-3 (CC3) expression was quantified as a neural injury marker and found to be significantly increased in the VILI group compared to spontaneously breathing or anesthetized and mechanically ventilated mice with 10 cc/kg tidal volume. VILI mice treated with systemic IL-6 inhibition had significantly reduced amygdalar and hippocampal CC3 expression compared to saline-treated animals and demonstrated amelioration in acute neuropsychiatric behaviors in open field, elevated plus maze, and Y-maze tests. Overall, these data provide evidence of a pathogenic role of systemic IL-6 in mediating structural and functional acute neuropsychiatric symptoms in VILI and provide preclinical justification to assess IL-6 inhibition as a potential intervention to ameliorate acute neuropsychiatric phenotypes following VILI.

Inflammatory and oxidative stress markers in post-traumatic stress disorder: a systematic review and meta-analysis

Post-traumatic stress disorder (PTSD) has been associated with persistent, low-degree inflammation, which could explain the increased prevalence of autoimmune conditions and accelerated aging among patients. The aim of the present study is to assess which inflammatory and oxidative stress markers are associated with PTSD. We carried out a meta-analytic and meta-regression analysis based on a systematic review of studies comparing inflammatory and oxidative stress markers between patients with PTSD and controls. We undertook meta-analyses whenever values of inflammatory and oxidative stress markers were available in two or more studies. Overall, 28,008 abstracts were identified, and 54 studies were included, with a total of 8394 participants. The Newcastle-Ottawa Quality Assessment Scale was used to evaluate the quality of the studies. Concentrations of C-reactive protein (SMD = 0.64; 95% CI: 0.21 to 1.06; p = 0.0031; k = 12), interleukin 6 (SMD = 0.94; 95% CI: 0.36 to 1.52; p = 0.0014; k = 32), and tumor necrosis factor-α (SMD = 0.89; 95% CI: 0.23 to 1.55; p = 0.0080; k = 24) were significantly increased in patients with PTSD in comparison with healthy controls. Interleukin 1β levels almost reached the threshold for significance (SMD = 1.20; 95% CI: -0.04 to 2.44; p = 0.0569; k = 15). No oxidative stress marker was associated with PTSD. These findings may explain why PTSD is associated with accelerated aging and illnesses in which immune activation has a key role, such as cardiovascular diseases and diabetes. In addition, they pointed to the potential role of inflammatory markers as therapeutic targets.

Is PTSD an Evolutionary Survival Adaptation Initiated by Unrestrained Cytokine Signaling and Maintained by Epigenetic Change?

INTRODUCTION

Treatment outcomes for PTSD with current psychological therapies are poor, with very few patients achieving sustained symptom remission. A number of authors have identified physiological and immune disturbances in Post Traumatic Stress Disorder (PTSD) patients, but there is no unifying hypothesis that explains the myriad features of the disorder.

MATERIALS AND METHODS

The medical literature was reviewed over a 6-year period primarily using the medical database PUBMED.

RESULTS

The literature contains numerous papers that have identified a range of physiological and immune dysfunction in association with PTSD. This paper proposes that unrestrained cytokine signaling induces epigenetic changes that promote an evolutionary survival adaptation, which maintains a defensive PTSD phenotype. The brain can associate immune signaling with past threat and initiate a defensive behavioral response. The sympathetic nervous system is pro-inflammatory, while the parasympathetic nervous system is anti-inflammatory. Prolonged cholinergic withdrawal will promote a chronic inflammatory state. The innate immune cytokine IL-1β has pleiotropic properties and can regulate autonomic, glucocorticoid, and glutamate receptor functions, sleep, memory, and epigenetic enzymes. Changes in epigenetic enzyme activity can potentially alter phenotype and induce an adaptation. Levels of IL-1β correlate with severity and duration of PTSD and PTSD can be prevented by bolus administration of hydrocortisone in acute sepsis, consistent with unrestrained inflammation being a risk factor for PTSD. The nervous and immune systems engage in crosstalk, governed by common receptors. The benefits of currently used psychiatric medication may arise from immune, as well as synaptic, modulation. The psychedelic drugs (3,4-Methylenedioxymethamphetamine (MDMA), psilocybin, and ketamine) have potent immunosuppressive and anti-inflammatory effects on the adaptive immune system, which may contribute to their reported benefit in PTSD. There may be distinct PTSD phenotypes induced by innate and adaptive cytokine signaling.

CONCLUSION

In order for an organism to survive, it must adapt to its environment. Cytokines signal danger to the brain and can induce epigenetic changes that result in a persistent defensive phenotype. PTSD may be the price individuals pay for the genomic flexibility that promotes adaptation and survival.

Changes in the Serum Levels of Cytokines: IL-1β, IL-4, IL-8 and IL-10 in Depression with and without Posttraumatic Stress Disorder

Background: Both depressive disorders (DD) and post-traumatic stress disorders (PTSD) are caused by immune system dysfunction. Affected individuals show increased proinflammatory cytokine concentration levels. Also, it has been hypothesized that DD and PTSD might be associated with a generalized proinflammatory cytokine signature. The study assessed the concentration of IL-1β, IL-4, IL-8 and IL-10 in depression alone and with PTSD. Methods: The study involved 460 participants. Out of them, 420 subjects comprised a study group and 40 subjects comprised a control group. Each study group consisted of 60 patients with mild depression (MD), moderate depression (MOD), severe depression (SeD), MD and PTSD (MD + PTSD), MOD and PTSD (MOD + PTSD), SeD and PTSD (SeD + PTSD), and with PTSD alone. All patients had serum concentration of IL-1β, IL-4, IL-8 and IL-10 measured with ELISA. Results: DD and PTSD are reflected in IL-1β, IL-4, IL-8 and IL-10 concentration levels. It was reported that mean levels of IL-1β, IL-4, IL-8 increase as depression became more severe. A regular decrease in IL-10 concentration levels was noted with the onset and exacerbation of depressive symptoms. Conclusion: The findings might be useful when considering chronic inflammation as a potential target or biomarker in depression and PTSD treatment.

Male adolescents with Interleukin 10 rs1800872 AA genotype had higher prevalence and slower recoveries of post-traumatic stress disorder at late stage of a follow-up

BACKGROUND

Pathophysiological mechanisms of post-traumatic stress disorder (PTSD) are elusive and heterogeneous relationships have been reported among PTSD, Interleukin 10 (IL-10), and other factors after stresses. The present study aimed to longitudinally investigate associations of PTSD with environmental factors and genetic variation of rs1800872 at IL-10 gene.

METHODS

Symptoms of PTSD were measured by PTSD Checklist-Civilian Version (PCL-C) in 462 high school students at 6, 12, and 18 months after Wenchuan earthquake in China. Genotypes of IL-10 rs1800872 were identified by polymerase chain reaction-restriction fragment length polymorphism analysis and verified by DNA sequencing.

RESULTS

AA homozygotes had higher PTSD prevalence than C allele carriers only at 18 months in male, but not female subjects. PTSD prevalence at 18 months was lowered in all subjects except male AA homozygotes when compared to that at 6 months, and only in female C allele carriers when compared to that at 12 months. PCL-C scores at 18 months were decreased in all students but not in male AA homozygotes when compared to those at 6 months. IL-10 rs1800872 was associated with PTSD at 18 months. Patterns of predictors of PCL-C scores were different between AA homozygotes and C allele carriers at different times during the follow-up.

CONCLUSION

There were different reciprocal actions of IL-10 rs1800872 with other potential factors or predictors on PTSD in a time-course and gender-dependent manner. Male students with IL-10 rs1800872 AA genotype had higher prevalence and slower recoveries of PTSD at late stage of the follow-up, suggesting requirements of special psychiatric care or drug supplementation at this stage.

Importance of sex and trauma context on circulating cytokines and amygdalar GABAergic signaling in a comorbid model of posttraumatic stress and alcohol use disorders

Alcohol use disorder (AUD) and anxiety disorders are frequently comorbid and share mechanisms that could be therapeutic targets. To facilitate mechanistic studies, we adapted an inhibitory avoidance-based "2-hit" rat model of posttraumatic stress disorder (PTSD) and identified predictors and biomarkers of comorbid alcohol (ethanol)/PTSD-like symptoms in these animals. Stressed Wistar rats received a single footshock on two occasions. The first footshock occurred when rats crossed into the dark chamber of a shuttle box. Forty-eight hours later, rats received the second footshock in a familiar (FAM) or novel (NOV) context. Rats then received 4 weeks of two-bottle choice (2BC) ethanol access. During subsequent abstinence, PTSD-like behavior responses, GABAergic synaptic transmission in the central amygdala (CeA), and circulating cytokine levels were measured. FAM and NOV stress more effectively increased 2BC drinking in males and females, respectively. Stressed male rats, especially drinking-vulnerable individuals (≥0.8 g/kg average 2-h ethanol intake with >50% ethanol preference), showed higher fear overgeneralization in novel contexts, increased GABAergic transmission in the CeA, and a profile of increased G-CSF, GM-CSF, IL-13, IL-6, IL-17a, leptin, and IL-4 that discriminated between stress context (NOV > FAM > Control). However, drinking-resilient males showed the highest G-CSF, IL-13, and leptin levels. Stressed females showed increased acoustic startle and decreased sleep maintenance, indicative of hyperarousal, with increased CeA GABAergic transmission in NOV females. This paradigm promotes key features of PTSD, including hyperarousal, fear generalization, avoidance, and sleep disturbance, with comorbid ethanol intake, in a sex-specific fashion that approximates clinical comorbidities better than existing models, and identifies increased CeA GABAergic signaling and a distinct pro-hematopoietic, proinflammatory, and pro-atopic cytokine profile that may aid in treatment.

Repeated cocaine exposure prior to fear conditioning induces persistency of PTSD-like symptoms and enhancement of hippocampal and amygdala cell density in male rats

Pre- and post-trauma drug use can interfere with recovery from post-traumatic stress disorder (PTSD). However, the biological underpinnings of this interference are poorly understood. Here we examined the effect of pre-fear conditioning cocaine self-administration on PTSD-like symptoms in male rats, and defined impairment of fear extinction as difficulty to recover from PTSD. We also examined cell density changes in brain regions suspected of being involved in resistance to PTSD recovery. Before footshock stress testing, rats were trained to self-administer cocaine during 20 consecutive days, after which they were exposed to footshocks, while other rats continued to self-administer cocaine until the end of the experiment. Upon assessment of three PTSD-like symptoms (fear during situational reminders, anxiety-like behavior, and impairment of recognition memory) and fear extinction learning and memory, changes in cell density were measured in the medial prefrontal cortex, hippocampus, and amygdala. Results show that pre-footshock cocaine exposure did not affect fear during situational reminders. Fear conditioning did not lead to an increase in cocaine consumption. However, in footshock stressed rats, cocaine induced a reduction of anxiety-like behavior, an aggravation of recognition memory decline, and an impairment of extinction memory. These behavioral alterations were associated with increased cell density in the hippocampal CA1, CA2, and CA3 regions and basolateral amygdala, but not in the medial prefrontal cortex. Our findings suggest that enhancement of cell density in the hippocampus and amygdala may be changes associated with drug use, interfering with PTSD recovery.

The impact of SARS-Cov-2 on the Nervous system and Mental Health

The World Health Organization declared the pandemic situation caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) in March 2020, but the detailed pathophysiological mechanisms of Coronavirus disease 2019 (COVID-19) are not yet completely understood. Therefore, to date, few therapeutic options are available for patients with mild-moderate or serious disease. In addition to systemic and respiratory symptoms, several reports have documented various neurological symptoms and impairments of mental health. The current review aims to provide the available evidence about the effects of SARS-CoV-2 infection on mental health. The present data suggest that SARS-CoV-2 produces a wide range of impairments and disorders of the brain. However, a limited number of studies investigated the neuroinvasive potential of SARS-CoV-2. Although the main features and outcomes of COVID-19 are linked to severe acute respiratory illness, the possible damages on the brain should be considered, too.

[Correlation between Anxiety, Depression and Changes in Th17/Treg and Inflammatory Levels in Patients with Pulmonary Nodules]

BACKGROUND

The incidence of lung cancer is increasing annually. Clinicians pay special attention to lung tests during physical examinations. Due to the popularity of low-dose computed tomography, not only can lung cancer be diagnosed early, but physical examinations often reveal the presence of pulmonary nodules, an important health issue that cannot be ignored. Patients with pulmonary nodules are prone to adverse emotions such as anxiety and depression. Many studies have shown that patients with emotional disorders have immune system dysfunction and changes in inflammation levels. This study aimed to investigate the changes in anxiety, depression, the ratios of T helper cells 17 (Th17) and regulatory T cells (Tregs), and inflammation levels in patients with pulmonary nodules.

METHODS

A total of 143 subjects from The First Affiliated Hospital of Anhui Medical University were included from April 2019 to July 2019. All of the subjects were assessed with the Beck Anxiety Inventory (BAI) and the Beck Depression Inventory-II (BDI-II). Overall, 40 cases were healthy controls (HC) and 103 cases were patients with pulmonary nodules. The patients were divided into two groups according to the scale scores: 62 cases in a non-anxiety and non-depression (NAD) group and 41 cases in an anxiety and/or depression (AD) group. The percentage of Th17 and Tregs in the peripheral blood and inflammatory factors in the serum were detected. The absolute Th17 cell counts were calculated and the differences between the groups and correlations between these indicators were analyzed.

RESULTS

There were statistically significant differences in the percentage of Th17 cells, the absolute counts of Th17 and Th17/Treg cells, and the levels of interleukin-2 (IL-2), IL-6, and tumor necrosis factor-α (TNF-α) among three groups (all P<0.001). The AD group was higher than the HC and NAD groups (all P<0.05). There was no statistically significant difference between the HC and NAD groups (all P>0.05). The previously described indicators had no significant correlation with the severity of anxiety and depression (P>0.05). There were no significant differences in the percentage of Tregs or levels of IL-4 and IL-10 between the groups (all P>0.05). The proportion of anxiety and/or depression in female patients with pulmonary nodules was higher than that in males (P<0.05).

CONCLUSIONS

Patients with pulmonary nodules are prone to varying degrees of anxiety and depression, which leads to immune dysfunction and low-grade inflammation.

The 5-HTTLPR-rs25531 S-A-S-A Haplotype and Chronic Stress Moderate the Association Between Acute Stress and Internalizing Mental Disorders Among HIV+ Children and Adolescents in Uganda

Background: Internalizing mental disorders (IMDs) among HIV-positive (HIV+) children and adolescents are associated with poor disease outcomes, such as faster HIV disease progression. Although it has been suggested that the development of IMDs is moderated by interaction of stressful life events and vulnerability factors, the underlying etiology is largely unknown. Serotonin transporter gene [solute carrier family 6 member A4 (SLC6A4)] and human tryptophan hydroxylase 2 gene (TPH2) polymorphisms have been implicated in the development of IMDs. This study investigated the association between acute stress and IMDs, and moderation by chronic stress and genetic variants in SLC6A4 and TPH2. Hypothesis: Acute stress acts through genetic and environmental vulnerability factors to increase the risk of developing IMDs. Methods: Polymorphisms in SLC6A4 (5-HTTLPR, rs25531, 5-HTTLPR-rs25531, and STin2 VNTR) and TPH2 (rs1843809, rs1386494, rs4570625, and rs34517220) were genotyped in 368 HIV+ children and adolescents (aged 5-17 years) with any internalizing mental disorder (depression, anxiety disorders, or posttraumatic stress disorder), and 368 age- and sex-matched controls, who were also HIV+. Chronic and acute stress categories were derived by hierarchical cluster analysis. Logistic regression analysis was used to assess the independent moderating effect of chronic stress and each selected polymorphism on the association between acute stress and IMDs. Results: We observed a statistically significant association between severe acute stress and IMDs (p = 0.001). Children and adolescents who experienced severe acute stress were twice as likely to develop IMDs, compared to children and adolescents who experienced mild acute stress (p = 0.001). Chronic stress interacted with severe acute stress to increase the risk of IMDs (p = 0.033). Acute stress was found to interact with 5-HTTLPR-rs25531 S-A-S-A haplotype to increase the risk for IMDs among Ugandan HIV+ children and adolescents (p = 0.049). We found no evidence for a combined interaction of acute stress, chronic stress, and 5-HTTLPR-rs25531 on IMDs. Conclusion: The odds of having an internalizing mental disorder (IMD) were higher among HIV+ children and adolescents who experienced severe acute stress compared to HIV+ children and adolescents who experienced mild acute stress. Chronic stress and 5-HTTLPR-rs25531 independently moderated the association between acute stress and IMDs.

Role of interleukin 8 in depression and other psychiatric disorders

Low grade neuroinflammation has been suggested as one of the underlying mechanisms of many psychiatric diseases as well as cognitive disorders. Interleukin 8 (IL-8), a proinflammatory cytokine produced by many cell types including macrophage and microglia, mainly functions as a neutrophil chemoattractant in the bloodstream. IL-8 is also found in the brain, where it is released from microglia in response to proinflammatory stimuli. In this review, we highlight studies focusing on the role of IL-8 in psychiatric diseases such as major depression, bipolar disorder, schizophrenia, sleep disorder, autism spectrum disorder, anxiety disorders and dementia. Increased peripheral IL-8 levels have been reported in these diseases, particularly in schizophrenic disorder, bipolar disorder, obstructive sleep apnea and autism spectrum disorder. The literature on IL-8 and major depression is inconsistent. IL-8 has been found to be a factor associated with schizophrenic prognosis and therapeutic response, and may affect a wide range of symptomatology. Considering that the exact role of immune alterations is still under research, the success of immune-based therapies in psychiatric diseases is limited for the time being.

The neuropsychiatric manifestations of COVID-19: Interactions with psychiatric illness and pharmacological treatment

The recent outbreak of the corona virus disease (COVID-19) has had major global impact. The relationship between severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection and psychiatric diseases is of great concern, with an evident link between corona virus infections and various central and peripheral nervous system manifestations. Unmitigated neuro-inflammation has been noted to underlie not only the severe respiratory complications of the disease but is also present in a range of neuro-psychiatric illnesses. Several neurological and psychiatric disorders are characterized by immune-inflammatory states, while treatments for these disorders have distinct anti-inflammatory properties and effects. With inflammation being a common contributing factor in SARS-CoV-2, as well as psychiatric disorders, treatment of either condition may affect disease progression of the other or alter response to pharmacological treatment. In this review, we elucidate how viral infections could affect pre-existing psychiatric conditions and how pharmacological treatments of these conditions may affect overall progress and outcome in the treatment of SARS-CoV-2. We address whether any treatment-induced benefits and potential adverse effects may ultimately affect the overall treatment approach, considering the underlying dysregulated neuro-inflammatory processes and potential drug interactions. Finally, we suggest adjunctive treatment options for SARS-CoV-2-associated neuro-psychiatric symptoms.

Chemokines in post-traumatic stress disorder: A network meta-analysis

BACKGROUND

Previous studies on the association between chemokines concentrations and post-traumatic stress disorder (PTSD) yielded inconsistent results. Therefore, the purpose of this network meta-analysis was to summarize these results.

METHODS

The databases of PubMed, Web of Science, Psyc-ARTICLES, Embase and Cochrane Library were searched for relevant articles published not later than January 15, 2020. Then, eligible studies were selected based on predefined study selection criteria. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated as group differences in chemokines concentrations. Moreover, network meta-analysis was used to rank chemokines effect values according to their respective surface under cumulative ranking curve (SUCRA) probabilities.

FINDINGS

A total of 18 eligible studies that investigated the association between 9 different chemokines and PTSD were identified. They involved 1,510 patients and 2,012 controls. Results of the meta-analysis showed that the concentrations of CCL3, CCL4 and CCL5 in the PTSD patients were significantly higher than that in the controls (SMDs of 4.12, 6.11 and 1.53 respectively). However, although not statistically significant, concentrations of CCL2 tended to be lower in PTSD patients than in the controls (SMD = -0.76); whereas concentrations of CXCL12 tended to be higher in PTSD patients than in the controls (SMD = 0.37). SUCRA probabilities showed that, among all the chemokines studied, the effect of CCL5 was the highest in PTSD patients.

INTERPRETATION

Concentrations of CCL3, CCL4 and CCL5 may be associated with a trauma and/or PTSD. Also, CXCL12 and CCL2 may be the underlying biomarkers for trauma and/or PTSD. Thus, future studies with large population based samples are needed to further assess these associations. In addition, future research should explore possible mechanisms underlying these associations, with the aim to develop new diagnostics for PTSD. PROSPERO CRD42019147703.

TNF-Alpha as an Initiator of Allodynia and Anxiety-Like Behaviors in a Preclinical Model of PTSD and Comorbid Pain

Post-Traumatic Stress Disorder (PTSD) is a debilitating mental health disorder that occurs after exposure to a traumatic event. Patients with comorbid chronic pain experience affective distress, worse quality of life, and poorer responses to treatments for pain or PTSD than those with either condition alone. FDA-approved PTSD treatments are often ineffective analgesics, requiring additional drugs to treat co-morbid symptoms. Therefore, development of new treatment strategies necessitate a better understanding of the pathophysiology of PTSD and comorbid pain. The single prolonged stress (SPS) model of PTSD induces the development of persistent mechanical allodynia and thermal hyperalgesia. Increased Nociceptin/Orphanin FQ (N/OFQ) levels in serum and CSF accompany these exaggerated nociceptive responses, as well as increased serum levels of the pro-inflammatory cytokine tumor necrosis factor (TNF-α). Therefore, the primary goal was to determine the role of TNF-α in the development of SPS-induced allodynia/hyperalgesia and elevated serum and CNS N/OFQ using two approaches: TNF-α synthesis inhibition, and blockade with anti-TNF-α antibody that acts primarily in the periphery. Administration of TNF-α synthesis blocker, thalidomide (THL), immediately after SPS prevented increased TNF-α and development of allodynia and hyperalgesia. The THL effect lasted at least 21 days, well after thalidomide treatment ended (day 5). THL also prevented SPS-induced increases in serum N/OFQ and reversed regional N/OFQ mRNA expression changes in the CNS. Serum TNF-α increases detected at 4 and 24 h post SPS were not accompanied by blood brain barrier disruption. A single injection of anti-TNF-α antibody to male and female rats during the SPS procedure prevented the development of allodynia, hyperalgesia, and elevated serum N/OFQ, and reduced SPS-induced anxiety-like behaviors in males. Anti-TNFα treatment also blocked development of SPS-induced allodynia in females, and blocked increased hypothalamic N/OFQ in males and females. This suggests that a peripheral TNF-α surge is necessary for the initiation of allodynia associated with SPS, as well as the altered central and peripheral N/OFQ that maintains nociceptive sensitivity. Therefore, early alleviation of TNF-α provides new therapeutic options for investigation as future PTSD and co-morbid pain treatments.

The immunology of SARS-CoV-2 infection, the potential antibody based treatments and vaccination strategies

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a potentially fatal agent for a new emerging viral disease (COVID-19) is of great global public health emergency. Herein, we represented potential antibody-based treatments especially monoclonal antibodies (mAbs) that may exert a potential role in treatment as well as developing vaccination strategies against COVID-19.Areas covered: We used PubMed, Google Scholar, and clinicaltrials.gov search strategies for relevant papers. We demonstrated some agents with potentially favorable efficacy as well as favorable safety. Several therapies are under assessment to evaluate their efficacy and safety for COVID19. However, the development of different strategies such as SARS-CoV-2-based vaccines and antibody therapy are urgently required beside other effective therapies such as plasma, anticoagulants, and immune as well as antiviral therapies. We encourage giving more attention to antibody-based treatments as an immediate strategy. Although there has not been any approved specific vaccine until now, developing vaccination strategies may have a protective effect against COVID-19.Expert opinion: An antiviral mAbs could be a safe and high-quality therapeutic intervention which is greatly recommended for COVID-19. Additionally, the high sequence homology between the SARS-CoV-2 and SARS/MERS viruses could shed light on developing to design a vaccine against SARS-CoV-2.

Inflammation in Post-Traumatic Stress Disorder (PTSD): A Review of Potential Correlates of PTSD with a Neurological Perspective

Post-traumatic stress disorder (PTSD) is a chronic condition characterized by symptoms of physiological and psychosocial burden. While growing research demonstrated signs of inflammation in PTSD, specific biomarkers that may be representative of PTSD such as the detailed neural correlates underlying the inflammatory responses in relation to trauma exposure are seldom discussed. Here, we review recent studies that explored alterations in key inflammatory markers in PTSD, as well as neuroimaging-based studies that further investigated signs of inflammation within the brain in PTSD, as to provide a comprehensive summary of recent literature with a neurological perspective. A search was conducted on studies published from 2009 through 2019 in PubMed and Web of Science. Fifty original articles were selected. Major findings included elevated levels of serum proinflammatory cytokines in individuals with PTSD across various trauma types, as compared with those without PTSD. Furthermore, neuroimaging-based studies demonstrated that altered inflammatory markers are associated with structural and functional alterations in brain regions that are responsible for the regulation of stress and emotion, including the amygdala, hippocampus, and frontal cortex. Future studies that utilize both central and peripheral inflammatory markers are warranted to elucidate the underlying neurological pathway of the pathophysiology of PTSD.

Reduced Expression of Immune Mediators by T-Cell Subpopulations of Combat-Exposed Veterans With Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) has been suggested to be associated with an inflammatory immune state, although few studies have examined peripheral blood lymphocytes in subjects that have PTSD and compared immune parameters to subjects that experienced similar trauma, but did not develop PTSD. An exploratory approach was undertaken to compare phenotypes of blood CD4⁺ and CD8⁺ subpopulations and their expression of immune mediators between Veterans of the Iraq and Afghanistan wars who experienced similar levels of combat, with some developing PTSD and other not. The results of this study did not demonstrate evidence of enhanced immune activation of peripheral blood lymphocytes. Instead, the results showed a decline in expression of the pro-inflammatory mediator IFN-γ and the cytotoxin granzyme B in CD8⁺ subpopulations from Veterans with PTSD. While the reductions in expression of IFN-γ and granzyme B did not reach statistical significance when examining the CD8⁺ cell population as a whole, the declines were significant when examining the CD8⁺ cell subpopulations, with different mediators being reduced in different subpopulations. The most prominent decline in IFN-γ expression was by the unconventional CD8^dimCD3⁺ T-cell subpopulation that has been associated with chronic infection and immune fatigue. The decline in granzyme B was most prominent in the NK-containing CD8^dimCD3^- subpopulation of Tcells. Consequently, analysis of blood leukocyte subpopulations, rather than bulk lymphocyte groups, reveals a dampened level of immune reactivity in combat-exposed Veterans with PTSD compared to combat-exposed Veterans without PTSD.