The effects of psychological stress on leukocyte subset distribution in humans: evidence of immune activation

Complex Intersections Between Adverse Childhood Experiences and Negative Life Events Impact the Phenome of Major Depression

Background

There is evidence that adverse childhood experiences (ACEs) and negative life events (NLEs) are associated with major depression (MDD).

Purpose

To determine whether ACEs affect all features of mild MDD, including suicidal tendencies, brooding, neuroticism, insomnia, cognitive deficits, severity of depression and anxiety, and cognitive deficits, and whether NLEs mediate these effects.

Sample of the Study and Methods

This study examines a cohort of 118 academic students, namely 74 students who satisfied the DSM-5-TR criteria for MDD and 44 normal control students. We assessed brooding, neuroticism, suicidal ideation and attempts, and the severity of depression, anxiety, insomnia, and the Stroop tests.

Results

One validated factor could be extracted from brooding, neuroticism, current suicidal behaviors, and the severity of depression, anxiety, and insomnia, labeled the phenome of depression. A large part of the variance in the phenome of depression (55.0%) was explained by the combined effects of self-, relationships, and academic-related NLEs in conjunction with ACEs, including family dysfunction and abuse and neglect (both physical and emotional). The latter ACEs significantly interacted (moderating effect) with NLEs to impact the depression phenome. Although sexual abuse did not have direct effects on the phenome, its effects were mediated by NLEs. We discovered that increased sexual abuse, physical and emotional abuse and neglect, and ACEs related to family dysfunction predicted 22.5% of the variance in NLEs. Up to 18.5% of the variance in the Stroop test scores was explained by sexual abuse and the phenome of depression. The latter mediated the effects of NLEs and abuse, neglect, and family dysfunction on the Stroop test scores.

Conclusion

Complex intersections between ACEs and NLEs impact the phenome of depression, which comprises neuroticism, brooding, suicidal tendencies, and the severity of insomnia, anxiety, and depression, while sexual abuse together with other ACEs and NLEs may impact cognitive interference inhibition.

B cells and the stressed brain: emerging evidence of neuroimmune interactions in the context of psychosocial stress and major depression

The immune system has emerged as a key regulator of central nervous system (CNS) function in health and in disease. Importantly, improved understanding of immune contributions to mood disorders has provided novel opportunities for the treatment of debilitating stress-related mental health conditions such as major depressive disorder (MDD). Yet, the impact to, and involvement of, B lymphocytes in the response to stress is not well-understood, leaving a fundamental gap in our knowledge underlying the immune theory of depression. Several emerging clinical and preclinical findings highlight pronounced consequences for B cells in stress and MDD and may indicate key roles for B cells in modulating mood. This review will describe the clinical and foundational observations implicating B cell-psychological stress interactions, discuss potential mechanisms by which B cells may impact brain function in the context of stress and mood disorders, describe research tools that support the investigation of their neurobiological impacts, and highlight remaining research questions. The goal here is for this discussion to illuminate both the scope and limitations of our current understanding regarding the role of B cells, stress, mood, and depression.

Research and Diagnostic Algorithmic Rules (RADAR) and RADAR Plots for the First Episode of Major Depressive Disorder: Effects of Childhood and Recent Adverse Experiences on Suicidal Behaviors, Neurocognition and Phenome Features

Recent studies have proposed valid precision models and valid Research and Diagnostic Algorithmic Rules (RADAR) for recurrent major depressive disorder (MDD). The aim of the current study was to construct precision models and RADAR scores in patients experiencing first-episode MDD and to examine whether adverse childhood experiences (ACE) and negative life events (NLE) are associated with suicidal behaviors (SB), cognitive impairment, and phenome RADAR scores. This study recruited 90 patients with major depressive disorder (MDD) in an acute phase, of whom 71 showed a first-episode MDD (FEM), and 40 controls. We constructed RADAR scores for ACE; NLE encountered in the last year; SB; and severity of depression, anxiety, chronic fatigue, and physiosomatic symptoms using the Hamilton Depression and Anxiety Rating Scales and the FibroFatigue scale. The partial least squares analysis showed that in FEM, one latent vector (labeled the phenome of FEM) could be extracted from depressive, anxiety, fatigue, physiosomatic, melancholia, and insomnia symptoms, SB, and cognitive impairments. The latter were conceptualized as a latent vector extracted from the Verbal Fluency Test, the Mini-Mental State Examination, and ratings of memory and judgement, indicating a generalized cognitive decline (G-CoDe). We found that 60.8% of the variance in the FEM phenome was explained by the cumulative effects of NLE and ACE, in particular emotional neglect and, to a lesser extent, physical abuse. In conclusion, the RADAR scores and plots constructed here should be used in research and clinical settings, rather than the binary diagnosis of MDD based on the DSM-5 or ICD.

Social stressors associated with age-related T lymphocyte percentages in older US adults: Evidence from the US Health and Retirement Study

Exposure to stress is a risk factor for poor health and accelerated aging. Immune aging, including declines in naïve and increases in terminally differentiated T cells, plays a role in immune health and tissue specific aging, and may contribute to elevated risk for poor health among those who experience high psychosocial stress. Past data have been limited in estimating the contribution of life stress to the development of accelerated immune aging and investigating mediators such as lifestyle and cytomegalovirus (CMV) infection. This study utilizes a national sample of 5,744 US adults over age 50 to assess the relationship of social stress (viz., everyday discrimination, stressful life events, lifetime discrimination, life trauma, and chronic stress) with flow cytometric estimates of immune aging, including naïve and terminally differentiated T cell percentages and the ratio of CD4+ to CD8+ cells. Experiencing life trauma and chronic stress was related to a lower percentage of CD4+ naïve cells. Discrimination and chronic stress were each associated with a greater percentage of terminally differentiated CD4+ cells. Stressful life events, high lifetime discrimination, and life trauma were related to a lower percentage of CD8+ naïve cells. Stressful life events, high lifetime discrimination, and chronic stress were associated with a higher percentage of terminally differentiated CD8+ cells. High lifetime discrimination and chronic stress were related to a lower CD4+:CD8+ ratio. Lifestyle factors and CMV seropositivity partially reduced these effects. Results identify psychosocial stress as a contributor to accelerating immune aging by decreasing naïve and increasing terminally differentiated T cells.

Immune Cell Plasticity in Inflammation: Insights into Description and Regulation of Immune Cell Phenotypes

Inflammation is a life-saving immune reaction occurring in response to invading pathogens. Nonetheless, inflammation can also occur in an uncontrolled, unrestricted manner, leading to chronic disease and organ damage. Mechanisms triggering an inflammatory response, hindering such a response, or leading to its resolution are well-studied but so far insufficiently elucidated with regard to precise therapeutic interventions. Notably, as an immune reaction evolves, requirements and environments for immune cells change, and thus cellular phenotypes adapt and shift, leading to the appearance of distinct cellular subpopulations with new functional features. In this article, we aim to highlight properties of, and overarching regulatory factors involved in, the occurrence of immune cell phenotypes with a special focus on neutrophils, macrophages and platelets. Additionally, we point out implications for both diagnostics and therapeutics in inflammation research.

The role of IL-6 in TBI and PTSD, a potential therapeutic target?

This literature review focuses on the role of IL-6 in TBI or PTSD-induced neuroinflammation. While TBI and PTSD are widely prevalent, these diagnoses are particularly common amongst veterans. Given the role of IL-6 in neuroprotection acutely, compared to detrimental chronically, targeting this cytokine at specific time points may be beneficial in modulating neuroinflammation. Current treatments for TBI or PTSD are variably affective. By reviewing the role of IL-6 in these two diagnoses, future studies can focus on therapeutics to treat neuroinflammation and ultimately reduce the devastating impacts of neuroinflammation on cognition in PTSD and TBI.

Enhanced Effects of Chronic Restraint-Induced Psychological Stress on Total Body Fe-Irradiation-Induced Hematopoietic Toxicity in Trp53-Heterozygous Mice

Humans are exposed to both psychological stress (PS) and radiation in some scenarios such as manned deep-space missions. It is of great concern to verify possible enhanced deleterious effects from such concurrent exposure. Pioneer studies showed that chronic restraint-induced PS (CRIPS) could attenuate Trp53 functions and increase gamma-ray-induced carcinogenesis in Trp53-heterozygous mice while CRIPS did not significantly modify the effects on X-ray-induced hematopoietic toxicity in Trp53 wild-type mice. As high-linear energy transfer (LET) radiation is the most important component of space radiation in causing biological effects, we further investigated the effects of CRIPS on high-LET iron-particle radiation (Fe)-induced hematopoietic toxicity in Trp53-heterozygous mice. The results showed that CRIPS alone could hardly induce significant alteration in hematological parameters (peripheral hemogram and micronucleated erythrocytes in bone marrow) while concurrent exposure caused elevated genotoxicity measured as micronucleus incidence in erythrocytes. Particularly, exposure to either CRISP or Fe-particle radiation at a low dose (0.1 Gy) did not induce a marked increase in the micronucleus incidence; however, concurrent exposure caused a significantly higher increase in the micronucleus incidence. These findings indicated that CRIPS could enhance the deleterious effects of high-LET radiation, particularly at a low dose, on the hematopoietic toxicity in Trp53-heterozygous mice.

Differential blood leukocyte populations based on individual variances and age

Blood was collected from the New York State Department of Health (NYSDOH) employees to assess variances in leukocyte numbers in January, May, and September throughout a year and over many years. Women and men of ages 20 to 80 volunteered to donate for this program. Most of the blood came from healthy individuals, and many remained healthy throughout the years of their blood donations. The major objective was to determine the extent that blood leukocyte numbers change so that transient vs more lingering changes may be helpful in assessing health status. Since some donors remained in the program for 14 years, age influences over time could be determined. Within a short period of 2-3 years, the flow cytometric immunophenotypic profile of blood lymphocyte is relatively stable with a CV% of < 20%. However, as humans age, the blood CD3⁺ T cell, CD8⁺ T cell, B cell, NKT cell, and CD4^-/CD8^- double-negative T cell (DN-T cell) subsets declined in cell numbers/μL, but the double-positive CD4⁺/CD8⁺ T cells (DP-T cells) increased in numbers. The extent and chronology of a variance, e.g., a subset exceeding its 75th or 90th percentile, might be indicative of a transient or chronic physiological or psychosocial stress affecting health or a developing pathology; however, because of the wide ranges of cell numbers/μL for each subset among individuals reported as healthy, everyone's immunity and health must be carefully evaluated. A CD4 to CD8 ratio (4/8R) of < 1 has been used to define an immunodeficiency such as HIV-induced AIDS, but a high 4/8R is less well associated with health status. A high 4/8R or granulocyte to lymphocyte ratio (GLR) might be an indicator of a stress, infection, or immune-related pathology. Sporadic and longitudinal increases of GLRs are reported. The results suggest that there are some age and sex differences in leukocyte numbers; stress influences on the blood profile of leukocytes likely exist. However, some values exceeding 2 standard deviations from means do not necessarily predict a health concern, whereas a longitudinal increase or decline might be indicative of a need for further evaluations.

Mental health issues among international touring professionals in the music industry

Music industry touring professionals are generally assumed to be at elevated risk for mental health issues, highlighted by numerous high-profile suicides in recent years. Few studies have explored the prevalence of depression, suicidality and associated factors within this population. This study aims to gain an empirical understanding of the mental health issues among international touring professionals, with a particular focus on risk for depression and suicidality, and to identify potential protective factors. Data were collected between February-March 2020 as part of the Tour Health Research Initiative's Touring Health and Wellness Survey 2020. Using a multidimensional questionnaire with a sample of 1154 international touring professionals (artists and crew members), participants who completed all psychosocial measures (n = 508) demonstrated elevated levels of suicidality, risk for clinical depression, stress, anxiety and burnout. The median depression score for completers matched the recommended cutoff score of 20, which qualified 254 participants as high risk for clinical depression, while 200 (39.4%) demonstrated high scores for suicidality. In ROC curve analyses, all psychosocial measures were significant predictors of high suicidality, with a combined emotional and social measure yielding the highest classification accuracy (80%). Moderate strength linear relations were observed for all pairs of measures. Positive correlations were found among all risk factors (depression, anxiety, stress, and burnout) and these measures yielded negative correlations with the protective factors (mindfulness and the emotional/social measure). Findings suggest that interventions enhancing mindfulness and emotional/social well-being may serve as valuable treatment components for this population.

White blood cell count profiles in multiple sclerosis during attacks before the initiation of acute and chronic treatments

Multiple sclerosis (MS) is a major demyelinating disease of the central nervous system; however, its exact mechanism is unknown. This study aimed to elucidate the profile of white blood cells (WBCs) in the acute phase of an MS attack. Sixty-four patients with MS at the time of diagnosis and 2492 age- and sex-adjusted healthy controls (HCs) were enrolled. Data regarding the blood cell counts were compared between the groups. The total WBC (p < 0.0001), monocyte (p < 0.0001), basophil (p = 0.0027), and neutrophil (p < 0.0001) counts were higher in the MS group than in the HC group, whereas the lymphocyte and eosinophil counts did not differ. Adjustments for the smoking status and body mass index yielded the same results. The total and differential WBC counts of the patients with MS did not correlate with the counts of T2 hyperintense brain lesions or the levels of neurological disturbance. In summary, patients with MS showed elevated counts of total WBCs, monocytes, basophils, and neutrophils at the time of diagnosis. However, the clinical relevance of these biomarkers in the context of the development and progression of MS remains unclear.

Effect of climatic factors on urinary cortisol and peripheral blood leukocytes in lambs grazing on a semi-natural grassland in the Hokuriku District of Japan

The effects of climatic factors on stress and immune functions of grazing lambs in summer and autumn in the Hokuriku District of Japan were evaluated by determining urinary cortisol (U-COR) levels and peripheral blood leukocyte populations and comparing those with lambs kept indoors. Two groups of five lambs, consisting of those grazed on a semi-natural grassland (GRL) and those housed indoors in a domestic animal shelter (INL), were maintained at from July to October. The temperature-humidity index at each location was indicative of heat stress during summer; however, the U-COR elevation was not observed in both groups. The elevation was observed in GRL in autumn and was higher than INL in October. Climatic conditions in autumn were characterized by high humidity and a sudden drop in temperature. U-COR was positively correlated with the relative humidity. The GRL was exposed to low-nutrient conditions for a relatively long time. The CD4⁺ /CD8⁺ T cell ratio in GRL decreased in October. Subsequently, the total leucocyte, including granulocytes, monocytes, and lymphocytes, sharply increased. The responses indicated an immune deficiency caused by immunosuppression because of a low nutrition caused by grazing and high-stress conditions in autumn.

Enduring neuroimmunological consequences of developmental experiences: From vulnerability to resilience

The immune system is crucial for normal neuronal development and function (neuroimmune system). Both immune and neuronal systems undergo significant postnatal development and are sensitive to developmental programming by environmental experiences. Negative experiences from infection to psychological stress at a range of different time points (in utero to adolescence) can permanently alter the function of the neuroimmune system: given its prominent role in normal brain development and function this dysregulation may increase vulnerability to psychiatric illness. In contrast, positive experiences such as exercise and environmental enrichment are protective and can promote resilience, even restoring the detrimental effects of negative experiences on the neuroimmune system. This suggests the neuroimmune system is a viable therapeutic target for treatment and prevention of psychiatric illnesses, especially those related to stress. In this review we will summarise the main cells, molecules and functions of the immune system in general and with specific reference to central nervous system development and function. We will then discuss the effects of negative and positive environmental experiences, especially during development, in programming the long-term functioning of the neuroimmune system. Finally, we will review the sparse but growing literature on sex differences in neuroimmune development and response to environmental experiences.

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The immune system is essential for development and function of the central nervous system (neuroimmune system)

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Environmental experiences can permanently alter neuroimmune function and associated brain development

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Altered neuroimmune function following negative developmental experiences may play a role in psychiatric illnesses

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Positive experiences can promote resilience and rescue the effects of negative experiences on the neuroimmune system

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The neuroimmune system is therefore a viable therapeutic target for preventing and treating psychiatric illnesses

Rheumatoid Arthritis: The Impact of Mental Health on Disease: A Narrative Review

Over 60% of rheumatoid arthritis (RA) patients achieve a good response after 12 months of treatment when following the European league against rheumatism (EULAR) guidelines for treatment. However, almost half of patients still suffer from moderate to severe disease activity despite this. In addition, mental health problems may remain despite reduced measures of inflammation systemically and within joints. Depression is two times more common in RA patients than in the general population, and intriguingly a bi-directional relationship with RA has been shown in cross-sectional studies. Chronic inflammation impairs the physiological responses to stress including effective coping behaviours, resulting in depression, which leads to a worse long-term outcome in RA. In RA patients, the pain score is not always solely related to inflammatory arthritis and immunological disease activity by Bąk et al. (Patient Prefer Adherence 13:223-231, [1]). Non-inflammatory pain secondary to anxiety, depression, sleep disturbance and the psychosocial situation needs to be considered whilst fibromyalgia, mechanical pain and neuropathic pain can also contribute to overall pain scores by Chancay et al. (Women's Midlife Health 5:3, [2]). Hence, the UK National Institute for Health and Care Excellence (NICE) guideline for the management of RA included psychological interventions for fatigue, low mood and social well-being (NICE NG100, 2018) [3], and the NICE clinical guidelines (CG91) [4] suggest managing mental health and depression in chronic medical conditions to improve treatment outcomes. This is a narrative review of the impact of mental health on RA disease activity in terms of patient-reported outcomes (PROs).

State-of-the-Art: Inflammatory and Metabolic Markers in Mood Disorders

Mounting evidence highlights the involvement of inflammatory/immune systems and their relationships with neurotransmitters and different metabolic processes in mood disorders. Nevertheless, there is a general agreement that available findings are still inconclusive. Therefore, further investigations are required, aimed at deepening the role of possible alterations of biomarkers in the pathophysiology of mood disorders that might lead to more focused and tailored treatments. The present study is a comprehensive review on these topics that seem to represent intriguing avenues for the development of real innovative therapeutic strategies of mood disorders.

Immune dysregulation among students exposed to exam stress and its mitigation by mindfulness training: findings from an exploratory randomised trial

Psychological distress persisting for weeks or more promotes pro-inflammatory immune dysregulation, a risk factor for a range of chronic diseases. We have recently shown that mindfulness training reduces distress among university students. Here we present an exploratory trial to study immune dysregulation in a cohort of students who were exposed to progressively greater stress as the exam period approached, and to explore whether mindfulness training mitigated this dysregulation. Healthy University of Cambridge students were randomised to join an 8-week mindfulness course (N = 27), or to mental health support as usual (N = 27). Psychological distress, immune cell proportions, cytokines, CRP and serum cortisol were measured at baseline and during the exam period. Increased distress was associated with statistically significant increases in the proportion of B cells, regardless of trial arm (*p = 0.027). There were no other associations between any of the measured parameters, distress or mindfulness. Our finding that the proportion of B cells increases with psychological distress supports the findings of other studies. However, we found no evidence that mindfulness training is able to buffer the effects of psychological distress on healthy participants' immune system. In order to detect these effects, should they exist, larger randomised trials will be required.

Inflammatory and immunological changes caused by noise exposure: A systematic review

Today, due to the growth of industries and spread of the use of various instruments and devices that produce high noise levels, it is necessary to pay more attention to the effects of exposure to noise on organs and tissues in the body. The importance of the immune system in fighting external and pathogenic factors has raised the need to consider external factors (such as harmful physical factors) and make efforts to avoid producing them. In this systematic review, 811 potentially relevant studies were found in Google Scholar, PubMed, and Web of Science databases, of which 32 different English-written articles were included in the study. The method of searching and systematically reviewing articles was based on the assessment tool of the multiple systematic reviews (AMSTAR) method. The results of this study suggested that noise could affect the function of the immune system and its components by affecting other systems and organs of the body, including the central nervous system, auditory system, circulatory system, and endocrine gland. Moreover, it can be hypothesized that noise affects immune system by producing the NADPH oxidase (Nox) and reactive oxygen species (ROS).

Transportation and Routine Veterinary Interventions Alter Immune Function in the Dog

Rapid activation of the hypothalamic pituitary adrenal axis and the sympathetic nervous system are hallmarks of the acute stress response and these systems interact with the immune system by signaling though glucocorticoid and adrenergic receptors on immune cells. There is limited information about the effect of these physiologic responses on immunologic parameters of pet dogs enrolled in clinical studies. The objective of this study was to evaluate how travel, instrumentation, and hospitalization alter immunologic parameters in pet dogs. Blood was collected from healthy dogs in a home environment and from healthy dogs at the time of presentation to the hospital and after instrumentation and 24 hours of hospitalization. We found that lipopolysaccharide (LPS)-induced downregulation of toll like receptor 4 (TLR4) was blunted in dogs exposed to stress. Neutrophil and monocyte major histocompatibility complex class II (MHCII) expression increased after transportation to the veterinary hospital but then became similar to that of the control dogs at the end of hospitalization. Peripheral blood mononuclear cell cytotoxicity function was blunted in dogs exposed to the stress of transportation as well as hospitalization. Neutrophil apoptosis was greater in dogs exposed to stress compared to controls although this effect significantly decreased after hospitalization stress. Conversely, stress did not alter induced or spontaneous cytokine production from leukocytes, neutrophil or monocyte expression of TLR4, LPS-induced downregulation of monocyte TLR4, LPS-induced neutrophil and monocyte expression of MHCII or peripheral blood lymphocyte phenotype. Transportation and instrumentation/hospitalization stress should be considered when interpreting immunologic studies in pet dogs.

A review of physiological and behavioral monitoring with digital sensors for neuropsychiatric illnesses

Physiological, behavioral, and psychological changes associated with neuropsychiatric illness are reflected in several related signals, including actigraphy, location, word sentiment, voice tone, social activity, heart rate, and responses to standardized questionnaires. These signals can be passively monitored using sensors in smartphones, wearable accelerometers, Holter monitors, and multimodal sensing approaches that fuse multiple data types. Connection of these devices to the internet has made large scale studies feasible and is enabling a revolution in neuropsychiatric monitoring. Currently, evaluation and diagnosis of neuropsychiatric disorders relies on clinical visits, which are infrequent and out of the context of a patient's home environment. Moreover, the demand for clinical care far exceeds the supply of providers. The growing prevalence of context-aware and physiologically relevant digital sensors in consumer technology could help address these challenges, enable objective indexing of patient severity, and inform rapid adjustment of treatment in real-time. Here we review recent studies utilizing such sensors in the context of neuropsychiatric illnesses including stress and depression, bipolar disorder, schizophrenia, post traumatic stress disorder, Alzheimer's disease, and Parkinson's disease.

Behavior and physiology of two different sow breeds in a farrowing environment during late 35-day lactation

To improve the overall welfare levels of sows and to reduce stress levels at late 35-day lactation, we selected targeted behavioral indicators that might be associated with stress. Therefore, we monitored and evaluated the adaptive capability of two different breeds of sows to the farrowing environment. In this study, Damin sows (Large White × Min pig sows, n = 20) and Large White sows (n = 20) were farrowed in individual pens. Saliva was collected and tested for cortisol density at –15 min, and then at +15, 30, 60, 90, 120, 180 and 240 min after an adrenocorticotropic hormone (ACTH) stimulation test conducted at 20, 27 and 34 d post-partum. The postures, including ventral and lateral recumbency to other postures, defecating, urinating, sham-chewing and bar-biting behavior, were observed by video from 07:00 to 09:00 and from 13:00 to 15:00 on the 7th day of each week from the 3rd to the 5th week post-parturition. In addition, the concentrations of salivary interleukin (IL)-6, tumor necrosis factor (TNF)-α and secretory immunoglobulin (SIgA) were assayed after the observed behaviors. The results showed no significant difference between Damin sows and Large White sows in terms of behaviors at the 3rd week. Additionally, there were no significant differences between Damin and Large White sows in terms of the behaviors of ventral recumbency and bar-biting with the exception of lateral recumbency to other postures, sham-chewing, defecation and urination in the fifth week. Meanwhlie, there was significant difference between two breeds in term of ventral recumbency at the 4th week. The result of the ACTH test showed a significant difference between the Damin and Large White sows by the 27th and 34th days postpartum (P<0.01). In addition, the serological concentrations of IL-6 and TNF-α were not significantly different between the two breeds at the 3rd week postpartum. However, these indicators were significantly different at the 5th week postpartum (P = 0.000, and P = 0.003, respectively). The SIgA concentrations in saliva were significantly different between breeds at the 3rd week postpartum (P<0.01). In conclusion, both breeds of sows maybe in a state of stress after the 4th week postpartum. However, the Damin sows may be better than the Large White sows in terms of adapting to this farrowing environment.

Body image dissatisfaction in pregnant and non-pregnant females is strongly predicted by immune activation and mucosa-derived activation of the tryptophan catabolite (TRYCAT) pathway

OBJECTIVES

The aim of the present study is to delineate the associations between body image dissatisfaction in pregnant women and immune-inflammatory biomarkers, i.e., C-reactive protein (CRP), zinc and IgA/IgM responses to tryptophan and tryptophan catabolites (TRYCATs).

METHODS

We assessed 49 pregnant and 24 non-pregnant females and assessed Body Image Satisfaction (BIS) scores at the end of term (T1), and 2-4 days (T2) and 4-6 weeks (T3) after delivery. Subjects were divided in those with a lowered BIS score (≤ 3) versus those with a higher score.

RESULTS

Logistic regression analysis showed that a lowered T1 BIS score was predicted by CRP levels and IgA responses to tryptophan (negative) and TRYCATs (positive), perinatal depression, body mass index (BMI) and age. The sum of quinolinic acid, kynurenine, 3-OH-kynurenine and 3-OH-anthranilic acid (reflecting brain quinolinic acid contents) was the single best predictor. In addition, a large part of the variance in the T1, T2 and T3 BIS scores was explained by IgA responses to tryptophan and TRYCATs, especially quinolinic acid.

CONCLUSIONS

Body image dissatisfaction is strongly associated with inflammation and mucosa-derived IDO activation independently from depression, pregnancy, BMI and age. IgA responses to peripheral TRYCATs, which determine brain quinolinic acid concentrations, also predict body image dissatisfaction.

Frailty and leucocyte count are predictors of all-cause mortality and hospitalization length in non-demented institutionalized older women

Alteration in the immune system such as the number of white blood cells count (WBC) has been associated with frailty syndrome but their role in institutionalized older individuals have been rarely investigated. We evaluated the relationships between white blood cell subtypes, geriatric assessment, depression and frailty syndrome based on the criteria of physical phenotype. In particular, we aimed to analyze by a two-year follow-up and prospective study the predictive value of alterations in WBC, frailty and functional impairment in terms of hospitalizations and all-cause mortality in institutionalized older women. There was a significant and inverse correlation between the frailty score and lymphocyte count at baseline but it did not display any predictive effect for the outcomes (hospitalizations and mortality). In contrast, monocytes count was significantly correlated with number of hospital stays and predicted hospitalizations in the follow-up. High frailty score directly and better functional status (Barthel score) inversely predicted mortality in the follow-up with an HR of 1.87 (95%CI: 1.04-3.35), and 0.97 (95% CI: 0.96-0.99) (p < .05 in both cases). Further investigation into the role of white blood cell subtypes in aging and its associated adverse outcomes in older adults is warranted. Physical phenotype of frailty besides general population, also predicted mortality in older institutionalized women and deserves specific intervention in this subgroup of older individuals.

Sex differences in the neuro-immune consequences of stress: Focus on depression and anxiety

Women appear to be more vulnerable to the depressogenic effects of inflammation than men. Chronic stress, one of the most pertinent risk factors of depression and anxiety, is known to induce behavioral and affective-like deficits via neuroimmune alterations including activation of the brain's immune cells, pro-inflammatory cytokine expression, and subsequent changes in neurotransmission and synaptic plasticity within stress-related neural circuitry. Despite well-established sexual dimorphisms in the stress response, immunity, and prevalence of stress-linked psychiatric illnesses, much of current research investigating the neuroimmune impact of stress remains exclusively focused on male subjects. We summarize and evaluate here the available data regarding sex differences in the neuro-immune consequences of stress, and some of the physiological factors contributing to these differences. Furthermore, we discuss the extent to which sex differences in stress-related neuroinflammation can account for the overall female bias in stress-linked psychiatric disorders including major depressive disorder and anxiety disorders. The currently available evidence from rodent studies does not unequivocally support the peripheral inflammatory changes seen in women following stress. Replication of many recent findings in stress-related neuroinflammation in female subjects is necessary in order to build a framework in which we can assess the extent to which sex differences in stress-related inflammation contribute to the overall female bias in stress-related affective disorders.

Influence of Perceived Stress on Incident Amnestic Mild Cognitive Impairment: Results From the Einstein Aging Study

Stress is a potentially remediable risk factor for amnestic mild cognitive impairment (aMCI). Our objective is to determine whether perceived stress predicts incident aMCI and to determine if the influence of stress on aMCI is independent of known aMCI risk factors, particularly demographic variables, depression, and apolipoprotein genotype. The Einstein Aging Study is a longitudinal community-based study of older adults. The Perceived Stress Scale (PSS) was administered annually in the Einstein Aging Study to participants (N=507; 71 developed incident aMCI; mean follow-up time=3.6 y, SD=2.0) who were aged 70 years and older, free of aMCI and dementia at baseline PSS administration, and had at least 1 subsequent annual follow-up. Cox hazard models were used to examine time to aMCI onset adjusting for covariates. High levels of perceived stress are associated with a 30% greater risk of incident aMCI (per 5-point increase in PSS: hazard ratio=1.30; 95% confidence interval, 1.08-1.58) independent of covariates. The consistency of results after covariate adjustment and the lack of evidence for reverse causation in longitudinal analyses suggest that these findings are robust. Understanding of the effect of perceived stress on cognition may lead to intervention strategies that prevent the onset of aMCI and Alzheimer dementia.

Psychometric properties of the Perceived Stress Scale (PSS): measurement invariance between athletes and non-athletes and construct validity

Background

Although Perceived Stress Scale (PSS, Cohen, Kamarack & Mermelstein, 1983) has been validated and widely used in many domains, there is still no validation in sports by comparing athletes and non-athletes and examining related psychometric indices.

Purpose

The purpose of this study was to examine the measurement invariance of PSS between athletes and non-athletes, and examine construct validity and reliability in the sports contexts.

Methods

Study 1 sampled 359 college student-athletes (males = 233; females = 126) and 242 non-athletes (males = 124; females = 118) and examined factorial structure, measurement invariance and internal consistency. Study 2 sampled 196 student-athletes (males = 139, females = 57, M_age = 19.88 yrs, SD = 1.35) and examined discriminant validity and convergent validity of PSS. Study 3 sampled 37 student-athletes to assess test-retest reliability of PSS.

Results

Results found that 2-factor PSS-10 fitted the model the best and had appropriate reliability. Also, there was a measurement invariance between athletes and non-athletes; and PSS positively correlated with athletic burnout and life stress but negatively correlated with coping efficacy provided evidence of discriminant validity and convergent validity. Further, the test-retest reliability for PSS subscales was significant (r = .66 and r = .50).

Discussion

It is suggested that 2-factor PSS-10 can be a useful tool in assessing perceived stress either in sports or non-sports settings. We suggest future study may use 2-factor PSS-10 in examining the effects of stress on the athletic injury, burnout, and psychiatry disorders.

The Association Between Perceived Stress and Mortality Among People With Multimorbidity: A Prospective Population-Based Cohort Study

Multimorbidity is common and is associated with poor mental health and high mortality. Nevertheless, no studies have evaluated whether mental health may affect the survival of people with multimorbidity. We investigated the association between perceived stress and mortality in people with multimorbidity by following a population-based cohort of 118,410 participants from the Danish National Health Survey 2010 for up to 4 years. Information on perceived stress and lifestyle was obtained from the survey. We assessed multimorbidity using nationwide register data on 39 conditions and identified 4,229 deaths for the 453,648 person-years at risk. Mortality rates rose with increasing levels of stress in a dose-response relationship (P-trend < 0.0001), independently of multimorbidity status. Mortality hazard ratios (highest stress quintile vs. lowest) were 1.51 (95% confidence interval (CI): 1.25, 1.84) among persons without multimorbidity, 1.39 (95% CI: 1.18, 1.64) among those with 2 or 3 conditions, and 1.43 (95% CI: 1.18, 1.73) among those with 4 or more conditions, when adjusted for disease severities, lifestyle, and socioeconomic status. The numbers of excess deaths associated with high stress were 69 among persons without multimorbidity, 128 among those with 2 or 3 conditions, and 255 among those with 4 or more conditions. Our findings suggested that perceived stress contributes significantly to higher mortality rates in a dose-response pattern, and more stress-associated deaths occurred in people with multimorbidity.

Stress, cortisol, and B lymphocytes: a novel approach to understanding academic stress and immune function

Animal and human in vitro models suggest that stress-related B lymphocyte decrements are due to high levels of glucocorticoids which cause apoptosis of pre-B-cells as they emerge from the bone marrow. The present study sought to explore the relationships among distress, salivary cortisol, and human B lymphocytes in vivo. Distress (perceived stress, negative affect, depressive symptoms), lymphocyte phenotype, and salivary cortisol were assessed among first-year graduate students (n = 22) and a community control sample (n = 30) at the start of classes in the fall and the week immediately before spring preliminary exams. Compared to controls, students reported greater distress on all measures at each time point except baseline perceived stress. Hierarchical linear regression with necessary control variables was used to assess the effect of student status on the three measures of distress, the four measures of lymphocyte phenotype, and cortisol AUC and CAR over time (T1-T2). Student status was associated with a significant decrease in CD19 + B lymphocytes and flattened cortisol awakening response (CAR). Change in CAR was associated with the decrease in CD19 + B lymphocytes. Results indicated that there are significant associations among student status, flattening of CAR, and decrements in CD19 + lymphocytes.

The importance of cytokines and autoantibodies in depression

The relationship between depression and immunity has been widely discussed. Cytokines, such as TNF-α, play an important role in immune system; these cytokines interact with virtually every pathophysiologic domain relevant to depression, including neurotransmitter metabolism, neuroendocrine function, and synaptic plasticity. Antibodies have also been implicated in the pathophysiology of depression. The association between decreased serotonin levels and excessive glutamatergic activity forms the first biochemical basis for cytokine-induced depression. Cytokines and antibodies (anti-ribosomal-P and anti-N-methyl-D-aspartate receptor antibodies) are deeply related to pathogenesis of neurodevelopmental disorders, especially depression. Tumor necrosis factor alpha (TNF-α) may underlie the mechanism of depression by an activation of the hypothalamo-pituitary-adrenocortical (HPA) axis, an activation of neuronal serotonin transporters and the stimulation of the indoleamine 2,3-dioxygenase which leads to tryptophan depletion. In the last 20 years since the initial reports of neural-immune interactions in depression, studies have shown a clear association between activation of the immune system mediated by proinflammatory cytokines. Genes encoding cytokines are highly polymorphic and single nucleotide polymorphisms, associated with increased or reduced cytokine production, have been described. To date, there are only few studies that investigated the relationship between depression and proinflammatory cytokines in patients with autoimmune diseases. Although an associative link between neuroinflammation and mood disorders is widely accepted, further studies are necessary to establish the cause-effect relationship. In this paper, we review the role of cytokines, focusing on TNF-α and antibodies in the depression and hypothesize how TNF-α may underlie and mediate the inflammatory process depression in patients with autoimmune disease.

Elevated levels of hs-CRP are associated with high prevalence of depression in japanese patients with type 2 diabetes: the Diabetes Distress and Care Registry at Tenri (DDCRT 6)

OBJECTIVE

Because of the absence of data on the direct association between inflammation and depression in patients with diabetes, we examined the association between hs-CRP levels and the high prevalence of depression in adult patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Cross-sectional data were obtained from 3,573 patients with type 2 diabetes recruited from a Japanese diabetes registry. A multiple logistic regression analysis adjusted for potential confounders was used to assess independent associations between hs-CRP levels and major depression, as defined by the Patient Health Questionnaire-9.

RESULTS

Mean age, BMI, and HbA1c levels were 66.0 years, 24.6 kg/m(2), and 7.4% (57.8 mmol/mol), respectively, and 122 patients (3.4%) suffered from major depression. In the age- and sex-adjusted model, the odds ratio (OR) for major depression was 1.86 (95% CI 1.01-3.42; P = 0.045) in the highest CRP quintile compared with that in the 3rd CRP quintile; however, this association disappeared after adjustment for other possible confounders (OR 1.58 [95% CI 0.85-2.94]; P = 0.148). Among patients with a BMI of ≥25 kg/m(2), a significant association was observed between the highest hs-CRP quintile and major depression (multivariable-adjusted OR 2.69 [95% CI 1.09-7.08]; P = 0.032).

CONCLUSIONS

We observed a significant positive association between high hs-CRP levels and depression in patients with diabetes who had a high BMI.

Perceived stress predicts allergy flares

BACKGROUND

A relation between stress and symptoms of rhinitis has not been established.

OBJECTIVE

To determine if participants' reporting of allergy flares correlated with perceived emotional stress, depression, mood, and a biomarker of stress (cortisol).

METHODS

This study was a secondary analysis of 179 university employees who participated in a study evaluating the influence of several lifestyle interventions on health symptoms and inflammation. Perceived stress and depressive symptom questionnaires were obtained before each 2-week study period. Online diary entries documenting same-day allergy flares, stressful events, perceived stress, mood, and salivary cortisol levels were collected daily during 2 14-day blocks.

RESULTS

Thirty-nine percent of subjects (n = 69) self-reported allergy symptoms. This allergy flare group had higher perceived stress scores than the group without allergy symptoms. Perceived stress, but not depressive symptoms, positively correlated with allergy flares evaluated during 2 independent 14-day periods. There also was a positive relation between negative mood scores and allergy flares over the course of the study. Cortisol had no association with allergy symptom flares.

CONCLUSION

These findings suggest that individuals with persistent emotional stress have more frequent allergy flares. Furthermore, those with more flares have greater negative mood.

Perceived stress predicts altered reward and loss feedback processing in medial prefrontal cortex

Stress is a significant risk factor for the development of psychopathology, particularly symptoms related to reward processing. Importantly, individuals display marked variation in how they perceive and cope with stressful events, and such differences are strongly linked to risk for developing psychiatric symptoms following stress exposure. However, many questions remain regarding the neural architecture that underlies inter-subject variability in perceptions of stressors. Using functional magnetic resonance imaging (fMRI) during a Monetary Incentive Delay (MID) paradigm, we examined the effects of self-reported perceived stress levels on neural activity during reward anticipation and feedback in a sample of healthy individuals. We found that subjects reporting more uncontrollable and overwhelming stressors displayed blunted neural responses in medial prefrontal cortex (mPFC) following feedback related to monetary gains as well monetary losses. This is consistent with preclinical models that implicate the mPFC as a key site of vulnerability to the noxious effects of uncontrollable stressors. Our data help translate these findings to humans, and elucidate some of the neural mechanisms that may underlie stress-linked risk for developing reward-related psychiatric symptoms.

Schizophrenia is primed for an increased expression of depression through activation of immuno-inflammatory, oxidative and nitrosative stress, and tryptophan catabolite pathways

Schizophrenia and depression are two common and debilitating psychiatric conditions. Up to 61% of schizophrenic patients have comorbid clinical depression, often undiagnosed. Both share significant overlaps in underlying biological processes, which are relevant to the course and treatment of both conditions. Shared processes include changes in cell-mediated immune and inflammatory pathways, e.g. increased levels of pro-inflammatory cytokines and a Th1 response; activation of oxidative and nitrosative stress (O&NS) pathways, e.g. increased lipid peroxidation, damage to proteins and DNA; decreased antioxidant levels, e.g. lowered coenzyme Q10, vitamin E, glutathione and melatonin levels; autoimmune responses; and activation of the tryptophan catabolite (TRYCAT) pathway through induction of indoleamine-2,3-dioxygenase. Both show cognitive and neurostructural evidence of a neuroprogressive process. Here we review the interlinked nature of these biological processes, suggesting that schizophrenia is immunologically primed for an increased expression of depression. Such a conceptualization explains, and incorporates, many of the current perspectives on the nature of schizophrenia and depression, and has implications for the nature of classification and treatment of both disorders. An early developmental etiology to schizophrenia, driven by maternal infection, with subsequent impact on offspring immuno-inflammatory responses, creates alterations in the immune pathways, which although priming for depression, also differentiates the two disorders.

A narrative review on the similarities and dissimilarities between myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and sickness behavior

It is of importance whether myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a variant of sickness behavior. The latter is induced by acute infections/injury being principally mediated through proinflammatory cytokines. Sickness is a beneficial behavioral response that serves to enhance recovery, conserves energy and plays a role in the resolution of inflammation. There are behavioral/symptomatic similarities (for example, fatigue, malaise, hyperalgesia) and dissimilarities (gastrointestinal symptoms, anorexia and weight loss) between sickness and ME/CFS. While sickness is an adaptive response induced by proinflammatory cytokines, ME/CFS is a chronic, disabling disorder, where the pathophysiology is related to activation of immunoinflammatory and oxidative pathways and autoimmune responses. While sickness behavior is a state of energy conservation, which plays a role in combating pathogens, ME/CFS is a chronic disease underpinned by a state of energy depletion. While sickness is an acute response to infection/injury, the trigger factors in ME/CFS are less well defined and encompass acute and chronic infections, as well as inflammatory or autoimmune diseases. It is concluded that sickness behavior and ME/CFS are two different conditions.

Review on depression and coronary heart disease

The impact of psychological factors on somatic disorders - and vice versa - and the involvement of biological mechanisms in psychic disorders have generated considerable interest in recent years, notably thanks to cutting-edge investigation techniques (immunohistochemistry, functional imaging, genetics, etc.). In the field of psychosomatics, coronary heart disease (CHD) is a frequent co-morbidity of mental disorders, particularly mood disorders. Indeed, there is a bidirectional relationship between CHD and mood disorders, with a strong co-occurrence of the two diseases accompanied by a reciprocal worsening of the prognosis for the two conditions. Various epidemiological studies have shown that depression is a psychic risk factor for CHD and that CHD is present in almost 30% of patients with affective disorders. In this review of the literature, we tackle the crucial question of the diagnosis of depression during myocardial infarction. This clinical approach is essential given the underevaluation of this psychic problem. Then, various psychological, biological and genetic arguments are presented in support of the hypothesis that various aetiological mechanisms of the two disorders are partly shared. We finally deal with the treatment of depression in the context of CHD with its pharmacological and psychological specificities. In conclusion, this review reiterates the need for a multidisciplinary approach, which is necessary to understand, diagnose and then treat this frequent co-morbid condition of heart disease and depression.

The role of the innate immune system in psychiatric disorders

There is by now substantial clinical evidence for an association between specific mood disorders and altered immune function. More recently, a number of hypotheses have been forwarded to explain how components of the innate immune system can regulate brain function at the cellular and systems levels and how these may underlie the pathology of disorders such as depression, PTSD and bipolar disorder. In this review we draw reference to biochemical, cellular and animal disease models, as well as clinical observations to elucidate the role of the innate immune system in psychiatric disorders. Proinflammatory cytokines, such as IL-1β IL-6 and TNFα, which feature prominently in the immune response to pathogen in the periphery, have unique and specific actions on neurons and circuits within the central nervous system. Effects of these signaling molecules on neurotransmission, memory, and glucocorticoid function, as well as animal behaviors such as social withdrawal and fear conditioning relevant to psychiatric disorders are elucidated. Finally, we highlight future directions for studies, including the use of peripheral biomarkers, relevant for developing new therapeutic approaches for treating psychiatric illnesses. This article is part of Special Issue entitled 'neuroinflammation in neurodegeneration and neurodysfunction'.

'Cosmeceuticals'. Of men, science and laws…

Through the hybrid term 'Cosmeceuticals', the present paper aims at reviewing some scientific and legal sources of ambiguities or uncertainties that, in many regulatory cases, added confusions to the respective roles of drugs and cosmetics. The origins of such questions, likely arose from new anti-ageing claims from the cosmetic industry in the late 80s which faced a rather old regulatory backdrop. Based on the analysis of some legal statements and scientific facts from a 2012 vision, this review tentatively aims at re-defining the respective roles of these two branches that both fill the two vital needs of humans, 'being' and 'well-being'.

Microvascular pathology in late-life depression

Since the era of Gaupp who introduced the concept of atheroscletic depressive disorder, the concept of late-life depression has been correlated with cerebrovascular comorbidities, microvascular lesions, frontal cortical and subcortical gray and white matter hyperintensities. The predominant neuropsychological deficits concern the domains of planning, organization and abstraction, with executive dysfunction being the predominant finding. MRI studies reveal a higher prevalence of white matter lesions in elderly patients with depression. Molecular mechanisms underlying the disease still remain unclear. Hyperhomocysteinemia has been associated with depression through its toxicity to neurons and blood vessels. Endothelial dysfunction is another possible mechanism referring to the loss of vasodilatation capacity. Inflammatory phenomena, such as increased peripheral leucocytes, elevated CRP and cytokine levels, could play a role in endothelial dysfunction. In this review we will briefly combine findings from neurobiological, epidemiological, structural and post-mortem data. A more complex model in late-life depression combining different modalities could be an elucidating approach to the disease's etiopathogeny in the future.

Lower serum IL-10 is an independent predictor of IBS among volunteers in Mexico

OBJECTIVES

Studies suggest that altered immune activation, manifested by an imbalance in anti- and pro-inflammatory cytokine levels, exists in a subgroup of irritable bowel syndrome (IBS) patients. However, similar studies have not been conducted in Latin populations. The objective of this study was to measure serum levels of interleukin (IL)-10 and tumor necrosis factor (TNF)-α in subjects fulfilling symptom criteria for IBS and controls.

METHODS

Volunteers (n=178) from a university population in Mexico City, participated in the study. Of the sample, 34.8% met Rome II criteria for IBS and 65.2% were designated as controls. Serum cytokines were measured by enzyme-linked immunoabsorbent assay. Analysis of covariance models were used to test main effects between gender, IBS symptoms, and bowel habit subtype to explain the cytokine serum levels. Statistical models were tested using body mass index as a covariate.

RESULTS

IL-10 levels were significantly lower in IBS vs. controls (mean (95% confidence interval): 15.6 (14.8, 16.3) vs. 18.6 (17.9, 19.4) pg/ml, P<0.001), while TNF-α levels were higher in IBS (20.9 (19.1, 23.0) vs. 17.9 (16.7, 19.3) pg/ml, P=0.010). IBS and female gender were independent predictors for IL-10 (P<0.05). In contrast, female gender was an independent predictor for TNF-α. In addition, women with IBS-D had the lowest IL-10 (P<0.001) and highest TNF-α (P=0.021) vs. other subtypes.

CONCLUSIONS

The lower serum IL-10 in our subjects fulfilling IBS Rome II symptom criteria suggests an altered immune regulation. Further studies are needed to elucidate if a lower serum IL-10 may be useful as a biomarker for IBS in the Mexican population, especially for women with IBS-D.

Psychobiological correlates of allostatic overload in a healthy population

The concept of allostatic load (AL) represents the cost of the continual adjustment of the internal milieu required by an organism to adapt to different challenges. The majority of studies concerning AL have focused mainly on identifying its biological components. Recently, new criteria for a clinimetric evaluation of AL have been introduced, adding a new definition of allostatic overload (AO). This study aims to identify psychological and biological correlates of AO in a population of blood donors, according to this new definition of AO. Participants included 240 blood donors recruited from May 2007 to December 2009 in 4 different blood Centers. Blood samples from each participant were collected for laboratory analysis and self-rating instruments were administered on the same day. Biological parameters included those usually assessed during blood donation. Individuals were selected based on the criteria for the clinimetric evaluation of AO. Differences in biomarkers between subjects with and without allostatic overload were performed using the GLM with biological measures as dependent variables, AO groups as the fixed factor and specific confounders as covariates. Based on the selection criteria for allostatic overload, 98 subjects have been identified as presenting with AO. Results showed that individuals with allostatic overload presented lower levels of serum proteins, erythrocytes and immune differential count than donors without allostatic overload. Further, greater mean corpuscular volume has been found in persons included in the AO group. The evaluation of the AO correlates, along with a biomarker profile, may help to identify those conditions that, by exceeding individual resources, may constitute a danger to health.

Stress and skin leukocyte trafficking as a dual-stage process

Stress responses are known to modulate leukocyte trafficking. In the skin, stress was reported both to enhance and reduce skin immunity, and the chronicity of stress exposure was suggested as a key determining factor. We here propose a dual-stage hypothesis, suggesting that stress, of any duration, reduces skin immunity during its course, while its cessation is potentially followed by a period of enhanced skin immunity. To start testing this hypothesis, rats were subcutaneously implanted with sterile surgical sponges for four-hours, during or after exposure to one of several acute stress paradigms, or to a chronic stress paradigm. Our findings, in both males and females, indicate that numbers of sponge-infiltrating leukocytes, and their specific subsets, were reduced during acute or chronic stress, and increased after stress cessation. Studying potential mediating mechanisms of the reduction in leukocyte numbers during acute stress, we found that neither adrenalectomy nor the administration of beta-adrenergic or glucocorticoid antagonists prevented this reduction. Additionally, administration of corticosterone or epinephrine to adrenalectomized rats did not impact skin leukocyte numbers, whereas, in the blood, these treatments did affect numbers of leukocytes and their specific subsets, as was also reported previously. Overall, our findings support the proposed dual-stage hypothesis, which can be evolutionally rationalized and accounts for most of the apparent inconsistencies in the literature regarding stress and skin immunity. Other aspects of the hypothesis should be tested, also using additional methodologies, and its predictions may bear clinical significance in treatment of skin disorders related to hyper- or hypo-immune function.

Effect of acetylcholine on mitogen response of peripheral lymphocytes isolated from rats exposed to chronic stress

The purpose of this study was to clarify the effects of acetylcholine (Ach) on lymphocyte function in rats under chronic stress. The authors isolated peripheral lymphocytes from rats 5 weeks after stress treatment and then measured interleukin-2 (IL-2) production after stimulation with concanavalin A or phytohemagglutinin-L. Although mitogen-induced IL-2 production of the stress group was lower than that of the control group, the addition of Ach significantly increased mitogen-induced IL-2 production in both groups. This effect of Ach was inhibited by atropine in the control group only. The changes (increasing rates) in mitogen-induced IL-2 production from basal condition showed a negative correlation with serum corticosterone concentrations. The authors observed no correlation between the effects of Ach (changes in mitogen-induced IL-2 production with Ach compared to those without Ach) and serum corticosterone concentration. These findings suggest that stimulation of the parasympathetic nervous system improves lymphocyte function during chronic stress.

Effect of academic psychological stress in post-graduate students: the modulatory role of cortisol on superoxide release by neutrophils

Experimental and clinical evidence shows that neutrophils play an important role in the mechanism of tissue injury in immune complex diseases through the generation of reactive oxygen species. In this study, we examined the influence of academic psychological stress in post-graduate students on the capacity of their blood neutrophils to release superoxide when stimulated by immune complexes bound to nonphagocytosable surfaces and investigated the modulatory effect of cortisol on this immune function. The tests were performed on the day before the final examination. The state-trait anxiety inventory questionnaire was used to examine whether this stressful event caused emotional distress. In our study, the psychological stress not only increased plasma cortisol concentration, but it also provoked a reduction in superoxide release by neutrophils. This decrease in superoxide release was accompanied by diminished mRNA expression for subunit p47(phox) of the phagocyte superoxide-generating nicotinamide adenine dinucleotide phosphate-oxidase. These inhibitory effects were also observed by in vitro exposure of neutrophils from control volunteers to 10(- 7) M hydrocortisone, and could be prevented by the glucocorticoid receptor antagonist RU-486. These results show that in a situation of psychological stress, the increased levels of cortisol could inhibit superoxide release by neutrophils stimulated by IgG immune complexes bound to nonphagocytosable surfaces, which could attenuate the inflammatory state.

Suppressed monocyte gene expression profile in men versus women with PTSD

There have been several attempts to use gene microarrays from peripheral blood mononuclear cells to identify new biological pathways or targets for therapy in Posttraumatic Stress Disorder (PTSD). The few studies conducted to date have yielded an unclear pattern of findings, perhaps reflecting the use of heterogeneous samples of circulating immune cells for analysis. We used gene microarrays on a homogeneous sample of circulating monocytes to test the hypothesis that chronic PTSD would be associated with elevated inflammatory activity and to identify new pathways dysregulated in the disorder. Forty-nine men (24 PTSD+ and 25 age-matched trauma-exposed PTSD- controls) and 18 women (10 PTSD+ and 8 age-matched PTSD- controls) were recruited. Gene expression microarray analysis was performed on CD14+ monocytes, immune cells that initiate and respond to inflammatory signaling. Male subjects with PTSD had an overall pattern of under-expression of genes on monocytes (47 under-expressed versus 4 over-expressed genes). A rigorous correction for multiple comparisons and verification with qPCR showed that of only 3 genes that were differentially expressed, all were under-expressed. There was no transcriptional evidence of chronic inflammation in male PTSD+ subjects. In contrast, preliminary data from our pilot female PTSD+ subjects showed a relatively balanced pattern of increased and decreased expression of genes and an increase in activity of pathways related to immune activation. The results indicate differential patterns of monocyte gene expression in PTSD, and the preliminary data from our female pilot subjects are suggestive of gender dimorphism in biologic pathways activated in PTSD. Changes in immune cell gene expression may contribute to medical morbidity in PTSD.

Academic stress differentially influences perceived stress, salivary cortisol, and immunoglobulin-A in undergraduate students

Academic examination stress is reported to increase physiological and self-report measures of stress and to decrease immune functioning. Here, we investigate biochemical and self-report measures of stress, immune functioning, and academic pressures before and during a midterm examination period. Undergraduate students were asked to complete a measure of global stress, the perceived stress scale (PSS-10), and to indicate their current level of perceived stress. They also answered questions regarding specific academic pressures and provided a saliva sample for cortisol and salivary immunoglobulin-A (S-IgA) quantification. Students showed increased salivary cortisol concentrations and also reported greater acute perceived stress during the examination period compared to the non-examination period. Although cortisol concentrations and perceived stress were significantly higher during the examination period, participants reported similar levels of global stress (PSS-10) during both testing sessions. Additional analyses showed a non-significant increase in the level of S-IgA from the non-examination period to the examination period. Specific pressure variables that appeared to contribute to stress regulation during the examination week included the amount of time spent studying and concern about the impact of examinations in the future. By demonstrating measures of chronic examination stress, these findings provide new insight into the complex relationship between examination stress, cortisol, and immune functioning.

Possible Association between Th1 Immune Polarization and Epithelial Permeability with Toll-Like Receptors 2 Dysfunction in the Pathogenesis of the Recurrent Aphthous Ulceration

Recurrent Aphthous Ulceration (RAU) is a chronic oral inflammatory disease that affects approximately 25% of the general population. The etiology of the disease is unknown; however, factors that favor the onset of RAU have been correlated with a Th1 immune polarization, while factors that reduce RAU episodes have been associated with down regulation of immune reaction or stimulation of the peripheral tolerance. In this context, the integrity of the epithelial barrier is also fundamental for the prevention of the disease and conditions that augment its permeability or produce disruption are considered potential triggers. The key factor responsible for increased susceptibility is unclear, though a deficiency of Toll-like receptor (TLR) activity seems to be a good candidate. TLRs are a group of membrane proteins that recognize conserved molecules derived from bacterial, virus, fungal, or host tissues. Particularly, the TLR2 is involved in both immune regulation and control of epithelial barrier integrity. Thus, based on literature review, we showed evidences that correlate the TLR2 dysfunction and the diverse predisposing factors with the elements considered critical for disease pathogenesis: the Th1 immune reaction and the increased epithelial permeability.

Immune Measures in Behavioral Medicine Research: Procedures and Implications

Immune system activity is heavily influenced by the central nervous system. These interactions provide us the means to study mind–body interactions and how they affect health. In general, measures of immune system activity can be divided into two categories: those that are evident in the circulation and those that need to be elicited. For example, leukocytes can be collected from the circulation, counted, and their function accessed in cell culture. To test the ability of the immune system to respond to an experimental challenge more directly, studies involving wound healing, or involving the response to an infectious agent, can be performed. The purpose of this chapter is briefly to describe immune assays that are commonly employed in behavioral medicine research, including a rationale for their use as well as a brief description of the methodology. This chapter also describes previous studies in which circulatory and elicited immune measures have been studied in human subjects experiencing different psychological stressors, with an emphasis on studies involving medical students experiencing academic stress and caregivers of a spouse with Alzheimer’s disease. Finally, the chapter discusses the important role that the employment of animal models can play in studies of stress and health and in defining how nervous system activity can influence the immune response.

The impact of vascular burden on late-life depression

Small vessel pathology and microvascular lesions are no longer considered as minor players in the fields of cognitive impairment and mood regulation. Although frequently found in cognitively intact elders, both neuroimaging and neuropathological data revealed the negative impact on cognitive performances of their presence within neocortical association areas, thalamus and basal ganglia. Unlike cognition, the relationship between these lesions and mood dysregulation is still a matter of intense debate. Early studies focusing on the role of macroinfarct location in the occurrence of post-stroke depression (PSD) led to conflicting data. Later on, the concept of vascular depression proposed a deleterious effect of subcortical lacunes and deep white matter demyelination on mood regulation in elders who experienced the first depressive episode. More recently, the chronic accumulation of lacunes in thalamus, basal ganglia and deep white matter has been considered as a strong correlate of PSD. We provide here a critical overview of neuroimaging and neuropathological sets of evidence regarding the affective repercussions of vascular burden in the aging brain and discuss their conceptual and methodological limitations. Based on these observations, we propose that the accumulation of small vascular and microvascular lesions constitutes a common neuropathological platform for both cognitive decline and depressive episodes in old age.