Reduced lymphocyte proliferation and interleukin-2 production in anxiety disorders

Association of interleukin-2 and interleukin-10 with the pathophysiology and development of generalized anxiety disorder: a case-control study

BACKGROUND

Generalized anxiety disorder (GAD) is a devastating mental health condition characterized by constant, uncontrolled worrying. Recent hypotheses indicate that pro-inflammatory cytokines and chemokines are potential contributors to the pathogenesis of GAD. Here, we aimed to assess the role of interleukin-2 (IL-2) and interleukin-10 (IL-10) in the pathophysiology and development of GAD.

METHODS

This study recruited 50 GAD patients diagnosed according to the DSM-5 criteria and 38 age-sex-matched healthy controls (HCs). A qualified psychiatrist evaluated all study subjects. The socio-demographic and clinical characteristics of the study population were determined using pre-structured questionnaires or interviews, and cytokine serum levels were estimated using commercially available ELISA kits.

RESULTS

We observed reduced serum IL-10 levels in GAD patients compared to HCs (33.69 ± 1.37 pg/ml vs. 44.12 ± 3.16 pg/ml). Also, we observed a significant negative correlation between altered IL-10 levels and GAD-7 scores (r=-0.315, p = 0.039). Moreover, IL-10 serum measurement exhibited good predictive value in receiver operating characteristics (ROC) analysis with an area under the curve (AUC) value of 0.793 (p < 0.001) with 80.65% sensitivity and 62.79% specificity at a cutoff value of 33.93 pg/ml. Conversely, we noticed elevated serum IL-2 levels in GAD patients than in HCs (14.81 ± 2.88 pg/ml vs. 8.08 ± 1.1 pg/ml); however, it failed to maintain any significant association with GAD-7 scores, implying that IL-2 might not be involved in GAD pathogenesis. The lower AUC value (0.640; p > 0.05) exhibited by IL-2 serum measurement in ROC analysis further supported that IL-2 might not be associated with GAD.

CONCLUSION

This study provides new insights into the complex interplay between anti-inflammatory cytokines and GAD pathogenesis. Based on the present findings, we can assume that IL-10 but not IL-2 may be associated with the pathophysiology and development of GAD. However, further research with a larger population size and longitudinal design is required to confirm the potential diagnostic efficacy of IL-10.

Immune marker levels in severe mental disorders: associations with polygenic risk scores of related mental phenotypes and psoriasis

Several lines of evidence implicate immune abnormalities in the pathophysiology of severe mental disorders (SMD) and comorbid mental disorders. Here, we use the data from genome-wide association studies (GWAS) of autoimmune diseases and mental phenotypes associated with SMD to disentangle genetic susceptibilities of immune abnormalities in SMD. We included 1004 patients with SMD and 947 healthy controls (HC) and measured plasma levels of IL-1Ra, sIL-2R, gp130, sTNFR-1, IL-18, APRIL, and ICAM-1. Polygenic risk scores (PRS) of six autoimmune disorders, CRP, and 10 SMD-related mental phenotypes were calculated from GWAS. General linear models were applied to assess the association of PRS with immune marker abnormalities. We found negative associations between PRS of educational attainment and IL-1Ra (P = 0.01) and IL-18 (P = 0.01). There were nominal positive associations between PRS of psoriasis and sgp130 (P = 0.02) and PRS of anxiety and IL-18 (P = 0.03), and nominal negative associations between PRS of anxiety and sIL-2R (P = 0.02) and PRS of educational attainment and sIL-2R (P = 0.03). Associations explained minor amounts of the immune marker plasma-level difference between SMD and HC. Different PRS and immune marker associations in the SMD group compared to HC were shown for PRS of extraversion and IL-1Ra ([interaction effect (IE), P = 0.002), and nominally for PRS of openness and IL-1Ra (IE, P = 0.02) and sTNFR-1 (IE, P = 0.04). Our findings indicate polygenic susceptibilities to immune abnormalities in SMD involving genetic overlap with SMD-related mental phenotypes and psoriasis. Associations might suggest immune genetic factors of SMD subgroups characterized by autoimmune or specific mental features.

Hemogram parameters in childhood anxiety disorders: Could anxiety disorders be related with inflammation?

In the etiology of anxiety disorders, immune system and inflammation are suggested to play a role. This study hypothesized that there is a relationship between anxiety disorders and inflammation. This retrospective study included 131 children and adolescents between the ages 6-17 who were diagnosed with anxiety disorders. Control group consisted of 131 healthy children with no history of psychiatric disorders or chronic inflammatory conditions. White blood cell (WBC), neutrophil (NEU), lymphocyte, monocyte, basophil, eosinophil values and other hematological markers were noted. From those values, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), and other ratios were calculated. WBC and NEU values were significantly higher in children and adolescents with anxiety disorder compared to the control group. In addition, NLR, MLR and PLR values were significantly higher than the control group. Other measured parameters and calculated values did not differ between study groups. No statistically significant difference was found between Generalized Anxiety Disorder (GAD) group, Social Anxiety Disorder group and Not Otherwise Specified Anxiety Disorders (AD-NOS) group in terms of hematological markers except RDW-CV. Only RDW-CV was found statistically significantly higher in AD-NOS group compared to GAD. These results show that there is an association between inflammation and anxiety disorders. Also, it is postulated that hematological parameters can be used as a useful marker in the follow-up of patients with anxiety disorders.

Individual differences in inflammatory and oxidative mechanisms of stress-related mood disorders

Emotional stress leads to the development of peripheral disorders and is recognized as a modifiable risk factor for psychiatric disorders, particularly depression and anxiety. However, not all individuals develop the negative consequences of emotional stress due to different stress coping strategies and resilience to stressful stimuli. In this review, we discuss individual differences in coping styles and the potential mechanisms that contribute to individual vulnerability to stress, such as parameters of the immune system and oxidative state. Initial differences in inflammatory and oxidative processes determine resistance to stress and stress-related disorders via the alteration of neurotransmitter content in the brain and biological fluids. Differences in coping styles may serve as possible predictors of resistance to stress and stress-related disorders, even before stressful conditions. The investigation of natural variabilities in stress resilience may allow the development of new methods for preventive medicine and the personalized treatment of stress-related conditions.

The More Similar, the Healthier: The Effect of Perceived Parent-Child Facial Resemblance on Parental Physical Health

Parent-child facial resemblance (PCFR) is one of the direct cues used to assess the genetic relationship between two individuals. Due to the inner fertilization of humans, fathers are liable to suffer from paternal uncertainty. When a father perceives low father-child facial resemblance, he would become anxious, which is detrimental to his immune system and physical health. For a mother, however, she can assure her genetic relationship to her children and does not need any external cues to verify her maternity. Thus, the mother-child facial resemblance does not influence the mothers' physical health. To test these hypotheses, we examined the moderating effect of parental gender and the mediating effect of trait anxiety on the relationship between PCFR and physical health of parents. The results showed that fathers' PCFR positively predicted their physical health, whereas the mothers' PCFR failed to show any predicting effect on mothers' physical health. Furthermore, trait anxiety mediated the relationship between fathers' PCFR and their physical health. The implications for paternal uncertainty, gender difference, and public policy were discussed.

The association between anxiety, traumatic stress, and obsessive-compulsive disorders and chronic inflammation: A systematic review and meta-analysis

BACKGROUND

Anxiety is characterized by prolonged preparation for real or perceived threat. This may manifest both as psychological and physiological activation, ultimately leading to greater risk for poor health. Chronic inflammation may play an integral role in this relationship, given the influential role that it has in chronic illness. The aim of this meta-analysis is to examine levels of chronic inflammation, measured by inflammatory cytokines and C-reactive protein, in people with anxiety disorders, PTSD (posttraumatic stress disorder), or obsessive-compulsive disorder compared to healthy controls. Several moderating variables, including specific diagnosis and depression comorbidity, were also assessed.

METHODS

Seventy six full-text articles were screened for eligibility with 41 studies ultimately included in analysis.

RESULTS

Results demonstrated a significant overall difference between healthy controls (HCs) and people with anxiety disorders in pro-inflammatory cytokines (P = 0.013, Hedge's g = -0.39), which appears to be largely driven by interleukin-1β (IL-1β; P = 0.009, Hedge's g = -0.50), IL-6 (P < 0.001, Hedge's g = -0.93), and tumor necrosis factor-α (P = 0.030, Hedge's g = -0.56). Moderation analyses revealed a moderating effect of diagnosis (P = 0.050), as only individuals with PTSD demonstrated differences in inflammation between HCs (P = 0.004, Hedge's g = -0.68).

CONCLUSIONS

These data demonstrate the association between inflammatory dysregulation and diagnoses associated with chronic, impactful, and severe anxiety and provides insight into the way that anxiety, and in particular PTSD, is related to certain inflammatory markers. In doing so, these findings may provide an initial step in disentangling the relationship between anxiety and basic health processes.

Inflammation and psychopathology in children following PICU admission: an exploratory study

Background

Survivors of critical illness in childhood commonly display subsequent psychiatric symptoms including emotional and behavioural difficulties, and manifestations of post-traumatic stress disorder (PTSD). Anomalies in inflammatory profiles are an established finding in these childhood psychiatric conditions.

Objective

This exploratory study aimed to investigate whether abnormal peripheral blood inflammatory markers measured during paediatric intensive care unit (PICU) admission were associated with psychiatric symptoms after discharge.

Methods

We performed a prospective observational cohort study on 71 children with septic illness, meningoencephalitis and other critical disorders admitted to two PICUs between 2007 and 2010. 3–6 months following discharge, subjects were assessed for global psychiatric risk (ie, presence of emotional and behavioural difficulties on the parental Strengths and Difficulties Questionnaire (SDQ)), and for PTSD risk using the child-rated Impact of Events Scale (IES-8). Inflammatory and related biological markers were transcribed from PICU admission notes (white cell count, lymphocytes, neutrophils, C reactive protein (CRP), platelets, fibrinogen and lactate).

Findings

Global psychiatric risk at follow-up was associated with abnormal lymphocyte count during admission (χ²=6.757, p=0.014, n=48). In children with sepsis, partial correlation analyses controlling for age and gender highlighted associations between (i) SDQ scores and low lymphocyte count (r=−0.712; p=0.009, n=14), and (ii) IES-8 score and high CRP levels (r=0.823; p=0.006, n=11). These associations remained after correction for multiple comparisons.

Conclusion

These results support the hypothesis that acute inflammation may play a role in determining the development of psychopathology following PICU admission.

Clinical implications

If the findings are replicated, they may help to better highlight which children are at risk of post-PICU psychopathology and appropriately target follow-up.

Biological markers of generalized anxiety disorder

Generalized anxiety disorder (GAD) is a prevalent and highly disabling mental health condition; however, there is still much to learn with regard to pertinent biomarkers, as well as diagnosis, made more difficult by the marked and common overlap of GAD with affective and anxiety disorders. Recently, intensive research efforts have focused on GAD, applying neuroimaging, genetic, and blood-based approaches toward discovery of pathogenetic and treatment-related biomarkers. In this paper, we review the large amount of available data, and we focus in particular on evidence from neuroimaging, genetic, and neurochemical measurements in GAD in order to better understand potential biomarkers involved in its etiology and treatment. Overall, the majority of these studies have produced results that are solitary findings, sometimes inconsistent and not clearly replicable. For these reasons, they have not yet been translated into clinical practice. Therefore, further research efforts are needed to distinguish GAD from other mental disorders and to provide new biological insights into its pathogenesis and treatment.

Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

OBJECTIVE

Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD).

METHODS

Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network.

RESULTS

The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics.

CONCLUSIONS

Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.

Relationship between neural activity and immunity in patients with undifferentiated somatoform disorder

It has been suggested that somatoform disorders are related to both the brain and the immune system, and that immune functions may be influenced by cerebral asymmetry. However, few studies have examined the relationship between brain activity and immune function in somatoform disorders. Thirty-two patients with non-medicated undifferentiated somatoform disorder were enrolled in this study. Blastogenic responses to phytohemagglutinin (PHA) were used to measure immunity. Regional cerebral perfusion was measured by 99m-Tc-ethyl cysteinate dimer single photon emission computed tomography (SPECT). Significant hypoperfusion was found at the left inferior parietal lobule and the left supramarginal gyrus in the more immune-suppressed (MIS) subgroup compared with the less immune-suppressed (LIS) subgroup. However, no regions of significant hyperperfusion were found in the MIS subgroup compared with the LIS subgroup. Decreased cerebral blood flow in the left inferior parietal lobule and the left supramarginal gyrus in the patient group was also significantly associated with reduced blastogenic responses to PHA regardless of sex and age. These results suggest that the left inferior parietal lobule and the left supramarginal gyrus might play an immunomodulating role in patients with undifferentiated somatoform disorder. In addition, these results suggest the role of cerebral asymmetry in altered immunity in the patients.

Epigenetic programming of the stress response in male and female rats by prenatal restraint stress

Exposure to hostile conditions results in a series of coordinated responses aimed at enhancing the probability of survival. The activation of the hypothalamo-pituitary-adrenocortical (HPA) axis plays a pivotal role in the stress response. While the short-term activation of the HPA axis allows adaptive responses to the challenge, in the long run this can be devastating for the organism. In particular, life events occurring during the perinatal period have strong long-term effects on the behavioral and neuroendocrine response to stressors. In male and female rats exposed to prenatal restraint stress (PRS), these effects include a long-lasting hyperactivation of the HPA response associated with an altered circadian rhythm of corticosterone secretion. Furthermore, male animals exhibit sleep disturbances. In males, these HPA dysfunctions have been reported in infant, young, adult and aged animals, thus suggesting a permanent effect of early stress. Interestingly, after exposure to an intense inescapable footshock, female PRS rats durably exhibit a blunted corticosterone secretion response to stress. In male PRS rats exposed to an alcohol challenge, the HPA axis is similarly hyporesponsive. Rats exposed to PRS also show behavioral disturbances. Both male and female PRS rats show high anxiety levels and depression-like behavior during adulthood, although some studies suggest that female PRS rats present low anxiety levels. With ageing, male and female PRS rats exhibit memory impairments in hippocampus-dependent tasks, while female PRS rats improve their memory performance during adulthood. The gender effect on behavior seems to be related to a reduction in hippocampal plasticity in male PRS rats, and an increase in female PRS rats. Despite the permanent imprinting induced by early stress, the dysfunctions observed after PRS can be reversed by environmental or pharmacological strategies such as environmental enrichment or antidepressive and neurotrophic treatments. Mechanisms underlying the effects of PRS on the offspring remain largely unknown. However, previous studies have demonstrated that maternal glucocorticoids during pregnancy play an important role in the HPA disturbances reported in male offspring. Finally, gestational stress has long-lasting effects on the HPA axis and on behavior in the dams. Alterations in maternal behavior could thus also make a strong contribution to the long-term effects of PRS, through epigenetic mechanisms.

Stress and wound healing

There are substantial data to suggest that stress-induced disruption of neuroendocrine immune equilibrium is detrimental to health, with the strongest evidence to date in wound healing. Murine and human studies demonstrated that the down-regulation of the early inflammatory response by an increase in cortisol levels results in delayed wound repair and identified several potential cellular mechanisms linking stress and wound healing. The impact of stress on wound healing has been studied almost exclusively in acute experimentally induced wounds. Because chronic wounds are different entities from acute wounds, the cellular/molecular mechanisms by which stress affects acute wound healing may not necessarily be applied to chronic wounds, hence, the need for studies in stress and chronic wound (eg, diabetic foot ulcer) healing.

The association between burnout, depression, anxiety, and inflammation biomarkers: C-reactive protein and fibrinogen in men and women

Following the demonstrated association of employee burnout or vital exhaustion with several risk factors for cardiovascular disease (CVD) and CVD risk, the authors investigated the possibility that one of the mechanisms linking burnout with CVD morbidity is microinflammation, gauged in this study by high-sensitivity C-reactive protein (hs-CRP) and fibrinogen concentrations. Their sample included 630 women and 933 men, all apparently healthy, who underwent periodic health examinations. The authors controlled for possible confounders including 2 other negative affective states: depression and anxiety. In women, burnout was positively associated with hs-CRP and fibrinogen concentrations, and anxiety was negatively associated with them. In men, depression was positively associated with hs-CRP and fibrinogen concentrations, but not with burnout or anxiety. Thus, burnout, depression, and anxiety are differentially associated with microinflammation biomarkers, dependent on gender.

Immunological aetiology of major psychiatric disorders: evidence and therapeutic implications

Historically, immunological research in psychiatry was based on empirical findings and early epidemiological studies indicating a possible relationship between psychiatric symptoms and acute infectious diseases. However, aetiopathological explanations for psychiatric disorders are no longer closely related to acute infection. Nevertheless, immune hypotheses have been discussed in schizophrenia, affective disorders and infantile autism in the last decades. Although the variability between the results of the epidemiological studies conducted to date is strikingly high, there is still some evidence that the immune system might play a role in the aetiopathogenesis of these three psychiatric diseases, at least in subgroups of patients. In anxiety disorders immunological research is still very much in its infancy, and the few and inconsistent data of immune changes in these patients are believed to reflect the influence of short- or long-term stress exposure. Nevertheless, there are also some hints raising the possibility that autoimmune mechanisms could interrupt neurotransmission, which would be of significance in certain patients with anxiety and panic disorders. Drug and alcohol (ethanol) dependence are not believed to be primarily influenced by an immunological aetiology. On the other hand, immune reactions due to different drugs of abuse and alcohol may directly or indirectly influence the course of concomitant somatic diseases. In different organic brain disorders the underlying somatic disease is defined as a primary immune or autoimmune disorder, for instance HIV infection or systemic lupus erythematosus (SLE). For other neurodegenerative disorders, such as Alzheimer's disease, immunoaetiopathological mechanisms are supported by experimental and clinical studies. Treatment strategies based on immune mechanisms have been investigated in patients with schizophrenia and affective disorders. Furthermore, some antipsychotics and most antidepressants are known to have direct or indirect effects on the immune system. Different immunotherapies have been used in autism, including transfer factor, pentoxifylline, intravenous immunoglobulins and corticosteroids. Immunosuppressive and/or immunomodulating agents are well established methods for treating the neuropsychiatric sequelae of immune or autoimmune disorders, for example AIDS and SLE. Therapeutic approaches in Alzheimer's disease also apply immunological methods such as strategies of active/passive immunisation and NSAIDs. Considering the comprehensive interactive network between mind and body, future research should focus on approaches linking targets of the different involved systems.

Stress and Psychoneuroimmunologic Factors in Dermatology

There is clinical and experimental evidence that the brain can start, influence, and stop biologic skin events. Studies suggest that the skin, as a relevant part of the "diffuse brain," can modify the quality of perceptions and feelings. The immune and the endocrine systems seem to represent the protagonists of the modulation of those events and, in this context, psychosocial stressors and interventions can lead to global health changes of great interest for dermatologists.

Cytokine mRNA levels in brain and peripheral tissues of the rat: relationships with plus-maze behavior

There is evidence that interleukin (IL)-2 may be related to anxiety as measured in the elevated plus-maze. Recently, we showed that normal adult male Wistar rats can differ systematically in this test of avoidance behavior, that is, time spent on the open arms of the elevated plus-maze. Rats with low open arm time had higher striatal levels of IL-2 mRNA than those with high open arm time, but did not differ significantly in expression of other striatal cytokine mRNA. Here, we investigated whether these expression effects are anatomically specific to the striatum. Therefore, we asked in this double-blind study whether elevated plus-maze behavior may also be related to endogenous levels of cytokine mRNA in other brain regions, which play a role for anxiety, namely the amygdala, hippocampus, and the prefrontal cortex. Additionally, and as peripheral controls, immuno-neuro-endocrine relevant tissues (adrenal glands, spleen) were analyzed. Based on open arm time in the elevated plus-maze, male Wistar rats were divided into sub-groups with either low or high open arm time behavior. Then, IL-1beta, IL-2, IL-6, and tumor necrosis factor (TNF)-alpha cDNA levels were measured post-mortem using semi-quantitative, competitive, reverse transcription polymerase chain reaction. First, we found that cytokine expressions differed considerably between and within these central and peripheral tissues. Secondly, rats with high compared to low open arm time behavior showed higher IL-2 mRNA levels in the prefrontal cortex, which is an inverse pattern to what we recently found in the striatum. These results provide new evidence indicating that cytokine mRNA in the brain can be related to elevated plus-maze behavior and that this relationship is site (prefrontal cortex, striatum)- and cytokine mRNA-specific (IL-2).

Immune parameters in patients with anxiety or depression during psychotherapy

BACKGROUND

Numerous studies have described distinctive immunological findings in patients with depression. In contrast, only very little is known about the possible influence of anxiety disorders on the immune system. It is also unknown whether treatment with psychotherapy alone has any influence on immunological variations in patients with psychiatric disorders.

METHODS

We measured immunological and psychological parameters in patients with minor depression (N=10) or anxiety disorder (N=13) over an 8-week course of inpatient psychotherapy. Data for patients and a group of healthy controls (N=11) were recorded three times in 4-week intervals. A FACS analysis revealed the composition of lymphocyte subpopulations. The production of reactive oxygen species (ROS) by phagocytes was analyzed using lucigenin-enhanced chemiluminescence.

RESULTS

On admission, patients with anxiety disorder showed a markedly elevated ratio of CD4(+) (T helper) versus CD8(+) (T suppressor/cytotoxic) lymphocytes compared to healthy controls (P<0.001) and minor depressives (P<0.01). The increased ratio in patients with anxiety disorder could mainly be attributed to a reduced count in CD8(+) T cells compared to healthy controls (P<0.01) and depressives (P<0.05). There were no differences between patients with depression and healthy controls with respect to the CD4(+)/CD8(+) ratio. We did not observe any differences in the production of ROS by phagocytes in patients compared to healthy controls. The CD4(+)/CD8(+) ratio remained elevated in patients with anxiety disorders during the following 8 weeks. There were no significant changes in this parameter over the course of the inpatient treatment.

LIMITATIONS

As a pilot study on the immune status in patients with anxiety disorders, the study's main limitation is the relatively low number of patients observed.

CONCLUSIONS

In this study we demonstrated for the first time marked immunological changes in patients with anxiety disorders. In addition, our results provide preliminary evidence that these immunological variations are not reversible by an 8-week course of inpatient psychotherapy alone.

Lymphocytes as a neural probe: potential for studying psychiatric disorders

There is an increasing body evidence pointing to a close integration between the central nervous system (CNS) and immunological functions with lymphocytes playing therein a central role. The authors provide arguments to consider blood lymphocytes as a convenient probe of--an albeit--limited number of cellular functions, including gene expression. The use of brain biopsies of living patients is unrealistic for biochemical investigation, therefore lymphocytes may be a convenient and accessible alternative. Numerous studies showed similarities between receptor expression and mechanisms of transduction processes of cells in the nervous system (e.g. neurons and glia) and lymphocytes. In several neuropsychiatric disorders, alteration of metabolism and cellular functions in the CNS, as well as disturbances in the main neurotransmitter and hormonal systems are concomitant with altered function and metabolism of blood lymphocytes. We summarize relevant investigations on depression, stress, Alzheimer's disease (AD) and schizophrenia. New techniques such as cDNA microarray gene expression and proteomics may give clues to define molecular abnormalities in psychiatric disorders and could eventually reveal information for diagnostic and treatment purposes. Taken together, these considerations suggest that lymphocyte could reflect the metabolism of brain cells, and may be exploited as a neural and possible genetic probe in studies of psychiatric disorders.

Neuroimmunological parameters in panic disorder

BACKGROUND

The interaction between immune cells, neurotransmitters and the neuroendocrinological systems plays a role in affective disorders, especially depression. Although panic disorder (PD) shares a lot of features with depression, it is clearly a distinct disorder. Reports on immunological parameters in PD don't provide a clear picture of the immunological status of PD patients. This can partly be attributed to methodological differences between studies and small patient groups.

OBJECTIVE

The present study aims to assemble all studies on immunological parameters in PD in order to combine all available data to gain a broader perspective on this matter.

METHOD

PubMed was searched for studies describing immunological parameters in PD patients without comorbid disorders or medication use. All studies had to include a healthy control group and the outcome measures had to be shared by at least one other study.

RESULTS

Fourteen articles were found. Although the T-lymphocytic branch and the innate immune system were normal, the B-lymphocytic branch showed some differences between PD patients and healthy controls. B-cell counts were increased in PD patients, which was underlined by increased human leucocyte antigen (HLA)-DR counts and increased immunoglobulin A levels. However, B-cell activity following mitogen stimulation was normal.

CONCLUSIONS

PD patients show increased B-cell numbers. The finding that B-cell activity is not increased can possibly be attributed to functional exhaustion of these cells. The meaning of this finding remains unclear, although it may be potentially important in affective disorders as the same has been found in depression.

The role of psychosocial factors in the progression of hepatocellular carcinoma

The number of deaths per year from hepatocellular carcinoma (HCC) exceeds 250000, placing it sixth as the cause of death from cancer worldwide. The primary etiology of most cases of HCC in the US is hepatitis B and/or C. Extensive research has demonstrated that the relationship between hepatitis B infection and the progression to HCC is mediated by the immune system. A substantial, but unrelated literature, describes the relationship between psychosocial factors (e.g., stress, psychiatric morbidity), immune system reactivity, and disease progression in patients with cancer. However, the role of these factors in the progression of HBV-HCC has not been explored. An understanding of the relationship among virology, immunology, and behavior in the development and recurrence of HCC may provide alternative methods for secondary prevention of HCC (e.g., behavioral) until a vaccine and/or pharmacological treatments are developed, feasible, and affordable.

Relationship between striatal levels of interleukin-2 mRNA and plus-maze behaviour in the rat

Our previous experiments have shown that adult male Wistar rats can differ systematically in elevated plus-maze (EPM) behaviour, which was related to the neurotransmitter serotonin in the ventral striatum. The EPM serves as a model of anxiety-like behaviour, and there is evidence that interleukin (IL)-2 in the brain may be related to anxiety-like behaviour, and that IL-2 interacts with the striatal serotonergic system. We asked whether EPM behaviour may also be related to constitutive levels of cytokines in the striatum. Based on open arm time in the EPM, male Wistar rats were divided into sub-groups with either low or high anxiety-like behaviour. Then, IL-1beta, IL-2, IL-6, and tumour necrosis factor (TNF)-alpha cDNA levels were measured post mortem in striatal tissues using semi-quantitative, competitive, reverse transcription polymerase chain reaction. Rats with high anxiety-like behaviour in the EPM showed significantly higher levels of IL-2 mRNA compared to those with low anxiety-like behaviour, but did not differ significantly in expression of IL-1beta, IL-6, and TNF-alpha mRNA. These results provide new evidence indicating that specific cytokine patterns in the striatum may be associated with EPM behaviour in adult male Wistar rats.

Panic disorder and immunity: few effects on circulating lymphocytes, mitogen response, and NK cell activity

Altered immune measures are commonly found in major depression (MD), however, less is known about the immune system in anxiety disorders. We examined quantitative and functional in vitro immune measures in patients with panic disorder (PD), which is often comorbid with MD. Fourteen otherwise healthy medication-free adults (ages 23-49; 11 female) meeting SCID-UP DSM-IIIR criteria for PD with agoraphobia and without current MD, were compared with 14 subjects free of PD, MD, or other major psychiatric disorders, matched by gender, age, and racial background. PD was associated with decreased percentage (p<.03) and total (p<.03) circulating CD19+ B lymphocytes, but no differences in other enumerative lymphocyte measures. Mitogen responses (Con A, PHA, PWM) did not differ except for possibly decreased PHA in PD (p<.06). NK cell activity did not differ between PD and control subjects. The few immune measure changes in PD contrast with those found in MD, providing further evidence for the specificity of immune changes in psychiatric disorders.

Gender and health in rural China: evidence from Hebei Province

Gender differences in health and health behavior are well established in Western societies, but little is known about gender health inequalities in rural China. We examine patterns of age-sex differences in health and health behavior of men and women in rural HeBei, People's Republic of China, and consider the extent to which these patterns resemble gender health inequalities observed in North America and Western Europe. The data analyzed were collected from 14,895 individuals residing in 288 villages in the HeBei Province. The results show that gender differences emerged at a later age than generally reported in Western societies. Poorer health among women, as compared with men, becomes observable during young adulthood (25-44) rather than at adolescence, and reached its peak among older adults (45-59) rather than during the productive and reproductive stage of the life course. Among the elderly, the differences between the health and the health behavior of men and women narrowed, similar to many reports in North America and Western Europe. Most importantly, no gender differences in mental health were observed. These findings suggest that the older adult age group (45-59) may be appropriate for interdisciplinary efforts to advance the understanding regarding the relative contributions of nature and nurture to gender differences in health.

Psychoneuroimmunology and psychosomatic medicine: back to the future

OBJECTIVE

Although psychological modulation of immune function is now a well-established phenomenon, much of the relevant literature has been published within the last decade. This article speculates on future directions for psychoneuroimmunology research, after reviewing the history of the field.

METHODS

This review focuses on human psychoneuroimmunology studies published since 1939, particularly those that have appeared in Psychosomatic Medicine. Studies were clustered according to key themes, including stressor duration and characteristics (laboratory stressors, time-limited naturalistic stressors, or chronic stress), as well as the influences of psychopathology, personality, and interpersonal relationships; the responsiveness of the immune system to behavioral interventions is also addressed. Additionally, we describe trends in populations studied and the changing nature of immunological assessments. The final section focuses on health outcomes and future directions for the field.

RESULTS

There are now sufficient data to conclude that immune modulation by psychosocial stressors or interventions can lead to actual health changes, with the strongest direct evidence to date in infectious disease and wound healing. Furthermore, recent medical literature has highlighted a spectrum of diseases whose onset and course may be influenced by proinflammatory cytokines, from cardiovascular disease to frailty and functional decline; proinflammatory cytokine production can be directly stimulated by negative emotions and stressful experiences and indirectly stimulated by chronic or recurring infections. Accordingly, distress-related immune dysregulation may be one core mechanism behind a diverse set of health risks associated with negative emotions.

CONCLUSIONS

We suggest that psychoneuroimmunology may have broad implications for the basic biological sciences and medicine.

Relation between immune variables and burnout in a sample of physicians

OBJECTIVES

To evaluate in a group of physicians the relation between burnout, demographic or job characteristics, anxiety, and immune variables.

METHODS

Seventy one physicians of all grades were recruited among different departments to a cross sectional survey. The Maslach burnout inventory, scales of emotional exhaustion, depersonalisation, and personal accomplishment, the trait scale of anxiety inventory (STAI-Y2), and a questionnaire on personal and professional characteristics were administered. The immune profile included quantitative (number (%) of lymphocytes and subsets) and functional (natural killer cytotoxicity) measures.

RESULTS

With a model of stepwise multiple regression analysis, emotional exhaustion was significantly affected by both personal (marital, sex) and job characteristics (qualification, working activity), whereas only patient contact explained a portion of variation in depersonalisation. Furthermore, trait anxiety was found to predict the Maslach burnout inventory scores. After correction for potential confounders, physicians who scored high levels of personal accomplishment showed significantly higher numbers of total lymphocytes, T cells (CD3), T helper cells (CD4), and T suppressor cells (CD8) than those who scored low levels. No other correlation was found between burnout and immune variables.

CONCLUSIONS

In our group of relatively young physicians a high degree of personal accomplishment was associated with an increase in the number of peripheral lymphocytes, particularly T subsets. The meaning of this is not clear, although it could be speculated that to evaluate oneself positively, particularly with regard to work with patients in the health services, might help to stimulate the immune system. By contrast, there is no evidence that to work hard, to feel tired from work, and to have a cynical reaction towards patient care is related to immunosuppression.