Cytokines, brain-derived neurotrophic factor and C-reactive protein in bipolar I disorder - Results from a prospective study

Inflammatory mediators in major depression and bipolar disorder

Major depressive disorder (MDD) and bipolar disorder (BD) are highly disabling illnesses defined by different psychopathological, neuroimaging, and cognitive profiles. In the last decades, immune dysregulation has received increasing attention as a central factor in the pathophysiology of these disorders. Several aspects of immune dysregulations have been investigated, including, low-grade inflammation cytokines, chemokines, cell populations, gene expression, and markers of both peripheral and central immune activation. Understanding the distinct immune profiles characterizing the two disorders is indeed of crucial importance for differential diagnosis and the implementation of personalized treatment strategies. In this paper, we reviewed the current literature on the dysregulation of the immune response system focusing our attention on studies using inflammatory markers to discriminate between MDD and BD. High heterogeneity characterized the available literature, reflecting the heterogeneity of the disorders. Common alterations in the immune response system include high pro-inflammatory cytokines such as IL-6 and TNF-α. On the contrary, a greater involvement of chemokines and markers associated with innate immunity has been reported in BD together with dynamic changes in T cells with differentiation defects during childhood which normalize in adulthood, whereas classic mediators of immune responses such as IL-4 and IL-10 are present in MDD together with signs of immune-senescence.

Alterations in Neurotrophins in Alcohol-Addicted Patients during Alcohol Withdrawal

BACKGROUND

Alcohol use disorder (AUD) is related to mental and somatic disorders that result in alcohol withdrawal syndrome (AWS), with 30% of AWS cases leading to life-threatening delirium tremens (DTs). Currently, studies do not support using any one biomarker in DTs. Neurotrophins affect neuromodulation, playing a role in the pathogenesis of AUD, AWS, and DTs.

METHODS

This review aims to summarize experimental and clinical data related to neurotrophins and S100B in neuroplasticity, as well as neurodegeneration in the context of AUD, AWS, and DTs. This work used publications that were selected based on the protocol consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement.

RESULTS

The BDNF level could be a good candidate biomarker for relapse susceptibility, as it is significantly reduced during consumption and gradually increases during abstinence. GDNF influences AUD through its integral role in the function of dopaminergic neurons and ablates the return to alcohol-drinking behavior. NGF protects neurons from ethanol-induced cytotoxic damage and affects recovery from cognitive deficits after brain damage. The NT-3 level is decreased after alcohol exposure and is involved in compensatory mechanisms for cognitive decline in AUD. NT-4 affects oxidative stress, which is associated with chronic alcohol consumption. S100B is used as a biomarker of brain damage, with elevated levels in serum in AUD, and can protect 5-HT neurons from the damage caused by alcohol.

CONCLUSIONS

BDNF, GDNF, NT-3, NT-4, NGF, and S100B may be valuable markers for withdrawal syndrome. In particular, the most relevant is their association with the development of delirium complications. However, there are few data concerning some neurotrophins in AWS and DTs, suggesting the need for further research.

Crocin (bioactive compound of Crocus sativus L.) potently restores REM sleep deprivation-induced manic- and obsessive-compulsive-like behaviors in female rats

Rapid-eye movement (REM) sleep deprivation (SD) can induce manic-like behaviors including hyperlocomotion. On the other hand, crocin (one of the main compounds of Crocus sativus L. or Saffron) may be beneficial in the improvement of mental and cognitive dysfunctions. Also, crocin can restore the deleterious effects of SD on mental and cognitive processes. In this study, we investigated the effect of REM SD on female rats' behaviors including depression- and anxiety-like behaviors, locomotion, pain perception, and obsessive-compulsive-like behavior, and also, the potential effect of crocin on REM SD effects. We used female rats because evidence on the role of REM SD in modulating psychological and behavioral functions of female (but not male) rats is limited. REM SD was induced for 14 days (6h/day), and crocin (25, 50, and 75 mg/kg) was injected intraperitoneally. Open field test, forced swim test, hot plate test, and marble burying test were used to assess rats' behaviors. The results showed REM SD-induced manic-like behavior (hyperlocomotion). Also, REM SD rats showed decreased anxiety- and depression-like behavior, pain subthreshold (the duration it takes for the rat to feel pain), and showed obsessive compulsive-like behavior. However, crocin at all doses partially or fully reversed REM SD-induced behavioral changes. In conclusion, our results suggested the possible comorbidity of OCD and REM SD-induced manic-like behavior in female rats or the potential role of REM SD in the etiology of OCD, although more studies are needed. In contrast, crocin can be a possible therapeutic choice for decreasing manic-like behaviors.

Peripheral inflammation is associated with impaired sadness recognition in euthymic bipolar patients

BACKGROUND

Inflammation impairs cognitive function in healthy individuals and people with psychiatric disorders, such as bipolar disorder (BD). This effect may also impact emotion recognition, a fundamental element of social cognition. Our study aimed to investigate the relationships between pro-inflammatory cytokines and emotion recognition in euthymic BD patients and healthy controls (HCs).

METHODS

We recruited forty-four euthymic BD patients and forty healthy controls (HCs) and measured their inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and TNF-α. We applied validated cognitive tasks, the Wisconsin Card-Sorting Test (WCST) and Continuous Performance Test (CPT), and a social cognitive task for emotion recognition, Diagnostic Analyses of Nonverbal Accuracy, Taiwanese Version (DANVA-2-TW). We analyzed the relationships between cytokines and cognition and then explored possible predictive factors of sadness recognition accuracy.

RESULTS

Regarding pro-inflammatory cytokines, TNF-α was elevated in euthymic BD patients relative to HCs. In euthymic BD patients only, higher TNF-α levels were associated with lower accuracy of sadness recognition. Regression analysis revealed that TNF-α was an independent predictive factor of sadness recognition in patients with euthymic BD when neurocognition was controlled for.

CONCLUSIONS

We demonstrated that enhanced inflammation, indicated by increased TNF-α, was an independent predictive factor of impaired sadness recognition in BD patients but not in HCs. Our findings suggested a direct influence of TNF-α on sadness recognition and indicated vulnerability to depression in euthymic BD patients with chronic inflammation.

Plasma IGFBP-3 and IGFBP-5 levels are decreased during acute manic episodes in bipolar disorder patients

Introduction: Bipolar disorder (BD) is a recurrent and disabling psychiatric disorder related to low-grade peripheral inflammation and altered levels of the members of the insulin-like growth factor (IGF) family. The aim of this study was to evaluate the plasma levels of IGF-2, insulin-like growth factor-binding protein 1 (IGFBP-1), IGFBP-3, IGFBP-5, IGFBP-7, and inflammatory markers such as tumor necrosis factor α (TNF-α), monocyte chemoattractant protein 1 (MCP-1), and macrophage inflammatory protein 1β (MIP-1β). Methods: We used the Young Mania Rating Scale (YMRS) to determine the severity of the symptomatology, while proteins were measured by enzyme-linked immunosorbent assay (ELISA). We included 20 patients with BD who suffered a manic episode and 20 controls. Some BD patients (n = 10) were evaluated after a period (17 ± 8 days) of pharmacological treatment. Results: No statistical difference was found in IGF-2, IGFBP-1, IGFBP-7, TNF-α, and MIP-1β levels. However, IGFBP-3 and IGFBP-5 levels were found to be statistically decreased in BD patients. Conversely, the MCP-1 level was significantly increased in BD patients, but their levels were normalized after treatment. Intriguingly, only IGFBP-1 levels were significantly decreased after treatment. No significant correlation was found between the YMRS and any of the proteins studied either before or after treatment or between IGF proteins and inflammatory markers. Discussion: To some extent, IGFBP-3 and IGFBP-5 might be further explored as potential indicators of treatment responsiveness or diagnosis biomarkers in BD.

Significant improvements in the olfactory sensitivity of bipolar I disorder patients during euthymia versus manic episodes: a longitudinal study

Introduction

Research has indicated that individuals diagnosed with bipolar disorder (BD) might experience alterations in their olfaction or levels of serum tumor necrosis factor-α (TNF-α), but no studies have investigated olfactory function and serum TNF-α in BD patients simultaneously. Moreover, there is a lack of existing research that compares the longitudinal olfactory function between individuals with manic and euthymic BD I.

Methods

Patients with manic BD I (BDM, n=44) and healthy controls (HCs, n=32) were evaluated symptoms (measured via the Young Manic Rating Scale, YRMS), social function (measured via the Global Assessment Function, GAF), serum TNF-α, and olfactory function (via the Sniffin' Sticks test) including olfactory sensitivity (OS) and olfactory identification (OI). The BDM patients were followed up to the remission period and re-evaluated again. We compared OS, OI and serum TNF-α in manic and euthymic patients with BD I and HCs. We examined the correlation between olfactory function and symptoms, social function, and serum TNF-α in patients with BD I.

Results

The BDM patients exhibited significantly lower OS and OI compared to the HCs (Z = -2.235, P = 0.025; t = -6.005, P < 0.001), while a positive correlation was observed between OS and GAF score (r = 0.313, P = 0.039). The OS in the BD I remission group (n=25) exhibited significantly superior performance compared to the BDM group (t = -4.056, P < 0.001), and the same as that in the HCs (P = 0.503). The change in OS showed a positive correlation with the decrease in YMRS score (r = 0.445, P = 0.026), and a negative correlation with the course of disease (r = -0.594, P = 0.002). The TNF-α in BD I patients was significantly lower compared to HCs (P < 0.001), and not significantly correlated with olfactory function (all P > 0.05).

Conclusion

The findings suggest that OS and OI are impaired in BDM patients, and the impaired OS in those patients can be recovered in the remission stage. OI may serve as a potential characteristic marker of BD. OS might be useful as an index for BDM treatment efficacy and prognosis.

Effects of inflammation, childhood adversity, and psychiatric symptoms on brain morphometrical phenotypes in bipolar II depression

BACKGROUND

The neuroanatomical alteration in bipolar II depression (BDII-D) and its associations with inflammation, childhood adversity, and psychiatric symptoms are currently unclear. We hypothesize that neuroanatomical deficits will be related to higher inflammation, greater childhood adversity, and worse psychiatric symptoms in BDII-D.

METHODS

Voxel- and surface-based morphometry was performed using the CAT toolbox in 150 BDII-D patients and 155 healthy controls (HCs). Partial Pearson correlations followed by multiple comparison correction was used to indicate significant relationships between neuroanatomy and inflammation, childhood adversity, and psychiatric symptoms.

RESULTS

Compared with HCs, the BDII-D group demonstrated significantly smaller gray matter volumes (GMVs) in frontostriatal and fronto-cerebellar area, insula, rectus, and temporal gyrus, while significantly thinner cortices were found in frontal and temporal areas. In BDII-D, smaller GMV in the right middle frontal gyrus (MFG) was correlated with greater sexual abuse (r = -0.348, q < 0.001) while larger GMV in the right orbital MFG was correlated with greater physical neglect (r = 0.254, q = 0.03). Higher WBC count (r = -0.227, q = 0.015) and IL-6 levels (r = -0.266, q = 0.015) was associated with smaller GMVs in fronto-cerebellar area in BDII-D. Greater positive symptoms was correlated with larger GMVs of the left middle temporal pole (r = 0.245, q = 0.03).

CONCLUSIONS

Neuroanatomical alterations in frontostriatal and fronto-cerebellar area, insula, rectus, temporal gyrus volumes, and frontal-temporal thickness may reflect a core pathophysiological mechanism of BDII-D, which are related to inflammation, trauma, and psychiatric symptoms in BDII-D.

Monoclonal antibody precision therapy targeting inflammation for bipolar disorder: a narrative review

Bipolar disorder (BD) is a severe mental disorder with various hypotheses regarding its pathogenesis. This article provides a summary of numerous studies on the variations in inflammatory cytokine levels in patients with BD and the effects of treatment with antipsychotics, mood stabilizers, and antidepressants on these levels. In addition, patients with autoimmune diseases who use anti-inflammatory monoclonal antibodies experience symptoms, such as depression, anxiety, and insomnia. These pieces of evidence suggest a potential association between immune inflammation and BD and offer new possibilities for therapy. Building upon this relationship, the authors propose an innovative approach for treating BD through individualized and precise therapy using anti-inflammatory monoclonal antibody drugs. To support this proposal, the authors compile information on pharmacological effects and relevant studies, including trials of various anti-inflammatory therapeutic monoclonal antibody drugs (e.g. infliximab, tocilizumab, and canakinumab) for the potential treatment of BD and its associated side effects in psychiatry. The authors categorize these anti-inflammatory monoclonal antibody drugs into levels I-IV through a comprehensive analysis of their advantages and disadvantages. Their potential is examined, and the need for further exploration of their pharmaceutical effects is established.

Elevated Brain-Derived Neurotrophic Factor Levels During Depressive Mixed States

OBJECTIVE

Neurotrophin-like brain-derived neurotrophic factor (BDNF) and pro-inflammatory cytokines may modulate the pathophysiology of mood disorders. Although several studies show alterations in these biomarkers during the depressive, manic, and euthymic states of mood disorders, evidence is lacking for those in a mixed state. Therefore, this study aimed to investigate the relationship between the depressive mixed state (DMX) and peripheral neurobiological factors.

METHODS

We enrolled 136 patients with major depressive episodes. Depressive symptoms were assessed using the Quick Inventory of Depressive Symptomatology Self-Report Japanese version (QIDS-SR-J). The severity of DMX was assessed using the self-administered 12-item questionnaire (DMX-12). Categorical screening as DMX-positive (n=54) was determined by a cutoff score of 13 or more in the specific eight symptoms from the DMX-12; the remaining were DMX-negative (n=82). Serum BDNF, tumor necrosis factor-α, highsensitivity C-reactive protein, and interleukin-6 levels were measured.

RESULTS

When comparing biomarkers between the DMX-positive and DMX-negative groups, higher serum BDNF concentration in the DMX-positive group than in the DMX-negative group was the only significant finding (p=0.009). A positive correlation existed between the total score of the eight specific symptoms of DMX-12 and the BDNF concentration (r=0.190, p=0.027). After adjustment for confounders, logistic regression analysis revealed that BDNF (odds ratio [OR]=1.07, 95% confidence interval [CI]=1.00-1.14, p=0.045), bipolar diagnosis (OR=3.43, 95% CI=1.36-8.66, p=0.009), and total QIDS-SR-J score (OR=1.29, 95% CI=1.15-1.43, p<0.001) were significantly associated with DMX positivity.

CONCLUSION

BDNF was positively associated with DMX severity, suggesting that higher BDNF concentrations may be involved in the pathophysiology of DMX.

Can Brain-Derived Neurotrophic Factor Be Considered a Biomarker for Bipolar Disorder? An Analysis of the Current Evidence

Brain-derived neurotrophic factor (BDNF) plays a key role in brain development, contributing to neuronal survival and neuroplasticity. Previous works have found that BDNF is involved in several neurological or psychiatric diseases. In this review, we aimed to collect all available data on BDNF and bipolar disorder (BD) and assess if BDNF could be considered a biomarker for BD. We searched the most relevant medical databases and included studies reporting original data on BDNF circulating levels or Val66Met polymorphism. Only articles including a direct comparison with healthy controls (HC) and patients diagnosed with BD according to international classification systems were included. Of the 2430 identified articles, 29 were included in the present review. Results of the present review show a reduction in BDNF circulating levels during acute phases of BD compared to HC, which increase after effective therapy of the disorders. The Val66Met polymorphism was related to features usually associated with worse outcomes. High heterogeneity has been observed regarding sample size, clinical differences of included patients, and data analysis approaches, reducing comparisons among studies. Although more studies are needed, BDNF seems to be a promising biomarker for BD.

Differences in intracellular protein levels in monocytes and CD4+ lymphocytes between bipolar depressed patients and healthy controls: A pilot study with tyramine-based signal-amplified flow cytometry

BACKGROUND

Molecular biomarkers for bipolar disorder (BD) that distinguish it from other manifestations of depressive symptoms remain unknown. The aim of this study was to determine if a very sensitive tyramine-based signal-amplification technology for flow cytometry (CellPrint™) could facilitate the identification of cell-specific analyte expression profiles of peripheral blood cells for bipolar depression (BPD) versus healthy controls (HCs).

METHODS

The diagnosis of psychiatric disorders was ascertained with Mini International Neuropsychiatric Interview for DSM-5. Expression levels for eighteen protein analytes previously shown to be related to bipolar disorder were assessed with CellPrint™ in CD4⁺ T cells and monocytes of bipolar patients and HCs. Implementation of protein-protein interaction (PPI) network and pathway analysis was subsequently used to identify new analytes and pathways for subsequent interrogations.

RESULTS

Fourteen drug-naïve or -free patients with bipolar I or II depression and 17 healthy controls (HCs) were enrolled. The most distinguishable changes in analyte expression based on t-tests included GSK3β, HMGB1, IRS2, phospho-GSK3αβ, phospho-RELA, and TSPO in CD4⁺ T cells and calmodulin, GSK3β, IRS2, and phospho-HS1 in monocytes. Subsequent PPI and pathway analysis indicated that prolactin, leptin, BDNF, and interleukin-3 signal pathways were significantly different between bipolar patients and HCs.

LIMITATION

The sample size of the study was small and 2 patients were on medications.

CONCLUSION

In this pilot study, CellPrint™ was able to detect differences in cell-specific protein levels between BPD patients and HCs. A subsequent study including samples from patients with BPD, major depressive disorder, and HCs is warranted.

Eveningness chronotype and depressive affective temperament associated with higher high-sensitivity C-reactive protein in unipolar and bipolar depression

BACKGROUND

Several studies investigated the role of inflammation in the etiopathogenesis of mood disorders. The aim of our cross-sectional study is evaluating baseline high-sensitivity C-reactive-protein (hsCRP) levels in a cohort of unipolar and bipolar depressive inpatients, in relation with psychopathological, temperamental and chronotype features.

METHODS

Among 313 screened inpatients, we retrospectively recruited 133 moderate-to-severe depressive patients who were assessed for hsCRP levels, chronotype with Morningness-Eveningness Questionnaire (MEQ) and affective temperament with Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS).

LIMITATIONS

The cross-sectional and retrospective design of the study, the small sample size, the exclusion of hypomanic, maniac and euthymic bipolar patients.

RESULTS

hsCRP levels were significantly higher among those with previous suicide attempt (p = 0.05), death (p = 0.018) and self-harm/self-injury thoughts (p = 0.011). Linear regression analyses, adjusted for all covariates, demonstrated that higher scores at the TEMPS-M depressive, while lower scores at the hyperthymic and irritable affective temperaments [F = 88.955, R² = 0.710, p < 0.001] and lower MEQ scores [F = 75.456, R² = 0.405, p < 0.001] statistically significantly predicted higher hsCRP.

CONCLUSION

Eveningness chronotype and a depressive affective temperament appeared to be associated with higher hsCRP levels during moderate-to-severe unipolar and bipolar depression. Further longitudinal and larger studies should better characterise patients with mood disorders by investigating the influence of chronotype and temperament.

Ferritin as a potential disease marker in patients with bipolar disorder

BACKGROUND

Low-grade inflammation and oxidative stress have been implicated as potential pathophysiological processes in bipolar disorder, but the underlying mechanism is unknown. Ferritin is a marker of iron stores and involved in redox processes and inflammation but its role in bipolar disorder is unclear.

METHODS

We investigated the possible association of increased plasma ferritin levels and bipolar disorder. We pooled two studies using similar longitudinal repeated measures designs and included 330 blood- and urinary samples from 95 patients with bipolar disorder across all affective states and 84 samples from 84 healthy control individuals. Plasma ferritin was measured along with multiple blood inflammatory markers and urinary markers of oxidatively generated damage to DNA and RNA.

RESULTS

Plasma ferritin levels, adjusting for multiple demographical- and lifestyle variables, did not differ between patients with bipolar disorder compared with healthy control individuals (b = 1.09, 95 % CI: 0.86 to 1.39, p = 0.49). Within patients with bipolar disorder ferritin levels were higher in a depressed state compared with euthymia (b = 1.12, 95 % CI: 1.01 to 1.24, p < 0.04), and ferritin levels were positively associated with Interleukin-18 blood levels and urinary levels of 8-oxodG.

LIMITATIONS

Patients with bipolar disorder received medication which could potentially influence iron metabolism.

CONCLUSION

Elevated ferritin levels in depressed patients with bipolar disorder may point to a role for iron metabolism in bipolar disorder pathophysiology, and potentially as a biomarker, linking low-grade inflammation with redox biology and the well-known increased risk of medical comorbidity and reduced life expectancy.

Clinical characteristics of bipolar 1 disorder in relation to interleukin-6: a cross-sectional study among Egyptian patients

Background

Strong evidence in the literature points to the role of pro-inflammatory cytokines in bipolar disorder (BD) pathophysiology. Interleukin-6 (IL-6) is a pro and anti-inflammatory cytokine that was repeatedly found higher in bipolar patients than in healthy controls. However, studies on the phasic differences of IL-6 in bipolar type I (BP-I) were limited. This study aims to explore the phasic differences of serum IL-6 levels in BP-I during euthymia, depression, and mania and their association with the disease’s clinical characteristics in a sample of Egyptian BP-I patients. Thirty currently euthymic, 24 currently depressed, 29 currently manic BP-I patients, and 20 healthy subjects were recruited. Serum IL-6 levels were compared among BP-I groups and then between each group and a group of 20 healthy controls. Serum IL-6 levels (pg/ml) were measured with a sandwich enzyme-linked immunosorbent assay (ELISA). Depression and mania symptoms were assessed using the Hamilton Depression Rating Scale (HDRS) and the Young Mania Rating Scale (YMRS), respectively. Clinical characteristics were evaluated through a semi-structured clinical psychiatric interview, and cognitive status was tested using the Montreal Cognitive Assessment (MoCA).

Results

Serum IL-6 levels were significantly higher in each bipolar phase than in healthy subjects. In the BP-I patients, IL-6 levels were lower in patients with a current manic episode than in patients with a current depressive episode (P < 0.05) or who were currently euthymic (P < 0.001). Moreover, IL-6 levels correlated inversely with the YMRS score (rs =  − 0.29; P < 0.05). Compared to patients without psychotic features, patients with psychotic features had decreased serum IL-6. Moreover, IL-6 levels were lower in inpatients compared to outpatients.

Conclusions

BP-I disorder is associated with an inflammatory state. The decreased levels of IL-6 during manic episodes, affective episodes with psychotic features, and their inverse correlation with the severity of mania symptoms indicate a possible anti-inflammatory role of IL-6 in mania and psychotic symptoms pathogenesis.

Can COVID-19 Vaccines Induce Premature Non-Communicable Diseases: Where Are We Heading to?

According to the WHO, as of January 2023, more than 850 million cases and over 6.6 million deaths from COVID-19 have been reported worldwide. Currently, the death rate has been reduced due to the decreased pathogenicity of new SARS-CoV-2 variants, but the major factor in the reduced death rates is the administration of more than 12.8 billion vaccine doses globally. While the COVID-19 vaccines are saving lives, serious side effects have been reported after vaccinations for several premature non-communicable diseases (NCDs). However, the reported adverse events are low in number. The scientific community must investigate the entire spectrum of COVID-19-vaccine-induced complications so that necessary safety measures can be taken, and current vaccines can be re-engineered to avoid or minimize their side effects. We describe in depth severe adverse events for premature metabolic, mental, and neurological disorders; cardiovascular, renal, and autoimmune diseases, and reproductive health issues detected after COVID-19 vaccinations and whether these are causal or incidental. In any case, it has become clear that the benefits of vaccinations outweigh the risks by a large margin. However, pre-existing conditions in vaccinated individuals need to be taken into account in the prevention and treatment of adverse events.

C-Reactive Protein (CRP): A Potent Inflammation Biomarker in Psychiatric Disorders

An increasing number of studies have investigated the role of inflammation in psychiatric disorders, by demonstrating how an altered/dysfunctional immunological and inflammatory system may underpin a psychiatric condition. Particularly, several studies specifically investigated the role of a neuroinflammatory biomarker, named C-reactive protein (CRP), in psychiatric disorders. Overall, even though scientific literature so far published still does not appear definitive, CRP is more likely reported to be elevated in several psychiatric disorders, including schizophrenia, mood disorders, anxiety disorders and post-traumatic stress disorder. Moreover, a low-grade inflammation (CRP >3 mg/L) has been more likely observed in a subgroup of patients affected with a more severe psychopathological symptomatology, more treatment resistance and worst clinical mental illness course, strengthening the hypothesis of the need for a different clinical and prognostic characterization based on this concomitant neuroinflammatory predisposition. However, even though further research studies are needed to confirm this preliminary evidence, CRP may represent a potential clinical routine biomarker which could be integrated in the clinical routine practice to better characterize clinical picture and course as well as address clinicians towards a personalized treatment.

The differences in serum C1q levels between first-episode patients with bipolar disorder and major depressive disorder

OBJECTIVE

This study aimed at exploring the changes of serum complement C1q levels in patients with Bipolar Disorder (BD) using a cross-sectional design, and the differences between Major Depressive Disorder (MDD) and BD. Moreover, the correlation between complement C1q and bech-rafaelsdn mania rating scales (BRMS) in patients with MDD and BD was assessed.

METHODS

Serum complement C1q levels were measured by ADVIA 2400 biochemical analyser in 104 patients with MDD, 71 patients with BD type I and 42 patients with BD type II diagnosed by Diagnostic and Statistical of Mental Disorder 5 (DSM-5). Then simple and multivariate linear regression analysis was conducted between the level of serum C1q and BRMS among patients with BD.

RESULTS

The serum complement C1q levels were higher in BD type I than BD type II (P < 0.001); Serum complement C1q levels were higher in MDD than BD type II (P < 0.001). We discovered that there was a positive correlation relationship between serum complement C1q levels and BRMS in BD type I (r = 0.756, P < 0.001).

CONCLUSION

We confirmed that serum complement C1q levels were higher in patients with BD type II than in MDD patients. These current results support the view that the complement C1q may play an important role in the pathophysiology of BD. Serum complement C1q was strongly associated with BD and is worth investigating in future studies.

C-Reactive Protein in Bipolar Disorder and Unipolar Depression

ABSTRACT

This study aimed to explore the role of C-reactive protein (CRP) in the pathological mechanism and differential diagnoses of bipolar disorder (BD) and unipolar depression (UD). We tested serum CRP levels of 176 BD and 86 UD patients, and 82 healthy controls (HCs), at acute and remission phases. In the acute phase, CRP levels were higher in BD than in UD patients and HC, and lower in UD patients than in HC. The CRP levels of BD patients in a manic episode were higher than those of HC; in a depressive or mixed episode, they were comparable to those of HC. The CRP levels of BD and UD patients during an acute depressive episode yielded an area under the curve of 0.676. CRP may be a state marker of acute manic episodes in BD and acute depressive episodes in UD, and a biomarker for distinguishing BD and UD.

Elevated C-reactive protein among symptomatic youth with bipolar disorder

RATIONALE AND OBJECTIVES

Increased levels of high-sensitivity C-reactive protein (CRP) are associated with mood symptoms in adults with bipolar disorder (BD). The few studies on this topic in youth with BD have not included controls. We, therefore, examined CRP levels in relation to symptomatic status in youth with and without BD.

METHODS

Participants included 154 youth (mean age 17 years; 48 asymptomatic BD, 39 symptomatic BD, 67 healthy controls (HC)). Rank analysis of covariance test examined group differences in CRP, controlling for age and sex. Correlation between CRP and mood symptom severity was examined using Spearman's correlation within the BD group.

RESULTS

There were significant group differences in CRP levels (F_(2,151) = 5.06, p = 0.007, ηp2=0.06); post hoc analyses showed higher CRP levels in the symptomatic BD group compared with HC (p = 0.01). In sensitivity analyses, this finding was no longer significant after controlling for body mass index (BMI). CRP was not significantly associated with symptomatic severity.

CONCLUSIONS

CRP levels are elevated among symptomatic youth with BD, partly related to BMI. As elevated BMI is associated with mood symptom burden, prospective studies are warranted to parse the associations among mood symptoms, BMI, and inflammation. Given the proportion of time that youth with BD are symptomatic, present findings raise concern about the long-term impact of elevated CRP on blood vessels, brain, and related clinical outcomes.

Inflammatory markers, brain-derived neurotrophic factor, and the symptomatic course of adolescent bipolar disorder: A prospective repeated-measures study

BACKGROUND

Numerous studies have found elevated pro-inflammatory markers and reduced brain-derived neurotrophic factor (BDNF) during symptomatic episodes of bipolar disorder (BD) in adults. There is a paucity of research examining these markers in youth with BD, or longitudinally in any BD age group.

METHODS

79 adolescents, ages 13-19 years, were enrolled, including 43 symptomatic adolescents with BD and 36 age-matched healthy controls (HC). Blood samples were collected from all participants at intake, and repeatedly from BD participants at pre-specified intervals over the course of two years. Serum was assayed for levels of pro-inflammatory markers (c-reactive protein [CRP], interleukin [IL]-6, tumor necrosis factor alpha [TNF-α]), BDNF and the anti-inflammatory marker, IL-10. Week-by-week severity of mood symptoms was assessed using semi-structured interviews.

RESULTS

Adolescents with BD provided an average of 4.6 blood samples, on average every 5.0 months. During the most severe symptomatic interval (i.e., highest sum of mood symptom scores) among BD adolescents, levels of CRP (p = 0.01) and pro- to anti-inflammatory ratios (CRP/IL-10; p < 0.001 and IL-6/IL-10; p = 0.046) were significantly greater, and IL-10 levels (p = 0.004) were significantly lower, vs. HC. There were no differences between BD and HC in IL-6, TNF-α or BDNF. Within BD participants, higher BDNF (p = 0.01) and IL-10 levels (p = 0.001) significantly predicted greater burden of mood symptoms over the subsequent epoch. Moreover, higher CRP levels (p = 0.009) at intake predicted greater time to recovery from the index symptomatic episode.

CONCLUSIONS

In the first repeated-measures study on this topic in adolescents with BD, we found evidence that CRP, an inexpensive and ubiquitous blood test, may be useful in predicting the prospective course of BD symptoms. Future larger studies are warranted.

Plasma BDNF and Cytokines Correlated with Protein Biomarkers for Bipolar II Disorder

We have previously identified five candidate proteins (matrix metallopeptidase 9 (MMP9), phenylalanyl-TRNA synthetase subunit beta (FARSB), peroxiredoxin 2 (PRDX2), carbonic anhydrase 1 (CA-1), and proprotein convertase subtilisin/kexin Type 9 (PCSK9)) as potential biomarkers for bipolar II disorder (BD-II). These candidate proteins have been associated with neuroprotective factors (BDNF) and inflammatory factors (cytokines, C-reactive protein (CRP), and tumor necrosis factor-α (TNF-α)). However, the correlations between these proteins with plasma BDNF and inflammatory factors remain unknown. We recruited a total of 185 patients with BD-II and 186 healthy controls. Plasma levels of candidate proteins, BDNF, cytokines (TNF-α, CRP, and interleukin-8 (IL-8)) were assessed from each participant. The correlations between levels of candidate proteins, BDNF, and cytokines were analyzed. In the BD-II group, we found that the level of FARSB was positively correlated with the BDNF level (r = 0.397, p < 0.001) and IL-8 (r = 0.320, p < 0.001). The CA-1 level positively correlated with IL-8 (r = 0.318, p < 0.001). In the control group, we found that the FARSB level positively correlated with the BDNF level (r = 0.648, p < 0.001). The CA-1 level positively correlated with TNF-α (r = 0.231, p = 0.002), while the MMP-9 level positively correlated with the CRP level (r = 0.227, p = 0.002). Our results may help in clarifying the underlying mechanism of these candidate proteins for BD-II.

Comparison of serum BDNF, IL-1β, IL-6, TNF-α, CRP and leucocyte levels in unipolar mania and bipolar disorder

OBJECTIVE

Unipolar mania is not included in the diagnostic and statistical manual of mental disorders-5 (DSM-5) as a separate diagnosis, although it is defined by widely accepted diagnostic criteria. The aim of this study was to investigate the differences between unipolar mania and bipolar disorder in terms of clinical and inflammatory parameters.

METHODS

The data of 495 hospitalised patients with bipolar disorder diagnoses were analysed retrospectively. Forty met the diagnostic criteria for unipolar mania. Two patients refused to participate in the study. Thirty-eight unipolar mania patients and 42 randomly selected patients with bipolar disorder diagnosis were included in the study. The two groups were compared in terms of sociodemographic, clinical characteristics, serum brain-derived neurotrophic factor, C-reactive protein (CRP), leucocyte and cytokine levels.

RESULTS

A total of 40 (8.08%) of 495 patients diagnosed with bipolar disorder met the unipolar mania diagnostic criteria. The number of manic episodes and the number of hospitalisations were statistically higher in the unipolar mania group than in the bipolar disorder group. Among all the manic symptoms, the incidence of symptoms such as euphoria, increased sexual interest, grandiosity and delusions were found to be statistically higher in the unipolar mania group. Interleukin (IL)-6 and CRP levels were significantly higher in the unipolar mania group than in the bipolar disorder group.

CONCLUSION

Unipolar mania differs from bipolar disorder in terms of clinical features and serum IL-6 and CRP levels.

A nation-wide population-based longitudinal study on life expectancy and cause specific mortality in patients with bipolar disorder and their siblings

OBJECTIVE

Mortality is increased in bipolar disorder due to both suicide and death by physical disorders, but it has never been investigated whether these mortalities translate into relatives to patients with bipolar disorder. The aim was to present the life expectancy and the overall mortality and mortality due to suicide and physical disorders among patients with bipolar disorder and their unaffected full siblings, respectively, compared with control individuals from the general population.

METHODS

We used Danish nation-wide population-based longitudinal register linkage to identify 19.955 patients with bipolar disorder, their 13.923 siblings and 20 sex, age and calendar matched control individuals from the general population. Follow-up was from 1995 to 2017.

RESULTS

Bipolar disorder was associated with a decreased life expectancy of 7.7 (95% CI: 7.4-8.1) years and increased mortality overall (hazard ratio (HR): 2.11 (95% CI: 2.04-2.18)) and due to suicide (HR: 18.23 (95% CI: 15.81-21.02) and physical disorders (HR: 2.01 (95% CI: 1.94-2.08). In contrast, siblings to patients with bipolar disorder who were unaffected by bipolar disorder did not have decreased life expectancy (0.45 (95% CI: -6.62-2.46)) or increased mortality overall (HR: 1.00 (95% CI: 0.88-1.14) or due to suicide (HR: 1.50 (95% CI: 0.95-2.36) or physical disorders (HR: 0.99 (95% CI: 0.87-1.34).

CONCLUSIONS

Increased mortality in bipolar disorder is mainly due to the impact of bipolar psychopathology and to a lesser degree to familial transmitted factors, highlighting the urgent need for preventive intervention studies in relation to suicide and physical disorders following onset of bipolar disorder.

Peripheral levels of C-reactive protein, tumor necrosis factor-α, interleukin-6, and interleukin-1β across the mood spectrum in bipolar disorder: A meta-analysis of mean differences and variability

IMPORTANCE

It is unclear whether differences exist in the magnitude and variability of pro-inflammatory mediators in the different phases of bipolar disorder (BD) and among subjects with BD, as compared to healthy controls.

OBJECTIVE

To run a comparative meta-analysis of C-Reactive Protein (CRP), IL-1, IL-6, TNF-α in BD vs healthy controls, measuring mean and variability effects on all subjects. Sensitivity analyses include disease activity.

DATA SOURCES

Systematic review of observational studies in PubMed and PsycInfo up to February 2nd, 2020.

STUDY SELECTION

Case-control studies reporting inflammatory mediators' levels in BD and controls.

DATA EXTRACTION AND SYNTHESIS

Summary distribution measures of circulating CRP, IL-1β, IL-6, TNF-α in participants with BD and control groups were extracted. Random-effects multivariate meta-analyses were conducted based on individual study/mediator effect sizes (Hedge's g).

MAIN OUTCOMES AND MEASURES

Co-primary outcomes were inflammatory mediators' levels (Hedge's g) and variability (coefficient of variance ratio (CVR)) differences between participants with BD across the mood spectrum and controls.

RESULTS

Out of the initial 729 papers, 72 were assessed and then excluded after full-text review, and ultimately 53 studies were included in the systematic review, while 49 were included in the meta-analysis. The mean age was 36.96 (SD: 9.29) years, and the mean female percentage was 56.31 (SD: 16.61). CRP (g = 0.70, 95% CI 0.31-1.09, k = 37, BD = 2,215 vs HC = 3,750), IL-6 (g = 0.81, 95% CI 0.46-1.16, k = 45, BD = 1,956 vs HC = 4,106), TNF-α (g = 0.49, 95% CI 0.19-0.78, k = 49, BD = 2,231 vs HC = 3,017) were elevated in subjects with BD vs HC, but not IL-1β (g = -0.28, 95% CI -0.68-0.12, k = 4, BD = 87 vs HC = 66). When considering euthymic, depressive, and manic episodes separately, CRP and TNF-α were elevated in both depressive and manic episodes, but not in euthymia, while IL-6 remained elevated regardless of the disease state. No difference in CVR emerged for CRP, IL-1β, and TNF-α, while a lower CVR was observed for IL-6. When considering disease phases, CVR was higher in BD than in HCs for CRP during depressive episodes, lower for IL-6 during euthymia, and higher during manic episodes for CRP, IL-6, and TNF-α. Sensitivity analyses after excluding outliers identified with funnel plot visual inspection, low-quality studies, and considering only studies matched per body mass index confirmed the main results. Meta-regression showed that age (IL-6, TNF-α), gender (CRP), duration of illness (CRP) moderated elevated individual inflammatory levels.

CONCLUSIONS AND RELEVANCE

Peripheral pro-inflammatory marker elevations were confirmed in BD. CRP and TNF-α could represent state markers, as they were only elevated during mood episodes, while IL-6 appeared to be a trait marker for BD. Increased variability of specific inflammatory mediators in specific disease active states suggests that a subset of subjects with BD may exhibit elevated inflammation as part of a manic or depressive episode.

Are Mannan-binding Lectine Serin Protease-2 and Alpha-1-microglobulin and Bukinin Precursor the Potential Biomarkers of Manic Episode? A Study via Urinary Proetomic Analysis

Objective

Investigating the molecular basis of bipolar disorder (BD) is crucial in terms of developing effective treatment strategies as well as objective laboratory-based diagnostic tools for the disease.

Methods

We examined the urine samples of BD patients both in manic episode and after remission and compared their urinary protein profiles with the controls. Twelve patients and twelve controls (C group) included to the study. Urinary samples of patients were first collected during manic episode (M group) and then after remission (R group). Two-dimensional gel electrophoresis (2-DE) coupled to MALDI-TOF/TOF massspectrometry approach and Western blot analysis were used.

Results

Alphα-1-microglobulin and bukinin precursor (AMBP), Mannan-binding lectine serin protease-2 (MASP-2), and Ig gamma-1-chain displayed significant increases in their abundance in the urine protein pool of M group in comparison to the C and R groups. Alpha-1B glycoprotein and prostaglandin-H2 D-isomerase (PGD2) levels were significantly higher in the urine protein pool of the M and R groups in comparison to the C group. Annexin A1 was downregulated significantly in the urine protein pool of the M group in comparison to the C group.

Conclusion

Intensities of MASP-2 and AMBP proteins discriminated manic episode from remission period and healthy controls indicating that these proteins may be candidate biomarkers for manic episode. The decrease in Annexin A1 and increase in Ig gamma-1 chain levels appeared to be associated with “Manic Episode” while the increase in PGD2 and alpha-1B glycoprotein levels appeared to be associated with “Bipolar Disorder”.

Effects of tDCS on neuroplasticity and inflammatory biomarkers in bipolar depression: Results from a sham-controlled study

OBJECTIVES

We investigated the role of peripheral biomarkers associated with neuroplasticity and immune-inflammatory processes on the effects of transcranial direct current stimulation (tDCS), a safe, affordable, and portable non-invasive neuromodulatory treatment, in bipolar depression.

METHODS

This is an exploratory analysis using a dataset from the sham-controlled study the Bipolar Depression Electrical Treatment Trial (BETTER)(clinicaltrials.govNCT02152878). Participants were 52 adults with type I or II bipolar disorder in a moderate-to-severe depressive episode, randomized to 12 bifrontal active or sham tDCS sessions over a 6-week treatment course. Plasma levels of brain derived neurotrophic factor (BDNF), glial cell derived neurotrophic factor (GDNF), interleukins (IL) 2, 4, 6, 8, 10, 18, 33, 1β, 12p70, 17a, interferon gamma (IFN), tumor necrosis factor alpha (TNF) and its soluble receptors 1 and 2, ST2, and KLOTHO were investigated at baseline and endpoint. We performed analyses unadjusted for multiple testing to evaluate whether baseline biomarkers were predictive for depression improvement and changed during treatment using linear regression models.

RESULTS

A time x group interaction (Cohen's d: -1.16, 95% CI = -1.96 to -0.3, p = .005) was found for IL-8, with greater reductions after active tDCS. Higher baseline IL-6 plasma levels was associated with symptomatic improvement after tDCS (F_(1,43) = 5.43; p = .025). Other associations were not significant.

CONCLUSIONS

Our exploratory findings suggested that IL-6 is a potential predictor of tDCS response and IL-8 might decrease after tDCS; although confirmatory studies are warranted due to the multiplicity of comparisons.

A nation-wide population-based longitudinal study mapping physical diseases in patients with bipolar disorder and their siblings

BACKGROUND

Patients with bipolar disorder may have increased risk of physical diseases due to genetic and environmental factors, but no study has systematically mapped all physical comorbidities in such subjects. The aim was to map rates of all physical diseases among patients and siblings to patients with bipolar disorder.

METHODS

We used Danish nation-wide population-based longitudinal register linkage to identify 19.955 patients with bipolar disorder, their 13.923 siblings and 20 sex, age and calendar matched control individuals from the general population. Follow-up was from 1995 to 2017.

RESULTS

Bipolar disorder was associated with increased rates of all physical disease categories compared with rates for control individuals, except for cancer. Further, bipolar disorder was associated with increased rates of separate disorders including ischemic heart disease, diabetes, dementia, hypertension, hypercholesterolemia and hyperlipidemia, hypothyroidism and infections. In contrast, siblings to patients with bipolar disorder who were unaffected by bipolar disorder had increased rates of certain disorders, only, comprising infectious and parasitic diseases, and diseases of the nervous system, digestive system and genitourinary system.

LIMITATIONS

Underdetection of physical disorders is likely because data are not available for persons who do not seek help for their disorders.

CONCLUSIONS

Bipolar disorder was associated with increased rates of all physical diseases categories, except cancer, and with separate disorders, likely involving inflammatory components in the pathogenesis. In contrast, unaffected siblings to patients with bipolar disorder had increased rates of certain disorders, only.

Concepts of Neuroinflammation and Their Relationship With Impaired Mitochondrial Functions in Bipolar Disorder

Bipolar disorder (BD) is a chronic psychiatric disease, characterized by frequent behavioral episodes of depression and mania, and neurologically by dysregulated neurotransmission, neuroplasticity, growth factor signaling, and metabolism, as well as oxidative stress, and neuronal apoptosis, contributing to chronic neuroinflammation. These abnormalities result from complex interactions between multiple susceptibility genes and environmental factors such as stress. The neurocellular abnormalities of BD can result in gross morphological changes, such as reduced prefrontal and hippocampal volume, and circuit reorganization resulting in cognitive and emotional deficits. The term "neuroprogression" is used to denote the progressive changes from early to late stages, as BD severity and loss of treatment response correlate with the number of past episodes. In addition to circuit and cellular abnormalities, BD is associated with dysfunctional mitochondria, leading to severe metabolic disruption in high energy-demanding neurons and glia. Indeed, mitochondrial dysfunction involving electron transport chain (ETC) disruption is considered the primary cause of chronic oxidative stress in BD. The ensuing damage to membrane lipids, proteins, and DNA further perpetuates oxidative stress and neuroinflammation, creating a perpetuating pathogenic cycle. A deeper understanding of BD pathophysiology and identification of associated biomarkers of neuroinflammation are needed to facilitate early diagnosis and treatment of this debilitating disorder.

Peripheral inflammation is associated with dysfunctional corticostriatal circuitry and executive dysfunction in bipolar disorder patients

Bipolar disorder (BD) has been linked to abnormal frontal and striatal function, and elevated inflammatory responses. However, the impact of peripheral inflammation on the corticostriatal functional connectivity (FC) remains obscure in BD. The current study aimed to explore the association between peripheral inflammation and corticostriatal connectivity in euthymic BD. We recruited 25 euthymic BD patients and 43 healthy controls (HCs) from the community. Resting state functional images were obtained using 3T magnetic resonance imaging (fMRI), and striatal seed-based whole-brain functional connectivity analyses were performed, with the fasting plasma high-sensitivity C-reactive protein (hs-CRP) level entered as a regressor of interest. The participants also completed the Wisconsin Card-Sorting Test (WCST) and the Continuous Performance Test (CPT). The euthymic BD group had a similar hs-CRP level to the HC group, but a significantly poorer cognitive performance. Compared with the HC group, a higher connectivity between the right dorsal caudal putamen (dcP) and the ventral lateral prefrontal cortex (vlPFC) in the BD group was significantly correlated with a higher hs-CRP level. Stronger dcP-vlPFC connectivity was correlated with a lower CPT unmasked d' in the BD group. BD patients might be particularly sensitive to the effects of inflammation on corticostriatal connectivity. The potentially greater sensitivity of BD patients to peripheral inflammation may differentially modulate the cognitive and reward related corticostriatal circuitry, which may contribute to the pathophysiology of cognitive-affective dysregulation in the euthymic state. Anti-inflammatory or other circuit-specific treatment is warranted for individualized treatment in BD.

Association of pro-inflammatory cytokines with clinical features in euthymic patients with Bipolar-I-Disorder

BACKGROUND

A chronic low-grade inflammatory state appears to be a relevant mechanism in the pathophysiology of bipolar disorder. Pro-inflammatory cytokines may influence disease course and individual symptomatology; and biological markers correlating with illness features may be of utility in clinical decision making during euthymia.

METHODS

51 euthymic outpatients with Bipolar-I-Disorder (BD-I) and 93 healthy controls (HC) were investigated. Comparisons between groups, and correlations with clinical features were performed. Serum concentrations of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and soluble interleukin-6 receptor (sIL-6R) were evaluated by ELISA under highly standardized conditions. Clinical features included duration of illness, number of previous suicide attempts and mood episodes (manic, hypomanic, depressive), scores of the Young Mania Rating Scale (YMRS), the Inventory of Depressive Symptoms (IDS-30), the Pittsburg Sleep Quality Index (PSQI), and the Global Assessment of Functioning (GAF).

RESULTS

No significant difference in serum concentrations of IL-1β, TNF-α, and sIL-6R between BD-I euthymic patients and HC could be identified. Among euthymic BD-I patients, a positive correlation of r_s = 0.47 (p = 0.004) between levels of IL-1β and IDS-30 score was identified.

LIMITATIONS

The design was cross-sectional, most patients were receiving medication, only 3 cytokines were assessed, only euthymic BD-I patients were evaluated.

CONCLUSIONS

The findings suggest that elevated pro-inflammatory cytokine concentrations are likely state rather than trait markers of BD-I. It also seems unlikely that cytokine concentrations are clinically informative interepisode. An inflammatory component might possibly be involved in the pathophysiology of subsyndromic depression in BD-I, and conceivably of bipolar depression per se.

High-sensitive C-reactive protein and homocysteine levels in patients with newly diagnosed bipolar disorder, their first-degree relatives, and healthy control persons-Results from a clinical study

Background

Changes in inflammatory and metabolic markers are implicated in the pathogenesis in both the development and progression of bipolar disorder (BD). Notwithstanding, these markers have not been investigated in newly diagnosed BD.

Methods

We compared high-sensitive C-reactive protein (hs-CRP) and homocysteine (Hcy) levels in 372 patients with newly diagnosed BD, 106 unaffected first-degree relatives (URs), and 201 healthy control persons (HCs). Within the patient group, we also investigated possible associations between hs-CRP and Hcy, respectively, with illness-related characteristics and psychotropic medication.

Results

No statistically significant differences in Hcy and hs-CRP levels were found when comparing BD and URs with HCs. Similarly, there were no differences when comparing only patients in remission or patients with affective symptoms, respectively, with HCs. Hcy levels were found to be 11.9% (95% CI: 1.030–1.219) higher in patients with BD when compared with their URs (p = 0.008), when adjusting for folate and cobalamin status, age, sex, and self-reported activity levels. Hcy levels were significantly associated with folate, cobalamin, gender, and age in all models (p < 0.05).

Conclusion

Our results do not support hs-CRP or Hcy as markers in newly diagnosed BD.

Chemokine alterations in bipolar disorder: A systematic review and meta-analysis

We aimed to perform a systematic review and meta-analysis of studies examining the levels of chemokines in peripheral blood of patients with bipolar disorder (BD) and healthy controls. Meta-analysis was based on random-effects models with Hedges' g as the effect size estimate. We included 13 eligible studies (1221 BD patients and 663 controls). The following chemokines were analysed: interleukin-8 (IL-8), monocyte-chemoattractant protein-1 (MCP-1), eotaxin-1, eotaxin-2 and interferon-γ-induced protein 10 (IP-10). The levels of IL-8 (N = 8, g = 0.26, 95%CI: 0.11-0.41, p < 0.001), MCP-1 (N = 8, g = 0.40, 95%CI: 0.18-0.63), eotaxin-1 (N = 3, g = 0.55, 95%CI: 0.21-0.89, p = 0.001) and IP-10 (N = 4, g = 0.95, 95%CI: 0.67-1.22, p < 0.001) were significantly higher in BD patients as compared with controls. Subgroup analyses revealed that elevated levels of IL-8 (N = 5, g = 0.75, 95%CI: 0.42-1.07, p < 0.001) and MCP-1 (N = 4, g = 0.57, 95%CI: 0.28-0.86, p < 0.001) appeared only in BD patients during their depressive phase. Illness duration was associated with significantly lower levels of IL-8 in meta-regression analysis. In turn, elevated levels of IP-10 were present during euthymia (N = 2, g = 0.76, 95%CI: 0.43-1.10, p < 0.001) but not depression (N = 2, g = 1.81, 95%CI: -0.16 to 3.77, p = 0.072). The analysis of eotaxin-1 levels was mainly based on studies of euthymic BD patients (N = 3). Our results suggest that chemokine alterations in BD might be related to mood state. Elevated levels of IL-8 and MCP-1 might be specific to depression. Available evidence indicates that increased levels of eotaxin-1 and IP-10 appear in euthymia; however, more studies are needed to address these alterations in other mood states.

Effects of adjunctive inflammatory modulation on IL-1β in treatment resistant bipolar depression

BACKGROUND

Adjunctive inflammatory modulation improved remission rates in treatment-resistant bipolar depression (TRBDD), but reliable biomarkers must be established to characterize the biosignature of TRBDD and the mechanisms underlying treatment response. In this molecular profiling study, we describe TRBDD and treatment response from the standpoint of interleukin-1 Beta (IL-1β) and KYN/TRP.

METHODS

47 TRBDD patients with moderately severe HAMD-17 scores were randomized to receive either escitalopram (ESC) (10 mg-40 mg daily dose range) + celecoxib (CBX) (200 mg twice daily), or ESC (10 mg-40 mg daily dose range) + placebo (PBO) (twice daily). Plasma cytokine levels were measured in both treatment arms at baseline and week 8, and in a healthy control (HC) group of subjects (N = 43) once. A linear mixed model (LMM) was applied to evaluate whether clinical outcome is related to CBX and changes to biomarkers throughout treatment. A binary logistic regression model was formulated from this series to predict both the primary outcome of treatment response to CBX, and the secondary outcome of diagnosis of TRBDD using age, BMI, gender, and IL-1β at baseline.

RESULTS

Patients receiving ESC + CBX had 4.278 greater odds of responding (p = 0.021) with NNT = 3, and 15.300 times more likely to remit (p < 0.001) with NNT = 2, compared with ESC + PBO patients. Patient BMI (p = 0.003), baseline IL-1β (p = 0.004), and baseline KYN/TRP (p = 0.001) were most predictive of TRBDD diagnosis. By Week 8, responders showed a downtrend in IL-1β compared to non-responders in the ESC + CBX treatment arm. However, there was no statistical difference in the IL-1β or KYN/TRP change after treatment between placebo and ESC + CBX group responders/non-responders (p = 0.239, and p = 0.146, respectively). While baseline IL-1β was elevated in TRBDD compared to HC (p < 0.001), there was no difference in IL-1β between treatment responders at Week 8 compared to HC (p = 0.067).

CONCLUSIONS

Elevated IL-1β and low KYN/TRP at baseline are components of the TRBDD molecular signature. CBX but not baseline IL-1β or KYN/TRP predict treatment response. Change in IL-1β and KYN/TRP did not predict treatment response.

Combination of dextromethorphan and memantine in treating bipolar spectrum disorder: a 12-week double-blind randomized clinical trial

Background

The aim of this study is to determine whether adding combination of agents with anti-inflammatory and neurotrophic effects is more efficacious than mood stabilizer alone in improving clinical symptoms, plasma brain-derived neurotrophic factor (BDNF), cytokine levels, and metabolic profiles in patients with bipolar spectrum disorder.

Methods

In a randomized, double-blind, controlled 12-week clinical trial, patients with moderate mood symptoms (HDRS ≥ 18 or YMRS ≥ 14) were recruited. The patients were randomly assigned to a group while still undergoing regular valproate (VPA) treatments: VPA + dextromethorphan (DM) (30 mg/day) + memantine (MM) (5 mg/day) (DM30 + MM5) (n = 66), VPA + DM (30 mg/day) (DM30) (n = 69), VPA + MM (5 mg/day) (MM5) (n = 66), or VPA + Placebo (Placebo) (n = 69). Symptom severity, immunological parameters [plasma tumor necrosis factor (TNF)-α and C-reactive protein (CRP)] and plasma brain-derived neurotrophic factor (BDNF) were regularly examined. Metabolic profiles [cholesterol, triglycerides, glycosylated hemoglobin (HbA1C), fasting serum glucose, body mass index (BMI)] were measured at baseline and at 2, 8, and 12 weeks.

Results

Depression scores were significantly (P = 0.03) decreases and BDNF levels significantly (P = 0.04) increased in the DM30 + MM5 group than in the Placebo group. However, neither depressive scores nor BDNF levels were significantly different between the DM30, MM5, and Placebo groups. Changes in certain plasma cytokine and BDNF levels were significantly correlated with metabolic parameters.

Conclusion

We concluded that add-on DM30 + MM5 was significantly more effective than placebo for clinical symptoms and plasma BDNF levels. Additional studies with larger samples and mechanistic studies are necessary to confirm our findings.

Trial registration NCT03039842 (https://register.clinicaltrials.gov/). Trial date was from 1 Jan 2013 to 31 December 2016 in National Cheng Kung University Hospital. Registered 28 February 1 2017-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03039842?term=NCT03039842&rank=1.

Neuroinflammation in Bipolar Depression

Bipolar disorder (BD) is a leading cause of worldwide disability among mood disorders. Pathological mechanisms are still vastly unclear, and current treatments with conventional medications are often unsatisfactory in maintaining symptoms control and an adequate quality of life. Consequently, current research is focusing on shedding new light on disease pathogenesis, to improve therapeutic effectiveness. Recent evidence has suggested a prominent role of inflammation in mood disorders. Elevated levels of peripheral proinflammatory mediators have been reported in BD, as well as in other mood disorders, and people with systemic autoimmune diseases have an increased risk of developing BD. These immunological alterations are stable, and current medications are unable to alter peripheral concentrations even when clinical improvement is evident. These findings have also been replicated in the central nervous system (CNS) milieu, whereas genetic studies have shown that these immune alterations are not due to the disorder itself, being detectable before the illness onset. Moreover, these inflammatory modifications seem to be affected by and linked to other biomarkers of the disorder, such as alterations of white matter (WM) microstructure, metabolism, kynurenine pathway, and circadian rhythmicity. Finally, these immune variations seem to be useful as predictors of therapeutic responsiveness to medications, and in discriminating between clinically different outcomes. The objective of this review is to summarize available evidence on the connection between inflammation and BD, focusing on peripheral inflammatory markers and recent findings on their connection with other typical features of BD, to outline a general overview of the disorder. Moreover, it is meant to analyze the issues with data gathering and interpretation, given the partially contradictory and inconsistent nature of results.

C-reactive protein concentration in bipolar disorder: association with genetic variants

Background

Several recent studies have investigated the role of C-reactive protein (CRP) in bipolar disorder (BD), but few studies have directly investigated the interaction between CRP genetic variants and peripheral CRP concentration across different phases of BD. In this study, we aimed to replicate previous findings that demonstrated altered CRP levels in BD, and to investigate whether there is an association of peripheral protein expression with genetic variants in the CRP gene.

Methods

221 patients were included in the study, of which 183 (all episodes, 46 not medicated, 174 medicated) were genotyped for CRP single-nucleotide polymorphisms (SNPs) shown to influence peripheral CRP protein expression (rs1800947, rs2808630, rs1417938, rs1205).

Results

There were no differences in CRP levels associated with the genotypes, only regarding the rs1205 SNP there were significantly different CRP protein expression between the genotypes when taking body mass index, age, BD polarity, subtype and leukocyte number into account. However, we could show significantly elevated CRP protein expression in manic patients compared to euthymic and depressed patients, independent from genotype. Medication was found to have no effect on CRP protein expression.

Conclusions

These results indicate that low grade inflammation might play a role in mania and might be rather a state than a trait marker of bipolar disorder.

Combination of Geniposide and Eleutheroside B Exerts Antidepressant-like Effect on Lipopolysaccharide-Induced Depression Mice Model

OBJECTIVE

To study the antidepressant-like effect and action mechanism of geniposide and eleutheroside B combination treatment on the lipopolysaccharide (LPS)-induced depression mice model.

METHODS

Depression mice model was established by lipopolysaccharide (LPS) injection. Totally 48 mice were randomly divided into 6 groups (8 rats per group) according to a random number table, including normal, model, fluoxetine (20 mg/kg), geniposide (100 mg/kg) + eleutheroside B (100 mg/kg), geniposide + eleutheroside B + WAY 100635 (0.03 mg/kg), geniposide + eleutheroside B+ N-methyl-D-aspartic acid receptor (NMDA, 75 mg/kg) groups, respectively. After continuous administration for 10 days, autonomic activity tests after 30 min of administration were performed on the 10th day. On the 11th day, except for the normal group, the mice in the other groups were intraperitoneally injected with LPS (1 mg/kg), and the behavioral tests were performed 4 h later. Enzyme linked immunosorbent assay was used to detect tumor necrosis factor alpha (TNF- α) and interleukin-1 β (IL-1 β) levels in mice serum. The mRNA expression of indoleamine 2,3-dioxygenase (IDO) and nuclear transcription factor (NF- κB) were detected by real-time quantitative polymerase chain reaction. Western-blot analysis was used to detect IDO and NF- κB protein expressions in hippocampus tissue.

RESULTS

Compared with the normal group, a single administration of LPS increased the immobility time in the forced swimming test (FST) and tail suspension test (TST, P<0.01), without affecting autonomous activity. Compared with the model group, fluoxetine and geniposide + eleutheroside B administration significantly improved the immobility time of depressed mice in the FST and TST, decreased serum IL-1 β content, inhibited the expression levels of NF- κ B gene and protein in hippocampus tissues (P<0.05 or P<0.01). Compared with the model group, geniposide + eleutheroside B treatment significantly reduced serum TNF-α content and inhibited IDO mRNA and protein expressions in hippocampus (P<0.05 or P<0.01). In addition, NMDA partly prevented the inhibition of IDO mRNA expression by geniposide + eleutheroside B; NMDA and WAY-100635 also partly prevented the reduction of IL-1 ß content induced by geniposide + eleutheroside B treatment (P<0.05 or P<0.01).

CONCLUSIONS

The combination of geniposide and eleutheroside B showed a certain antidepression-like effect. Its main mechanism of action may be contributed to inhibiting the activation of NF- κB, decreasing the proinflammatory cytokines such as TNF-α, IL-1 β, and inhibiting in the neuroinflammatory reaction. Additionally, it also affects tryptophan metabolism, reduces the expression of a key enzyme of tryptophan metabolism, IDO. And this antidepressant-like effect may be mediated by 5-hydroxytryptamine and glutamate systems.

Changes in inflammation with treatment for bipolar II depression: Pilot trial data on differential effects of psychotherapy and medication

OBJECTIVES

Limited prospective data, mostly focused on bipolar I disorder, suggests that pro-inflammatory cytokines are elevated in abnormal mood states. We evaluated whether treatment normalizes peripheral markers of inflammation in bipolar II disorder.

METHODS

Using data from a randomized clinical trial of Interpersonal and Social Rhythm Therapy (IPSRT) + quetiapine vs. IPSRT + placebo for bipolar II depression, we examined whether these treatments for bipolar II depression impact inflammatory cytokines and whether observed changes in cytokines are associated with changes in depressive symptomatology as measured by the Hamilton Rating Scale for Depression (HRSD-17).

RESULTS

Cytokine values were available for 33 participants who completed baseline and 20-week followup visits. After excluding those with CRP values >=10 mg/L, there were 27 patients available for analysis (IPSRT+quetiapine N=10, IPSRT+placebo N=17). Baseline measure of inflammation did not appear to moderate treatment response, nor was change in HRSD-17 score correlated with changes in cytokines. Those who received IPSRT+quetiapine had significantly greater increases in IL-6 (p=0.02) and TNF-α (p=0.04), even after adjusting for changes in body mass index, than the IPSRT alone group. Descriptively, the quetiapine group showed increases in pro-inflammatory and decreases in anti-inflammatory cytokines and the psychotherapy group showed reduced pro-inflammatory cytokines.

CONCLUSIONS

Despite both groups showing depression improvement, this small study suggests a more pro-inflammatory cytokine profile over time with quetiapine plus psychotherapy compared to psychotherapy alone. Elevated risk of cardiovascular morbidity and mortality among those with bipolar II disorder underscores the importance of delivering treatments that do not exacerbate these risk factors.

A review on shared clinical and molecular mechanisms between bipolar disorder and frontotemporal dementia

Mental disorders are highly prevalent and important causes of medical burden worldwide. Co-occurrence of neurological and psychiatric symptoms are observed among mental disorders, representing a challenge for their differential diagnosis. Psychiatrists and neurologists have faced challenges in diagnosing old adults presenting behavioral changes. This is the case for early frontotemporal dementia (FTD) and bipolar disorder. In its initial stages, FTD is characterized by behavioral or language disturbances in the absence of cognitive symptoms. Consequently, patients with the behavioral subtype of FTD (bv-FTD) can be initially misdiagnosed as having a psychiatric disorder, typically major depression disorder (MDD) or bipolar disorder (BD). Bipolar disorder is associated with a higher risk of dementia in older adults and with cognitive impairment, with a subset of patients presents a neuroprogressive pattern during the disease course. No mendelian mutations were identified in BD, whereas three major genetic causes of FTD have been identified. Clinical similarities between BD and bv-FTD raise the question whether common molecular pathways might explain shared clinical symptoms. Here, we reviewed existing data on clinical and molecular similarities between BD and FTD to propose biological pathways that can be further investigated as common or specific markers of BD and FTD.

The Relationship Between Neuroimmunity and Bipolar Disorder: Mechanism and Translational Application

Neuroimmune system may be involved in the pathological process of bipolar disorder (BD), but the essential association is not fully understood. Accumulating evidence has shown that BD involves the activation of immune cells and the release of inflammatory substances in the central nerve system (CNS). Meanwhile, neuroimmune responses also interact with other hypothesis of the etiology of BD that are widely recognized, such as neurotransmitter systems, neuroendocrine systems, neurotrophic factors, and oxidative stress. Simultaneously, related genes and immune changes in peripheral blood vary with it. Overall, neuroimmunity may play an important role in the pathogenesis of BD, and the inflammatory cytokines, especially interleukin-6 and tumor necrosis factor-alpha, have potential value for the clinical diagnosis and prognosis of BD, as well as predicting the therapeutic effects of drugs. Large-scale studies are needed to extend the evidence on neuroimmunity in BD, and to examine its clinical value for applications such as early prediction and treatment.

Altered irisin/BDNF axis parallels excessive daytime sleepiness in obstructive sleep apnea patients

STUDY OBJECTIVES

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a sleep-related breathing disorder, characterized by excessive daytime sleepiness (EDS), paralleled by intermittent collapse of the upper airway. EDS may be the symptom of OSAHS per se but may also be due to the alteration of central circadian regulation. Irisin is a putative myokine and has been shown to induce BDNF expression in several sites of the brain. BDNF is a key factor regulating photic entrainment and consequent circadian alignment and adaptation to the environment. Therefore, we hypothesized that EDS accompanying OSAHS is reflected by alteration of irisin/BDNF axis.

METHODS

Case history, routine laboratory parameters, serum irisin and BDNF levels, polysomnographic measures and Epworth Sleepiness Scale questionnaire (ESS) were performed in a cohort of OSAHS patients (n = 69). Simple and then multiple linear regression was used to evaluate data.

RESULTS

We found that EDS reflected by the ESS is associated with higher serum irisin and BDNF levels; β: 1.53; CI: 0.35, 6.15; p = 0.012 and β: 0.014; CI: 0.0.005, 0.023; p = 0.02, respectively. Furthermore, influence of irisin and BDNF was significant even if the model accounted for their interaction (p = 0.006 for the terms serum irisin, serum BDNF and their interaction). Furthermore, a concentration-dependent effect of both serum irisin and BDNF was evidenced with respect to their influence on the ESS.

CONCLUSIONS

These results suggest that the irisin-BDNF axis influences subjective daytime sleepiness in OSAS patients reflected by the ESS. These results further imply the possible disruption of the circadian regulation in OSAHS. Future interventional studies are needed to confirm this observation.

Adjunctive tianeptine treatment for bipolar disorder: A 24-week randomized, placebo-controlled, maintenance trial

OBJECTIVE

The purpose of this study was to assess the efficacy and tolerability of tianeptine as an adjunctive maintenance treatment for bipolar depression.

METHODS

This is a multicenter double-blind randomized placebo-controlled maintenance trial of adjunctive tianeptine 37.5 mg/day. Participants ( n=161) had a Montgomery-Asberg Depression Rating Scale ⩾12 at entry. After eight weeks of open-label tianeptine treatment, those who responded to tianeptine ( n=69) were randomized to adjunctive tianeptine ( n=36) or placebo ( n=33) in addition to usual treatment. Kaplan-Meier estimates and the Mantel-Cox log-rank test were used to evaluate differences in time to intervention for a mood episode between the tianeptine and placebo groups. We also assessed overall functioning, biological rhythms, quality of life, rates of manic switch and serum brain-derived neurotrophic factor levels.

RESULTS

There were no differences between adjunctive tianeptine or placebo regarding time to intervention or depression scores in the 24-week double-blind controlled phase. Patients in the tianeptine group showed better performance in the letter-number sequencing subtest from the Wechsler Adult Intelligence Scale at the endpoint ( p=0.014). Tianeptine was well tolerated and not associated with higher risk for manic switch compared to placebo.

CONCLUSION

Tianeptine was not more effective than placebo in the maintenance treatment of bipolar depression. There is preliminary evidence suggesting a pro-cognitive effect of tianeptine in working memory compared to placebo.

The association between low-grade inflammation and the clinical features of bipolar disorder in Han Chinese population

Variety of evidence suggests that low-grade inflammation may be involved in the pathophysiology of bipolar disorder (BD). However, the conclusion regarding the relationship between inflammation and BD has been inconsistent. In this study, we aimed to survey the prevalence of low-grade inflammation in a large Han Chinese population with BD and assess its impact on the clinical features of BD. 430 eligible cases were drawn from patients who were admitted or had ever been admitted for BD to the inpatient service of the psychiatric department of the Third Hospital of Sun Yat-sen University. Subjects with current active physical diseases or white blood count (WBC) >19.0 × 10⁹/L (2 times the upper reference) were excluded. Serum C-reactive protein (CRP) levels and WBC were measured with fast blood sample. Low-grade inflammation was defined as CRP>3 mg/L or WBC > 9.5 × 10⁹/L(the upper reference). Clinical features of BD were collected through semi-structural interview conducted by trained interviewers with background of psychiatric education. If defined as CRP>3 mg/L, the prevalence of low-grade inflammation among BD was 10.1% (41/404), it was positively associated with BMI (p = 0.012), comorbidity of glycolipid metabolic diseases(p = 0.018). After adjusting for BMI, it was found to be positively related to recent suicide attempt (p = 0.03), initiation with (hypo)manic episode(p = 0.047), leaden paralysis (p = 0.037) and family history of mental disorders(p = 0.012), while the association between comorbidity of glycolipid metabolic diseases and low-grade inflammation disappeared (p = 0.330). If defined as WBC > 9.5 × 10⁹/L, the prevalence of low-grade inflammation was 8.1% (33/409), it was positively associated with psychotic features (p = 0.011) and adverse life events before the onset of illness(p < 0.001), but was not significantly influenced by BMI (p = 0.077). A much lower prevalence of low-grade inflammation in BD is found among Han Chinese population than among western population. Low-grade inflammation of different definition impacts differentially on the clinical features of BD.

Increased levels of plasma IL-1b and BDNF can predict resistant depression patients

SUMMARY BACKGROUND: There is no strong evidence on the link between inflammatory profile and pattern of drug treatment response in depressive patients that could result in Coronary Artery Disease occurrence. OBJECTIVE: This study aimed to compare the subclinical atherosclerosis markers, inflammatory profile, and BDNF production in Resistant Depression (RD) or Bipolar Affective Disorder (BAD) patients under conventional treatment. METHODS: The population evaluated was comprised of 34 RD, 43 BAD, and 41 controls. Subclinical atherosclerosis markers were evaluated using ultrasonography, tomography, and exercise stress test. Plasma concentrations of TNFα, IL-1β, IL-6, and BDNF were measured using Luminex100™. The usCRP concentration was measured using turbidimetric immunoassay. IL1B, IL6, and TNFA expression were determined using TaqMan®. For the statistical analysis, the significance level was established at p<0.05. RESULTS: Concerning subclinical atherosclerosis markers, only O2 consumption was reduced in the BAD group (p = 0.001). Although no differences were found in gene expression, BDNF and IL-1β plasma concentration was increased in the RD group (p = 0.002 and p = 0.005, respectively) even with an antidepressant treatment, which suggests that these drugs have no effect in IL-1β secretion and that the inflammasome may play a role in therapy response. CONCLUSION: Taken together, both BDNF and IL-1β plasma concentrations could be used to the early identification of RD patients.

Neurotrophins, cytokines, oxidative stress mediators and mood state in bipolar disorder: systematic review and meta-analyses

BACKGROUND

A reliable biomarker signature for bipolar disorder sensitive to illness phase would be of considerable clinical benefit. Among circulating blood-derived markers there has been a significant amount of research into inflammatory markers, neurotrophins and oxidative stress markers.AimsTo synthesise and interpret existing evidence of inflammatory markers, neurotrophins and oxidative stress markers in bipolar disorder focusing on the mood phase of illness.

METHOD

Following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) guidelines, a systematic review was conducted for studies investigating peripheral biomarkers in bipolar disorder compared with healthy controls. We searched Medline, Embase, PsycINFO, SciELO and Web of Science, and separated studies by bipolar mood phase (mania, depression and euthymia). Extracted data on each biomarker in separate mood phases were synthesised using random-effects model meta-analyses.

RESULTS

In total, 53 studies were included, comprising 2467 cases and 2360 controls. Fourteen biomarkers were identified from meta-analyses of three or more studies. No biomarker differentiated mood phase in bipolar disorder individually. Biomarker meta-analyses suggest a combination of high-sensitivity C-reactive protein/interleukin-6, brain derived neurotrophic factor/tumour necrosis factor (TNF)-α and soluble TNF-α receptor 1 can differentiate specific mood phase in bipolar disorder. Several other biomarkers of interest were identified.

CONCLUSIONS

Combining biomarker results could differentiate individuals with bipolar disorder from healthy controls and indicate a specific mood-phase signature. Future research should seek to test these combinations of biomarkers in longitudinal studies.Declaration of interestNone.

Different levels of pro- and anti-inflammatory cytokines in patients with unipolar and bipolar depression

BACKGROUND

Immune system dysregulation is critical in the physiopathology of major depressive disorder (MDD) and bipolar disorder (BD). However, it is unclear whether both diseases present the same inflammatory patterns during depressive episodes. We explored the differences in pro- and anti-inflammatory cytokines between unipolar and bipolar depression (BDD) and the trajectory of these cytokines after acute-phase treatment.

METHODS

Sixty-four MDD patients, 61 BDD patients, and 62 healthy controls (HCs) were enrolled. We assessed the clinical features and cytokines plasma levels at baseline and week 12. The pro-inflammatory cytokines (IL-6, TNF-α) and anti-inflammatory cytokines (IL-4, IL-13) of all subjects were assessed by multiplexed sandwich ELISA-based quantitative arrays.

RESULTS

Before acute-phase treatment, the initial levels of TNF-α and IL-13 were significantly lower in the BDD patients than in the MDD patients. The results demonstrated that there was no relationship between each cytokine level and clinical features of unipolar and bipolar depressions. After 12 weeks, TNF-α, IL-4, and IL-13 levels became lower in MDD patients than in the other two groups regardless of the patients' response to treatment while the levels of TNF-α and IL-4 increased only in the BDD responders.

LIMITATIONS

The effects of different drugs on inflammatory cytokines in MDD or BDD could not be explored further due to the relatively small sample size.

CONCLUSION

Even within the same depressive states, MDD and BDD patients present different inflammatory features, particularly in regard to pro-inflammatory TNF-α and anti-inflammatory IL-13. In addition, the fluctuations of cytokines induced by medication may provide a hint regarding the prediction of treatment response.

Association between Elevated C-Reactive Protein and Manic Polarity in Acute Psychiatric Inpatients with Affective Symptomatology

The interplay between the immune system and behaviour is of increasing interest in psychiatry research. Specifically, accumulating data points to a link between inflammation and psychopathology, including affective symptomatology. We investigated the association between inflammation and affective polarity in psychiatric inpatients who were hospitalized due to an affective exacerbation. Data was collected retrospectively and comparisons were made between manic and depressed patients. C-reactive protein (CRP), a general laboratory marker of immune activation and inflammation, was used as a non-specific inflammatory biomarker. Age, smoking and body mass index were considered covariates. Manic polarity (n = 89) was associated with statistically significant elevated CRP levels compared to depressed polarity (n = 44, 56%; p = 0.036), after controlling for covariates. No differences were observed in CRP levels across Diagnostic and Statistical Manual of Mental Disorders-IV Edition-Text Revised psychiatric diagnoses. These findings suggest a transdiagnostic association between inflammation and manic polarity in affective inpatients.

Electro-Acupuncture Alleviates Chronic Unpredictable Stress-Induced Depressive- and Anxiety-Like Behavior and Hippocampal Neuroinflammation in Rat Model of Depression

Depression is the second leading cause of disability worldwide. The effects of clinical depression may be mediated by neuroinflammation such as activation of microglia and high levels of proinflammatory cytokines in certain brain areas. Traditional Chinese medicine techniques such as electro-acupuncture (EA) are used extensively in Asia to treat mental health disorders. However, EA has not been rigorously studied in treatment of depression. This study was designed to assess the effectiveness of EA on depressive-like behavior and explore the role of hippocampal neuroinflammation in the potential antidepressant effect of EA. In this study, we used six chronic unpredictable stressors daily in a random sequence for 10 weeks. EA were performed on “Bai-Hui” (Du-20) (+) and “Yang-Ling-Quan” (GB-34, the right side; −) acupoints by an EA apparatus (HANS Electronic Apparatus, LH202H, 2/100 Hz, 0.3 mA) for 30 min once every other day for last 4 weeks. The behavior tests including open field test and forced swimming test, which are widely used to assess depressive and anxiety-like behavior were performed on the Monday and Tuesday of the eleventh week. The results showed that 10 week of chronic unpredictable stress (CUS) caused behavioral deficits in rats and neuroinflammation in hippocampus, such as increased expression of NLRP3 inflammasome components, upregulated mRNA level of IL-1β and the protein level of IL-1β mature form (p17) and activation of microglia. Moreover, 4 weeks of EA treatment significantly attenuated behavioral deficits caused by CUS. EA’s antidepressant effect was accompanied by markedly decreased expression of certain NLRP3 inflammasome components and matured IL-1β. Meanwhile, EA treatment can significantly reverse CUS-induced increases in P2X7 receptor, Iba-1, IL-18, TNFα and IL-6 expression and decreases in GFAP expression. In conclusion, EA exhibited the antidepressant effect and alleviated the hippocampal neuroinflammation. These findings may provide insight into the role of hippocampal neuroinflammation in the antidepressant effect of EA.

Brain-derived neurotrophic factor (BDNF) serum level in women with first-episode depression, correlation with clinical and metabolic parameters

BACKGROUND

Brain-derived neurotrophic factor (BDNF) influences neuron differentiation during development, as well as the synaptic plasticity and neuron survival in adulthood. BDNF has been implicated in the pathogenesis of psychiatric disorders and its serum level is a potential biomarker for depression. The aim of this study was to examine serum levels of BDNF in first-episode depression and its correlation with clinical and metabolic parameters.

MATERIALS AND METHODS

The study was performed on a group of 60 women: 30 diagnosed with a first-episode of depression and 30 healthy controls. 17-Item Hamilton Depression Rating Scale (HDRS-17) was used to assess the severity of depression. Patients were randomly chosen for treatment with sertraline or venlafaxine. BDNF serum levels and metabolic parameters: fasting serum glucose, cholesterol, triglyceride (TG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C) were measured at baseline and week 8 of treatment.

RESULTS

There were no differences between BDNF level in depressed patients compared with the healthy controls. Lack of differences in medication effect of sertraline or venlafaxine on HDRS-17 scores during 8 weeks of treatment was observed. Correlation of BDNF at baseline and fasting serum glucose at baseline and week 8 was detected.

CONCLUSIONS

Correlations of BDNF serum levels with metabolic parameters were observed.