The role of tumor necrosis factor-alpha and other cytokines in depression: what dermatologists should know

Effects on peripheral and central nervous system of key inflammatory intercellular signalling peptides and proteins in psoriasis

Psoriasis is a chronic systemic inflammatory cutaneous disease. Where the immune system plays an important role in its pathogenesis, with key inflammatory intercellular signalling peptides and proteins including IL-17 and IL-23. The psychoneurological system also figures prominently in development of psoriasis. There is a high prevalence of comorbidity between psoriasis and mental health disorders such as depression, anxiety and mania. Patients with psoriasis often suffer from pathological pain in the lesions, and their neurological accidents could improve the lesions in innervated areas. The immune system and the psychoneurological system interact closely in the pathogenesis of psoriasis. Patients with psoriasis exhibit abnormal levels of neuropeptides both in circulating and localized lesion, acting as immunomodulators involved in the inflammatory response. Moreover, receptors for inflammatory factors are expressed in both peripheral and central nervous systems (CNSs), suggesting that nervous system can receive and be influenced by signals from immune system. Key inflammatory intercellular signalling peptides and proteins in psoriasis, such as IL-17 and IL-23, can be involved in sensory signalling and may affect synaptic plasticity and the blood-brain barrier of CNS through the circulation. This review provides an overview of the multiple effects on the peripheral and CNS under conditions of systemic inflammation in psoriasis, providing a framework and inspiration for in-depth studies of neuroimmunomodulation in psoriasis.

Correlation of Specific Inflammatory Markers With the Occurrence of Depression in Patients With Psoriasis and Their Use as Biomarkers for the Diagnosis of Depression

INTRODUCTION

Psoriasis is a systemic disease of the skin and nails associated with a wide range of comorbidities such as depression, psoriatic arthritis and metabolic syndrome.

OBJECTIVES

The study aimed to examine a potential association between inflammatory markers (C- reactive protein [CRP] and erythrocyte sedimentation rate [ESR]) and depression in patients with psoriasis.

METHODS

A total of 80 individuals were enrolled in the study. Case participants included 28 patients diagnosed with Psoriasis (Beck Depression Inventory-II: :0-13) and 24 patients diagnosed with Psoriasis and Depression (Beck Depression Inventory-II:14-63). Twenty-eight (28) healthy participants comprised the control group.Psoriasis severity was evaluated by using Psoriasis Area and Severity Index, Physician Global Assessment, Body Surface Area and Dermatology Life Quality Index. Written approval was obtained for its use in this study: Cardiff University (09/2015). Other factors considered in the study were obesity using the Body Mass Index, the levels of stress using the Beck Anxiety Inventory, and the presence of insomnia using the Athens Insomnia Scale. Blood draws and inflammatory markers measurements were performed for all participants.

RESULTS

Both CRP and ESR levels were higher in the case group (ie Psoriasis and Depression and Psoriasis) compared to healthy controls. Furthermore, psoriatic patients with depression showed increased CRP and ESR levels compared to those of psoriatic patients without depression.

CONCLUSIONS

The evaluation of both CRP and ESR and their use to detect the presence of depression in patients with psoriasis can be an important tool for their holistic treatment of theirs.

Assessing and Improving Psychological Well-Being in Psoriasis: Considerations for the Clinician

Psoriasis is a common chronic, systemic inflammatory disease, affecting approximately 2% of the population worldwide. Psoriasis is associated with profound psychosocial comorbidity with a burden that extends well beyond the physical signs and symptoms. Psychosocial comorbidities strongly associated with psoriasis include anxiety and depression, suicidal ideation, and substance misuse. There is a substantial unmet need for access to psychological support for people with skin disease in the UK. Recent reports found that while up to 98% of patients felt that their skin disease had affected their emotional or psychological well-being, only 18% sought help. This care gap is largely due to a lack of awareness about the limited available services alongside poor recognition, diagnosis, and triaging. Addressing psychosocial support needs starts with early identification, which can be complex and challenging. Once patients who need further support are identified, outcomes can be improved through prompt and effective treatment of inflammation, cognitive behavioural therapy, meditation and mindfulness-based therapy (including motivational interviewing), and to some extent psychotropic medication. Finally, resources for mental health support are notoriously limited, with dire consequences for patients. It is imperative that a proportion of the new funding promised for mental health services is bookmarked for dermatology patients and adequate provision of multidisciplinary psychodermatology teams to best serve the needs of this population. Ultimately, psoriasis is a complex condition with multifactorial psychological and biological drivers. Psoriasis is associated with high levels of distress, which is often under-recognized. Fully addressing this condition requires a holistic approach to the physical and psychosocial aspects to maximise adherence, efficacy, and optimise patient quality of life.

The Brain-Skin Axis in Psoriasis-Psychological, Psychiatric, Hormonal, and Dermatological Aspects

Psoriasis is a chronic inflammatory skin disease with systemic manifestation, in which psychological factors play an important role. The etiology of psoriasis is complex and multifactorial, including genetic background and environmental factors such as emotional or physical stress. Psychological stress may also play a role in exacerbation of psoriasis, by dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, sympathetic–adrenal–medullary axis, peripheral nervous system, and immune system. Skin cells also express various neuropeptides and hormones in response to stress, including the fully functional analog of the HPA axis. The deterioration of psoriatic lesions is accompanied by increased production of inflammatory mediators, which could contribute to the imbalance of neurotransmitters and the development of symptoms of depression and anxiety. Therefore, deregulation of the crosstalk between endocrine, paracrine, and autocrine stress signaling pathways contributes to clinical manifestations of psoriasis, which requires multidisciplinary approaches.

Effects of High-fat Diet and Chronic Mild Stress on Depression-like Behaviors and Levels of Inflammatory Cytokines in the Hippocampus and Prefrontal Cortex of Rats

Obesity and depression tend to co-occur, and obese patients with chronic low-grade inflammation have a higher risk of developing depression. However, mechanisms explaining these connections have not been fully elucidated. Here, an animal model of comorbid obesity and depression induced by high-fat diet (HFD) combined with chronic unpredictable mild stress (CUMS) was used, and sucrose preference, open field, elevated plus maze and Morris water maze tests were used to detected depression-and anxiety-like behaviors and spatial memory. The levels of inflammatory cytokines and NF-κB and microglial activation in the hippocampus and prefrontal cortex were examined in the study. Our results revealed that the comorbidity group exhibited the most severe depression-like behavior. Obesity but unstressed rats had the highest serum lipid levels among groups. The HFD and CUMS alone and combination of them increased levels of IL-1β, IL-6 and TNF-α in the hippocampus and prefrontal cortex, which was significantly related to depression-like behaviors. Further, NF-κB protein and mRNA levels and microglial activation in the hippocampus and prefrontal cortex significantly increased in stressed, obese and comorbid groups, with animals in comorbid group having the highest NF-κB mRNA levels in the hippocampus and level of NF-κB proteins in the prefrontal cortex, and the highest microglial activation in both brain areas. The study concluded that HFD and CUMS alone and combination induce depression-like symptoms, abnormal serum lipid levels, microglial activation and increased inflammatory cytokines in the brain, effects that are possibly mediated by TLR4-NF-κB signaling.

Neuro-dermatological association between psoriasis and depression: an immune-mediated inflammatory process validating skin-brain axis theory

Objective

Our study's motive was to recognize various immune-mediated inflammatory processes involved in the pathogenesis of depression and psoriasis and interlink between them based on inflammatory mediators.

Methods

A careful and comprehensive literature search was done through various databases like PubMed, Google Scholar, and EBSCO. A total of 56 studies were included in our study after careful screening.

Results

The immune-mediated inflammatory process was significantly associated with the pathogenesis of both depression and psoriasis. Most of the inflammatory markers involved in Psoriasis (TNF-α, IL-2, IL-6, IL-23, IL-1β, IL-10), and increased serotonin transporters (5-HTT) were also found in the pathogenesis of depression, showing the immune-inflammatory linkage between psoriasis and major depression. Based on immune chemistry, the levels of CD2⁺, CD4⁺, CD8⁺ T-lymphocytes were also found to be raised in both depression and psoriasis, validating their relationship. Hyperactivity of HPA-axis was also found another interlink between them along with reduced melatonin amount.

Conclusions

According to various studies, the neuro-dermatological association between psoriasis and depression is significant. Different immune markers involved in the pathogenesis of depression and psoriasis also show the bidirectional association between them. However, this association between psoriasis and depression is positively correlated, but more work is required to answer why all depressed patients fail to develop psoriasis and why all psoriatic patients fail to develop depression.

Dysregulation of the gut-brain-skin axis and key overlapping inflammatory and immune mechanisms of psoriasis and depression

The occurrence, progression and recurrence of psoriasis are thought to be related to mood and psychological disorders such as depression. Psoriasis can lead to depression, and depression, in turn, exacerbates psoriasis. No specific mechanism can explain the association between psoriasis and depression. The gut-brain-skin axis has been used to explain correlations among the gut microbiota, emotional states and systemic and skin inflammation, and this axis may be associated with overlapping mechanisms between psoriasis and depression. Therefore, in the context of the gut-brain-skin axis, we systematically summarized and comparatively analysed the inflammatory and immune mechanisms of psoriasis and depression and illustrated the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and the gut microbiota. This review provides a theoretical basis and new targets for the treatment of psoriasis and depression.

An update on the impact of depression on the treatment of psoriasis

Introduction: Estimates of the prevalence of comorbid depression vary, ranging from 9 and 62%. Deterioration of mental health may emerge as a result of psoriasis; however, it is theorized that depression alone may independently predispose patients to new-onset psoriasis.Areas covered: The aim of this brief review is to explore the impact of depression on psoriasis treatment.Expert opinion: The two studies that directly assess the role of depression in psoriasis treatment outcomes are important, as unaddressed depression can undermine the success of a given treatment. This may reflect the notion that depressed individuals are less likely to be adherent. Thus, it may be valuable for clinicians to not only screen for depression, but to ensure that it is adequately treated. Our knowledge of treatment preferences in psoriasis patients with comorbid depression is limited. Expanding our understanding of preferences may allow providers to better align their recommendations to ultimately increase adherence. Additionally, given that many psoriasis treatments have an impact on depression, it may be beneficial for clinicians to evaluate patients for psychiatric risk factors to optimize the treatment regimen.

Association Between Psoriasis and Depression: A Traditional Review

Psoriasis is a chronic inflammatory disease of the skin with multiple comorbidities, depression being one of them. Psoriasis affects the personal, social, and sexual lives of the patients resulting in psychological strain. 

Psoriasis and depression amplify each other. Supporting evidence has proven multiple common mechanisms between the two diseases: inflammatory overlap, genetic evidence, low vitamin D3, and melatonin levels are common in both psoriasis and depression. Fear of social rejection and self-stigmatization act as a fuel to fire inflaming depression in psoriatic patients.

The study explains the link between psoriasis and depression and their effects on quality of life. There is a need to highlight the importance of addressing the psychological effects of psoriasis along with its physical aspects for better treatment outcomes. 

The cytokine network in the pathogenesis of major depressive disorder. Close to translation?

Major depressive disorder (MDD) is a common condition that afflicts the general population across a broad spectrum of ages and social backgrounds. MDD has been identified by the World Health Organization as a leading cause of disability worldwide. Approximately 30% of patients are poor responsive to standard of care (SOC) treatment and novel therapeutic approaches are warranted. Since chronic inflammation, as it is often observed in certain cancers, type 2 diabetes, psoriasis and chronic arthritis, are accompanied by depression, it has been suggested that immunoinflammatory processes may be involved in the pathogenesis of MDD. Cytokines are a group of glycoproteins secreted from lymphoid and non-lymphoid cells that orchestrate immune responses. It has been suggested that a dysregulated production of cytokines may be implicated in the pathogenesis and maintenance of MDD. On the basis of their functions, cytokines can be subdivided in pro-inflammatory and anti-inflammatory cytokines. Since abnormal blood and cerebrospinal fluid of both pro and anti-inflammatory cytokines are altered in MDD, it has been suggested that abnormal cytokine homeostasis may be implicated in the pathogenesis of MDD and possibly to induction of therapeutic resistance. We review current data that indicate that cytokines may represent a useful tool to identify MDD patients that may benefit from tailored immunotherapeutic approaches and may represent a potential tailored therapeutic target.

The efficacy of psychological interventions on psoriasis treatment: a systematic review and meta-analysis of randomized controlled trials

Background

Previous observational studies have shown comorbidity between psoriasis and psychological disorders. However, the evidence of the efficacy of psychological interventions, including cognitive behavioral therapy (CBT) and other treatments, on psoriasis is still debated.

Objectives

The aim of this study was to systematically review the psychological interventions used in the treatment of psoriasis and to meta-analyze the efficacy of psychological interventions on psoriasis with respect to area and severity reduction.

Materials and methods

A systematic review and meta-analysis were conducted. PubMed, Web of Science, EMbase, and major Chinese academic journal databases were searched for articles published before January 2018. Studies of randomized controlled trials (RCTs) that applied psychological interventions in the treatment of psoriasis and used area and severity as the outcome measures were meta-analyzed. The pooled mean difference between groups was estimated using either fixed-effects models or random-effects models in the presence of heterogeneity. Subgroup analysis was performed by method of intervention and severity of psoriasis.

Results

Out of the 4,152 potentially relevant studies, 8 RCTs were included. The pooled mean difference was −1.36 (95% CI: −2.52 to −0.19; P=0.02). The pooled estimate was −1.80 (95% CI: −2.57 to −1.03; P<0.001) for CBT intervention and was −0.70 (95% CI: −2.39 to 0.99; P=0.42) for non-CBT intervention. The pooled estimates for mild and moderate-to-severe psoriasis were −1.95 (95% CI: −3.91 to 0.00; P=0.05) and −0.61 (95% CI: −1.61 to 0.38; P=0.23), respectively.

Conclusion

CBT is effective in the treatment of psoriasis in terms of area and severity reduction. Systemic treatment does not further enhance the efficacy of CBT. The effect of the psychological intervention is stronger in patients with moderate-to-severe psoriasis.

Infliximab ameliorating depression-like behavior through inhibiting the activation of the IDO-HAAO pathway mediated by tumor necrosis factor-α in a rat model

In recent years, some studies have suggested that the activation of inflammatory system plays a role in the occurrence of depression. Tumor necrosis factor-α (TNF-α), as one of the preinflammatory cytokines, has been reported to be involved in the occurrence of various diseases including depression. Infliximab, an antagonist of TNF-α, is usually used to treat some autoimmune diseases such as Crohn's disease and can perhaps be used to treat other diseases. In this study, the antidepressant effect and a possible mechanism of infliximab were investigated by studying the depression-like behavior and expression of TNF-α, indoleamine 2, 3-dioxygenase (IDO), and 3-hydroxyl amino acid oxygenase (HAAO) from the cortex and hippocampus in rat exposed to chronic unpredicted stress. Forty male Sprague-Dawley rats were divided into a control group (CG), an infliximab-treated control group, a model group (MG), and an infliximab-treated model group (IFXM). Infliximab (5 mg/kg once week) was administered to the infliximab-treated control group and IFXM rats by an intraperitoneal injection, whereas an equivalent volume of vehicle was administered to CG and MG rats. Rat behaviors and the expression of TNF-α, IDO, and HAAO in the cortex and hippocampus were determined. It was found that a significant relief in depression-like behaviors was observed with a downregulation of TNF-α, IDO, and HAAO expression in the IFXM rats compared with MG rats. The results show the antidepressant effect of infliximab and suggest that its mechanism is partly related to inhibition of IDO-HAAO pathway activation mediated by TNF-α in rat brain.

The risk of depression, suicidal ideation and suicide attempt in patients with psoriasis, psoriatic arthritis or ankylosing spondylitis

BACKGROUND

Sparse information is available concerning mental health issues in psoriasis, psoriatic arthritis (PsA) and ankylosing spondylitis (AS) patients.

OBJECTIVE

To estimate risk of depression, suicidal ideation and suicide attempt in patients with psoriasis, PsA and AS, respectively, compared with the general population.

METHODS

This population-based cohort study analysed 36 214 psoriasis patients, 5138 PsA patients and 1878 AS patients who were frequency-matched with a general population cohort. Annual incidence rate of depression, suicidal ideation and suicide attempt was calculated separately for psoriasis, PsA and AS.

RESULTS

There was an increased risk of depression in the three cohorts; adjusted IRR: psoriasis, 1.14 (95% CI, 1.11, 1.17); PsA, 1.22 (95% CI, 1.16, 1.29); AS, 1.34 (95% CI, 1.23, 1.47). There was no significantly increased risk for suicidal ideations or suicide attempt among psoriasis, PsA or AS patients.

LIMITATIONS

Patients were not excluded if previously diagnosed with depression, suicidal ideation or suicide attempt. Suicide attempt and completed suicide analyses were not adjusted for presence of depression. Use of systemic psoriasis treatment to measure severe psoriasis could lead to psoriasis severity misclassification.

CONCLUSION

The risk of depression, but not suicidal ideation or suicide attempt, was significantly increased in patients with psoriasis, PsA and AS.

Stress-Related Immune Markers in Depression: Implications for Treatment

Major depression is a serious psychiatric disorder; however, the precise biological basis of depression still remains elusive. A large body of evidence implicates a dysregulated endocrine and inflammatory response system in the pathogenesis of depression. Despite this, given the heterogeneity of depression, not all depressed patients exhibit dysregulation of the inflammatory and endocrine systems. Evidence suggests that inflammation is associated with depression in certain subgroups of patients and that those who have experienced stressful life events such as childhood trauma or bereavement may be at greater risk of developing depression. Consequently, prolonged exposure to stress is thought to be a key trigger for the onset of a depressive episode. This review assesses the relationship between stress and the immune system, with a particular interest in the mechanisms by which stress impacts immune function, and how altered immune functioning, in turn, may lead to a feed forward cascade of multiple systems dysregulation and the subsequent manifestation of depressive symptomology. The identification of stress-related immune markers and potential avenues for advances in therapeutic intervention is vital. Changes in specific biological markers may be used to characterize or differentiate depressive subtypes or specific symptoms and may predict treatment response, in turn facilitating a more effective, targeted, and fast-acting approach to treatment.

Patient Preferences for Biologicals in Psoriasis: Top Priority of Safety for Cardiovascular Patients

Patients with psoriasis are often affected by comorbidities, which largely influence treatment decisions. Here we performed conjoint analysis to assess the impact of comorbidities on preferences of patients with moderate-to-severe psoriasis for outcome (probability of 50% and 90% improvement, time until response, sustainability of success, probability of mild and severe adverse events (AE), probability of ACR 20 response) and process attributes (treatment location, frequency, duration and delivery method) of biologicals. The influence of comorbidities on Relative Importance Scores (RIS) was determined with analysis of variance and multivariate regression. Among the 200 participants completing the study, 22.5% suffered from psoriatic arthritis, 31.5% from arterial hypertension, 15% from cardiovascular disease (myocardial infarction, stroke, coronary artery disease, and/or arterial occlusive disease), 14.5% from diabetes, 11% from hyperlipidemia, 26% from chronic bronchitis or asthma and 12.5% from depression. Participants with psoriatic arthritis attached greater importance to ACR 20 response (RIS = 10.3 vs. 5.0, p<0.001; β = 0.278, p<0.001) and sustainability (RIS = 5.8 vs. 5.0, p = 0.032) but less value to time until response (RIS = 3.4 vs. 4.8, p = 0.045) than those without arthritis. Participants with arterial hypertension were particularly interested in a low risk of mild AE (RIS 9.7 vs. 12.1; p = 0.033) and a short treatment duration (RIS = 8.0 vs. 9.6, p = 0.002). Those with cardiovascular disease worried more about mild AE (RIS = 12.8 vs. 10, p = 0.027; β = 0.170, p = 0.027) and severe AE (RIS = 23.2 vs. 16.2, p = 0.001; β = 0.203, p = 0.007) but cared less about time until response (β = -0.189, p = 0.013), treatment location (β = -0.153, p = 0.049), frequency (β = -0.20, p = 0.008) and delivery method (β = -0.175, p = 0.023) than others. Patients’ concerns should be addressed in-depth when prescribing biologicals to comorbid patients, keeping in mind that TNF antagonists may favourably influence cardiovascular risk.

[Depression and psoriasis]

Psychiatric co-morbidity is very frequently associated with psoriasis and depression is observed in numerous patients with psoriasis. Early detection and treatment are very important. The links between psoriasis and depression are not only psychopathological. Biological factors could also explain this association. There is a vicious circle psoriasis-alteration of quality of life-depression, but psoriasis improvement is not always followed by an improvement of depression. A contrario, it is obvious that a depressive patient has a bad observance of treatment.