The IL-6 antagonist tocilizumab is associated with worse depression and related symptoms in the medically ill

Activation of the interleukin-23/Th17 axis in major depression: a systematic review and meta-analysis

The interleukin-23/Th17 axis is a promising modifiable target for depression. However, its association with depression has not been systematically evaluated. We systematically searched four databases (EMBASE, Web of Science, Pubmed and PsycINFO) for studies comparing patients with major depression and healthy controls for plasma/serum levels of Th17 cells and their canonical cytokines (interleukin-17A [IL-17A], IL-22, granulocyte macrophage colony stimulating factor [GM-CSF]). We also compared counts of Th1, Th2 and Th9 cells between depressed/non-depressed patients and their respective canonical cytokines. We performed random-effects meta-analysis of the standardised mean difference (SMD) in immune measures between groups. Risk of bias was assessed using the Newcastle-Ottawa scale. Of 3154 studies screened, 36 studies were included in meta-analysis. Patients with depression had elevated IL-17A compared to controls (SMD = 0.80 [95% CI 0.03 to 1.58], p = 0.042), an association moderated by antidepressant use (Z = 2.12, p = 0.034). Patients with depression had elevated GM-CSF (SMD = 0.54 [95% CI 0.16 to 0.91], p = 0.0047), and a trend towards higher Th17 counts (SMD = 0.44 [- 0.01 to 0.88], p = 0.052). Whilst the Th2-associated cytokine IL-5 was elevated in depression (SMD = 0.36 [95% CI 0.05 to 0.66], p = 0.02), Th2 cell counts (p = 0.97), Th1 cell counts (p = 0.17) and interferon-γ (p = 0.22) were not. Data for Th9 cells, IL-9 and IL-22 were insufficient for meta-analysis. Respectively, 22, 25 and 5 studies were good, fair and poor in quality. Patients with major depression show peripheral over-activation of the IL-23/Th17 axis. Future interventional studies should test whether this is a modifiable target for depression.

Exploratory assessment of the effect of systemic administration of soluble glycoprotein 130 on cognitive performance and chemokine levels in a mouse model of experimental traumatic brain injury

Uncontrolled neuroinflammation mediates traumatic brain injury (TBI) pathology and impairs recovery. Interleukin-6 (IL-6), a pleiotropic inflammatory regulator, is associated with poor clinical TBI outcomes. IL-6 operates via classical-signaling through membrane-bound IL-6 receptor (IL-6R) and trans-signaling through soluble IL-6 receptor (s)IL-6R. IL-6 trans-signaling specifically contributes to neuropathology, making it a potential precision therapeutic TBI target. Soluble glycoprotein 130 (sgp130) prevents IL-6 trans-signaling, sparing classical signaling, thus is a possible treatment. Mice received either controlled cortical impact (CCI) (6.0 ± 0.2 m/s; 2 mm; 50-60ms) or sham procedures. Vehicle (VEH) or sgp130-Fc was subcutaneously administered to sham (VEH or 1 µg) and CCI (VEH, 0.25 µg or 1 µg) mice on days 1, 4, 7, 10 and 13 post-surgery to assess effects on cognition [Morris Water Maze (MWM)] and ipsilateral hemisphere IL-6 related biomarkers (day 21 post-surgery). CCI + sgp130-Fc groups (0.25 µg and 1 µg) were combined for analysis given similar behavior/biomarker outcomes. CCI + VEH mice had longer latencies and path lengths to the platform and increased peripheral zone time versus Sham + VEH and Sham + sgp130-Fc mice, suggesting injury-induced impairments in learning and anxiety. CCI + sgp130-Fc mice had shorter platform latencies and path lengths and had decreased peripheral zone time, indicating a therapeutic benefit of sgp130-Fc after injury on learning and anxiety. Interestingly, Sham + sgp130-Fc mice had shorter platform latencies, path lengths and peripheral zone times than Sham + VEH mice, suggesting a beneficial effect of sgp130-Fc, independent of injury. CCI + VEH mice had increased brain IL-6 and decreased sgp130 levels versus Sham + VEH and Sham + sgp130-Fc mice. There was no treatment effect on IL-6, sIL6-R or sgp130 in Sham + VEH versus Sham + sgp130-Fc mice. There was also no treatment effect on IL-6 in CCI + VEH versus CCI + sgp130-Fc mice. However, CCI + sgp130-Fc mice had increased sIL-6R and sgp130 versus CCI + VEH mice, demonstrating sgp130-Fc treatment effects on brain biomarkers. Inflammatory chemokines (MIP-1β, IP-10, MIG) were increased in CCI + VEH mice versus Sham + VEH and Sham + sgp130-Fc mice. However, CCI + sgp130-Fc mice had decreased chemokine levels versus CCI + VEH mice. IL-6 positively correlated, while sgp130 negatively correlated, with chemokine levels. Overall, we found that systemic sgp130-Fc treatment after CCI improved learning, decreased anxiety and reduced CCI-induced brain chemokines. Future studies will explore sex-specific dosing and treatment mechanisms for sgp130-Fc therapy.

Pro-inflammatory cytokines in stress-induced depression: Novel insights into mechanisms and promising therapeutic strategies

Stress-mediated depression is one of the common psychiatric disorders with a high prevalence and suicide rate, there is a lack of effective treatment. Accordingly, effective treatments with few adverse effects are urgently needed. Pro-inflammatory cytokines (PICs) may play a key role in stress-mediated depression. Thereupon, both preclinical and clinical studies have found higher levels of IL-1β, TNF-α and IL-6 in peripheral blood and brain tissue of patients with depression. Recent studies have found PICs cause depression by affecting neuroinflammation, monoamine neurotransmitters, hypothalamic pituitary adrenal axis and neuroplasticity. Moreover, they play an important role in the symptom, development and progression of depression, maybe a potential diagnostic and therapeutic marker of depression. In addition, well-established antidepressant therapies have some relief on high levels of PICs. Importantly, anti-inflammatory drugs relieve depressive symptoms by reducing levels of PICs. Collectively, reducing PICs may represent a promising therapeutic strategy for depression.

Nonspecific Orbital Inflammation (NSOI): Unraveling the Molecular Pathogenesis, Diagnostic Modalities, and Therapeutic Interventions

Nonspecific orbital inflammation (NSOI), colloquially known as orbital pseudotumor, sometimes presents a diagnostic and therapeutic challenge in ophthalmology. This review aims to dissect NSOI through a molecular lens, offering a comprehensive overview of its pathogenesis, clinical presentation, diagnostic methods, and management strategies. The article delves into the underpinnings of NSOI, examining immunological and environmental factors alongside intricate molecular mechanisms involving signaling pathways, cytokines, and mediators. Special emphasis is placed on emerging molecular discoveries and approaches, highlighting the significance of understanding molecular mechanisms in NSOI for the development of novel diagnostic and therapeutic tools. Various diagnostic modalities are scrutinized for their utility and limitations. Therapeutic interventions encompass medical treatments with corticosteroids and immunomodulatory agents, all discussed in light of current molecular understanding. More importantly, this review offers a novel molecular perspective on NSOI, dissecting its pathogenesis and management with an emphasis on the latest molecular discoveries. It introduces an integrated approach combining advanced molecular diagnostics with current clinical assessments and explores emerging targeted therapies. By synthesizing these facets, the review aims to inform clinicians and researchers alike, paving the way for molecularly informed, precision-based strategies for managing NSOI.

Effect of Anti-Interleukin-6 Agents on Psychopathology in a Sample of Patients with Post-COVID-19 Syndrome: An Observational Study

Interleukin 6 (IL-6) receptor inhibitors tocilizumab and sarilumab have recently been approved for severe coronavirus disease 2019 (COVID-19). They also affect mood, even though their effect on the post-COVID-19 syndrome-related psychopathology still has to be investigated. The aim of this study was to investigate their effect on psychopathology in a sample of patients with post-COVID-19 syndrome. We included 246 patients (34% female, 66% male) aged 18-75 years who had been hospitalized for COVID. Patients were split into those who received anti-IL-6 receptor agents (Anti-IL-6-R, N = 88) and those who did not (Ctrl, N = 158). The former group was further split into those receiving tocilizumab (TOC, N = 67) and those receiving sarilumab (SAR, N = 21). Groups were compared based on clinical characteristics before and during COVID-19 as well as on physical and psychiatric symptoms after COVID-19. Ctrl had less psychiatric and physical symptoms during hospitalization and more post-COVID-19 diarrhea, headache, cough, and dyspnea upon exertion than those receiving IL-6-receptor inhibitors. Ctrl also showed greater difficulties in emotion regulation. These differences were driven by TOC vs. Ctrl, whereas differences between SAR and Ctrl or TOC did not reach significance. IL-6 receptor inhibitors are related to a lower post-COVID-19 illness burden and seem to be effective in emotion regulation. Further research is needed to confirm these findings.

Examining the biological pathways underlying clinical heterogeneity in Sjogren's syndrome: proteomic and network analysis

OBJECTIVES

Stratification approaches are vital to address clinical heterogeneity in Sjogren's syndrome (SS). We previously described that the Newcastle Sjogren's Stratification Tool (NSST) identified four distinct clinical subtypes of SS. We performed proteomic and network analysis to analyse the underlying pathobiology and highlight potential therapeutic targets for different SS subtypes.

METHOD

We profiled serum proteins using O-link technology of 180 SS subjects. We used 5 O-link proteomics panels which included a total of 454 unique proteins. Network reconstruction was performed using the ARACNE algorithm, with differential expression estimates overlaid on these networks to reveal the key subnetworks of differential expression. Furthermore, data from a phase III trial of tocilizumab in SS were reanalysed by stratifying patients at baseline using NSST.

RESULTS

Our analysis highlights differential expression of chemokines, cytokines and the major autoantigen TRIM21 between the SS subtypes. Furthermore, we observe differential expression of several transcription factors associated with energy metabolism and redox balance namely APE1/Ref-1, FOXO1, TIGAR and BACH1. The differentially expressed proteins were inter-related in our network analysis, supporting the concept that distinct molecular networks underlie the clinical subtypes of SS. Stratification of patients at baseline using NSST revealed improvement of fatigue score only in the subtype expressing the highest levels of serum IL-6.

CONCLUSIONS

Our data provide clues to the pathways contributing to the glandular and non-glandular manifestations of SS and to potential therapeutic targets for different SS subtypes. In addition, our analysis highlights the need for further exploration of altered metabolism and mitochondrial dysfunction in the context of SS subtypes.

Methodological advice for the young at heart investigator: Triangulation to build better foundations

In medicine and science, one is typically taught the main theories in a discipline or field along with standard models before receiving more instructions on how to apply certain methods. The aim of this work is not to address one method, but rather methodology, the study and evaluation of methods, by taking a philosophy of science detour. In this, a critique of biomedicine will be used as a starting point to address some positions regarding reductionism, specifying notions such as systems and mechanisms, as well as regarding the mind-body problem discussing psychosomatic medicine and psychoneuroimmunology. Some recommendations to make science more pluralistic, robust and translationally-relevant will then be made as a way to foster constructive debates on reductionism and the mind-body problem and, in turn, favor more interdisciplinary research.

Inflammation in Posttraumatic Stress Disorder: Dysregulation or Recalibration?

Despite ample experimental data indicating a role of inflammatory mediators in the behavioral and neurobiological manifestations elicited by exposure to physical and psychologic stressors, causative associations between systemic low-grade inflammation and central nervous system inflammatory processes in posttraumatic stress disorder (PTSD) patients remain largely conceptual. As in other stress-related disorders, pro-inflammatory activity may play an equivocal role in PTSD pathophysiology, one that renders indiscriminate employment of anti-inflammatory agents of questionable relevance. In fact, as several pieces of preclinical and clinical research convergingly suggest, timely and targeted potentiation rather than inhibition of inflammatory responses may actually be beneficial in patients who are characterized by suppressed microglia function in the face of systemic low-grade inflammation. The deleterious impact of chronic stress-associated inflammation on the systemic level may, thus, need to be held in context with the - often not readily apparent - adaptive payoffs of low-grade inflammation at the tissue level.

Anorexia Nervosa in vivo cytokine production: a systematic review

INTRODUCTION

The underlying psychobiology that contributes to Anorexia Nervosa (AN) onset and disease progression remains unclear. New research is emerging suggesting a possible link between inflammation and a variety of mental illnesses. Alterations of cytokines may play a role in the pathogenesis of AN. Some studies have found differences in the cytokine profile of those with AN compared to healthy controls, but results are heterogeneous. The aim of this work was to systematically review existing studies investigating in-vivo cytokine production in those with AN before and after weight restoration compared to controls.

METHODS

A comprehensive literature search of four electronic databases (PubMed, PsychInfo, EMBASE and CINAH) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify human in-vivo studies investigating the relationship between AN and cytokine production. Data extracted from included studies related to population characteristics (e.g. age, gender, mean mBMI/%IBW), cytokine measurement and relevant findings. Confounding factors (e.g. smoking status, co-morbid mental illness, menstruation status) were also collected.

RESULTS

36 studies were eligible for this systematic review of which the majority were conducted in Europe (77.8%) and involved female subjects (97.2%). Those with AN ranged in age from 13 to 47 years and had an illness duration of 3 months to 24 years. 15 candidate cytokines and 3 receptors were identified (TNF-alpha, IL-6, IL-1B, CRP, IL-2, IL-7, IL-10, IFN-γ, TNF-R2, IL-1 α, IL-15, TNF-R1, IL-17, IL-18, TGF-B1, IL-12, IL-6R and TGF-B2) exploring in-vivo levels in patients with AN and comparing to controls. TNF-alpha and IL-6 were the most extensively studied with IL-6 being significantly elevated in 4 out of 8 (50%) of longitudinal studies when comparing AN patients at baseline compared to post weight restoration. Following weight restoration, there was no difference in IL-6 levels when comparing to HC in 7 of 8 (87.5%) longitudinal studies examined.

CONCLUSIONS

The most promising cytokine potentially involved in the pathogenesis of AN appears to be IL-6, and possibly TNF-alpha pathways. The heterogeneity of clinical and methodology factors impedes the generalizability of results. Future studies may wish to address these methodological shortcomings as alterations in cytokine levels in AN could act as therapeutic targets assisting with weight restoration and psychopathology and may offer diagnostic potential.

Potential value of Interleukin-6 as a diagnostic biomarker in human MDD and the antidepressant effect of its receptor antagonist tocilizumab in lipopolysaccharide-challenged rats

Depression is a common mental disease with disastrous effect on the health and wealth globally. Focusing on the role for inflammation and immune activation in the pathogenesis of depression, many tries have been taken into effect targeting at the blockage of inflammatory cytokines, among which interleukin- 6 (IL-6) and its receptor antagonist tocilizumab attracts more attention, with inconsistent findings. Moderate to severe depressive disorder (MSDD) patients were enrolled and the serum concentrations of IL-6 and tumor necrosis factor-α (TNF-α) measured, their correlation with the Hamilton Depression Rating Scale-24 (HAMD-24) scores was analyzed, and their role in discriminating MSDD patients from the health controls were evaluated. Meanwhile, a depression rat model was established by intraperitoneal injection of LPS, and tocilizumab was administrated doing 50 mg/kg via intravenous injection. The behavioral performance was observed, the serum concentration of IL-6, TNF-α, and C-reactive protein (CRP) was measured, and the protein expression of IL-6 and TNF-α in the hippocampus were also detected. The activity of the Hypothalamic-pituitary-adrenal (HPA) axis was observed, and the protein expression levels in the hippocampus were detected via western blot. Moreover, the immunofluorescence staining (IF) technique was used to investigate the co-location of IL-6 and neuron (MAP2), astrocyte (GFAP), or microglial (IBA-1). The results showed that the serum IL-6 level was significantly increased in the MSDD patients and lipopolysaccharide (LPS)-challenged rats, with a significant correlation with the HAMD-24 scores or struggling time in the FST and corticosterone (CORT) abundance. Results of ROC analysis showed a significant diagnosis value of IL-6 in discriminating MSDD patients or depression rats from the controls in the present study. Tocilizumab could relieve the depression-like behaviors induced by LPS, together with a normal abundance of serum CORT and hypothalamic CRH expression. Moreover, tocilizumab could alleviate the "inflammatory storm" and impaired hippocampal synaptic plasticity in LPS-challenged depression rats, inhibiting the hyperactivation of astrocyte and microglia, decreasing the peripheral and central abundance of IL-6, CRP, and TNF-α, and balancing the hippocampal expression levels of synaptic plasticity-associated proteins and key molecular in Wnt/β-catenin signaling pathway. These results indicated a predictive role of IL-6 in discriminating depression from controls, and demonstrated an antidepressant effect of tocilizumab in LPS-challenged rats, targeting at the inflammatory storm and the subsequent impairments of hippocampal synaptic plasticity.

Pre-pregnancy obesity is associated with greater systemic inflammation and increased risk of antenatal depression

BACKGROUND

Pre-pregnancy obesity is an emerging risk factor for perinatal depression. However, the underlying mechanisms remain unclear. We investigated the association between pre-pregnancy body mass index (BMI) and perinatal depressive symptoms in a large population-based pre-birth cohort, the Barwon Infant Study. We also assessed whether the levels of circulating inflammatory markers during pregnancy mediated this relationship.

METHODS

Depressive symptoms were assessed in 883 women using the Edinburgh Postnatal Depression Scale (EPDS) and psychological stress using the Perceived Stress Scale (PSS) at 28 weeks gestation and 4 weeks postpartum. Glycoprotein acetyls (GlycA), high-sensitivity C-reactive protein (hsCRP) and cytokines were assessed at 28 weeks gestation. We performed regression analyses, adjusted for potential confounders, and investigated mediation using nested counterfactual models.

RESULTS

The estimated effect of pre-pregnancy obesity (BMI ≥ 30 kg/m2) on antenatal EPDS scores was 1.05 points per kg/m2 increase in BMI (95% CI: 0.20, 1.90; p = 0.02). GlycA, hsCRP, interleukin (IL) -1ra and IL-6 were higher in women with obesity, compared to healthy weight women, while eotaxin and IL-4 were lower. Higher GlycA was associated with higher EPDS and PSS scores and partially mediated the association between pre-pregnancy obesity and EPDS/PSS scores in unadjusted models, but this association attenuated upon adjustment for socioeconomic adversity. IL-6 and eotaxin were negatively associated with EPDS/PSS scores, however there was no evidence for mediation.

CONCLUSIONS

Pre-pregnancy obesity increases the risk of antenatal depressive symptoms and is also associated with systemic inflammation during pregnancy. While discrete inflammatory markers are associated with antenatal depressive symptoms and perceived stress, their role in mediating the effects of pre-pregnancy obesity on antenatal depression requires further investigation.

The role of cytokines and Indolamine-2.3 dioxygenase in experiencing a psycho-neurological symptom cluster in hematological cancer patients: IL-1alpha, IL-1beta, IL-4, IL-6, TNF-alpha, kynurenine, and tryptophan

OBJECTIVE

This study examined (a) whether there are a subgroup of cancer patients experiencing the selected psycho-neurological symptoms as a cluster (depression, cognitive impairment, fatigue, sleep disturbance, and pain); (b) whether demographic and clinical characteristics and pro-inflammatory cytokines (IL-1α, IL-1β, IL-4, IL-6, TNF-alpha) are associated with subgroup membership; and (c) whether the activity of indolamine-2.3 dioxygenase(IDO) is associated with pro-inflammatory cytokine activity and psycho-neurological symptom cluster experience.

METHODS

This was a prospective cohort study where 149 hematologic patients were recruited from a university hospital and 65 healthy volunteers provided control data. Latent profile analyses were conducted to identify subgroups at two time points: the last day of chemotherapy and 1 week after chemotherapy completion. Influencing factors of subgroup membership were examined by logistic regression.

RESULTS

A substantial number of patients (33%, 34% at each time point) experienced the selected psycho-neurological symptoms as a cluster. Older age and elevated IL-1α and IL-6 were associated with experiencing the psycho-neurological symptom cluster. IDO activity was higher in the patients experiencing psycho-neurological symptom cluster; and was positively associated with IL-6. Symptom severity, IL-1α, IL-6, and IDO activity were all significantly higher in cancer patients than in the healthy controls. The findings were preserved across time points.

CONCLUSIONS

The activation of pro-inflammatory cytokines and their cross-talk with IDO may be a common biological mechanism, underlying a psycho-neurological symptom cluster experience. The novel approaches for symptom assessment and management can be developed by assessing multiple psycho-neurological symptoms as a cluster and by targeting their common biological pathway.

Psychiatric sequelae of traumatic brain injury - future directions in research

Despite growing appreciation that traumatic brain injury (TBI) is an important public health burden, our understanding of the psychiatric and behavioural consequences of TBI remains limited. These changes are particularly detrimental to a person's sense of self, their relationships and their participation in the wider community, and they continue to have devastating individual and cumulative effects long after TBI. This Review relates specifically to TBIs that confer objective clinical or biomarker evidence of structural brain injury; symptomatic head injuries without such evidence are outside the scope of this article. Common psychiatric, affective and behavioural sequelae of TBI and their proposed underlying mechanisms are outlined, along with a brief overview of current treatments. Suggestions for how scientists and clinicians can work together in the future to address the chasms in clinical care and knowledge are discussed in depth.

Inflammatory cytokines and depression symptoms following hematopoietic cell transplantation

Increased synthesis and release of inflammatory signalling proteins is common among individuals with hematologic malignancies undergoing hematopoietic cell transplantation (HCT) due to intensive conditioning regimens and complications such as graft-versus-host-disease and infections. Prior research indicates that inflammatory responses can activate central nervous system pathways that evoke changes in mood. This study examined relationships between markers of inflammatory activity and depression symptoms following HCT. Individuals undergoing allogeneic (n = 84) and autologous (n = 155) HCT completed measures of depression symptoms pre-HCT and 1, 3, and 6 months post-HCT. Proinflammatory (IL-6, TNF-α) and regulatory (IL-10) cytokines were assessed by ELISA in peripheral blood plasma. Mixed-effects linear regression models indicated that patients with elevated IL-6 and IL-10 reported more severe depression symptoms at the post-HCT assessments. These findings were replicated when examining both allogeneic and autologous samples. Follow-up analyses clarified that relationships were strongest for neurovegetative, rather than cognitive or affective, symptoms of depression. These findings suggest that anti-inflammatory therapeutics targeting an inflammatory mediator of depression could improve quality of life of HCT recipients.

Effect of type of disease-modifying antirheumatic drugs on depression and anxiety of patients with rheumatoid arthritis in Saudi Arabia: a cross-sectional study

Background

Rheumatoid arthritis (RA) can cause depression and anxiety. This study evaluated the factors associated with depression and anxiety in patients with RA and examined the effect of conventional and biologic disease-modifying antirheumatic drugs (DMARDs).

Methods

This cross-sectional study was conducted in a regional hospital in Riyadh between March and November 2022 and included 213 patients with RA. Depression and anxiety were measured using the Hospital Anxiety and Depression Scale (HADS) and data about patients' DMARDs use was obtained from the hospital's medical records.

Results

Based on the HADS scores, 35 (16.4%) and 49 (23%) patients with RA had depression and anxiety, respectively. There was a significant association between the level of depression and anxiety and the use of leflunomide and tocilizumab among patients with RA (p = 0.006 and p = 0.009, respectively). Patients with RA who took leflunomide had significantly higher scores for anxiety (β = 0.158, value of p = 0.037) when compared to patients who did not take leflunomide. Patients with RA who took etanercept showed a significantly lower depression score even after adjusting for confounders, including sociodemographic, clinical, and lifestyle factors (β = -0.189, p = 0.043).

Conclusion

The present study highlighted the prevalence of psychiatric disorders among patients with RA and the level of depression and anxiety may differ between patients with RA depending on the type of DMARDs used. We recommend patients with RA be screened regularly for depression and anxiety to avoid further extra-articular systemic complications associated with RA.

Reduced epilepsy development in synapsin 2 knockout mice with autistic behavior following early systemic treatment with interleukin-6 receptor antibody

BACKGROUND

Individuals with autism spectrum disorder (ASD) have an increased risk of developing epilepsy. Both ASD and epilepsy have been associated with increased levels of immune factors in the blood, including the proinflammatory cytokine interleukin 6 (IL-6). Mice lacking the synapsin 2 gene (Syn2 KO) exhibit ASD-like behavior and develop epileptic seizures. Their brains display neuroinflammatory changes including elevated IL-6 levels. We aimed to investigate the effect of systemic IL-6 receptor antibody (IL-6R ab) treatment on seizure development and frequency in Syn2 KO mice.

MATERIAL AND METHODS

Weekly systemic (i.p.) injections of IL-6R ab or saline were given to Syn2 KO mice starting either early in life at 1 month of age, before seizure debut or at 3 months of age, directly after seizure debut and continued for 4 or 2 months, respectively. Seizures were provoked by handling the mice three times per week. The neuroinflammatory response and synaptic protein levels in the brain were determined by ELISA, immunohistochemistry and western blots. In an additional group of Syn2 KO mice, with IL-6R ab treatment early in life, ASD-related behavioral tests including social interaction and repetitive self-grooming, as well as cognitive memory and depressive-/anxiety-like tests, and actigraphy measurements of circadian sleep-awake rhythm were analyzed.

RESULTS

The IL-6R ab treatment reduced seizure development and frequency in Syn2 KO mice when initiated before, but not after, seizure debut. However, early treatment did not reverse the neuroinflammatory response or the imbalance in synaptic protein levels in the brain previously reported in Syn2 KO mice. The treatment did not affect social interaction, performance in memory, depressive-/anxiety-like tests or the sleep-awake rhythm of Syn2 KO mice.

CONCLUSION

These findings suggest the involvement of IL-6 receptor signaling during epilepsy development in Syn2 KO mice, without significant alterations of the immune reaction in the brain, and independently of cognitive performance, mood and circadian sleep-awake rhythm.

Microbiota-immune-brain interactions: A lifespan perspective

There is growing appreciation of key roles of the gut microbiota in maintaining homeostasis and influencing brain and behaviour at critical windows across the lifespan. Mounting evidence suggests that communication between the gut and the brain could be the key to understanding multiple neuropsychiatric disorders, with the immune system coming to the forefront as an important mechanistic mediator. Throughout the lifespan, the immune system exchanges continuous reciprocal signals with the central nervous system. Intestinal microbial cues alter immune mediators with consequences for host neurophysiology and behaviour. Several factors challenge the gut microbiota composition, which in response release molecules with neuro- and immuno-active potential that are crucial for adequate neuro-immune interactions. In this review, multiple factors contributing to the upkeep of the fine balance between health and disease of these systems are discussed, and we elucidate the potential mechanistic implications for the gut microbiota inputs on host brain and behaviour across the lifespan.

Depression, Anxiety, and Quality of Life in Patients Treated with Single Infusion Tocilizumab for COVID-19: A Follow-up, Controlled Study

BACKGROUND

The inflammatory state that characterizes COVID-19 may contribute to depression, anxiety, other morbidities, and mortality. Interleukin-6 blocker tocilizumab has been used as a treatment modality in COVID-19 as an anti-inflammatory agent. Tocilizumab has also been studied for its potential use in preventing depression in other patient groups, with mixed results. This study was designed to study subsequent depression, anxiety, and quality of life (QOL) in patients treated with tocilizumab plus standard care versus standard care alone, for moderate to severe COVID-19 pneumonia.

METHODS

Patients admitted with moderate to severe COVID pneumonia, treated with tocilizumab plus standard treatment, and discharged from the hospital were identified. Age- and gender-matched controls who had received standard treatment alone for COVID-19 pneumonia during the same time frame were identified. After obtaining consent, these patients were followed up and assessed at 3 and 6 months on measures of depression (PHQ-9), anxiety (GAD-7), and QOL (EQ-5D-5L).

RESULTS

39 patients in the tocilizumab group and 41 in the control group were followed up at 3 and 6 months. Patients in both groups were comparable in sociodemographic and clinical parameters. The prevalence of clinically significant depression in the tocilizumab group at 3 and 6 months was 33.33% and 5.12%, respectively, whereas in control group it was 31.7% and 4.87%, respectively. Analysis of EQ-5D health profiles revealed that the maximum problems were reported in the dimension of mobility: 43.7% at 3 months and 35% at 6 months.

CONCLUSIONS

Depressive and anxiety symptoms and impairment in QOL were reported more frequently and with greater severity in patients in the tocilizumab group at three months but not at six months. Psychological morbidity and impairment in QOL were modest and improved from 3 to 6 months.

Biobehavioral Implications of Chimeric Antigen Receptor T-cell Therapy: Current State and Future Directions

Chimeric antigen receptor (CAR) T-cell therapy has demonstrated remarkable clinical responses in hematologic malignancies. Recent advances in CAR T-cell therapy have expanded its application into other populations including older patients and those with central nervous system and solid tumors. Although its clinical efficacy has been excellent for some malignancies, CAR T-cell therapy is associated with severe and even life-threatening immune-mediated toxicities, including cytokine release syndrome and neurotoxicity. There is a strong body of scientific evidence highlighting the connection between immune activation and neurocognitive and psychological phenomena. To date, there has been limited investigation into this relationship in the context of immunotherapy. In this review, we present a biobehavioral framework to inform current and future cellular therapy research and contribute to improving the multidimensional outcomes of patients receiving CAR T-cell therapy.

Inflammatory pathophysiological mechanisms implicated in postpartum depression

Postpartum Depression (PPD) is a serious psychiatric disorder of women within the first year after delivery. It grievously damages women's physical and mental health. Inflammatory reaction theory is well-established in depression, and also has been reported associated with PPD. This review summarized the inflammatory pathophysiological mechanisms implicated in PPD, including decreased T cell activation, increased proinflammatory cytokines secretion, active kynurenine pathway, and initiated NLRP3 inflammasome. Clinical and preclinical research are both gathered. Potential therapeutical alternatives targeting the inflammatory mechanisms of PPD were introduced. In addition, this review briefly discussed the differences of inflammatory mechanisms between PPD and depression. The research of inflammation in PPD is limited and seems just embarking, which indicates the direction we can further study. As a variety of risky factors contribute to PPD collectively, therapy for women with PPD should be comprehensive, and clinical heterogeneity should be taken into consideration. As PPD has a predictability, early clinical screening and interventions are also needed. This review aims to help readers better understand the inflammatory pathological mechanisms in PPD, so as to identify biomarkers and potential therapeutic targets in the future.

Long-term cognitive performance and its relation to anti-inflammatory therapy in a cohort of survivors of severe COVID-19

Background and objectives

Long-term cognitive performance data in former critically ill COVID-19 patients are sparse. Current evidence suggests that cognitive decline is related to neuroinflammation, which might be attenuated by COVID-19 related anti-inflammatory therapies. The objective of this prospective cohort study was to study long term cognitive outcomes following severe COVID-19 and the relation to anti-inflammatory therapies.

Methods

Prospective observational cohort of patients that survived an intensive care unit (ICU) admission due to severe COVID-19. Six months after hospital discharge, we extensively assessed both objective cognitive functioning and subjective cognitive complaints. Furthermore, patients were stratified in cohorts according to their anti-inflammatory treatment (i.e. no immunomodulatory therapy, dexamethasone, or both dexamethasone and interleukin-6 receptor antagonist tocilizumab).

Results

96 patients were included (March 2020–June 2021, median [IQR] age 61 [55–69] years). 91% received invasive mechanical ventilation, and mean ± SD severity-of-disease APACHE–II–score at admission was 15.8 ± 4.1. After 6.5 ± 1.3 months, 27% of patients scored cognitively impaired. Patients that did or did not develop cognitive impairments were similar in ICU-admission parameters, clinical course and delirium incidence. Patients with subjective cognitive complaints (20%) were more likely women (61% vs 26%), and had a shorter ICU stay (median [IQR] 8 [5–15] vs 18 [9–31], p = 0.002). Objective cognitive dysfunction did not correlate with subjective cognitive dysfunction. 27% of the participants received dexamethasone during intensive care admission, 44% received additional tocilizumab and 29% received neither. Overall occurrence and severity of cognitive dysfunction were not affected by anti-inflammatory therapy, although patients treated with both dexamethasone and tocilizumab had worse executive functioning scores (Trail Making Test interference) than patients without anti-inflammatory treatment (T-score 40.3 ± 13.5 vs 49.1 ± 9.3, p = 0.007).

Discussion

A relevant proportion of critically ill COVID-19 patients shows deficits in long-term cognitive functioning. Apart from more pronounced executive dysfunction, overall, anti-inflammatory therapy appeared not to affect long-term cognitive performance. Our findings provide insight in long-term cognitive outcomes in patients who survived COVID-19, that may facilitate health-care providers counseling patients and their caregivers.

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Up to a third of survivors of severe COVID-19 develops long-term cognitive impairment.

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Subjective cognitive complaints six months following severe COVID-19 do not correlate with objective cognitive impairment.

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COVID-19 related immunomodulatory therapy is not associated with the overall incidence of cognitive dysfunction.

Is SARS-CoV-2 a Risk Factor of Bipolar Disorder?-A Narrative Review

For 2.5 years we have been facing the coronavirus disease (COVID-19) and its health, social and economic effects. One of its known consequences is the development of neuropsychiatric diseases such as anxiety and depression. However, reports of manic episodes related to COVID-19 have emerged. Mania is an integral part of the debilitating illness-bipolar disorder (BD). Due to its devastating effects, it is therefore important to establish whether SARS-CoV-2 infection is a causative agent of this severe mental disorder. In this narrative review, we discuss the similarities between the disorders caused by SARS-CoV-2 and those found in patients with BD, and we also try to answer the question of whether SARS-CoV-2 infection may be a risk factor for the development of this affective disorder. Our observation shows that disorders in COVID-19 showing the greatest similarity to those in BD are cytokine disorders, tryptophan metabolism, sleep disorders and structural changes in the central nervous system (CNS). These changes, especially intensified in severe infections, may be a trigger for the development of BD in particularly vulnerable people, e.g., with family history, or cause an acute episode in patients with a pre-existing BD.

Elucidating a bidirectional association between rheumatoid arthritis and depression: A systematic review and meta-analysis

BACKGROUND

Rheumatoid arthritis (RA) and depression are conditions which commonly co-exist. Recent longitudinal studies now suggest a bidirectional association between these disorders, with inconsistent results. We conducted a systematic review and meta-analysis to examine this relationship.

METHODS

Three electronic databases (PubMed, Embase and PsycINFO) were searched from inception to September 4, 2021 for cohort studies evaluating either the risk of depression in RA patients or the risk of RA in patients with depression, as well as the secondary outcome of all-cause mortality risk in RA patients with depression. A random effects model was used to summarize the included studies.

RESULTS

Eleven cohort studies were included, comprising a total of 39,130 RA patients, 550,782 patients with depression and 7,802,230 controls. RA patients had a 47% greater risk of incident depression compared to controls, while patients with depression had a 34% greater risk of developing RA. Subgroup analysis by age was only significant in the ≥60 years old age group. RA patients with depression had an 80% increased risk of all-cause mortality compared to those without depression.

LIMITATIONS

The results may have been confounded by factors such as differing methods of depression ascertainment across studies and overlap in presentation between the two conditions.

CONCLUSION

There exists a bidirectional association between RA and depression especially in the elderly which increases mortality risk. This invites the need for clinicians to screen and be vigilant for the presence of these conditions.

Biobehavioral Implications of Covid-19 for Transplantation and Cellular Therapy Recipients

A growing body of literature has emphasized the importance of biobehavioral processes - defined as the interaction of behavior, psychology, socioenvironmental factors, and biological processes - for clinical outcomes among transplantation and cellular therapy (TCT) patients. TCT recipients are especially vulnerable to distress associated with pandemic conditions and represent a notably immunocompromised group at greater risk for SARS-CoV-2 infection with substantially worse outcomes. The summation of both the immunologic and psychologic vulnerability of TCT patients renders them particularly susceptible to adverse biobehavioral sequelae associated with the Covid-19 pandemic. Stress and adverse psychosocial factors alter neural and endocrine pathways through sympathetic nervous system and hypothalamic-pituitary-adrenal axis signaling that ultimately affect gene regulation in immune cells. Reciprocally, global inflammation and immune dysregulation related to TCT contribute to dysregulation of neuroendocrine and central nervous system function, resulting in the symptom profile of depression, fatigue, sleep disturbance, and cognitive dysfunction. In this article, we draw upon literature on immunology, psychology, neuroscience, hematology and oncology, Covid-19 pathophysiology, and TCT processes to discuss how they may intersect to influence TCT outcomes, with the goal of providing an overview of the significance of biobehavioral factors in understanding the relationship between Covid-19 and TCT, now and for the future. We discuss the roles of depression, anxiety, fatigue, sleep, social isolation and loneliness, and neurocognitive impairment, as well as specific implications for sub-populations of interest, including pediatrics, caregivers, and TCT donors. Finally, we address protective psychological processes that may optimize biobehavioral outcomes affected by Covid-19.

The effect of tocilizumab on patient reported outcomes and inflammatory biomarkers in hematopoietic cell transplantation

Inflammatory physiology has been linked to behavioral and emotional symptoms in a variety of contexts and experimental paradigms. Hematopoietic cell transplantation (HCT) represents an intersection of significant immune dysregulation and psychosocial stress, and this biobehavioral relationship can influence important clinical outcomes. For those undergoing HCT with inflammation-related neuropsychiatric symptoms, using targeted agents such as the IL-6 receptor antagonist tocilizumab may be an effective therapeutic approach. We conducted an observational cohort study to explore patient reported outcomes (PROs) and inflammatory biomarkers among allogeneic HCT recipients who received tocilizumab compared to those who did not. Individuals on a larger trial of tocilizumab for prevention of graft-versus-host disease received a single dose of tocilizumab 24 h prior to stem cell infusion. Measures of anxiety, depression, pain, fatigue, and sleep quality and parallel blood samples for inflammatory cytokines were collected from participants and an analogous comparison cohort at baseline and Day 28 after stem cell infusion. Demographic and medical characteristics were reported; an analysis of covariance regression model was fitted to evaluate differences in PROs and distance correlation t-tests assessed for associations between biomarkers and PRO measures. For n = 18 tocilizumab-treated and n = 22 comparison patients, there were no significant differences between patient demographics, but the tocilizumab cohort had a different distribution of primary diagnoses (p = 0.009) with more patients with leukemias and a higher proportion of patients in their first remission (64% vs 28%, p = 0.024). Depression was higher at Day 28 compared to baseline in both groups (comparison group: +5.1 [95% CI 0.14-10, p = 0.045], tocilizumab: +8.6 [95% CI 2.3-15, p = 0.011]), though the difference between groups did not reach statistical significance. The tocilizumab group had significantly increased circulating IL-6 and decreased CRP at Day 28 (all p < 0.05). There was an association between collective baseline biomarkers and PROs (distance correlation dCor = 0.110, p = 0.005), but this same association was not present at Day 28 (dCor = -0.001, p = 0.5). In univariate analyses, a 10-fold increase in plasma IL-6 was associated with a 3.6-point higher depression score (95% CI 1.0-6.2, p = 0.008). In this exploratory analysis of PROs and inflammatory biomarkers in patients undergoing HCT, tocilizumab was not associated with favorable patient-reported symptom profiles. This finding is aligned with our prior work in the HCT population but diverges from hypothesized therapeutic effects of tocilizumab on depressive symptoms, thus highlighting the need for larger prospective translational studies in biobehavioral HCT research.

The effects of SARS-CoV-2 infection on modulating innate immunity and strategies of combating inflammatory response for COVID-19 therapy

The global pandemic of COVID-19 has caused huge causality and unquantifiable loss of social wealth. The innate immune response is the first line of defense against SARS-CoV-2 infection. However, strong inflammatory response associated with dysregulation of innate immunity causes severe acute respiratory syndrome (SARS) and death. In this review, we update the current knowledge on how SARS-CoV-2 modulates the host innate immune response for its evasion from host defense and its corresponding pathogenesis caused by cytokine storm. We emphasize Type I interferon response and the strategies of evading innate immune defense used by SARS-CoV-2. We also extensively discuss the cells and their function involved in the innate immune response and inflammatory response, as well as the promises and challenges of drugs targeting excessive inflammation for antiviral treatment. This review would help us to figure out the current challenge questions of SARS-CoV-2 infection on innate immunity and directions for future studies.

Genetic estimates of correlation and causality between blood-based biomarkers and psychiatric disorders

There is a long-standing interest in exploring the relationship between blood-based biomarkers and psychiatric disorders, despite their causal role being difficult to resolve in observational studies. In this study, we leverage genome-wide association study data for a large panel of heritable serum biochemical traits to refine our understanding of causal effect in biochemical-psychiatric trait pairings. We observed widespread positive and negative genetic correlation between psychiatric disorders and biochemical traits. Causal inference was then implemented to distinguish causation from correlation, with strong evidence that C-reactive protein (CRP) exerts a causal effect on psychiatric disorders. Notably, CRP demonstrated both protective and risk-increasing effects on different disorders. Multivariable models that conditioned CRP effects on interleukin-6 signaling and body mass index supported that the CRP-schizophrenia relationship was not driven by these factors. Collectively, these data suggest that there are shared pathways that influence both biochemical traits and psychiatric illness.

Depression and Autoimmune Hypothyroidism—Their Relationship and the Effects of Treating Psychiatric and Thyroid Disorders on Changes in Clinical and Biochemical Parameters Including BDNF and Other Cytokines—A Systematic Review

Various autoimmune diseases, including autoimmune hypothyroidism (AHT), are associated with a higher risk of developing mood disorders throughout life. Depression is accompanied by the changes in the levels of inflammatory and trophic factors, including interleukins (IL-1beta, IL-2, IL-6), interferon alpha (IFN-alpha), tumor necrosis factor alpha (TNF-alpha), C-reactive protein (CRP), and brain derived neurotrophic factor (BDNF). Disclosure of the relationship between the coexistence of depression and AHT indicates that the pathomechanism of depression may be related to the changes in the immune system, it is also possible that both conditions may be caused by the same immune processes. The above hypothesis is indirectly supported by the observations that the treatment with both antidepressants and levothyroxine leads to a decrease in the levels of proinflammatory cytokines with an increase in BDNF concentrations, simultaneously correlating with an improvement in the clinical parameters. However, so far there are no long-term studies determining the causal relationship between depression, thyroid autoantibodies, and cytokine profile, which could bring us closer to understanding the interrelationships between them and facilitate the use of an adequate pharmacotherapy, not necessarily psychiatric. We consider the above issues to be insufficiently investigated but of great importance. This article is an overview of the available literature as well as an introduction to our research project.

SARS-CoV-2 Psychiatric Sequelae: A Review of Neuroendocrine Mechanisms and Therapeutic Strategies

From the earliest days of the coronavirus disease 2019 (COVID-19) pandemic, there have been reports of significant neurological and psychological symptoms following Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. This narrative review is designed to examine the potential psychoneuroendocrine pathogenic mechanisms by which SARS-CoV-2 elicits psychiatric sequelae as well as to posit potential pharmacologic strategies to address and reverse these pathologies. Following a brief overview of neurological and psychological sequelae from previous viral pandemics, we address mechanisms by which SARS-CoV-2 could enter or otherwise elicit changes in the CNS. We then examine the hypothesis that COVID-19-induced psychiatric disorders result from challenges to the neuroendocrine system, in particular the hypothalamic-pituitary-adrenal stress axis and monoamine synthesis, physiological mechanisms that are only further enhanced by the pandemic-induced social environment of fear, isolation, and socioeconomic pressure. Finally, we evaluate several FDA-approved therapeutics in the context of COVID-19-induced psychoneuroendocrine disorders.

Translational evidence for the Inflammatory Response System (IRS)/Compensatory Immune Response System (CIRS) and neuroprogression theory of major depression

Major depressive disorder (MDD) is a common, severe and disabling neuropsychiatric disorder with a heterogenous etiology. Among the most widely recognized etiological models, immunopathogenesis is a predominant one. Numerous studies have demonstrated aberrant levels of inflammatory markers in the peripheral blood, cerebrospinal fluid (CSF) and brain of patients with MDD. Multiple studies including meta-analyses have reported increased peripheral levels of acute phase proteins, and pro-inflammatory cytokines, particularly IL-1β, TNF-α, and IL-6 in MDD. Postmortem brain studies similarly demonstrated upregulated expressions of these pro-inflammatory cytokines. This along with evidence of monocytic, lymphocytic and microglial activation, suggest an activated inflammatory response system (IRS) in MDD. A few studies show increased levels of anti-inflammatory cytokines or defective inflammatory pathways and a deficit in T cell maturation and responses in MDD patients. This suggests the presence of a Compensatory Immune Response System (CIRS), which can counterbalance the effects of IRS in major depression. More recently, simultaneously increased levels of both the pro-and anti-inflammatory cytokines are reported in the brain of MDD patients; this indicates activity of both the IRS and CIRS in MDD. The IRS and CIRS are the evolutionarily conserved and integral elements of an overarching system. The relevance of a dysregulated IRS-CIRS system in the neurobiological construct of MDD is just beginning to be understood. Speculation is rife that the disrupted IRS-CIRS elements might determine the onset, episodes, neuroprogressive processes, treatment response as well as recovery of patients with MDD. Notably, the signatures of an activated IRS-CIRS might emerge as potential biomarkers of MDD. Herein, an attempt has been made to highlight the biology and pathobiological relevance of IRS-CIRS activation in MDD and provide an insight into the role of these components in pharmacological therapy.

Systemic effects of IL-6 blockade in rheumatoid arthritis beyond the joints

Interleukin (IL)-6 is produced locally in response to an inflammatory stimulus, and is able to induce systemic manifestations at distance from the site of inflammation. Its unique signaling mechanism, including classical and trans-signaling pathways, leads to a major expansion in the number of cell types responding to IL-6. This pleiotropic cytokine is a key factor in the pathogenesis of rheumatoid arthritis (RA) and is involved in many extra-articular manifestations that accompany the disease. Thus, IL-6 blockade is associated with various biological effects beyond the joints. In this review, the systemic effects of IL-6 in RA comorbidities and the consequences of its blockade will be discussed, including anemia of chronic disease, cardiovascular risks, bone and muscle functions, and neuro-psychological manifestations.

Unravelling the broader complexity of IL-6 involvement in health and disease

The classification of interleukin-6 (IL-6) as a pro-inflammatory cytokine undervalues the biological impact of this cytokine in health and disease. With broad activities affecting the immune system, tissue homeostasis and metabolic processes, IL-6 displays complex biology. The significance of these involvements has become increasingly important in clinical settings where IL-6 is identified as a prominent target for therapy. Here, clinical experience with IL-6 antagonists emphasises the need to understand the context-dependent properties of IL-6 within an inflammatory environment and the anticipated or unexpected consequences of IL-6 blockade. In this review, we will describe the immunobiology of IL-6 and explore the gamut of IL-6 bioactivity affecting the clinical response to biological drugs targeting this cytokine pathway.

A Highly Selective In Vitro JNK3 Inhibitor, FMU200, Restores Mitochondrial Membrane Potential and Reduces Oxidative Stress and Apoptosis in SH-SY5Y Cells

Current treatments for neurodegenerative diseases (ND) are symptomatic and do not affect disease progression. Slowing this progression remains a crucial unmet need for patients and their families. c-Jun N-terminal kinase 3 (JNK3) are related to several ND hallmarks including apoptosis, oxidative stress, excitotoxicity, mitochondrial dysfunction, and neuroinflammation. JNK inhibitors can play an important role in addressing neuroprotection. This research aims to evaluate the neuroprotective, anti-inflammatory, and antioxidant effects of a synthetic compound (FMU200) with known JNK3 inhibitory activity in SH-SY5Y and RAW264.7 cell lines. SH-SY5Y cells were pretreated with FMU200 and cell damage was induced by 6-hydroxydopamine (6-OHDA) or hydrogen peroxide (H₂O₂). Cell viability and neuroprotective effect were assessed with an MTT assay. Flow cytometric analysis was performed to evaluate cell apoptosis. The H₂O₂-induced reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm) were evaluated by DCFDA and JC-1 assays, respectively. The anti-inflammatory effect was determined in LPS-induced RAW264.7 cells by ELISA assay. In undifferentiated SH-SY5Y cells, FMU200 decreased neurotoxicity induced by 6-OHDA in approximately 20%. In RA-differentiated cells, FMU200 diminished cell death in approximately 40% and 90% after 24 and 48 h treatment, respectively. FMU200 reduced both early and late apoptotic cells, decreased ROS levels, restored mitochondrial membrane potential, and downregulated JNK phosphorylation after H₂O₂ exposure. In LPS-stimulated RAW264.7 cells, FMU200 reduced TNF-α levels after a 3 h treatment. FMU200 protects neuroblastoma SH-SY5Y cells against 6-OHDA- and H₂O₂-induced apoptosis, which may result from suppressing the JNK pathways. Our findings show that FMU200 can be a useful candidate for the treatment of neurodegenerative disorders.

Research priorities for neuroimmunology: identifying the key research questions to be addressed by 2030

Neuroimmunology in the broadest sense is the study of interactions between the nervous and the immune systems. These interactions play important roles in health from supporting neural development, homeostasis and plasticity to modifying behaviour. Neuroimmunology is increasingly recognised as a field with the potential to deliver a significant positive impact on human health and treatment for neurological and psychiatric disorders. Yet, translation to the clinic is hindered by fundamental knowledge gaps on the underlying mechanisms of action or the optimal timing of an intervention, and a lack of appropriate tools to visualise and modulate both systems. Here we propose ten key disease-agnostic research questions that, if addressed, could lead to significant progress within neuroimmunology in the short to medium term. We also discuss four cross-cutting themes to be considered when addressing each question: i) bi-directionality of neuroimmune interactions; ii) the biological context in which the questions are addressed (e.g. health vs disease vs across the lifespan); iii) tools and technologies required to fully answer the questions; and iv) translation into the clinic. We acknowledge that these ten questions cannot represent the full breadth of gaps in our understanding; rather they focus on areas which, if addressed, may have the most broad and immediate impacts. By defining these neuroimmunology priorities, we hope to unite existing and future research teams, who can make meaningful progress through a collaborative and cross-disciplinary effort.