Fatigue favors in vitro Th1 and Th17-like cell expansion and reduces corticoid sensitivity in MS patients

Inflammation, Dopaminergic Brain and Bilirubin

Dopamine is a well-known neurotransmitter due to its involvement in Parkinson's disease (PD). Dopamine is not only involved in PD but also controls multiple mental and physical activities, such as the pleasure of food, friends and loved ones, music, art, mood, cognition, motivation, fear, affective disorders, addiction, attention deficit disorder, depression, and schizophrenia. Dopaminergic neurons (DOPAn) are susceptible to stressors, and inflammation is a recognized risk for neuronal malfunctioning and cell death in major neurodegenerative diseases. Less is known for non-neurodegenerative conditions. Among the endogenous defenses, bilirubin, a heme metabolite, has been shown to possess important anti-inflammatory activity and, most importantly, to prevent DOPAn demise in an ex vivo model of PD by acting on the tumor necrosis factor-alpha (TNFα). This review summarizes the evidence linking DOPAn, inflammation (when possible, specifically TNFα), and bilirubin as an anti-inflammatory in order to understand what is known, the gaps that need filling, and the hypotheses of anti-inflammatory strategies to preserve dopamine homeostasis with bilirubin included.

Network analysis characterizes key associations between subjective fatigue and specific depressive symptoms in early relapsing-remitting multiple sclerosis

BACKGROUND

Fatigue is common and disabling in multiple sclerosis (MS), yet its mechanisms are poorly understood. In particular, overlap in measures of fatigue and depression complicates interpretation. We applied a multivariate network approach to quantify relationships between fatigue and other variables in early MS.

METHODS

Data were collected from patients with newly diagnosed immunotherapy-naïve relapsing-remitting MS at baseline and month 12 follow-up in FutureMS, a Scottish nationally representative cohort. Subjective fatigue was assessed by Fatigue Severity Scale. Detailed phenotyping included measures assessing each of physical disability, affective disorders, cognitive performance, sleep quality, and structural brain imaging. Network analysis was conducted to estimate partial correlations between variables. Baseline networks were compared between those with persistent and remitted fatigue at one-year follow up.

RESULTS

Data from 322 participants at baseline, and 323 at month 12, were included. At baseline, 154 patients (47.8%) reported clinically significant fatigue. In the network analysis, fatigue severity showed strongest connections with depression, followed by Expanded Disability Status Scale. Conversely, fatigue severity was not linked to objective cognitive performance or brain imaging variables. Even after controlling for measurement of "tiredness" in our measure of depression, four specific depressive symptoms remained linked to fatigue. Results were consistent at baseline and month 12. Overall network strength was not significantly different between groups with persistent and remitted fatigue (4.89 vs 2.90, p = 0.11).

CONCLUSIONS

Our findings support robust links between subjective fatigue and depression in early relapsing-remitting MS. Shared mechanisms between specific depressive symptoms and fatigue could be key targets of treatment and research in MS-related fatigue.

Th17-cells in depression: Implication in multiple sclerosis

Depression is one of the most common neuropsychological symptoms of multiple sclerosis. However, in addition to mood disorder, depression can also influence on multiple sclerosis course. The mechanism of this dependence is not fully understood. The recent studies suggest the possible common immune mechanisms in the pathogenesis of depression and multiple sclerosis. In particular, it was shown that along with biogenic amines disturbance, neuroinflammation also play an important role in the pathogenesis of depression. Significant attention is drawn to Th17-cells subsets, which are considered as critical players in the pathogenesis of inflammatory diseases of the central nervous system, including multiple sclerosis. This brief report reviews the literature data on the role of neuroinflammation in the reciprocal influence of multiple sclerosis and depression with focus on Th17-cells, which may underlie pathogenetic mechanisms of both this diseases.

Fatigue in Multiple Sclerosis Is Associated with Reduced Expression of Interleukin-10 and Worse Prospective Disease Activity

In multiple sclerosis (MS), fatigue is a frequent symptom that negatively affects quality of life. The pathogenesis of fatigue is multifactorial and inflammation may play a specific role. To explore the association between fatigue, central inflammation and disease course in MS in 106 relapsing-remitting (RR)-MS patients, clinical characteristics, including fatigue and mood, were explored at the time of diagnosis. NEDA (no evidence of disease activity)-3 status after one-year follow up was calculated. Cerebrospinal fluid (CSF) levels of a set of proinflammatory and anti-inflammatory molecules and peripheral blood markers of inflammation were also analyzed. MRI structural measures were explored in 35 patients. A significant negative correlation was found at diagnosis between fatigue measured with the Modified Fatigue Impact Scale (MFIS) and the CSF levels of interleukin (IL)-10. Conversely, no significant associations were found with peripheral markers of inflammation. Higher MFIS scores were associated with reduced probability to reach NEDA-3 status after 1-year follow up. Finally, T2 lesion load showed a positive correlation with MFIS scores and a negative correlation with CSF IL-10 levels at diagnosis. CSF inflammation, and particularly the reduced expression of the anti-inflammatory molecule IL-10, may exacerbate fatigue. Fatigue in MS may reflect subclinical CSF inflammation, predisposing to greater disease activity.

Guselkumab demonstrated an independent treatment effect in reducing fatigue after adjustment for clinical response-results from two phase 3 clinical trials of 1120 patients with active psoriatic arthritis

Background

The interleukin-23p19-subunit inhibitor guselkumab effectively treats signs and symptoms of psoriatic arthritis (PsA). We evaluated the effect of guselkumab on fatigue.

Methods

Across two phase 3 trials of guselkumab (DISCOVER-1, DISCOVER-2), patients with active PsA despite standard therapy were randomized to subcutaneous injections of guselkumab 100 mg every 4 weeks (Q4W, N = 373); guselkumab 100 mg at week 0, week 4, and then Q8W (N = 375); or placebo (N = 372) through week 24, after which patients in the placebo group crossed over to guselkumab Q4W. Fatigue was measured as a secondary endpoint using the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue instrument (range 0–52, higher scores indicate less fatigue). Least-squares mean changes in FACIT-Fatigue scores were compared between treatments using a mixed-effect model for repeated measures. Mediation analysis was used to adjust for indirect effects on fatigue deriving from improvement in other outcomes, including ≥20% improvement in American College of Rheumatology criteria (ACR20; prespecified), minimal disease activity (MDA; post hoc), or C-reactive protein (CRP; post hoc).

Results

Baseline mean (SD) FACIT-Fatigue scores in DISCOVER-1 (N = 381) and DISCOVER-2 (N = 739), ranging from 29.1 (9.5) to 31.4 (10.1), indicated substantial levels of fatigue relative to the United States general population (43.6 [9.4]). Across studies, mean improvements, and proportions of patients with ≥4-point improvements, in FACIT-Fatigue scores at week 24 with guselkumab Q4W and Q8W (5.6–7.6 and 54–63%, respectively) were larger vs placebo (2.2–3.6 and 35–46%). Improvement in FACIT-Fatigue scores with guselkumab was sustained from week 24 to week 52, with moderate-to-large effect sizes (Cohen’s d = 0.52–0.81 at week 24; 0.66–0.91 at week 52). Mediation analyses demonstrated that substantial proportions of the effects of guselkumab vs placebo on fatigue were direct effect, after adjusting for achievement of ACR20 (Q4W 69–70%, Q8W 12–36% direct effect) or MDA (72–92% across dosing regimens) response or for change in serum CRP concentrations (82–88% across dosing regimens).

Conclusions

In patients with active PsA, guselkumab 100 mg Q4W or Q8W led to clinically meaningful and sustained improvements in fatigue through 1 year. A substantial portion of the improvement in FACIT-Fatigue scores induced by guselkumab was independent of effects on the achievement of other select outcomes.

Trial registration

Name of the registry: ClinicalTrials.gov

Trial registrations: DISCOVER-1, NCT03162796; DISCOVER-2, NCT03158285

Date of registration: DISCOVER-1, May 22, 2017; DISCOVER-2, May 18, 2017

URLs of the trial registry record:

DISCOVER-1, https://clinicaltrials.gov/ct2/show/NCT03162796?term=NCT03162796&draw=1&rank=1

DISCOVER-2, https://clinicaltrials.gov/ct2/show/NCT03158285?term=NCT03158285&draw=2&rank=1

Role of Th22 Cells in the Pathogenesis of Autoimmune Diseases

Upon antigenic stimulation, naïve CD4+T cells differentiate into different subsets and secrete various cytokines to exert biological effects. Th22 cells, a newly identified CD4+T cell subset,are distinct from the Th1, Th2 and Th17 subsets. Th22 cells secrete certain cytokines such as IL-22, IL-13 and TNF-α, but not others, such as IL-17, IL-4, or interferon-γ (IFN-γ), and they express chemokine receptors CCR4, CCR6 and CCR10. Th22 cells were initially found to play a role in skin inflammatory diseases, but recent studies have demonstrated their involvement in the development of various autoimmune diseases. Here, we review research advances in the origin, characteristics and effector mechanisms of Th22 cells, with an emphasis on the role of Th22 cells and their main effector cytokine IL-22 in the pathogenesis of autoimmune diseases. The findings presented here may facilitate the development of new therapeutic strategies for targeting these diseases.

Dopaminergic Receptor Targeting in Multiple Sclerosis: Is There Therapeutic Potential?

Dopamine is a neurotransmitter that mediates neuropsychological functions of the central nervous system (CNS). Recent studies have shown the modulatory effect of dopamine on the cells of innate and adaptive immune systems, including Th17 cells, which play a critical role in inflammatory diseases of the CNS. This article reviews the literature data on the role of dopamine in the regulation of neuroinflammation in multiple sclerosis (MS). The influence of dopaminergic receptor targeting on experimental autoimmune encephalomyelitis (EAE) and MS pathogenesis, as well as the therapeutic potential of dopaminergic drugs as add-on pathogenetic therapy of MS, is discussed.

Chronic fatigue and depression due to multiple sclerosis: Immune-inflammatory pathways, tryptophan catabolites and the gut-brain axis as possible shared pathways

Chronic fatigue and major depression (MDD)-like symptoms are common manifestations of multiple sclerosis (MS), both with huge impact on quality of life. Depression can manifest itself as fatigue, and depressive symptoms are often mistaken for fatigue, and vice versa. The two conditions are sometimes difficult to differentiate, and their relationship is unclear. Whether chronic fatigue and depression occur primarily, secondarily or coincidentally with activated immune-inflammatory pathways in MS is still under debate. We have carried out a descriptive review aiming to gain a deeper understanding of the relationship between chronic fatigue and depression in MS, and the shared pathways that underpin both conditions. This review focuses on immune-inflammatory pathways, the kynurenine pathway and the gut-brain axis. It seems likely that proinflammatory cytokines, tryptophan catabolites (the KYN pathway) and the gut-brain axis are involved in the mechanisms causing chronic fatigue and MDD-like symptoms in MS. However, the evidence base is weak, and more research is needed. In order to advance our understanding of the underlying pathological mechanisms, MS-related fatigue and depression should be examined using a longitudinal design and both immune-inflammatory and KYN pathway biomarkers should be measured, relevant clinical characteristics judiciously registered, and self-report instruments for both fatigue and depression should be used.

Fatigue scores correlate with other self-assessment data, but not with clinical and biomarker parameters, in CIS and RRMS

BACKGROUND

Fatigue is common in multiple sclerosis and is associated with reduced quality of life. This study aimed to assess the correlation between fatigue scores and data from other self-assessment questionnaires, neuropsychological tests and neuroimaging, as well as data on neuroimmunological markers in cerebrospinal fluid (CSF) and serum/plasma, in clinically isolated syndrome (CIS) and relapsing remitting MS (RRMS).

METHODS

Modified fatigue impact scale (MFIS) scores were determined in 38 patients with newly diagnosed CIS or RRMS at baseline and after one year in a prospective longitudinal cohort study. Non-parametric correlation analyses were used to assess associations between MFIS scores and other self-assessment questionnaire data (Hospital Anxiety and Depression scale (HAD), Multiple Sclerosis Impact Scale 29 (MSIS-29) and Short Form 36 (SF-36)), as well as with neuropsychological test performances (e.g. Auditory Consonant Trigram Test (ACTT)), clinical parameters (e.g. disease duration and expanded disability status scale (EDSS)), magnetic resonance imaging (MRI) data (number of T2 lesions in brain MRI and total brain volume) and several neurodegenerative/neuroinflammatory markers in CSF and serum/plasma (IL-1β, IL-6, CXCL1, CXCL10, CXCL13, CCL-22 in plasma; neurofilament light chain (NFL) in serum; IL-6, CXCL1, CXCL10, CXCL13, CCL22, NFL and chitinase-3-like-1 (CHI3L1) in CSF. CSF and serum/plasma from 21 age- and sex-matched healthy controls were available for comparison.

RESULTS

At both baseline and one-year follow-up, fatigue scores correlated significantly with HAD, MSIS-29 and SF-36 scores and ACTT performance (Spearman´s rho 0.45-0.78, all p ≤ 0.01) but not with the other neuropsychological test results, disease duration, EDSS ratings, number of T2 lesions, total brain volume or neurodegenerative/neuroinflammatory markers, including neurofilament light chain levels in CSF and serum. In group comparisons, MFIS scores were similar in patients fulfilling no evidence of disease activity-3 (NEDA-3) (n = 18) and patients not fulfilling NEDA-3 (n = 20) during one year of follow-up (p > 0.01).

CONCLUSIONS

In this cohort of patients with newly diagnosed CIS and RRMS, fatigue scores were associated with mood, disease impact on daily life and quality of life as well as with alterations of attentive functions. Study results indicate that subjective fatigue scores are not well reflected by some commonly used and objectively measurable disease parameters like EDSS, T2 lesions and NFL levels.

The role of interleukin 22 in multiple sclerosis and its association with c-Maf and AHR

The aim of this paper was to summarise knowledge of IL-22 involvement in multiple sclerosis (MS) and the possible link between IL-22 and two transcription factors - AHR and c-Maf. The conclusion is that despite numerous studies, the exact role of IL-22 in the pathogenesis of MS is still unknown. The expression and function of c-Maf in MS have not been studied. It seems that the functions of c-Maf and AHR are at least partly connected with IL-22, as both directly or indirectly influence the regulation of IL-22 expression. This possible connection has never been studied in MS.

Effects of moderate- versus high- intensity swimming training on inflammatory and CD4+ T cell subset profiles in experimental autoimmune encephalomyelitis mice

Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS). Evidence about experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, has been shown to modulate disease parameters within exercise intervention. However, these initial studies weren't carried out intensity of exercise in mice. This study explored the impacts of different-intensity swimming training on EAE mice. Female mice were given access to swimming with predetermined weight (moderated-intensity (ME) group is 0% body weight; high-intensity (HE) group is 4% body weight) for 6 weeks, were immunized to induce EAE and then continued swimming until sacrificed. Compared to non-exercise mice, ME training didn't affect EAE clinical symptoms and neuropathology. However, HE swimming attenuated EAE clinical scores, reduced infiltrating cells and demyelination of spinal cords. Analysis of CD4⁺ T cell subsets from CNS of EAE showed the reduction of Th1 and Th17 populations and an increase of Treg in HE, not ME mice. Accordingly, HE training lead to a decrease of IFN-γ and IL-17 and an increase of IL-10 and TGF-β. Of note, HE, not ME, swimming induced an increase of brain derived neurotrophic factor in the CNS of EAE. Moreover, HE training upregulated Treg and downregualted antigen-specific T cell proliferation and Th1 and Th17 populations from draining lymph node cells. These results suggest that HE swimming training might have benefits on attenuating the progression and pathological hallmarks of EAE, thus representing an important non-pharmacological intervention for improvement of chronic inflammation or T-cell mediated autoimmunity.

Is there a link between inflammation and fatigue in multiple sclerosis?

Purpose

Among autoimmune diseases of the central nervous system stands multiple sclerosis (MS), which is characterized by demyelination, synaptopathy, and neurodegeneration. MS fatigue can affect up to 90% of patients and be very disabling, with a drastic impact on their quality of life. To date, the evaluation of MS fatigue has relied mainly on subjective scales, and actual therapeutic interventions are challenged by modest efficacy and numerous undesirable effects. Therefore, finding biomarkers of MS fatigue might help in optimizing evaluation and treatment strategies. The main objective here was to assess the relationship between MS fatigue and inflammatory or other immunomediated markers.

Methods

Research was conducted according to PRISMA guidelines. Computerized databases (ie, PubMed/Medline and Scopus) were consulted till February 2018 aiming to identify articles that addressed inflammation and MS fatigue. Studies in English and French published at any time were considered.

Results

A total of 27 studies matched the research criteria. Inconsistency existed regarding the relationship between fatigue and the orexin A system, hypothalamus–pituitary–adrenal axis, and cerebrospinal fluid inflammatory markers. As for peripheral markers, although there was scarcity in the available data, serum proinflammatory cytokines (ie, IL6, TNFα, and IFNγ) seem to be associated with MS fatigue. Finally, no link was found between MS fatigue and T-cell populations (ie, CD3⁺CD4⁺ T lymphocytes, regulatory T cells) or other peripheral markers of inflammation (ie, CRP, erythrocyte-sedimentation rate, soluble ICAM1).

Conclusion

Future large-scale studies would benefit from comparing the relationship between fatigue and immune measures in patients with different disease phenotypes with and without disease-modifying drugs. With the subjective nature of fatigue scales, finding objective biomarkers for fatigue would be of great help.

Serotonin decreases the production of Th1/Th17 cytokines and elevates the frequency of regulatory CD4+ T-cell subsets in multiple sclerosis patients

Excessive levels of proinflammatory cytokines in the CNS are associated with reduced serotonin (5-HT) synthesis, a neurotransmitter with diverse immune effects. In this study, we evaluated the ability of exogenous 5-HT to modulate the T-cell behavior of patients with MS, a demyelinating autoimmune disease mediated by Th1 and Th17 cytokines. Here, 5-HT attenuated, in vitro, T-cell proliferation and Th1 and Th17 cytokines production in cell cultures from MS patients. Additionally, 5-HT reduced IFN-γ and IL-17 release by CD8⁺ T cells. By contrast, 5-HT increased IL-10 production by CD4⁺ T cells from MS patients. A more accurate analysis of these IL-10-secreting CD4⁺ T cells revealed that 5-HT favors the expansion of FoxP3⁺ CD39⁺ regulatory T cells (Tregs) and type 1 regulatory T cells. Notably, this neurotransmitter also elevated the frequency of Treg17 cells, a novel regulatory T-cell subset. The effect of 5-HT in upregulating CD39⁺ Treg and Treg17 cells was inversely correlated with the number of active brain lesions. Finally, in addition to directly reducing cytokine production by purified Th1 and Th17 cells, 5-HT enhanced in vitro Treg function. In summary, our data suggest that serotonin may play a protective role in the pathogenesis of MS.

Validation of the Modified Fatigue Impact Scale and the relationships among fatigue, pain and serum interleukin-6 levels in patients with neuromyelitis optica spectrum disorder

Fatigue and pain are disabling symptoms in patients with neuromyelitis optica spectrum disorder (NMOSD). The Modified Fatigue Impact Scale (MFIS) has not yet been validated in patients with NMOSD, and anti-interleukin-6 (IL-6) receptor antibody was reported to decrease pain and fatigue in patients with NMOSD. The aim of this study was to validate MFIS and to investigate the relationships among fatigue, pain and serum IL-6 levels in patients with NMOSD. MFIS and the Multidimensional Fatigue Inventory (MFI), an established scale for fatigue, were administered to patients with NMOSD and age- and sex-matched healthy controls (HCs). The Pain Effects Scale score and serum IL-6 levels were also measured in patients with NMOSD. Correlations among clinical characteristics, laboratory data and each score were investigated. To validate MFIS in patients with NMOSD, MFIS was administered twice within 4days from the first administration. Fifty-one patients answered the first MFIS, and 26 patients answered the second MFIS. There was no difference between the first and second MFIS scores. Patients with NMOSD had higher MFIS and MFI scores than HCs. No correlations were observed between serum IL-6 levels and either score. MFIS was validated in patients with NMOSD. Serum IL-6 levels may not be involved in the pathogenesis of fatigue and pain in patients with NMOSD.