Endogenous type-I interferon activity is not associated with depression or fatigue in systemic lupus erythematosus

Interferons and systemic lupus erythematosus: Pathogenesis, clinical features, and treatments in interferon-driven disease

Type I interferons (IFNs) have recently received a lot of attention with the elucidation of the pathogenesis of systemic lupus erythematosus (SLE). Type I IFNs are associated with many SLE symptoms and play a role in the pathogenesis of autoimmune diseases that may occur concurrently with SLE, such as Sjögren's syndrome, antiphospholipid syndrome, myositis, scleroderma, and interferonopathy. Type I IFNs could be the link between these diseases. However, direct measurement of type I IFN levels and the IFN gene signature is currently unavailable in clinical practice. This review discusses type I IFN signalling in SLE, investigates the role of type I IFN in the clinical manifestations and symptoms associated with SLE and other IFN-related diseases, and discusses the clinical tests that can be used to diagnose SLE and measure disease activity. In addition, the role of type I IFN-blocking therapies as potential treatments for SLE is discussed.

Type I interferon pathway assays in studies of rheumatic and musculoskeletal diseases: a systematic literature review informing EULAR points to consider

OBJECTIVES

To systematically review the literature for assay methods that aim to evaluate type I interferon (IFN-I) pathway activation and to harmonise-related terminology.

METHODS

Three databases were searched for reports of IFN-I and rheumatic musculoskeletal diseases. Information about the performance metrics of assays measuring IFN-I and measures of truth were extracted and summarised. A EULAR task force panel assessed feasibility and developed consensus terminology.

RESULTS

Of 10 037 abstracts, 276 fulfilled eligibility criteria for data extraction. Some reported more than one technique to measure IFN-I pathway activation. Hence, 276 papers generated data on 412 methods. IFN-I pathway activation was measured using: qPCR (n=121), immunoassays (n=101), microarray (n=69), reporter cell assay (n=38), DNA methylation (n=14), flow cytometry (n=14), cytopathic effect assay (n=11), RNA sequencing (n=9), plaque reduction assay (n=8), Nanostring (n=5), bisulphite sequencing (n=3). Principles of each assay are summarised for content validity. Concurrent validity (correlation with other IFN assays) was presented for n=150/412 assays. Reliability data were variable and provided for 13 assays. Gene expression and immunoassays were considered most feasible. Consensus terminology to define different aspects of IFN-I research and practice was produced.

CONCLUSIONS

Diverse methods have been reported as IFN-I assays and these differ in what elements or aspects of IFN-I pathway activation they measure and how. No 'gold standard' represents the entirety of the IFN pathway, some may not be specific for IFN-I. Data on reliability or comparing assays were limited, and feasibility is a challenge for many assays. Consensus terminology should improve consistency of reporting.

Association between type I interferon pathway activation and clinical outcomes in rheumatic and musculoskeletal diseases: a systematic literature review informing EULAR points to consider

BACKGROUND

Type I interferons (IFN-I) contribute to a broad range of rheumatic and musculoskeletal diseases (RMDs). Compelling evidence suggests that the measurement of IFN-I pathway activation may have clinical value. Although several IFN-I pathway assays have been proposed, the exact clinical applications are unclear. We summarise the evidence on the potential clinical utility of assays measuring IFN-I pathway activation.

METHODS

A systematic literature review was conducted across three databases to evaluate the use of IFN-I assays in diagnosis and monitor disease activity, prognosis, response to treatment and responsiveness to change in several RMDs.

RESULTS

Of 366 screened, 276 studies were selected that reported the use of assays reflecting IFN-I pathway activation for disease diagnosis (n=188), assessment of disease activity (n=122), prognosis (n=20), response to treatment (n=23) and assay responsiveness (n=59). Immunoassays, quantitative PCR (qPCR) and microarrays were reported most frequently, while systemic lupus erythematosus (SLE), rheumatoid arthritis, myositis, systemic sclerosis and primary Sjögren's syndrome were the most studied RMDs. The literature demonstrated significant heterogeneity in techniques, analytical conditions, risk of bias and application in diseases. Inadequate study designs and technical heterogeneity were the main limitations. IFN-I pathway activation was associated with disease activity and flare occurrence in SLE, but their incremental value was uncertain. IFN-I pathway activation may predict response to IFN-I targeting therapies and may predict response to different treatments.

CONCLUSIONS

Evidence indicates potential clinical value of assays measuring IFN-I pathway activation in several RMDs, but assay harmonisation and clinical validation are urged. This review informs the EULAR points to consider for the measurement and reporting of IFN-I pathway assays.

Effects of illness perception on negative emotions and fatigue in chronic rheumatic diseases: Rumination as a possible mediator

BACKGROUND

Illness perception has long been hypothesized to be linked to psychological well-b eing in patients with rheumatic diseases, although substantial evidence is lacking, and the contribution of ruminative coping style to this relationship is unclear.

AIM

To investigate the roles of illness perception and rumination in predicting fatigue and negative emotions in patients with chronic rheumatic diseases.

METHODS

Illness perception, rumination, fatigue and negative emotions (i.e. depression, anxiety and stress) were assessed by the Illness Perception Questionnaire-Revised, Stress Reactive Rumination Scale, Multidimensional Assessment of Fatigue, and the Depression, Anxiety and Stress Scale respectively. Multivariate regression analysis, the Sobel test, and the bootstrap were used to identify the mediating effect of rumination.

RESULTS

All five subscales of illness perception, including perceived illness identity, chronicity, cyclical nature, consequences and coherence of illness, were significantly associated with fatigue and negative emotions. In mediational analysis, rumination was found to mediate three components of illness perception (the identity, cyclical nature and consequences of illness) and negative emotions/fatigue.

CONCLUSION

Perceived identity, cyclical nature, and consequences of illness are significantly associated with fatigue and negative emotions in patients with chronic rheumatic diseases and these associations are mediated by rumination. Our findings suggest that psychological intervention should target rumination to improve physical and emotional well-being of patients with chronic rheumatic diseases.

The immunologic etiology of psychiatric manifestations in systemic lupus erythematosus: A narrative review on the role of the blood brain barrier, antibodies, cytokines and chemokines

INTRODUCTION

The aim of this narrative review is to provide an overview of the literature on the possible immunologic pathophysiology of psychiatric manifestations of neuropsychiatric systemic lupus erythematosus (NPSLE).

METHODS

A systematic search on PubMed was conducted. English studies with full text availability that investigated the correlation between blood-brain barrier (BBB) dysfunction, intrathecal synthesis of antibodies, antibodies, cytokines, chemokines, metalloproteinases, complement and psychiatric NPSLE manifestations in adults were included.

RESULTS

Both transient BBB-dysfunction with consequent access of antibodies to the cerebrospinal fluid (CSF) and intrathecal synthesis of antibodies could occur in psychiatric NPSLE. Anti-phospholipid antibodies, anti-NMDA antibodies and anti-ribosomal protein p antibodies seem to mediate concentration dependent neuronal dysfunction. Interferon-α may induce microglial engulfment of neurons, direct neuronal damage and production of cytokines and chemokines in psychiatric NPSLE. Several cytokines, chemokines and matrix metalloproteinase-9 may contribute to the pathophysiology of psychiatric NPSLE by attracting and activating Th1-cells and B-cells.

DISCUSSION

This potential pathophysiology may help understand NPSLE and may have implications for the diagnostic management and therapy of psychiatric NPSLE. However, the presented pathophysiological model is based on correlations between potential immunologic etiologies and psychiatric NPSLE that remain questionable. More research on this topic is necessary to further elucidate the pathophysiology of NPSLE.

Predictors of fatigue and severe fatigue in a large international cohort of patients with systemic lupus erythematosus and a systematic review of the literature

OBJECTIVE

Fatigue is reported in up to 90% of patients with SLE. This study was conducted to identify the determinants associated with fatigue in a large cohort of patients with SLE, as well as to provide a systematic review of the literature.

METHODS

Patients from the Lupus BioBank of the upper Rhein, a large German-French cohort of SLE patients, were included in the FATILUP study if they fulfilled the 1997 ACR criteria for SLE and had Fatigue Scale for Motor and Cognitive Functions scores collected. Multivariate logistic regression analyses were performed to assess the determinants of fatigue and severe fatigue.

RESULTS

A total of 570 patients were included (89.1% female). The median age was 42 years (interquartile range 25-75: 34-52). The median value of the SAfety of Estrogens in Lupus Erythematosus National Assessment (SELENA)-SLEDAI was 2 (0-4). Fatigue was reported by 386 patients (67.7%) and severe fatigue by 209 (36.7%). In multivariate analyses, fatigue was associated with depression [odds ratio (OR): 4.72 (95% CI: 1.39-16.05), P = 0.01], anxiety [OR: 4.49 (95% CI: 2.60-7.77), P < 0.0001], glucocorticoid treatment [OR: 1.59 (95% CI 1.05-2.41), P = 0.04], SELENA-SLEDAI scores [OR: 1.05 (95% CI: 1.00-1.12) per 1 point increase, P = 0.043] and age at sampling [OR: 1.01 (95% CI: 1.00-1.03) per 1 year increase, P = 0.03]. Severe fatigue was independently associated with anxiety (P < 0.0001), depression (P < 0.0001), glucocorticoid treatment (P = 0.047) and age at sampling (P = 0.03).

CONCLUSION

Both fatigue and severe fatigue are common symptoms in SLE, and are strongly associated with depression and anxiety. Disease activity and the use of glucocorticoids were also independently associated with fatigue, although more weakly.

Paradoxical association between blood modular interferon signatures and quality of life in patients with systemic lupus erythematosus

Objectives

Blood transcriptomic IFN signature is a hallmark of SLE. The impaired health-related quality of life (HRQOL) observed in SLE is poorly related to disease activity. The aim of this study was to test how IFN signatures were associated with HRQOL in SLE patients.

Methods

Among consecutive patients, blood transcriptomic profiles were analysed with a modular framework comprising 3 IFN modules: M1.2, M3.4 and M5.12. Disease activity was evaluated by the SLEDAI score, and HRQOL was assessed with the SF-36 questionnaire, which includes eight domains: physical function, role physical, bodily pain, general health, vitality, social functioning, role emotional, and mental health (MH) and physical component summary and mental component summary scores.

Results

A total of 57 SLE patients were evaluated, among whom 27 (47%) were clinically quiescent, 30 (53%) were flaring, and 19 (33%) had active lupus nephritis. All SF-36 domains were altered in SLE patients compared with the general French population (P &lt; 0.0001). In multivariate analysis, taking into account flares, age, ethnicity, smoking and renal severity, social functioning was independently associated with the IFN score (P = 0.027). Analyses restrained to quiescent patients (n = 27) yielded greater associations between social functioning and the three IFN modules, and between MH and M3.4. Considering all quiescent visits (n = 51), the IFN score was independently correlated with social functioning (P = 0.022) and MH (P = 0.038).

Conclusion

This unexpected paradoxical association between IFN signature and some specific HRQOL domains argues against a pivotal role of IFNs in the persistently altered HRQOL of SLE patients.

Depression in Patients with Systemic Lupus Erythematosus: A Multicenter Study

Background and Objective:

Neuropsychiatric disorders including depression are common clinical manifestations of systemic lupus erythematosus (SLE). Depression in patients with SLE is under-recognized, although it is a treatable clinical entity. The present study aimed to determine the prevalence of depression and identify the relationship between depression and SLE disease characteristics.

Patients and Methods:

This multicenter cross-sectional study was conducted in the rheumatology clinics of four tertiary referral hospitals in Saudi Arabia between April and September 2014. Patients' demographic data and SLE disease characteristics such as disease duration, severity and drug treatments were collected. A validated Arabic Beck Depression Inventory (BDI) score was used to estimate the prevalence of depression.

Results:

A total of 68 patients with SLE (64 women, 4 men) were enrolled in the study. Forty-six (67.6%) patients were found to have BDI scores indicating depression; of them, only four patients (8.7%) were receiving antidepressant treatments. Higher prevalence of depression was associated with steroid treatment (P = 0.046).

Conclusions:

The study results revealed high prevalence of depression among Saudi patients with SLE. Most of the study population were not adequately treated, suggesting inadequate recognition and treatment of depression in SLE.

Fatigue and cognitive function in systemic lupus erythematosus: associations with white matter microstructural damage. A diffusion tensor MRI study and meta-analysis

Objective The objective of this study was to investigate fatigue and cognitive impairments in systemic lupus erythematous (SLE) in relation to diffuse white matter microstructural brain damage. Methods Diffusion tensor MRI, used to generate biomarkers of brain white matter microstructural integrity, was obtained in patients with SLE and age-matched controls. Fatigue and cognitive function were assessed and related to SLE activity, clinical data and plasma biomarkers of inflammation and endothelial dysfunction. Results Fifty-one patients with SLE (mean age 48.8 ± 14.3 years) were included. Mean diffusivity (MD) was significantly higher in all white matter fibre tracts in SLE patients versus age-matched healthy controls ( p < 0.0001). Fatigue in SLE was higher than a normal reference range ( p < 0.0001) and associated with lower MD ( ß = -0.61, p = 0.02), depression ( ß = 0.17, p = 0.001), anxiety ( ß = 0.13, p = 0.006) and higher body mass index ( ß = 0.10, p = 0.004) in adjusted analyses. Poorer cognitive function was associated with longer SLE disease duration ( p = 0.003) and higher MD ( p = 0.03) and, in adjusted analysis, higher levels of IL-6 ( ß = -0.15, p = 0.02) but not with MD. Meta-analysis (10 studies, n = 261, including the present study) confirmed that patients with SLE have higher MD than controls. Conclusion Patients with SLE have more microstructural brain white matter damage for age than the general population, but this does not explain increased fatigue or lower cognition in SLE. The association between raised IL-6 and worse current cognitive function in SLE should be explored in larger datasets.

Serum levels of brain-derived neurotrophic factor are associated with depressive symptoms in patients with systemic lupus erythematosus

OBJECTIVE

The aim of this study was to explore potential relationships between serum BDNF levels and depression in systemic lupus erythematosus (SLE) patients.

METHODS

We included 208 consecutive SLE patients and 100 age-and sex-matched healthy controls. The presence of depressive symptoms was determined through the Beck Depression Inventory-II (BDI-II) score.

RESULTS

The serum BDNF levels were significantly (P<0.0001) higher in SLE patients as compared to normal controls. There was a negative correlation between levels of BDNF and the SLE disease activity index 2000 (SLEDAI-2K) (r=-0.349, P<0.0001). Depression (defined as BDI-II score≥18) was identified in 54 SLE patients (26.0%, 95%CI: 20%-31.9%). The serum BDNF levels were significantly lower in depression patients at the time of admission as compared with patients without depression [27.6(IQR, 23.2-30.4)ng/ml vs. 36.2(IQR, 31.7-42.3)ng/ml; P<0.0001]. Compared with the first quartile of serum BDNF levels, the second quartile OR for depression was 0.72 (95% CI, 0.61-0.80, P=0.033). For the third and fourth quartiles, it was 0.42 (95% CI, 0.33-0.52, P=0.002) and 0.16 (95% CI, 0.09-0.24; P<0.001).

CONCLUSION

Serum BDNF levels are decreased in SLE patients with depressive symptoms. In SLE, serum BNDF levels are independently associated with depressive disorders, suggesting the role of neurotrophic factors in depression.

Depression in Autoimmune Diseases

Up to 50% of patients with autoimmune diseases show an impairment of health-related quality of life and exhibit depression-like symptoms. The immune system not only leads to inflammation in affected organs, but also mediates behavior abnormalities including fatigue and depression-like symptoms. This review focuses on the different pathways involved in the communication of the immune system with the neuronal network and the body's timing system. The latter is built up by a hierarchically organized expression of clock genes. As discussed here, the activation of the immune system interferes with high amplitude expression of clock genes, an effect which may play a pivotal role in depression-like behavior in autoimmune diseases.

Mood Disorders in Systemic Lupus Erythematosus: Results From an International Inception Cohort Study

OBJECTIVE

To examine the frequency, characteristics, and outcome of mood disorders, as well as clinical and autoantibody associations, in a multiethnic/racial, prospective inception cohort of patients with systemic lupus erythematosus (SLE).

METHODS

Patients were assessed annually for mood disorders (4 types, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) and 18 other neuropsychiatric events. Global disease activity scores (SLE Disease Activity Index 2000 [SLEDAI-2K]), damage scores (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index [SDI]), and Short Form 36 subscales, mental and physical component summary scores were collected. Time to event, linear and ordinal regressions, and multi-state models were used as appropriate.

RESULTS

Among the 1,827 patients with SLE, 88.9% were female, and 48.9% were Caucasian. The mean ± SD age of the patients was 35.1 ± 13.3 years, disease duration was 5.6 ± 4.8 months, and the length of followup was 4.7 ± 3.5 years. During the course of the study, 863 (47.2%) of the 1,827 patients had 1,627 neuropsychiatric events. Mood disorders occurred in 232 (12.7%) of 1,827 patients, and 98 (38.3%) of 256 mood disorder events were attributed to SLE. The estimated cumulative incidence of any mood disorder after 10 years was 17.7% (95% confidence interval 15.1, 20.2%). A greater risk of mood disorder was associated with concurrent neuropsychiatric events (P ≤ 0.01), and a lower risk was associated with Asian race/ethnicity (P = 0.01) and treatment with immunosuppressive drugs (P = 0.003). Mood disorders were associated with lower mental health and mental component summary scores but not with the SLEDAI-2K, SDI, or lupus autoantibodies. Among the 232 patients with depression, 168 (72.4%) were treated with antidepressants. One hundred twenty-six (49.2%) of 256 mood disorders resolved in 117 (50.4%) of 232 patients.

CONCLUSION

Mood disorders, the second most frequent neuropsychiatric event in patients with SLE, have a negative impact on health-related quality of life and improve over time. The lack of association with global SLE disease activity, cumulative organ damage, and lupus autoantibodies emphasizes the multifactorial etiology of mood disorders and a role for non-lupus-specific therapies.

Silent Burdens in Disease: Fatigue and Depression in SLE

At a time when health is being recognized as more than just avoiding death, age and comorbidity are becoming increasingly important aspects of chronic disease. Systemic Lupus Erythematous (SLE) is probably one of the best paradigms of modern chronic disease, sitting at the crossroads of numerous somatic health problems, immune activation, depression, pain, and fatigue. One hundred forty-eight female participants were enrolled in the present study: 50 diagnosed with SLE, 45 with major depressive disorder (MDD), and 53 age-matched controls. Statistically significant lower scores in quality-of-life dimensions related to physical impairment were found in SLE. Patients with MDD presented significant levels of pain, reduced physical summary component (PSC), and general health scores different from healthy controls. Fatigue was reported in 90% of women with SLE and 77.8% of the MDD patients in contrast with 39.6% in the control group. Significant correlations were seen among fatigue severity, age, and educational level in SLE. From our own previous work and more recent work on the association of immune activation and depression, unexplained fatigue in SLE may signify an early sign of immune activation flare-up. The search for cytokine markers should perhaps be extended to fatigue in SLE.

Depression in systemic lupus erythematosus, dependent on or independent of severity of disease

OBJECTIVES

To estimate the prevalence of depression in subjects with systemic lupus erythematosus (SLE) in relation to the general population and to unravel the relation between depression and SLE disease characteristics.

METHODS

One hundred and two subjects with SLE (mean age 44.4 years) were studied using the Beck Depression Inventory (BDI) score to estimate the prevalence of depression. The BDI scores in subjects with SLE were compared with BDI scores from a pan-European population based study (Outcome in Depression International Network (ODIN) study, n = 7934), i.e. the general population.

RESULTS

The mean BDI score was higher in SLE subjects (10.1 points) compared with the BDI scores derived from the general population (10.1 versus 5.6 points, respectively, p < 0.001). This corresponds to a prevalence of depression of 16.6% and 6.7%, respectively. There was no association between disease activity or organ damage and BDI scores in subjects with SLE (p > 0.1). Only 7% of SLE subjects with high BDI scores used antidepressants.

CONCLUSION

The mean BDI score and prevalence of depression are significantly higher in SLE subjects compared with the general population. No association was found between SLE disease characteristics and BDI scores. The number of depressed SLE subjects treated with antidepressants is low, suggesting inadequate recognition and treatment of depression in SLE.

What do we know about self-reported fatigue in systemic lupus erythematosus?

Fatigue is one of the most complex and ill understood symptoms of chronic illness often reported as the number one complaint by patients with systemic lupus erythematosus (SLE). This paper aims to provide a comprehensive review of the literature on fatigue in SLE. A pool of 55 relevant articles was retrieved via electronic searches of six databases including MEDLINE, EMBASE, CINAHL, AMED, PsychINFO and PubMed. Fatigue in the studies reviewed was assessed by a range of self-report instruments, the content of which is varied. The results displayed a consensus on the high prevalence of fatigue in SLE, which is significantly higher when compared with controls. The aetiology of fatigue appears to be multifactorial. Disease activity is not always significantly associated with fatigue, in comparison with other secondary features of SLE and psychological variables. The literature is limited by the cross-sectional nature of most of the studies, which does not permit for any firm conclusion regarding the direction of causal relationships to be made. The high prevalence of fatigue in SLE emphasizes the need for further detailed prospective research to inform the understanding of its aetiology, course and management.

Activation of type I interferon pathway in systemic lupus erythematosus: association with distinct clinical phenotypes

Growing evidence over the last few years suggests a central role of type I IFN pathway in the pathogenesis of systemic autoimmune disorders. Data from clinical and genetic studies in patients with systemic lupus erythematosus (SLE) and lupus-prone mouse models, indicates that the type I interferon system may play a pivotal role in the pathogenesis of several lupus and associated clinical features, such as nephritis, neuropsychiatric and cutaneous lupus, premature atherosclerosis as well as lupus-specific autoantibodies particularly against ribonucleoproteins. In the current paper, our aim is to summarize the latest findings supporting the association of type I IFN pathway with specific clinical manifestations in the setting of SLE providing insights on the potential use of type I IFN as a therapeutic target.

Evaluating fatigue in lupus-prone mice: preliminary assessments

Fatigue is a debilitating condition suffered by many as the result of chronic disease, yet relatively little is known about its biological basis or how to effectively manage its effects. This study sought to evaluate chronic fatigue by using lupus-prone mice and testing them at three different time periods. Lupus-prone mice were chosen because fatigue affects over half of patients with Systemic Lupus Erythematosus. Eleven MLR⁺/(+) (genetic controls) and twelve MLR/MpJ-Fas<lpr>/J (MRL/lpr; lupus-prone) mice were tested three times: once at 12, 16 and 20 weeks of age. All mice were subjected to a variety of behavioral tests including: forced swim, post-swim grooming, running wheel, and sucrose consumption; five of the MLR⁺/(+) and five of the MLR/lpr mice were also tested on a fixed ratio-25 operant conditioning task. MRL/lpr mice showed more peripheral symptoms of lupus than controls, particularly lymphadenopathy and proteinuria. Lupus mice spent more time floating during the forced swim test and traveled less distance in the running wheel at each testing period. There were no differences between groups in post-swim grooming or in number of reinforcers earned in the operant conditioning task indicating the behavioral changes were not likely due simply to muscle weakness or motivation. Correlations between performance in the running wheel, forced swim test and sucrose consumption were conducted and distance traveled in the running wheel was consistently negatively correlated with time spent floating. Based on these data, we conclude that the lupus-prone mice were experiencing chronic fatigue and that running wheel activity and floating during a forced swim test can be used to evaluate fatigue, although these data cannot rule out the possibility that both fatigue and a depressive-like state were mediating these effects.