Pain and depression are associated with both physical and mental fatigue independently of comorbidities and medications in primary Sjögren's syndrome

The role of fatty acid metabolism on B cells and B cell-related autoimmune diseases

Fatty acid metabolism plays a critical role in regulating immune cell function, including B cells, which are central to humoral immunity and the pathogenesis of autoimmune diseases. Emerging evidence suggests that fatty acid metabolism influences B cell development, activation, differentiation, and antibody production, thereby impacting B cell-related autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). In this review, we discuss the mechanisms by which fatty acid metabolism modulates B cell biology, including energy provision, membrane composition, and signaling pathways. We highlight how alterations in fatty acid synthesis, oxidation, and uptake affect B cell function and contribute to autoimmune pathogenesis. Additionally, we explore the therapeutic potential of targeting fatty acid metabolism in B cells to treat autoimmune diseases. Understanding the interplay between fatty acid metabolism and B cell immunity may provide novel insights into the development of precision therapies for B cell-mediated autoimmune disorders.

Improved Fatigue Management in Primary Sjögren's Syndrome: A Retrospective Analysis of the Efficacy of Methotrexate in Chinese Patients

Objective

To assess the efficacy of methotrexate (MTX) and hydroxychloroquine (HCQ) in improving fatigue symptoms in patients with primary Sjögren's syndrome (pSS).

Methods

A single-center retrospective study was conducted on pSS patients experiencing fatigue symptoms. All patients received either MTX, HCQ, or a combination of MTX + HCQ for a period of six months. Clinical efficacy was measured using the European League Against Rheumatism (EULAR) Sjögren's Syndrome Disease Activity Index (ESSDAI), EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), fatigue severity scale (FSS), and visual analog scale (VAS) score. These measures were assessed at baseline and at 1, 2, 3, and 6 months.

Results

A total of 86 pSS patients with fatigue symptoms were enrolled (27 received MTX, 29 received HCQ, and 30 received MTX + HCQ). Patients receiving MTX and MTX + HCQ showed significant improvements at 6th month in ESSDAI, ESSPRI, FSS, FACIT-F, and VAS scores (all P < 0.01) compared with baseline. Repeated-measures analysis of variance revealed that patients treated with MTX and MTX + HCQ experienced significant improvements in ESSDAI, FSS, FACIT-F, and VAS scores (all P < 0.01) from baseline to the 6th month. The HCQ group did not show significant improvement in FSS, FACIT-F, and VAS scores (all P > 0.05), although their ESSDAI and ESSPRI scores did improve significantly (all P < 0.01). Patients in the MTX group showed the most improvement in mean changes of ESSDAI score, FSS score, FACIT-F score, and VAS score from baseline to the 6th month. And patients received MTX treatment significantly had more fatigue remission numbers (all P < 0.05).

Conclusion

In clinical practice, methotrexate is more effective than hydroxychloroquine in improving fatigue symptoms, as measured by patient-reported fatigue scales (FSS, FACIT-F, and VAS scores) in patients with pSS.

Depression is the most significant independent predictor of fatigue in patients with primary Sjögren's syndrome

Objectives

The study aimed to evaluate the level of fatigue and the relationship between mood, pain, fibromyalgia, insomnia, disease activity, and dryness with fatigue in primary Sjögren's syndrome (PSS) patients.

Patients and methods

In this case-control study, the participants were recruited between January 2021 and July 2021. Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-F), pain DETECT questionnaire, Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Insomnia Severity Index (ISI) were administered to 50 PSS patients (48 females, 2 males; mean age: 48.9±10.8 years; median age: 47 years; range, 29 to 71 years) and 60 healthy controls (HCs; 57 females, 3 males; mean age: 49.8±8.4 years, median age: 52 years; range, 32 to 72 years). In addition, EULAR Sjögren's syndrome disease activity index (ESSPRI), EULAR Sjögren's Syndrome Patient Reported Index (ESSDAI), pain thresholds, Schirmer tests, and whole unstimulated salivary flow rate measurements were determined in PSS patients. Independent predictors of fatigue (fatigue subscale scores <30.5) were investigated by logistic regression analysis.

Results

The frequency of fatigue in PSS patients and HCs was 54.0% and 8.3%, respectively. The rates of mood disturbance (BDI ≥11) in PSS patients with and without fatigue were 70.4% and 13.1%, respectively. BDI (Rho=-0.804), BAI (Rho=-0.586), ISI (Rho=-0.483), and ESSDAI (Rho=-0.345) were negatively correlated with the fatigue subscale score. Depression [Odds ratio (OR): 1.214, confidence interval (CI): 1.007-1.463], fibromyalgia (OR: 21.674, CI: 1.470-319.469), disease activity (OR: 1.440; CI: 1.005-2.065), and insomnia (OR: 1.223, CI: 1.003-1.4922) were identified as independent predictors of fatigue in PSS patients. It was determined that BD alone could predict fatigue by 84% in PSS patients.

Conclusion

Depression can be a prominent predictor of fatigue in PSS patients. There is a need for studies evaluating the effect of antidepressant treatment approaches on fatigue accompanied by mood disturbance in PSS patients.

Mortality risk factors in primary Sjögren syndrome: a real-world, retrospective, cohort study

Background

What baseline predictors would be involved in mortality in people with primary Sjögren syndrome (SjS) remains uncertain. This study aimed to investigate the baseline characteristics collected at the time of diagnosis of SjS associated with mortality and to identify mortality risk factors for all-cause death and deaths related to systemic SjS activity measured by the ESSDAI score.

Methods

In this international, real-world, retrospective, cohort study, we retrospectively collected data from 27 countries on mortality and causes of death from the Big Data Sjögren Registry. Inclusion criteria consisted of fulfilling 2002/2016 SjS classification criteria, and exclusion criteria included chronic HCV/HIV infections and associated systemic autoimmune diseases. A statistical approach based on a directed acyclic graph was used, with all-cause and Sjögren-related mortality as primary endpoints. The key determinants that defined the disease phenotype at diagnosis (glandular, systemic, and immunological) were analysed as independent variables.

Findings

Between January 1st, 2014 and December 31, 2023, data from 11,372 patients with primary SjS (93.5% women, 78.4% classified as White, mean age at diagnosis of 51.1 years) included in the Registry were analysed. 876 (7.7%) deaths were recorded after a mean follow-up of 8.6 years (SD 7.12). Univariate analysis of prognostic factors for all-cause death identified eight Sjögren-related variables (ocular and oral tests, salivary biopsy, ESSDAI, ANA, anti-Ro, anti-La, and cryoglobulins). The multivariate CPH model adjusted for these variables and the epidemiological features showed that DAS-ESSDAI (high vs no high: HR = 1.68; 95% CI, 1.27-2.22) and cryoglobulins (positive vs negative: HR = 1.72; 95% CI, 1.22-2.42) were independent predictors of all-cause death. Of the 640 deaths with available information detailing the specific cause of death, 14% were due to systemic SjS. Univariate analysis of prognostic factors for Sjögren-cause death identified five Sjögren-related variables (oral tests, clinESSDAI, DAS-ESSDAI, ANA, and cryoglobulins). The multivariate competing risks CPH model adjusted for these variables and the epidemiological features showed that oral tests (abnormal vs normal results: HR = 1.38; 95% CI, 1.01-1.87), DAS-ESSDAI (high vs no high: HR = 1.55; 95% CI, 1.22-1.96) and cryoglobulins (positive vs negative: HR = 1.52; 95% CI, 1.16-2) were independent predictors of SjS-related death.

Interpretation

The key mortality risk factors at the time of SjS diagnosis were positive cryoglobulins and a high systemic activity scored using the ESSDAI, conferring a 2-times increased risk of all-cause and SjS-related death. ESSDAI measurement and cryoglobulin testing should be considered mandatory when an individual is diagnosed with SjS.

Funding

Novartis.

Depression in Sjögren's syndrome mediates the relationship between pain, fatigue, sleepiness, and overall quality of life

Objectives

Sjögren's syndrome (SS) includes many extra-glandular symptoms such as fatigue, pain, sleepiness and depression, which impact on quality of life (QoL). These symptoms also influence each other and could be linked by autonomic nervous system (ANS) dysregulation. Our aim was to model the role of putative predictive variables, including depression in the relationships between ANS function, fatigue, and QoL in SS.

Methods

Cross-sectional analysis of self-reported data from the multicentre UK primary SS registry. The Composite Autonomic Symptom Scale (COMPASS) was used to assess autonomic function, the Hospital Anxiety and Depression Scale (HADS) to assess anxiety and depression and the EuroQol-5 Dimension (EQ-5D) to assess QoL. Validated scales were used for other clinical variables. Using multiple regression analysis and structural equation modelling (SEM), we investigated how the QoL of people with SS is impacted by the direct and indirect effects of fatigue, sleepiness, depression, symptom burden and ANS function, and their interactions.

Results

Data was obtained for 1046 people with SS, 56% COMPASS completers. Symptoms of ANS dysregulation were common. Participants with ANS dysregulation had more severe depression, anxiety, dryness, fatigue, pain, sleepiness and QoL (P < 0.01 for all). Depression, anxiety, dryness, and pain were independent predictors of ANS function in the multiple regression model (P < 0.05 for all). ANS function could not be included in the SEM. The SEM model had good fit to the data (comparative fit index = 0.998) and showed that, in people with SS, depression mediates the effects of pain, fatigue and sleepiness on QoL.

Conclusion

Our results show that diagnosing and treating depression in people with SS could have direct positive impact on QoL, and significantly ameliorate the impact of fatigue and pain.

Genetic Variants of the BAFF Gene and Risk of Fatigue Among Patients With Primary Sjögren's Syndrome

Background/Purpose

Primary Sjögren's Syndrome (SS) is characterized by B lymphocyte hyperactivity with B cell activating factor (BAFF) acting as an important regulator. Single Nucleotide Polymorphisms (SNPs) of the BAFF gene have been implicated in the pathogenesis of several autoimmune diseases characterized by heightened fatigue levels, including primary SS. We aimed to explore potential associations between BAFF SNPs and fatigue status of primary SS patients.

Methods

Fatigue status was assessed in 199 consecutive primary SS patients (Greek cohort) using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) scale. Clinical, histological, laboratory, psychometric and personality data were also collected. DNA extracted from peripheral blood of all patients underwent evaluation for the presence of five BAFF SNPs (rs9514827, rs1041569, rs9514828, rs1224141, rs12583006) by PCR. To confirm our findings, an independent replicative cohort of 62 primary SS patients (Dutch cohort) was implemented. Finally, 52 multiple sclerosis (MS) patients were served as disease controls (MS cohort). Analysis of BAFF SNPs in association with fatigue levels was performed by the online platforms SNPStats and SHEsis and the SPSS 26 and Graph Pad Prism 8.00 software.

Results

TT genotype of the rs9514828 BAFF polymorphism was significantly less frequent in the fatigued primary SS patients of the Greek cohort compared to the non-fatigued (14.1% vs 33.3%). The corresponding ORs [95%CI] in the dominant and overdominant models were 0.33 [0.15-0.72], p=0.003 and 0.42 [0.23-0.78], p=0.005 respectively. The association remained significant after adjustment for the variables contributing to fatigue in the univariate analysis (OR [95% CI]: 0.3 [0.1-0.9], p=0.026). Accordingly, in the Dutch cohort, there was a trend of lower mental fatigue among patients carrying the TT rs9514828 BAFF genotype compared to their CC counterparts (4.1 ± 2.4 vs 6.0 ± 2.2 respectively, p=0.06). The rs9514828 BAFF SNP was not significantly associated with fatigue in the MS cohort.

Conclusions

We report a novel association between genetic makeup and primary SS-associated fatigue with the rs9514828 TT genotype decreasing the likelihood of fatigue development among these patients. These findings need validation in multi-center studies.

Work productivity among Sjögren's Syndrome and non-Sjögren's dry eye patients: a systematic review and meta-analysis

BACKGROUND

Dry eye disease (DED) is one of the most common conditions presenting to eye care providers and is increasingly recognized to have poor outcomes on quality of life, activities of daily living, and social and emotional well-being. Here, we aim to understand the association between dry eye symptoms and workplace productivity experienced by patients with non-Sjögren's dry eye and Sjögren's Syndrome.

METHODS

MEDLINE, PubMed, Embase, Cochrane Library, CINAHL, Healthstar, and PsycINFO were searched from inception to May 2019.

RESULTS

Thirty-one studies consisting of 50,446 study participants from 14 countries were included in this systematic review. Among non-Sjögren's dry eye patients, there was significant absenteeism (ES = 0.19; 95% CI: [0.04, 0.35]), presenteeism (ES = 0.25; 95% CI: [0.15. 0.35]), productivity impairment (ES = 0.24; 95% CI: [0.20, 0.27]), activity impairment (ES = 0.30; 95% CI: [0.21, 0.38]), and subjective difficulties at work (ES = 0.58; 95% CI: [0.40, 0.75]). Patients with Sjögren's Syndrome demonstrated significant absenteeism (ES = 0.13, 95% CI: [0.10, 0.17]), presenteeism (ES = 0.28, 95% CI: [0.24, 0.32]), productivity impairment (ES = 0.31, 95% CI: [0.27, 0.35]), and activity impairment (ES = 0.39, 95% CI: [0.32, 0.47]) in the workplace. In addition, patients with Sjögren's Syndrome demonstrated significantly lower employment rate (ES = 0.42, 95% CI: [0.34, 0.50]), decreased number of hours worked (SMD = -0.21, 95% CI: [-0.39, -0.02]), and increased work disability (ES = 0.18; 95% CI: [0.09, 0.27]).

CONCLUSIONS

This is the first systematic review and meta-analysis to demonstrate the negative association between DED and several work productivity measures.

Fatigue in inflammatory rheumatic diseases: current knowledge and areas for future research

Fatigue is a complex phenomenon and an important health concern for many people with chronic inflammatory rheumatic diseases, such as rheumatoid arthritis, psoriatic arthritis, primary Sjögren syndrome and systemic lupus erythematosus. Although some clinical trials have shown the benefits of cognitive behavioural therapy in fatigue management, the effect of this approach is relatively modest, and no curative treatment has been identified. The pathogenesis of fatigue remains unclear. Despite many challenges and limitations, a growing body of research points to roles for the immune system, the central and autonomic nervous systems and the neuroendocrine system in the induction and maintenance of fatigue in chronic diseases. New insights indicate that sleep, genetic susceptibility, metabolic disturbances and other biological and physiological mechanisms contribute to fatigue. Furthermore, understanding of the relationships between psychosocial factors and fatigue is increasing. However, the interrelationships between these diverse mechanisms and fatigue remain poorly defined. In this Review, we outline various biological, physiological and psychosocial determinants of fatigue in inflammatory rheumatic diseases, and propose mechanistic and conceptual models of fatigue to summarize current understanding, stimulate debate and develop further research ideas.

Autonomic Nervous System Dysfunction in Primary Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is an autoimmune disease which primarily affects the exocrine glands, but can also affect other organs, including the nervous system. Many studies have reported evidence of autonomic nervous system (ANS) dysfunction in pSS which may contribute to a wide range of symptoms and functional burden. Symptoms of ANS dysfunction are common and widespread among patients with pSS and are associated with other features of the disease, particularly fatigue. Accumulating data on the inter-relationship between the ANS and the immune system via the vagus nerve have been reported. Vagus nerve stimulation (VNS) has also been associated with improvement in fatigue in patients with pSS. Taken together, these data suggest that the ANS may be a potential treatment target for pSS, in particularly those with fatigue being a predominant symptom. Future research to dissect the link between the ANS, immune dysregulation and clinical manifestations in pSS and to evaluate the potential of VNS as a therapy for pSS is warranted.

Neuropathic Pain in the Eyes, Body, and Mouth: Insights from the Sjögren's International Collaborative Clinical Alliance

OBJECTIVE

To evaluate how ocular, oral, and bodily neuropathic pain symptoms, which characterize small fiber neuropathies, are associated with Sjögren's syndrome (SS) classification based on the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria.

METHODS

Participants enrolled in the Sjögren's International Collaborative Clinical Alliance (SICCA) registry had ocular, rheumatologic, oral, and labial salivary gland (LSG) biopsy examinations, blood and saliva samples collected, and completed questionnaires at baseline. We used mixed effects modeling with age, country, gender, and depression being fixed effects and study site, a random effect, to determine if neuropathic pain indicators (assessed via questionnaires) were associated with being classified as SS.

RESULTS

A total of 3,514 participants were enrolled into SICCA, with 1,541 (52.9%) meeting the 2016 ACR/EULAR classification criteria for SS. There was a negative association between being classified as SS and experiencing bodily neuropathic pain features of needle-like pain, prickling/tingling sensation, ocular neuropathic pain of constant burning, and constant light sensitivity, and having a presumptive diagnosis of neuropathic oral pain.

CONCLUSIONS

We found that those classified as SS had lower scores/reports of painful neuropathies compared with those classified as non-SS. Non-SS patients with dry eye disease or symptoms could benefit from pain assessment as they may experience painful small-fiber neuropathies (SFNs). Pain questionnaires may help identify pain associated with SFNs in patients with SS and non-SS dry eye. Future studies would be helpful to correlate self-reports of pain to objective measures of SFNs in those with SS, non-SS dry eye, and healthy controls.

Understanding Fatigue in Sjögren's Syndrome: Outcome Measures, Biomarkers and Possible Interventions

Sjögren’s syndrome (SS) is an autoimmune disease affecting the salivary and lacrimal glands. Symptoms range from dryness to severe extra-glandular disease involving manifestations in the skin, lungs, nervous system, and kidney. Fatigue occurs in 70% of patients, characterizing primary SS (pSS) and significantly impacting the patient’s quality of life. There are some generic and specific instruments used to measure fatigue in SS. The mechanisms involved with fatigue in SS are still poorly understood, but it appears fatigue signaling pathways are more associated with cell protection and defense than with pro-inflammatory pathways. There are no established pharmacological treatment options for fatigue in pSS. So far, exercise and neuromodulation techniques have shown positive effects on fatigue in pSS. This study briefly reviews fatigue in pSS, with special attention to outcome measures, biomarkers, and possible treatment options.

Transcranial direct current stimulation for fatigue in patients with Sjogren's syndrome: A randomized, double-blind pilot study

BACKGROUND

Transcranial direct-current stimulation (tDCS) has shown promise to decrease fatigue. However, it has never been examined in primary Sjogren Syndrome (pSS).

OBJECTIVE

To assess the effect of a tDCS protocol on fatigue in patients with pSS.

METHODS

This is a parallel, double-blind pilot study (NCT04119128). Women aged 18-65 years, with pSS, on stable pharmacological therapy, with complaints of fatigue for at least three months, and with scores >5 on Fatigue Severity Scale (FSS) were included. We randomized 36 participants to receive five consecutive or sham tDCS sessions, with an intensity of 2 mA, for 20 min/day.

RESULTS

After five tDCS sessions, fatigue severity assessed by the FSS (primary outcome) demonstrated a mean group difference of -0.85 [95% confidence interval (CI) -1.57, -0.13; effect size 0.80] favouring the active group. The active group presented significantly greater reductions in fatigue as measured by the EULAR Sjögren's Syndrome Patient Reported Index after five tDCS sessions [mean group difference: 1.40; 95%CI -2.33, -0.48; effect size 1.04]. Although there were no between-group differences in the secondary outcomes of sleep, mood and anxiety, within-group comparisons evidenced a small but significant difference in the active group for pain and sleep. There were no significant cortisol changes. All reported adverse events were mild and transitory.

CONCLUSION

tDCS seems to be safe and reduce fatigue in pSS. A differential effect on pain and sleep may underlie its effects. Further studies are needed to optimise tDCS treatment strategies in pSS.

Fatigue in inflammatory arthritis

Fatigue is highly prevalent in inflammatory arthritis, and people living with the symptom have described it as overwhelming and a challenge to manage. In this article, we explore the experience, impact and non-pharmacological management of fatigue from a multi-disciplinary perspective. We start by presenting qualitative evidence from people living with fatigue, including the physical, cognitive and emotional nature of the symptom and its impact on daily life. This is followed by discussion of current conceptual models of mechanisms and factors that may cause and maintain fatigue, within and between individuals. We then address the issue of fatigue measurement and modes of assessment, which is an integral aspect of management and evaluating support provision. This leads to a review of the research evidence for non-pharmacological interventions to reduce fatigue severity and impact. Finally, we consider implementation of this evidence in clinical practice and we introduce some key practical tools and techniques.