The level of BLyS (BAFF) correlates with the titre of autoantibodies in human Sjögren's syndrome

Role of belimumab in recurrent spontaneous abortions amongst patients with lymphocyte dysfunction: a retrospective case-control study

OBJECTIVE

In order to examine the impact of belimumab on recurrent spontaneous abortion (RSA) women exhibiting B lymphocyte dysfunction.

METHODS

This study conducted a retrospective case-control analysis of RSA patients with confirmed B lymphocyte dysfunction. The study included 102 women who had experienced at least two consecutive miscarriages and demonstrated elevated peripheral blood B cell percentages and/or counts. Participants were separated into two distinct groups: the belimumab group (n = 51), which received basic treatment supplemented with belimumab (BENLYSTA) at a dosage of 10 mg/kg BW at 2-week intervals for the first 3 doses and at 4-week intervals thereafter, from the end of menstrual period until the 12th week of pregnancy, if necessary; and the control group (n = 51), which received only standard treatment. Comparisons of Pregnancy outcomes, B cell percentage, B cell count and adverse reactions were made between 2 groups.

RESULTS

Healthy newborns were delivered by 45 participants (88.23%) in belimumab group and 36 participants (70.59%) in control group [P = 0.048, odds ratio (OR) = 3.13; 95% confidence interval (CI) (1.10-8.87)]. The belimumab group exhibited significantly lower peripheral blood B cell percentage and B cell count compared to the control group during gestational weeks 2-12 (P < 0.05).

CONCLUSION

The findings suggest that belimumab is both safe and effective for treating RSA with lymphocyte dysfunction, indicating its potential as a therapeutic strategy for RSA.

Blockade of B-cell-activating factor may alleviate liver injury by restraining interferon-γ expression in T cells in experimental biliary atresia

BACKGROUND

The primary pathogenetic factor for biliary atresia is an atypical immune response. Previous studies have suggested that the expression of B cell-activating factor is upregulated in BA and BAFF is related to T-cell function. However, the way in which BAFF influences T cell function in BA is still not fully clarified. We therefore investigated the effects of BAFF on T cells in experimental biliary atresia.

METHODS

BAFF levels were measured in serum and liver of patients with BA and controls. Immunofluorescence analysis was performed to assess the co-localization of BAFF with myeloid cells (CD14 or CD68) in liver biopsies. A multiplex assay (MAGPIX) was used to measure the levels of Th1 [interferon (IFN)-γ], Th2 [interleukin (IL)-4], and Th17 (IL-17). IFN-γ expression was measured in CD4+ and CD8+ T cells in vitro. An anti-BAFF antibody was administered in a rhesus rotavirus (RRV)-induced BA model to assess the effect of BAFF. Finally, survival, histology, liver function index, liver immune cell subsets, and cytokine production were analyzed.

RESULTS

BAFF expression was significantly higher in patients with BA than controls. Furthermore, BAFF levels in liver supernatants significantly correlated with liver inflammation severity in patients with BA. In addition, BAFF levels positively correlated with IFN-γ levels. Serum BAFF combined with GGT may offer a more reliable approach for confirming the diagnosis of BA. In vitro experiments revealed that BAFF increased IFN-γ expression in CD4+ and CD8+ T cells of infants with BA. BAFF inhibition was associated with a decrease in portal tract inflammation and IFN-γ expression in CD4+ and CD8+ T cells, with the simultaneous expansion of regulatory T cells in an RRV-induced BA model.

CONCLUSION

BAFF may participate in inflammatory responses in BA by affecting T cells, suggesting the potential role of BAFF in BA pathogenesis.

Subpopulation dynamics of T and B lymphocytes in Sjögren's syndrome: implications for disease activity and treatment

Sjögren's syndrome (SS) is an autoimmune disorder primarily affecting the body's exocrine glands, particularly the salivary and lacrimal glands, which lead to severe symptoms of dry eyes and mouth. The pathogenesis of SS involves the production of autoantibodies by activated immune cells, and secretion of multiple cytokines, which collectively lead to tissue damage and functional impairment. In SS, the Immune interaction among T and B cells is particularly significant. Lymphocytic infiltration in the salivary glands is predominantly composed of CD4+ T cells, whose activation cause the death of glandular epithelial cells and subsequent tissue destruction. The excessive activity of T cells contributes significantly to the disease mechanism, with helper T cells (CD4+) differentiating into various subgroups including Th1/Th2, Th17, as well as Treg, each contributing to the pathological process through distinct cytokine secretion. In patients with SS, B cells are excessively activated, leading to substantial production of autoantibodies. These antibodies can attack self-tissues, especially the lacrimal and salivary glands, causing inflammation and tissue damage. Changes in B cell subpopulations in SS patients, such as increases in plasmablasts and plasma cells, correlate positively with serum autoantibody levels and disease progression. Therapies targeting T cells and B cells are extensively researched with the aim of alleviating symptoms and improving the quality of life for patients. Understanding how these cells promote disease development through various mechanisms, and further identifying novel T and B cell subgroups with functional characterization, will facilitate the development of more effective strategies to treat SS.

Iguratimod suppresses plasma cell differentiation and ameliorates experimental Sjögren's syndrome in mice by promoting TEC kinase degradation

Primary Sjögren's syndrome (pSS) is a chronic inflammatory autoimmune disease with an unclear pathogenesis, and there is currently no approved drug for the treatment of this disease. Iguratimod, as a novel clinical anti-rheumatic drug in China and Japan, has shown remarkable efficacy in improving the symptoms of patients with pSS in clinical studies. In this study we investigated the mechanisms underlying the therapeutic effect of iguratimod in the treatment of pSS. Experimental Sjögren's syndrome (ESS) model was established in female mice by immunizing with salivary gland protein. After immunization, ESS mice were orally treated with iguratimod (10, 30, 100 mg·kg-1·d-1) or hydroxychloroquine (50 mg·kg-1·d-1) for 70 days. We showed that iguratimod administration dose-dependently increased saliva secretion, and ameliorated ESS development by predominantly inhibiting B cells activation and plasma cell differentiation. Iguratimod (30 and 100 mg·kg-1·d-1) was more effective than hydroxychloroquine (50 mg·kg-1·d-1). When the potential target of iguratimod was searched, we found that iguratimod bound to TEC kinase and promoted its degradation through the autophagy-lysosome pathway in BAFF-activated B cells, thereby directly inhibiting TEC-regulated B cells function, suggesting that the action mode of iguratimod on TEC was different from that of conventional kinase inhibitors. In addition, we found a crucial role of TEC overexpression in plasma cells of patients with pSS. Together, we demonstrate that iguratimod effectively ameliorates ESS via its unique suppression of TEC function, which will be helpful for its clinical application. Targeting TEC kinase, a new regulatory factor for B cells, may be a promising therapeutic option.

Efficacy of BAFF inhibition and B-cell depletion in non-obese diabetic mice as a spontaneous model for Sjögren's disease

INTRODUCTION

The therapeutic interest of targeting B-cell activating factor (BAFF) in Sjögren's disease (SjD) can be suspected from the results of two phase II clinical trials but has not been evaluated in an animal model of the disease. We aimed to evaluate the therapeutic efficacy of this strategy on dryness and salivary gland (SG) infiltrates in the NOD mouse model of SjD.

MATERIAL AND METHODS

Female NOD mice between ages 10 and 18 weeks were treated with a BAFF-blocking monoclonal antibody, Sandy-2 or an isotype control. Dryness was measured by the stimulated salivary flow. Salivary lymphocytic infiltrates were assessed by immunohistochemistry. Blood, SGs, spleen and lymph-node lymphocyte subpopulations were analysed by flow cytometry. SG mRNA expression was analysed by transcriptomic analysis.

RESULTS

BAFF inhibition significantly decreased SG lymphocytic infiltrates, which was inversely correlated with salivary flow. The treatment markedly decreased B-cell number in SGs, blood, lymph nodes and spleen and increased Foxp3+ regulatory and CD3+CD4-CD8- double negative T-cell numbers in SGs.

CONCLUSION

A monoclonal antibody blocking BAFF and depleting B cells had therapeutic effectiveness in the NOD mouse model of SjD. The increase in regulatory T-lymphocyte populations might underlie the efficacy of this treatment.

Advances in cellular and molecular pathways of salivary gland damage in Sjögren's syndrome

Sjögren's Syndrome (SS) is an autoimmune disorder characterized by dysfunction of exocrine glands. Primarily affected are the salivary glands, which exhibit the most frequent pathological changes. The pathogenesis involves susceptibility genes, non-genetic factors such as infections, immune cells-including T and B cells, macrophage, dendritic cells, and salivary gland epithelial cells. Inflammatory mediators such as autoantibodies, cytokines, and chemokines also play a critical role. Key signaling pathways activated include IFN, TLR, BAFF/BAFF-R, PI3K/Akt/mTOR, among others. Comprehensive understanding of these mechanisms is crucial for developing targeted therapeutic interventions. Thus, this study explores the cellular and molecular mechanisms underlying SS-related salivary gland damage, aiming to propose novel targeted therapeutic approaches.

The titers of antinuclear antibodies are associated with the degree of inflammation and organ damage in Primary Sjögren's Syndrome

Primary Sjögren's Syndrome (pSS) falls within the category of connective tissue diseases, characterized by the presence of autoantibodies such as antinuclear antibodies (ANA). However, according to the classification criteria for pSS, some patients may exhibit a negative result for autoantibodies. Patients with a negative result for autoantibodies may lack typical features of connective tissue diseases, and the immunological state as well as the extent of organ involvement and damage may differ from those with positive autoantibodies. This study aims to compare the clinical phenotypes of patients with positive and negative autoantibodies, providing insights for disease classification and treatment selection for clinicians. Patients with pSS were grouped based on the presence and titers of their autoantibodies. Subsequently, differences in organ damage and laboratory indicators were compared between these groups, aiming to analyze the value of autoantibody titers in assessing the condition of pSS. (1) Patients with positive ANA exhibited elevated levels of inflammatory indicators, including ESR, IgG levels, lip gland biopsy pathology grade, and overall organ involvement, in comparison with patients with negative ANA (P < 0.05). Furthermore, ANA-positivity correlated with a higher occurrence of multi-organ damage, particularly affecting the skin, mucous membranes, and the hematological system (P < 0.05). (2) As ANA titers increased, patients demonstrated elevated levels of IgG and an escalation in organ involvement (P < 0.05). (3) Patients in the positive autoantibody group (positive for antinuclear antibodies, anti-SSA, or anti-SSB antibodies) had higher IgG levels compared to the negative group (P < 0.05). (4) Patients with positive anti-SSA and anti-SSB antibodies exhibited higher levels of inflammatory indicators and IgG compared to other patients (P < 0.05); however, no significant differences were observed in terms of organ involvement and organ damage. Patients with positive ANA in pSS typically exhibit higher levels of inflammation and an increased likelihood of experiencing multi-organ damage. Furthermore, as the ANA titers increase, both inflammation levels and the risk of multi-organ damage also escalate. Additionally, the presence of anti-SSA and anti-SSB antibodies may contribute to an elevated risk of increased inflammation levels, but does not increase the risk of organ damage.

Elevated serum B-cell activator factor levels predict rapid progressive interstitial lung disease in anti-melanoma differentiation associated protein 5 antibody positive dermatomyositis

BACKGROUND

Rapid progressive interstitial lung disease (RP-ILD) is the leading cause of anti-melanoma differentiation associated protein 5 antibody positive dermatomyositis (anti-MDA5+DM) related death. Elevated serum B-cell activating factor (BAFF) levels have been implicated in connective tissue diseases associated ILD. Here, we evaluate whether BAFF could be a prognostic biomarker for predicting RP-ILD in anti-MDA5+DM patients.

METHODS

Serums were collected from 39 patients with anti-MDA5+DM (20 with RP-ILD and 19 with non-RP-ILD), 20 antisynthase syndrome (ASS) patients and 20 healthy controls (HC). BAFF concentration was measured by an enzyme-linked immunosorbent assay.

RESULTS

Serum BAFF level was higher in anti-MDA5+DM patients than those in ASS patients and HC (3882.32 ± 1880.09 vs. 2540.89 ± 1403.04 and 2486.28 ± 767.97 pg/mL, p = 0.0056 and 0.0038, respectively). Within anti-MDA5+DM groups, RP-ILD patients exhibited higher BAFF concentration than non-RP-ILD group (4549.78 ± 1839.97 vs. 3297.28 ± 1794.69 pg/mL, p = 0.04). The BAFF concentration was positively correlated with levels of C-reactive protein (CRP), dehydrogenase (LDH) and cytokeratin (CK) in anti-MDA5+DM patients (r = 0.350, p = 0.035; r = 0.393, p = 0.016; r = 0.518, p = 0.001; respectively). The best cut-off value of BAFF concentration was 2971.5 pg/mL by ROC curve (AUC area = 0.690, p = 0.045) and BAFF > 2971.5 pg/mL was an independent risk factor for RP-ILD using multivariate analysis (OR = 9.389, 95% CI = 1.609-54.769; p = 0.013).

CONCLUSIONS

Serum BAFF could be a useful prognostic biomarker for early detecting RP-ILD risk in anti-MDA5+DM patients.

B cell focused transient immune suppression protocol for efficient AAV readministration to the liver

Adeno-associated virus (AAV) vectors are used for correcting multiple genetic disorders. Although the goal is to achieve lifelong correction with a single vector administration, the ability to redose would enable the extension of therapy in cases in which initial gene transfer is insufficient to achieve a lasting cure, episomal vector forms are lost in growing organs of pediatric patients, or transgene expression is diminished over time. However, AAV typically induces potent and long-lasting neutralizing antibodies (NAbs) against capsid that prevents re-administration. To prevent NAb formation in hepatic AAV8 gene transfer, we developed a transient B cell-targeting protocol using a combination of monoclonal Ab therapy against CD20 (for B cell depletion) and BAFF (to slow B cell repopulation). Initiation of immunosuppression before (rather than at the time of) vector administration and prolonged anti-BAFF treatment prevented immune responses against the transgene product and abrogated prolonged IgM formation. As a result, vector re-administration after immune reconstitution was highly effective. Interestingly, re-administration before the immune system had fully recovered achieved further elevated levels of transgene expression. Finally, this immunosuppression protocol reduced Ig-mediated AAV uptake by immune cell types with implications to reduce the risk of immunotoxicities in human gene therapy with AAV.

Beyond sicca: high prevalence and predictors of baseline and worsening systemic involvement in patients with Sjögren's disease

Objectives

Systemic extraglandular involvement in SS has been reported in one-third of patients but may be more frequent. We aimed to evaluate systemic disease prevalence at baseline and throughout follow-up and find its predictors.

Methods

We conducted a retrospective cohort study including SS patients followed in a tertiary centre. The cumulative EULAR SS disease activity index (ESSDAI) was calculated by adding each domain's maximum score throughout follow-up. We identified independent predictors of systemic involvement (ESSDAI ≥1 at baseline and/or follow-up) through logistic regression modelling. A survival analysis was conducted to identify predictors of new/worsening ESSDAI domains.

Results

A total of 216 patients were included, most of whom had systemic involvement (86%), frequently at diagnosis (76%). Biological (53%) and articular ESSDAI domains (44%) were most commonly involved, but all were affected at least once. Around half of the patients with baseline systemic disease developed an additional/worsening domain throughout follow-up. Although most patients had low disease activity at baseline, 60% eventually reached moderately active disease. Younger age at diagnosis [odds ratio (OR) 0.95 (95% CI 0.91, 0.99)], a positive minor salivary gland biopsy [OR 4.08 (95% CI 1.40, 11.86)] and RF [OR 4.67 (95% CI 1.52, 14.33)] were independent predictors of systemic involvement. Patients with baseline constitutional involvement [hazard ratio (HR) 2.23 (95% CI 1.13, 4.40)] and RF [HR 1.89 (95% CI 1.20, 3.00)] were more likely to develop new/worsening systemic disease activity.

Conclusion

Systemic involvement is seen in most SS patients. Younger and RF and salivary gland biopsy-positive patients are at higher risk of systemic disease. Around half of patients with systemic involvement experienced aggravated disease over time, especially those with constitutional involvement or RF.

Efficacy and safety of telitacicept in primary Sjögren's syndrome: a randomized, double-blind, placebo-controlled, phase 2 trial

OBJECTIVE

To evaluate the efficacy and safety of telitacicept in adult patients with primary SS (pSS) in a phase II randomized double-blind placebo-controlled trial.

METHODS

Patients with pSS with positive anti-SSA antibody and ESSDAI ≥ 5 were randomly assigned, in a 1:1:1 ratio, to receive weekly subcutaneous telitacicept 240 mg, 160 mg, or placebo for 24 weeks. The primary end point was the change from baseline in the ESSDAI at week 24. Safety was monitored.

RESULTS

A total of 42 patients were enrolled and randomized (n = 14 per group). Administration of telitacicept 160 mg resulted in a significant reduction in ESSDAI score from baseline to week 24 compared with placebo (P < 0.05). The placebo-adjusted least-squares mean change from baseline was -4.3 (95% CI -7.0, -1.6; P = 0.002). While, mean change of ESSDAI in telitacicept 240 mg was -2.7(-5.6-0.1) with no statistical difference when compared that in placebo group (P = 0.056). In addition, MFI-20 and serum immunoglobulins decreased significantly (P < 0.05) at week 24 in both telitacicept groups compared with placebo. No serious adverse events were observed in the telitacicept treating group.

CONCLUSION

Telitacicept showed clinical benefits and good tolerance and safety in the treatment of pSS.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT04078386.

New investigational drugs to treat Sjogren's syndrome: lessons learnt from immunology

INTRODUCTION

Sjögren's syndrome is a heterogeneous autoimmune condition that impairs quality of life because of dryness, fatigue, pain, and systemic involvements. Current treatment largely depends on empirical evidence, with no effective therapy approved. Clinical trials on targeted drugs often fail to report efficacy due to common factors.

AREAS COVERED

This review summarizes the pathogenesis and what caused the failure of new investigational drugs in clinical trials, highlighting solutions for more effective investigations, with greater consistency between research outcomes, clinical use, and patient needs.

EXPERT OPINION

Unlinked pathobiology with symptoms resulted in misidentified targets and disappointing trials. Useful stratification tools are necessary for the heterogeneous SS patients. Composite endpoints or improvements in ESSDAI scores are needed, considering the high placebo response, and the unbalance between symptom burden and disease activity. Compared to classic biologics, targeted cell therapy will be a more promising field of investigation in the coming years.

Associations between TNFSF13B polymorphisms and primary Sjögren's syndrome susceptibility in primary Sjögren's syndrome patients: A meta-analysis

OBJECTIVE

B-cell activating factor (BAFF) is a key regulator of primary Sjögren's syndrome (pSS), which is characterized by B-lymphocyte hyperactivity. BAFF, also known as tumor necrosis factor ligand superfamily member 13B, is encoded by TNFSF13B. This study aimed to explore the possible relationships between five single-nucleotide polymorphisms (SNPs) of TNFSF13B (rs9514827, rs1041569, rs9514828, rs1224141, and rs12583006) and pSS susceptibility.

METHODS

We searched the following databases for articles on TNFSF13B polymorphism and pSS published up to January 2023: PubMed, Cochrane, Elsevier, Web of Science, CNKI, CQVIP, and WanFang. The odds ratios (with 95% confidence intervals) of genotypes and SNP alleles of TNFSF13B were investigated in patients with pSS to determine their relationships with pSS.

RESULTS

This meta-analysis employing the fixed-effect model comprised three studies of pSS patients and randomly selected healthy controls (HCs), revealing statistically significant relationships between pSS susceptibility and two SNPs: rs1041569 and rs12583006. Because rs1041569 was not in Hardy-Weinberg equilibrium in the HC group, it was eliminated from the analysis.

CONCLUSIONS

Polymorphisms in the BAFF (TNFSF13B) gene were related to vulnerability to pSS among pSS patients and HCs alike. The SNP rs12583006 was significantly related to pSS susceptibility in pSS patients.

The contribution of a proliferation-inducing ligand (APRIL) and other TNF superfamily members in pathogenesis and progression of IgA nephropathy

Advances in our understanding of the pathogenesis of immunoglobulin A nephropathy (IgAN) have led to the identification of novel therapeutic targets and potential disease-specific treatments. Specifically, a proliferation-inducing ligand (APRIL) has been implicated in the pathogenesis of IgAN, mediating B-cell dysregulation and overproduction of pathogenic galactose-deficient IgA1 (Gd-IgA1). Animal and clinical studies support the involvement of APRIL in the pathogenesis and progression of IgAN. An elevated level of APRIL is found in IgAN when compared with controls, which correlates with the level of Gd-IgA1 and associates with more severe disease presentation and worse outcomes. Conversely, anti-APRIL therapy reduces pathogenic Gd-IgA1 and IgA immune complex formation and ameliorates the severity of kidney inflammation and injury. Genome-wide association studies in IgAN have identified TNFSF13 and TNFRSF13B, a cytokine ligand-receptor gene pair encoding APRIL and its receptor, respectively, as risk susceptibility loci in IgAN, further supporting the causal role of the APRIL signalling pathway in IgAN. Several novel experimental agents targeting APRIL, including atacicept, telitacicept, zigakibart and sibeprenlimab, are currently under investigation as potential therapies in IgAN. Preliminary results suggest that these agents are well-tolerated, and reduce levels of Gd-IgA1, with corresponding improvement in proteinuria. Further studies are ongoing to confirm the safety and efficacy of anti-APRIL approaches as an effective therapeutic strategy in IgAN.

Association Between Bruton's Tyrosine Kinase Gene Overexpression and Risk of Lymphoma in Primary Sjögren's Syndrome

OBJECTIVE

We undertook this study to analyze whole blood gene expression and to investigate the role of B cell genes in primary Sjögren's syndrome-related non-Hodgkin lymphoma (primary SS-NHL).

METHODS

Peripheral whole blood samples were collected from 345 well-phenotyped patients with primary SS enrolled in the prospective Assessment of Systemic Signs and Evolution in Sjögren's Syndrome (ASSESS) cohort. Transcriptomic analysis was performed using human Clariom S Arrays (Affymetrix). In our primary analysis, we considered patients with incident lymphoma (i-primary SS-NHL) as the case group and all patients without lymphoma as the comparison group. In our sensitivity analyses, we considered all patients with primary SS-NHL, including those with a history of lymphoma (h-primary SS-NHL), as the case group and primary SS patients without lymphoma, stratified on their risk factors of lymphoma, as the comparison group.

RESULTS

Twenty-one patients with primary SS-NHL (including 8 with i-primary SS-NHL and 13 h-primary SS-NHL) were eligible for transcriptomic analysis; we compared these patients to 324 primary SS controls without lymphoma, including 110 with moderate to severe disease activity and 61 with no risk factor of lymphoma. Functional clustering analyses revealed an enrichment of genes related to innate and adaptive immunity, including B cell-related genes. Bruton's tyrosine kinase (BTK) and a proliferation-inducing ligand (APRIL) genes were overexpressed before the occurrence of lymphoma in patients with incident lymphoma compared with patients without lymphoma. In sensitivity analyses, BTK was consistently up-regulated across all comparisons performed. BTK expression was associated with risk of lymphoma on multivariate analyses, which considered 9 validated predictors of lymphoma in primary SS.

CONCLUSION

BTK and APRIL were overexpressed in the peripheral blood of primary SS patients prior to lymphoma. The association between BTK, APRIL, and primary SS-NHL requires confirmation in other prospective cohorts.

Post-transcriptional checkpoints in autoimmunity

Post-transcriptional regulation is a fundamental process in gene expression that has a role in diverse cellular processes, including immune responses. A core concept underlying post-transcriptional regulation is that protein abundance is not solely determined by transcript abundance. Indeed, transcription and translation are not directly coupled, and intervening steps occur between these processes, including the regulation of mRNA stability, localization and alternative splicing, which can impact protein abundance. These steps are controlled by various post-transcription factors such as RNA-binding proteins and non-coding RNAs, including microRNAs, and aberrant post-transcriptional regulation has been implicated in various pathological conditions. Indeed, studies on the pathogenesis of autoimmune and inflammatory diseases have identified various post-transcription factors as important regulators of immune cell-mediated and target effector cell-mediated pathological conditions. This Review summarizes current knowledge regarding the roles of post-transcriptional checkpoints in autoimmunity, as evidenced by studies in both haematopoietic and non-haematopoietic cells, and discusses the relevance of these findings for developing new anti-inflammatory therapies.

Alterations of CD8+ T cells in the blood and salivary glands of patients with primary Sjögren's syndrome

OBJECTIVE

To identify the alterations of CD8+ T cells in blood and labial salivary glands (LSGs) of patients with Primary Sjögren's syndrome (pSS).

METHODS

Blood samples from 24 pSS patients were assayed for CD38+ HLA-DR+ CD8+ (activated CD8+, aCD8+) T cells and serum IFN-γ and TNF-α, using flow cytometry and ELISA respectively, and compared with samples from 27 healthy controls. Immunohistochemistry was used to count CD8+ T cells in LSG tissues of 24 pSS patients and of 6 control patients with normal pathology.

RESULTS

pSS patients had more aCD8+ T cells than aCD4+ T cells (medians 33.13% vs. 9.43%, p < 0.0001), and had an increased level of aCD8+ T cells (medians 33.13% vs. 16.48%, p < 0.0001) and serum IFN-γ (medians 1026 pg/mL vs. 0.00 pg/mL, p < 0.0001) compared to the healthy controls. The levels of aCD8+ T cells and IFN-γ were both significant positively correlated with European League Against Rheumatism Sjögren's Syndrome Disease Activity Index, IgG, anti-nuclear antibodies, rheumatoid factor. The LSGs focus score (FS) ≥1 group had more CD8+ T cell counts than 0≤ FS <1 group and control group (medians 256/mm2 vs. 126/mm2 and 256/mm2 vs. 64/mm2 respectively, both p < 0.05).

CONCLUSION

The aCD8+ T cells and IFN-γ are positively correlated with each other, and predominantly elevated in the blood of pSS patients. In the LSG tissues of pSS, CD8+ T cell counts increase with severity of the lesions. CD8+ T cells may play crucial role in the pathogenesis of pSS. Key Points • Primary Sjögren's syndrome (pSS) is a chronic and systemic autoimmune disease. pSS patients had elevated blood levels of CD38 + HLA-DR+ CD8+ T cells and IFN-γ. • The CD38 + HLA-DR+ CD8+ T cells positively correlated with disease parameters and serum IFN-γ. • The salivary glands of pSS patients had appreciable CD8 + lymphocyte infiltration. CD8+ T cells may play crucial role in the pathogenesis of pSS.

Graves' disease as a driver of depression: a mechanistic insight

Graves' disease (GD) is characterized by diffuse enlargement and overactivity of the thyroid gland, which may be accompanied by other physical symptoms. Among them, depression can dramatically damage patients' quality of life, yet its prevalence in GD has not received adequate attention. Some studies have established a strong correlation between GD and increased risk of depression, though the data from current study remains limited. The summary of mechanistic insights regarding GD and depression has underpinned possible pathways by which GD contributes to depression. In this review, we first summarized the clinical evidence that supported the increased prevalence of depression by GD. We then concentrated on the mechanistic findings related to the acceleration of depression in the context of GD, as mounting evidence has indicated that GD promotes the development of depression through various mechanisms, including triggering autoimmune responses, inducing hormonal disorders, and influencing the thyroid-gut-microbiome-brain axis. Finally, we briefly presented potential therapeutic approaches to decreasing the risk of depression among patients with GD.

Oxidative Stress and Epigenetics: miRNA Involvement in Rare Autoimmune Diseases

Autoimmune diseases (ADs) such as Sjögren’s syndrome, Kawasaki disease, and systemic sclerosis are characterized by chronic inflammation, oxidative stress, and autoantibodies, which cause joint tissue damage, vascular injury, fibrosis, and debilitation. Epigenetics participate in immune cell proliferation and differentiation, which regulates the development and function of the immune system, and ultimately interacts with other tissues. Indeed, overlapping of certain clinical features between ADs indicate that numerous immunologic-related mechanisms may directly participate in the onset and progression of these diseases. Despite the increasing number of studies that have attempted to elucidate the relationship between miRNAs and oxidative stress, autoimmune disorders and oxidative stress, and inflammation and miRNAs, an overall picture of the complex regulation of these three actors in the pathogenesis of ADs has yet to be formed. This review aims to shed light from a critical perspective on the key AD-related mechanisms by explaining the intricate regulatory ROS/miRNA/inflammation axis and the phenotypic features of these rare autoimmune diseases. The inflamma-miRs miR-155 and miR-146, and the redox-sensitive miR miR-223 have relevant roles in the inflammatory response and antioxidant system regulation of these diseases. ADs are characterized by clinical heterogeneity, which impedes early diagnosis and effective personalized treatment. Redox-sensitive miRNAs and inflamma-miRs can help improve personalized medicine in these complex and heterogeneous diseases.

An Overview of the Dry Eye Disease in Sjögren's Syndrome Using Our Current Molecular Understanding

Sjögren's syndrome is a chronic and insidious auto-immune disease characterized by lymphocyte infiltration of exocrine glands. The patients typically present with ocular surface diseases related to dry eye and other systemic manifestations. However, due to the high prevalence of dry eye disease and the lack of objective and clinically reliable diagnostic tools, discriminating Sjögren's syndrome dry eye (SSDE) from non-Sjögren's syndrome dry eye (NSSDE) remains a challenge for clinicians. Diagnosing SS is important to improve the quality of life of patients through timely referral for systemic workups, as SS is associated with serious systemic complications such as lymphoma and other autoimmune diseases. The purpose of this article is to describe the current molecular understanding of Sjögren's syndrome and its implications for novel diagnostic modalities on the horizon. A literature review of the pre-clinical and clinical studies published between 2016 and 2022 was conducted. The SSDE pathophysiology and immunology pathways have become better understood in recent years. Novel diagnostic modalities, such as tear and saliva proteomics as well as exosomal biomarkers, provide hope on the horizon.

A randomized, phase II study of sequential belimumab and rituximab in primary Sjögren's syndrome

BACKGROUNDPrimary Sjögren's syndrome (pSS) is characterized by B cell hyperactivity and elevated B-lymphocyte stimulator (BLyS). Anti-BLyS treatment (e.g., belimumab) increases peripheral memory B cells; decreases naive, activated, and plasma B cell subsets; and increases stringency on B cell selection during reconstitution. Anti-CD20 therapeutics (e.g., rituximab) bind and deplete CD20-expressing B cells in circulation but are less effective in depleting tissue-resident CD20+ B cells. Combined, these 2 mechanisms may achieve synergistic effects.METHODSThis 68-week, phase II, double-blind study (GSK study 201842) randomized 86 adult patients with active pSS to 1 of 4 arms: placebo, s.c. belimumab, i.v. rituximab, or sequential belimumab + rituximab.RESULTSOverall, 60 patients completed treatment and follow-up until week 68. The incidence of adverse events (AEs) and drug-related AEs was similar across groups. Infections/infestations were the most common AEs, and no serious infections of special interest occurred. Near-complete depletion of minor salivary gland CD20+ B cells and a greater and more sustained depletion of peripheral CD19+ B cells were observed with belimumab + rituximab versus monotherapies. With belimumab + rituximab, reconstitution of peripheral B cells occurred, but it was delayed compared with rituximab. At week 68, mean (± standard error) total EULAR Sjögren's syndrome disease activity index scores decreased from 11.0 (1.17) at baseline to 5.0 (1.27) for belimumab + rituximab and 10.4 (1.36) to 8.6 (1.57) for placebo.CONCLUSIONThe safety profile of belimumab + rituximab in pSS was consistent with the monotherapies. Belimumab + rituximab induced enhanced salivary gland B cell depletion relative to the monotherapies, potentially leading to improved clinical outcomes.TRIAL REGISTRATIONClinicalTrials.gov NCT02631538.FUNDINGFunding was provided by GSK.

Not all autoantibodies are clinically relevant. Classic and novel autoantibodies in Sjögren’s syndrome: A critical review

Sjögren’s syndrome (SjS) is a heterogeneous systemic disease. The abnormal responses to La/SSB and Ro/SSA of both B-cells and T-cells are implicated as well as others, in the destruction of the epithelium of the exocrine glands, whose tissue characteristically shows a peri-epithelial lymphocytic infiltration that can vary from sicca syndrome to systemic disease and lymphoma. Despite the appearance of new autoantibodies, anti-Ro/SSA is still the only autoantibody included in the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria and is used extensively as a traditional biomarker in clinical practice. The study and findings of new autoantibodies in SjS has risen in the previous decade, with a central role given to diagnosis and elucidating new aspects of SjS physiopathology, while raising the opportunity to establish clinical phenotypes with the goal of predicting long-term complications. In this paper, we critically review the classic and the novel autoantibodies in SjS, analyzing the methods employed for detection, the pathogenic role and the wide spectrum of clinical phenotypes.

Association of and polymorphisms with sarcoidosis in a Greek patient cohort

INTRODUCTION

Sarcoidosis is a disease that results from a combination of environmental and genetic factors. Its genetic basis however, is yet to be clarified. The purpose of this study is to determine whether single nucleotide polymorphisms (SNPs) of the B-cell activating factor (BAFF) and its receptor (BAFF-R) are associated with sarcoidosis.

MATERIAL AND METHODS

Blood samples from one hundred and seventy-three sarcoidosis patients and one hundred and sixty-four controls were collected. All samples were genotyped for BAFF rs2893321, rs1041569 and rs9514828, and for BAFF-R rs61756766.

RESULTS

Out of the three BAFF polymorphisms, none genotype had any significant association with sarcoidosis, although the T allele in rs1041569 and rs9514828 was overrepresented in sarcoidosis patients. A marginally significant association with sarcoidosis was found in the case of the CT genotype and T allele of BAFF-R rs61756766. Haplotype analysis of the BAFF polymorphisms was also performed, revealing an overrepresentation of the ATT, GTA and GTT haplotypes in the group of patients with cardiac involvement.

CONCLUSIONS

Taken together, the results of this study suggest a possible relationship between BAFF SNPs, rs1041569 and rs9514828, and BAFF-R SNP rs61756766 with sarcoidosis susceptibility and their potential as biomarkers for the disease.

Sjögren's syndrome: shedding light on emerging and key drug targets

INTRODUCTION

Sjögren's syndrome (SS) is an immune-mediated inflammatory condition characterized by sicca syndrome, musculoskeletal pain, and fatigue. Extra-glandular manifestations are common and there is a markedly increased risk of lymphoma development. SS is associated with high health-economic burden driven largely by the symptom burden on patients. Currently, there is no approved disease-modifying treatment and management is based on empirical evidence. Progress in the understanding of SS pathogenesis has led to an expanding portfolio of more targeted therapies under development.

AREAS COVERED

This review summarizes the key development in targeted biological therapies in SS including emerging targets. It also highlights the challenges in therapeutic development in SS such as disease heterogeneity and defining appropriate disease assessment tools to evaluate therapeutic efficacy.

EXPERT OPINION

Early trials in SS failed to meet their primary outcomes which may in part due to the use of inappropriate or insensitive study endpoints. Recent trials targeting B-cells, B-T cell co-stimulation and IFN signaling have shown promising results. Development of composite endpoints including patient reported outcomes and objective disease measure may provide a more holistic approach to disease assessment. The impact of these new tools on therapeutic development that benefit patients remains to be fully evaluated.

Biomarkers of lymphoma in Sjögren's syndrome: what's the latest?

INTRODUCTION

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease standing in the crossroads of autoimmunity and lymphomagenesis, characterized by chronic B-cell hyperactivity and ectopic lymphoid tissue neoformation, potentially driving lymphoid malignant transformation. Lymphoma development is considered the most serious complication of pSS.

AREAS COVERED: “

Old-classical" biomarkers (clinical, serological, hematological, and histological) validated in the past are analyzed under the perspective of recently published research. Biomarkers that have emerged during the last decade are subdivided to "old-new" and "newly proposed-novel" ones, including biomarkers pathophysiologically related to B-cell differentiation, lymphoid organization, and immune responses, identified in serum and tissue, both at genetic and protein level. Upcoming new imaging biomarkers, promising for further patient stratification, are also analyzed.

EXPERT OPINION

Salivary gland enlargement and cryoglobulinemia still remain the best validated "classical-old" biomarkers for lymphoma development. Though new biomarkers still need to be validated, some can be used for the identification of high-risk patients long before lymphoma diagnosis, some might be more relevant in distinct age subgroups, while others have an added value in the assessment of lymphoma remission or relapse. Future development of composite indices integrating old and recently proposed biomarkers could contribute to a more precise lymphoma prediction model.

Belimumab combined with standard therapy does not increase adverse effects compared with a control treatment: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

The increasing administration of belimumab has demonstrated its biological benefits. Prior meta-analyses have examined the overall adverse events (AEs) associated with belimumab, but such knowledge needs to be updated with a high volume of new trials. However, little is known about the occurrence of AEs associated with different underlying diseases. This study aimed to address the safety of the intravenous (IV) administration of belimumab combined with standard of care (SoC) therapy in Systemic lupus erythematosus (SLE) patients.

METHODS

We used PubMed, Embase, and the Cochrane Library to systematically search for randomised controlled trials (RCTs) reporting AEs and specific AEs in SLE patients receiving belimumab and SoC therapy before 30 November 2021. We extracted the data of the eligible studies and calculated pooled risk ratios (RRs) and their 95% confidence intervals (CIs) in SLE patients receiving belimumab and SoC therapy and experiencing various AEs. The main outcomes were as follows: (1) any AEs, any serious AEs (SAEs), and any severe AEs; (2) serious organ specific adverse events; (3) adverse events of special interest (AESIs).

RESULTS

Of the 1,621 studies identified, nine RCTs involving 7,974 patients were eligible for the meta-analysis. There were no significant differences between the experimental and control groups in terms of the incident of AEs: AEs (RR = 0.99, 95% CI: 0.97-1.02, P = 0.68), SAEs (RR = 0.91, 95% CI: 0.81-1.02, P = 0.09), and severe AEs (RR = 0.92, 95% CI: 0.75-1.14, P = 0.46). The pooled data also showed that there was no significant correlation between five types of SAEs grouped by organ class and the IV belimumab (10 mg/kg) intervention, except for 'infections and infestations' (RR = 0.82, 95% CI: 0.70-0.97, P = 0.02) and 'musculoskeletal and connective tissue disorders' (RR = 0.46, 95% CI: 0.32-0.67, P < 0.0001). In addition, we found no significant association between AESIs and the IV administration of belimumab (10 mg/kg) (all malignancies: RR = 1.53, 95% CI: 0.69-3.36, P = 0.3; all post-infusion systemic reactions: RR = 1.05, 95% CI: 0.85-1.30, P = 0.63; depression: RR = 1.42, 95% CI: 0.92-2.20, P = 0.11; serious depression: RR = 2.60, 95% CI: 0.85-7.93, P = 0.09; suicide or self-injury: RR = 0.97, 95% CI: 0.48-1.96, P = 0.92; serious suicide or self-injury: RR = 1.26, 95% CI: 0.59-2.70, P = 0.56).

CONCLUSIONS

According to the results of the meta-analysis, SLE patients did not have significantly increased risk of experiencing any type of AEs when receiving SoC therapy. Special caution should be exercised during close follow-ups and individual clinical management before drug prescription.

Can the cGAS-STING Pathway Play a Role in the Dry Eye?

Dry eye is one of the most common ocular surface diseases in the world and seriously affects the quality of life of patients. As an immune-related disease, the mechanism of dry eye has still not been fully elucidated. The cGAS-STING pathway is a recently discovered pathway that plays an important role in autoimmune and inflammatory diseases by recognizing dsDNA. As an important signal to initiate inflammation, the release of dsDNA is associated with dry eye. Herein, we focused on the pathophysiology of the immune-inflammatory response in the pathogenesis of dry eye, attempted to gain insight into the involvement of dsDNA in the dry eye immune response, and investigated the mechanism of the cGAS-STING pathway involved in the immune-inflammatory response. We further proposed that the cGAS-STING pathway may participate in dry eye as a new mechanism linking dry eye and the immune-inflammatory response, thus providing a new direction for the mechanistic exploration of dry eye.

Analysis of TNFSF13B polymorphisms and BAFF expression in rheumatoid arthritis and primary Sjögren's syndrome patients

Background

The increased expression of B cell‐activating factor (BAFF) has been linked to autoantibody production in autoimmune diseases (ADs). The aim of this study was to investigate the association among TNFSF13B gene (OMIM: 603969) single nucleotide polymorphisms (SNPs), TNFSF13B mRNA, and soluble BAFF (sBAFF) expression in patients with rheumatoid arthritis (RA) and primary Sjögren's syndrome (pSS). The diagnostic value of sBAFF also was evaluated by the area under the curve (AUC) of receiver operating characteristic or receptor (ROC) curves.

Methods

Genotypes of the TNFSF13B rs9514827 (−2841 T > C), rs1041569 (−2701 A > T) and rs9514828 (−871 C > T) SNPs were determined by PCR‐RFLP assay. TNFSF13B mRNA and sBAFF expression were performed by RT‐qPCR and ELISA, respectively. The study included 320 RA patients, 101 pSS patients, and 309 healthy subjects (HS).

Results

The rs9514828 T allele and the TAT haplotype were associated with an increased risk to develop RA. In both ADs, the TNFSF13B mRNA levels were increased in comparison with HS. The rs9514828 (−871 C > T) polymorphism was associated with increased gene expression in RA patients. Also, sBAFF levels were higher in both ADs, however pSS patients showed the highest sBAFF levels. sBAFF showed higher diagnostic performance for pSS with an AUC of 0.968, with a similar accuracy of anti‐SSA/Ro antibody diagnosis (AUC = 0.974).

Conclusions

Our findings demonstrate that the TNFSF13B rs9514828 (−871 C > T) polymorphism is a risk factor for RA in the western Mexican population. sBAFF levels may be a potential diagnosis biomarker in pSS.

Decreased BAFF Receptor Expression and Unaltered B Cell Receptor Signaling in Circulating B Cells from Primary Sjögren's Syndrome Patients at Diagnosis

Animal models of autoimmunity and human genetic association studies indicate that the dysregulation of B-cell receptor (BCR) signaling is an important driver of autoimmunity. We previously showed that in circulating B cells from primary Sjögren’s syndrome (pSS) patients with high systemic disease activity, protein expression of the BCR signaling molecule Bruton’s tyrosine kinase (BTK) was increased and correlated with T-cell infiltration in the target organ. We hypothesized that these alterations could be driven by increased B-cell activating factor (BAFF) levels in pSS. Here, we investigated whether altered BCR signaling was already present at diagnosis and distinguished pSS from non-SS sicca patients. Using (phospho-)flow cytometry, we quantified the phosphorylation of BCR signaling molecules, and investigated BTK and BAFF receptor (BAFFR) expression in circulating B cell subsets in an inception cohort of non-SS sicca and pSS patients, as well as healthy controls (HCs). We found that both BTK protein levels and BCR signaling activity were comparable among groups. Interestingly, BAFFR expression was significantly downregulated in pSS, but not in non-SS sicca patients, compared with HCs, and correlated with pSS-associated alterations in B cell subsets. These data indicate reduced BAFFR expression as a possible sign of early B cell involvement and a diagnostic marker for pSS.

Toll-like receptor 10 expression in B cells is negatively correlated with the progression of primary Sjögren's disease

Primary Sjögren's Disease (pSjD) is considered a B cell-mediated disease. Toll-like receptor 10 (TLR10) is highly expressed in human B cells, indicating that TLR10 probably plays a vital role in pSjD. We examined TLR10 expression in peripheral B subsets of pSjD patients and analyzed their association with disease activity. We observed that TLR10 expression in total, naïve, memory, and switched memory B cells was significantly increased in low-activity pSjD patients as compared with healthy controls and high-activity patients. TLR10 expression in the above mentioned B subsets (except naïve B) was negatively correlated with serum levels of anti-SSA antibody and BAFF, respectively. Moreover, a higher proportion of high-activity pSjD patients was observed in TLR10 low- than high-expressed patients. Our study concluded that TLR10 expression in CD19+ B and memory B was negatively correlated with pSjD disease activity, suggesting that TLR10 might take part in the progression of pSjD.

Sjögren's syndrome: a systemic autoimmune disease

Sjögren's syndrome is a chronic autoimmune disease characterized by ocular and oral dryness resulting from lacrimal and salivary gland dysfunction. Besides, a variety of systemic manifestations may occur, involving virtually any organ system. As a result, the disease is characterized by pleomorphic clinical manifestations whose characteristics and severity may vary greatly from one patient to another. Sjögren's syndrome can be defined as primary or secondary, depending on whether it occurs alone or in association with other systemic autoimmune diseases, respectively. The pathogenesis of Sjögren's syndrome is still elusive, nevertheless, different, not mutually exclusive, models involving genetic and environmental factors have been proposed to explain its development. Anyhow, the emergence of aberrant autoreactive B-lymphocytes, conducting to autoantibody production and immune complex formation, seems to be crucial in the development of the disease. The diagnosis of Sjögren's syndrome is based on characteristic clinical signs and symptoms, as well as on specific tests including salivary gland histopathology and autoantibodies. Recently, new classification criteria and disease activity scores have been developed primarily for research purposes and they can also be useful tools in everyday clinical practice. Treatment of Sjögren's syndrome ranges from local and symptomatic therapies aimed to control dryness to systemic medications, including disease-modifying agents and biological drugs. The objective of this review paper is to summarize the recent literature on Sjögren's syndrome, starting from its pathogenesis to current therapeutic options.

Safety and efficacy of subcutaneous ianalumab (VAY736) in patients with primary Sjögren's syndrome: a randomised, double-blind, placebo-controlled, phase 2b dose-finding trial

BACKGROUND

Sjögren's syndrome is an autoimmune disease characterised by dry eyes and mouth, systemic features, and reduced quality of life. There are no disease-modifying treatments. A new biologic, ianalumab (VAY736), with two modes of suppressing B cells, has previously shown preliminary efficacy. This dose-finding trial aimed to assess the safety and efficacy of different subcutaneous doses of ianalumab in patients with moderate to severe primary Sjögren's syndrome.

METHODS

VAY736A2201 was a randomised, parallel, double-blind, placebo-controlled, phase 2b dose-finding study done in 56 centres in 19 countries. Patients aged 18-75 years with primary Sjögren's syndrome with moderate to severe disease activity (European Alliance of Associations for Rheumatology [EULAR] Sjögren's Syndrome Disease Activity Index [ESSDAI] score ≥6) and symptom severity (EULAR Sjögren's Syndrome Patient Reported Index score ≥5) were eligible. Participants were randomly assigned (1:1:1:1) to receive subcutaneous placebo or ianalumab (5 mg, 50 mg, or 300 mg) every 4 weeks for 24 weeks using a secure, online randomisation system. Randomisation was stratified by the ESSDAI score at baseline (≥10 or <10). Study personnel and patients were masked to treatment assignment. The primary outcome was the change in ESSDAI score from baseline to 24 weeks in all randomly assigned patients. Dose-related change in disease activity (ESSDAI) from baseline at week 24 was assessed by multiple comparison procedure with modelling analysis. Safety was measured in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT02962895.

FINDINGS

Between June 27, 2017, and Dec 06, 2018, 293 patients were screened, 190 of whom were randomly assigned (placebo n=49, ianalumab 5 mg n=47, ianalumab 50 mg n=47, ianalumab 300 mg n=47). Statistically significant dose-responses were seen for overall disease activity (ESSDAI score) in four of the five dose-response models tested (p<0·025 in four models, p=0·060 in one model). The ESSDAI score decreased from baseline in all ianalumab groups, with the maximal ESSDAI score change from baseline observed in the ianalumab 300 mg group: placebo-adjusted least-squares mean change from baseline -1·92 points (95% CI -4·15 to 0·32; p=0·092). There were four serious adverse events in three patients considered treatment-related (pneumonia [n=1] and gastroenteritis [n=1] in the placebo group; appendicitis plus tubo-ovarian abscess in the same patient in the ianalumab 50 mg group).

INTERPRETATION

The study met its primary objective, showing a dose-related decrease in disease activity as measured by ESSDAI at week 24. Overall, ianalumab was well tolerated and safe, with no increase in infections. To our knowledge, this is the first large, randomised, controlled trial in primary Sjögren's syndrome that met its primary endpoint, and its results mean there is potential for more studies of this mechanism in the future.

FUNDING

Novartis.

Differential serum interferon-β levels in autoimmune thyroid diseases

INTRODUCTION

Interferon (IFN)-β is known as an environmental trigger for the occurrence of autoimmune thyroid disease (AITD). However, the association of another type-1 IFN, IFN-β, with AITD is unknown.

MATERIAL AND METHODS

In the study, we explored the association of serum IFN-β levels with AITD in an ethnic Chinese (i.e., Taiwanese) population. We enrolled 160 patients with Graves' disease (GD), 47 patients with Hashimoto's thyroiditis (HT), and 119 healthy controls. Serum IFN-β and B-cell activating factor (BAFF) levels were quantified in healthy controls at the baseline and in patients with AITD either prior to receiving medication or while under medication. Thyroid function and thyroid-stimulating hormone receptor antibody (TSHRAb) levels were measured at the time of serum collection.

RESULTS

Serum IFN-β levels were lower in the HT group than in the control group (p = 0.031). A significant inverse correlation was observed between IFN-β and TSHRAb levels in men with GD (r = -0.433, p = 0.044). Serum IFN-β levels were also negatively associated with BAFF levels in men with GD, HT, and AITD (r = -0.320, p = 0.032; r = -0.817, p = 0.047; and r = -0.354, p = 0.011, respectively), but not in women with GD, HT, or AITD.

CONCLUSIONS

Serum IFN-β levels were lower in HT patients. Correlations of serum IFN-β with TSHRAb and BAFF levels were found to be gender-specific. Further well-designed studies with larger sample sizes are required to confirm our findings.

Autoantibodies in Sjögren's syndrome and its classification criteria

Sjögren's syndrome (SS) is a systemic autoimmune disease characterized by immune-mediated injury of exocrine glands. Extensive lymphocytic infiltrates may contribute to the destruction and loss of secretory function of glands. B-cell hyperactivity is a key feature of the disease resulting in the production of a diverse array of autoantibodies in these patients. Although not specific for SS, anti-Ro/SSA and anti-La/SSB antibodies have been useful biomarkers for disease classification and diagnosis. During recent years, novel autoantibodies have been discovered in SS. In this review, we summarize the historical role and clinical relevance that autoantibodies have played in the classification criteria of Sjögren's syndrome, discuss laboratory aspects in antibody detection and review the role of novel autoantibodies in predicting particular stages of the disease, clinical phenotypes and long-term complications.

Role of B-Cell Activating Factor (BAFF) in Inflammatory Bowel Disease

As early commencement of inflammatory bowel disease (IBD) treatment has been shown to substantially improve outcomes, it is of utmost importance to make a timely diagnosis of this disease. Despite undisputed sensitivity of fecal calprotectin, the most widely accepted IBD biomarker, in discriminating between irritable bowel syndrome (IBS) and IBD, as well as recognized role in monitoring disease activity and response to therapy, perhaps the biggest setback of calprotectin use in IBD is lack of specificity. Therefore, an additional biomarker in IBD is warranted. B-cell activating factor (BAFF), a member of the tumor necrosis factor (TNF) superfamily, recently emerged as a viable candidate for this role. So far, overproduction of BAFF has been observed in various autoimmune diseases, most notably in systemic lupus erythematosus, where BAFF-inhibitor belimumab was approved for treatment. As BAFF levels were also shown to correlate with indices of IBD, in this review we aimed to summarize the current evidence with respect to the role of BAFF in diagnosis and assessing the activity of IBD, as well as putative therapeutic implications that may arise from exploring of this relation.

Targeted Therapy for Primary Sjögren's Syndrome: Where are We Now?

Primary Sjögren's syndrome (pSS) is an autoimmune exocrinopathy characterized by dryness symptoms. This review briefly describes recent advances in the targeted therapies for pSS. Biologics evaluated for pSS treatment mainly include B cell-depleting agents, inhibitors of B cell activation, and agents that target co-signaling molecules or proinflammatory cytokines. Small molecule inhibitors that target signaling pathways have also been evaluated. However, current evidence for the efficacy of targeted therapies in pSS is still sparse. Although ianalumab (an anti-B cell-activating factor [BAFF]-receptor antibody) and iscalimab (an anti-CD40 antibody) are promising biologics for pSS, their efficacy still needs to be evaluated in larger clinical trials. For other biologics, clinical trials have found no differences versus placebo in the change from baseline in European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI) score and fatigue score. Possible causes of the disappointing outcomes mainly include the inefficacy of those evaluated biologics in treating pSS, the high heterogeneous nature of pSS, irreversible exocrine glandular failure at advanced disease stages, inappropriate recruitment strategy in clinical trials, and outcome measures. Early diagnosis and glandular function-centered outcome measures may help to improve the current situation in the systemic therapy of pSS.

Possible interplay between estrogen and the BAFF may modify thyroid activity in Graves' disease

A link between sex hormones and B-cell activating factor (BAFF), a crucial immunoregulator of autoimmune thyroid disease (AITD), may exist. The study aimed to elucidate the role of estrogen (E2) in regulating BAFF in Graves' disease (GD). In clinical samples, serum BAFF levels were higher in women than in men in both the GD and control groups. serum BAFF levels were associated with thyroid-stimulating hormone receptor antibody levels and thyroid function only in women and not in men. BAFF transcripts in peripheral blood mononuclear cells were higher in women with GD than those in the control group. Among GD patients with the AA genotype of rs2893321, women had higher BAFF transcripts and protein levels than men. In the progression of a spontaneous autoimmune thyroiditis (SAT) murine model, NOD.H-2h4, serum free thyroxine and BAFF levels were higher in female than in male mice. Moreover, exogenous E2 treatment increased serum BAFF levels in male SAT mice. Meanwhile, female SAT mice exhibited higher thyroid BAFF transcripts levels than either the E2-treated or untreated male SAT mouse groups. Our results showed that E2 might be implicated in modulating BAFF expression, and support a possible mechanism for the higher incidence of AITD in women.

Fecal Microbiota Transplantation Modulates Renal Phenotype in the Humanized Mouse Model of IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis. Several observations suggest that gut microbiota could be implicated in IgAN pathophysiology. Aiming at exploring whether microbiota modulation is able to influence disease outcome, we performed fecal microbiota transplantation (FMT) from healthy controls (HC-sbjs), non-progressor (NP-pts) and progressor (P-pts) IgAN patients to antibiotic-treated humanized IgAN mice (α1KI-CD89Tg), by oral gavage. FMT was able to modulate renal phenotype and inflammation. On one hand, the microbiota from P-pts was able to induce an increase of serum BAFF and galactose deficient-IgA1 levels and a decrease of CD89 cell surface expression on blood CD11b⁺ cells which was associated with soluble CD89 and IgA1 mesangial deposits. On the other hand, the microbiota from HC-sbjs was able to induce a reduction of albuminuria immediately after gavage, an increased cell surface expression of CD89 on blood CD11b⁺ cells and a decreased expression of KC chemokine in kidney. Higher serum BAFF levels were found in mice subjected to FMT from IgAN patients. The main bacterial phyla composition and volatile organic compounds profile significantly differed in mouse gut microbiota. Microbiota modulation by FMT influences IgAN phenotype opening new avenues for therapeutic approaches in IgAN.

Review article: targeting the B cell activation system in autoimmune hepatitis

BACKGROUND

The B cell activation system, consisting of B cell activating factor and a proliferation-inducing ligand, may have pathogenic effects in autoimmune hepatitis.

AIMS

To describe the biological actions of the B cell activation system, indicate its possible role in autoimmune diseases, and evaluate its prospects as a therapeutic target in autoimmune hepatitis METHODS: English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed.

RESULTS

The B cell activating factor is crucial for the maturation and survival of B cells, and it can co-stimulate T cell activation, proliferation, and survival. It can also modulate the immune response by inducing interleukin 10 production by regulatory B cells. A proliferation-inducing ligand modulates and diversifies the antibody response by inducing class-switch recombination in B cells. It can also increase the proliferation, survival, and antigen activation of T cells. These immune stimulatory actions can be modulated by inducing proliferation of regulatory T cells. The B cell activation system has been implicated in diverse autoimmune diseases, and therapeutic blockade is a management strategy now being evaluated in autoimmune hepatitis.

CONCLUSIONS

The B cell activation system has profound effects on B and T cell function in autoimmune diseases. Blockade therapy is being actively evaluated in autoimmune hepatitis. Clarification of the critical pathogenic components of the B cell activation system will improve the targeting, efficacy, and safety of blockade therapy in this disease.

The Transcriptomic Profile of Monocytes from Patients With Sjögren's Syndrome Is Associated With Inflammatory Parameters and Is Mimicked by Circulating Mediators

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by infiltration of the exocrine glands and prominent B cell hyperactivity. Considering the key role of monocytes in promoting B cell hyperactivity, we performed RNA-sequencing analysis of CD14⁺ monocytes from patients with pSS, non-Sjögren's sicca (nSS), and healthy controls (HC). We demonstrated that the transcriptomic profile of pSS patients is enriched in intermediate and non-classical monocyte profiles, and confirmed the increased frequency of non-classical monocytes in pSS patients by flow-cytometry analysis. Weighted gene co-expression network analysis identified four molecular signatures in monocytes from pSS patients, functionally annotated for processes related with translation, IFN-signaling, and toll-like receptor signaling. Systemic and local inflammatory features significantly correlated with the expression of these signatures. Furthermore, genes highly associated with clinical features in pSS were identified as hub-genes for each signature. Unsupervised hierarchical cluster analysis of the hub-genes identified four clusters of nSS and pSS patients, each with distinct inflammatory and transcriptomic profiles. One cluster showed a significantly higher percentage of pSS patients with higher prevalence of anti-SSA autoantibodies, interferon-score, and erythrocyte sedimentation rate compared to the other clusters. Finally, we showed that the identified transcriptomic differences in pSS monocytes were induced in monocytes of healthy controls by exposure to serum of pSS patients. Representative hub-genes of all four signatures were partially inhibited by interferon-α/β receptor blockade, indicating that the circulating inflammatory mediators, including type I interferons have a significant contribution to the altered transcriptional profile of pSS-monocytes. Our study suggests that targeting key circulating inflammatory mediators, such as type I interferons, could offer new insights into the important pathways and mechanisms driving pSS, and holds promise for halting immunopathology in Sjögren's Syndrome.

Biological Therapy in Primary Sjögren's Syndrome: Effect on Salivary Gland Function and Inflammation

Primary Sjögren's syndrome (pSS) is a chronic, systemic autoimmune disease. It is the second most common rheumatic autoimmune disorder, affecting 0.7% of European Americans and up to 1% of people globally. pSS is characterized by the impaired secretory function of exocrine glands, including salivary and lachrymal glands. A lymphocytic infiltration of these organs leads to the common and debilitating symptoms of oral and ocular dryness, majorly affecting the quality of life of these patients. Currently, no disease-modifying drug has been approved for the treatment of pSS, with therapies largely aimed at relieving symptoms of dry mouth and dry eyes. In particular, management of oral dryness still represents a major unmet clinical need in pSS and a significant burden for patients with this condition. Recently, several randomized clinical trials in pSS with biological therapies targeting specific mechanistic pathways implicated in the disease pathogenesis, including B-cell hyperactivity, T-cell co-stimulation and the aberrant role of cytokines, have been completed with mixed results. In this review, we summarize evidence from recent clinical trials investigating biological therapy in pSS, specifically highlighting efficacy, or lack thereof, in modulating local inflammation and improving salivary gland function.

Shared Pathogenetic Features Between Common Variable Immunodeficiency and Sjögren's Syndrome: Clues for a Personalized Medicine

Common variable immunodeficiency disorders (CVID) are a group of rare diseases of the immune system and the most common symptomatic primary antibody deficiency in adults. The “variable” aspect of CVID refers to the approximately half of the patients who develop non-infective complications, mainly autoimmune features, in particular organ specific autoimmune diseases including thyroiditis, and cytopenias. Among these associated conditions, the incidence of lymphoma, including mucosal associated lymphoid tissue (MALT) type, is increased. Although these associated autoimmune disorders in CVID are generally attributed to Systemic Lupus Erythematosus (SLE), we propose that Sjogren’s syndrome (SS) is perhaps a better candidate for the associated disease. SS is an autoimmune disorder characterized by the lymphocytic infiltrates of lacrimal and salivary glands, leading to dryness of the eyes and mouth. Thus, it is a lymphocyte aggressive disorder, in contrast to SLE where pathology is generally attributed to auto-antibody and complement activation. Although systemic lupus erythematosus (SLE) shares these features with SS, a much higher frequency of MALT lymphoma distinguishes SS from SLE. Also, the higher frequency of germ line encoded paraproteins such as the monoclonal rheumatoid factor found in SS patients would be more consistent with the failure of B-cell VDJ switching found in CVID; and in contrast to the hypermutation that characterizes SLE autoantibodies. Thus, we suggest that SS may fit as a better “autoimmune” association with CVID. Examining the common underlying biologic mechanisms that promote lymphoid infiltration by dysregulated lymphocytes and lymphoma in CVID may provide new avenues for treatment in both the diseases. Since the diagnosis of SLE or rheumatoid arthritis is usually based on specific autoantibodies, the associated autoimmune features of CVID patients may not be recognized in the absence of autoantibodies.

Genetics and epigenetics in primary Sjögren's syndrome

Primary Sjögren’s syndrome (pSS) is considered to be a multifactorial disease, where underlying genetic predisposition, epigenetic mechanisms and environmental factors contribute to disease development. In the last 5 years, the first genome-wide association studies in pSS have been completed. The strongest signal of association lies within the HLA genes, whereas the non-HLA genes IRF5 and STAT4 show consistent associations in multiple ethnicities but with a smaller effect size. The majority of the genetic risk variants are found at intergenic regions and their functional impact has in most cases not been elucidated. Epigenetic mechanisms such as DNA methylation, histone modifications and non-coding RNAs play a role in the pathogenesis of pSS by their modulating effects on gene expression and may constitute a dynamic link between the genome and phenotypic manifestations. This article reviews the hitherto published genetic studies and our current understanding of epigenetic mechanisms in pSS.

The PI3Kδ inhibitor parsaclisib ameliorates pathology and reduces autoantibody formation in preclinical models of systemic lupus erythematosus and Sjӧgren's syndrome

Dysregulation of phosphoinositide 3-kinase δ (PI3Kδ) signaling pathway has been implicated in the pathogenesis of inflammatory and autoimmune diseases. Parsaclisib (INCB050465) represents a potent and selective PI3Kδ inhibitor, which is being clinically investigated for treatment of autoimmune hemolytic anemia and hematological malignancies. We characterized the potential of parsaclisib to ameliorate autoimmune mechanisms implicated in the pathophysiology of systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS). Spontaneous mouse models of SLE and SS were utilized to elucidate the efficacy of orally administered parsaclisib on autoreactive B-cell-mediated antibody-driven disease. Parsaclisib significantly reduced disease symptoms and pathology in three distinct mouse models of SLE. Parsaclisib effectively preserved renal function as measured by glomerular filtration rate, abrogated histopathological evidence of nephritis, modulated discrete immune cell subsets, and decreased anti-dsDNA antibody level. Furthermore, parsaclisib demonstrated efficacy in two spontaneous mouse models of SS. Oral parsaclisib treatment ameliorated the severity of salivary gland inflammation and reduced circulating levels of autoantibodies. Parsaclisib mediated improvement of salivary gland inflammation coincided with reduced B-cell activating cytokine (BAFF) in saliva. Transcriptomic analysis of kidney and salivary gland tissues revealed a downregulation in inflammatory gene expression consistent with PI3Kδ pathway inhibition. Parsaclisib reduced autoreactive B-cells and autoantibody levels, and significantly improved nephritis and salivary gland inflammation. These data provide the scientific rationale for PI3Kδ inhibition as a therapeutic strategy for treatment of B-cell-mediated antibody-driven autoimmune diseases.

IL-14α as a Putative Biomarker for Stratification of Dry Eye in Primary Sjögren's Syndrome

Background

Dry eye is often the first presenting manifestation of primary Sjögren’s syndrome (pSS). Because of the high prevalence of dry eye disease in normal population, ophthalmologists urgently need a non-invasive and reliable screening test to diagnose dry eye associated SS patients, other than ocular symptoms and signs. Currently, there is no single test available. The correlation of serum IL-14α with pSS has been found in pSS mouse model.

Purpose

To evaluate whether IL-14α can serve as a biomarker to stratify dry eye in primary Sjögren’s syndrome and its correlation to BAFF in a cohort of patients with non-SS dry eye (NSDE), pSS with dry eye disease, rheumatoid arthritis (RA), and healthy controls (HC).

Methods

Retrospective study based on serum levels of IL-14α (defined by Western Blot) and BAFF (measured by ELISA) were evaluated among pSS with dry eye disease, NSDE, RA, and HC groups. Serum levels of SS related autoantibodies (Ro, La, SP1, PSP, and CA6) were also measured by ELISA.

Results

One hundred and eighty patients were included for the current study, patients were separated into four groups as defined by pSS (n=65), NSDE (n=20), RA (n=50) and HC (n=45). The level of serum IL-14α in pSS was significantly higher compared to NSDE, RA, and HC (p=0.0011, p=0.0052 and p<0.0001, respectively). The levels of serum BAFF in pSS was significantly higher than in NSDE and HC (p=0.0148 and p<0.0001, respectively, whereas the levels of serum BAFF in RA was only significantly higher than in HC (p=0.001), but the level of BAFF was no significant difference between pSS and RA. In pSS, there was a decrease in the serum levels of IL-14α associated with a longer duration of the disease. Also, there was a correlation between the serum levels of IL-14α and SS related autoantibodies such as anti-SSA/Ro and anti-SSB/La in pSS patients.

Conclusions

This is the first paper to report both IL-14α and BAFF could serve as a critical cytokine biomarker for the stratification of dry eye in primary Sjögren’s syndrome. This may help ophthalmologists to develop non-invasive metrics for the diagnosis of dry eye associated pSS.

B-cell activating factor (BAFF) expression is associated with Crohn's disease and can serve as a potential prognostic indicator of disease response to Infliximab treatment

BACKGROUND

Several studies correlated elevated B-cell activating factor (BAFF) levels and its polymorphisms (SNPs) in patients with autoimmunity. Limited data existed regarding the role of BAFF in Crohn's Disease (CD) susceptibility and/or treatment response to infliximab.

AIM

This study aims to evaluate BAFF expression in CD patients, investigate if its expression can predict response to infliximab treatment, and examine the association of BAFF SNPs with CD susceptibility.

METHODS

One hundred twelve CD patients and 164 healthy controls were recruited. Serum BAFF levels were determined using an enzyme-linked immunosorbent assay. Participants were genotyped for rs9514828, rs1041569 and rs2893321 SNPs.

RESULTS

Serum BAFF concentration was elevated in CD patients (472.86 ± 223.60 pg/ml) compared with controls (128.16 ± 70.10 pg/ml) before treatment. Responders to IFX treatment had increased serum BAFF levels at baseline (610.03 ± 167.55 pg/ml) compared to non-responders (267.09 ± 107 pg/ml). In responders, BAFF concentration reduced after IFX administration, while increased in non-responders. The rs1041569, TA and AA genotypes frequencies, and the minor allele A were increased significantly in CD patients, indicating an association of the SNP with CD susceptibility.

CONCLUSIONS

Our study suggests that BAFF could be a potential biomarker of CD, while SNP rs1041569 was associated with CD susceptibility.

Association between nucleos(t)ide analogue therapy for hepatitis B and Sjögren's syndrome: 15-year analysis of the national database of Taiwan

Hepatitis B virus (HBV) infection has been proposed to play a role in the development of Sjögren's syndrome. However, to date, there are no reports on the risk of SS in HBV-infected patients following nucleos(t)ide analogue therapy. Due to Taiwan has higher prevalence of HBV infection and therapy was well recorded in the Taiwan's single-payer national health insurance database, we hypothesized that a long-term retrospective analysis of the risk of Sjögren's syndrome in HBV-infected patients following nucleotide therapy will increase our understanding of Sjögren's syndrome development following HBV infection. We identified 26,147 adults diagnosed with HBV infection between 1997 and 2012 in claims data. Finally, a total of 3268 HBV-infected patients who ever received nucleotide therapy (treated cohort) were frequency-matched on age and sex at 1:4 ratios to select a control group of 13,072 counterparts without therapy (untreated cohort). To identify Sjögren's syndrome risk, competing risk analysis adjusted for all covariates was performed. The risk was significantly lower in the treated cohort (15-year cumulative incidence, 2.4%; 95% confidence interval [CI], 1.4%-3.7%) than in the untreated cohort (7.1%; 95% CI, 2.5%-15.2%) (p = .015), and the adjusted HR was 0.6 (95% CI, 0.41-0.88; p = .009). Multivariable stratified analysis further verified the consistent associations between nucleoside therapy and risk reduction of Sjögren's syndrome across all strata. Our finding suggests that HBV infection treated with nucleotides is associated with lower risk of Sjögren's syndrome, implying a potential role of HBV infection in the development of Sjögren's syndrome.

LncRNAs in adaptive immunity: role in physiological and pathological conditions

The adaptive immune system is responsible for generating immunological response and immunological memory. Regulation of adaptive immunity including B cell and T cell biology was mainly understood from the protein and microRNA perspective. However, long non-coding RNAs (lncRNAs) are an emerging class of non-coding RNAs (ncRNAs) that influence key factors in lymphocyte biology such as NOTCH, PAX5, MYC and EZH2. LncRNAs were described to modulate lymphocyte activation by regulating pathways such as NFAT, NFκB, MYC, interferon and TCR/BCR signalling (NRON, NKILA, BCALM, GAS5, PVT1), and cell effector functions (IFNG-AS1, TH2-LCR). Here we review lncRNA involvement in adaptive immunity and the implications for autoimmune diseases (multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis) and T/B cell leukaemias and lymphomas (CLL, MCL, DLBCL, T-ALL). It is becoming clear that lncRNAs are important in adaptive immune response and provide new insights into its orchestration.

Pro- and anti-inflammatory response in neurological disorders associated to anti-glutamate decarboxylase antibodies

Rare conditions showing psychiatric symptoms and movement disorders have been linked with the presence of anti-glutamate decarboxylase antibodies. Proinflammatory and antiinflammatory immune responses were assessed in patients with neurological disorders associated to anti-glutamic acid decarboxylase antibodies (NDGAD). Immunoregulatory and proinflammatory cell populations were quantified by flow cytometry. No polarization toward Th1, Th2, or Th17 phenotypes was observed in NDGAD patients. Immunoregulatory responses were significantly reduced for Breg, activated Treg, Tr1, and Th3 cells, suggesting a deficient regulatory response, while intermediate monocyte levels were increased. The reduced levels of regulatory T and B cells suggest an impairment in regulatory immune response, while intermediate monocytes could be playing a role in the increased proinflammatory response.