Dysregulated serum lipid profile is associated with inflammation and disease activity in primary Sjögren's syndrome: a retrospective study in China.

PURPOSE: To investigate the relationship between the lipid profiles of patients with primary Sjögren's syndrome (pSS) and other clinical characteristics, laboratory examination, disease activity, and inflammatory factors. In addition, the risk factors for hyperlipidemia-related complications of pSS and the effect of hydroxychloroquine (HCQ) usage on the lipid profile were incorporated into this study. METHODS: This is a single-center, retrospective study that included 367 patients who were diagnosed with pSS at Tongji Hospital, School of Medicine, Tongji University, China from January 2010 to March 2022. Initially, demographic information, clinical characteristics, medication records, and complications of the patients were gathered. A case-control analysis compared the 12 systems involvement (ESSDAI domain), clinical symptoms, and laboratory tests between pSS patients with and without dyslipidemia. A simple linear regression model was employed to investigate the relationship between serum lipid profile and inflammatory factors. Logistics regression analysis was performed to assess variables for hyperlipidemia-related complications of pSS. The paired t-test was then used to evaluate the improvement in lipid profile among pSS patients. RESULTS: 48.7 % of all pSS patients had dyslipidemia, and alterations in lipid levels were related to gender, age, and smoking status but not body mass index (BMI). Dyslipidemia is more prevalent in pSS patients who exhibit heightened autoimmunity and elevated levels of inflammation. Higher concentrations of multiple highly inflammatory factors correlate with a more severe form of dyslipidemia. Non-traditional cardiovascular risk factors may contribute to hyperlipidemia-related complications of pSS, such as increased, low complement 3 (C3) and low C4. According to our study, HCQ usage may protect against lipid-related disease in pSS. CONCLUSION: Attention should be paid to the dyslipidemia of pSS. This research aims to clarify the population portrait of pSS patients with abnormal lipid profiles and provides insights into the correlation between metabolism and inflammation in individuals with pSS and the potential role they play in the advancement of the disease. These findings provide novel avenues for further understanding the underlying mechanisms of pSS pathogenesis.

The role of M1/M2 macrophage polarization in primary Sjogren's syndrome.

BACKGROUND: The purpose of this study was to investigate the role of macrophage polarization in the pathogenesis of primary Sjogren's syndrome (pSS). METHODS: Peripheral venous blood samples were collected from 30 patients with pSS and 30 healthy controls. Minor salivary gland samples were abtainted from 10 of these patients and 10 non-pSS controls whose minor salivary gland didn't fulfill the classification criteria for pSS. Enzyme-linked immuno sorbent assay was used to examine the serum concentration of M1/M2 macrophage related cytokines (TNF-a, IL-6, IL-23, IL-4, IL-10 and TGF-ß). Flow cytometry was used to examine the numbers of CD86+ M1 macrophages and CD206+ M2 macrophages in peripheral blood mononuclear cells (PBMCs). Immunofluorescence was used to test the infiltration of macrophages in minor salivary glands. RESULTS: This study observed a significant increase in pSS patients both in the numbers of M1 macrophages in peripheral blood and serum levels of M1-related pro-inflammatory cytokines (IL-6, IL-23 and TNF-α). Conversely, M2 macrophages were downregulated in the peripheral blood of pSS patients. Similarly, in the minor salivary glands of pSS patients, the expression of M1 macrophages was increased, and that of M2 macrophages was decreased. Furthermore, a significantly positive correlation was found between the proportions of M1 macrophages in PBMCs and serum levels of IgG and RF. CONCLUSIONS: This study reveals the presence of an significant imbalance in M1/M2 macrophages in pSS patients. The M1 polarization of macrophages may play an central role in the pathogenesis of pSS.

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.

Serum CXCL13, BAFF, IL-21 and IL-22 levels are related to disease activity and lymphocyte profile in primary Sjögren's syndrome.

OBJECTIVES: To investigate the utility of serum BAFF, IL-17, IL-18, IL-21, IL-22, CXCL13, TNF-R2 and PD-L2 as biomarkers of disease activity in primary Sjögren's syndrome (pSS), their relationship with lymphocyte subpopulations and their accuracy to discriminate pSS from Sicca syndrome. METHODS: We conducted an observational study on 66 pSS patients and 48 controls (25 with Sicca syndrome and 23 healthy volunteers). Serum levels of BAFF, IL-17 A/F, IL-18, IL-21, IL-22, CXCL13, TNF-R2 and PD-L2 were measured using a multiplex immunoassay. Lymphocyte subpopulations were analysed by flow cytometry. Disease activity of pSS was assessed with ESSDAI at study inclusion. RESULTS: Patients with pSS presented higher serum CXCL13 (364.7 vs. 205.2 pg/mL), IL-21 (43.2 vs. 0 pg/mL) and BAFF (1646 vs. 1369 pg/mL), and lower PD-L2 levels (1950.8 vs. 2792.3 pg/mL) than controls. ESSDAI was associated with BAFF, IL-18 and IL-22. Patients with ESSDAI >0 exhibited higher CXCL13, IL-21, IL-22 and TNFR2 concentrations. IL-21 levels correlated with lower memory B-cell and higher naïve B-cell percentages and IL-22 levels correlated with increased circulating activated CD4+ T-cells. The combination of serum CXCL13, BAFF and PDL2 levels using the formula [ln(CXCL13)+ln(BAFF)]/ln(PDL2) exhibit an AUC of 0.854 (95% CI: 0.750-0.919) to discriminate between pSS and Sicca syndrome (sensitivity 77.2% and specificity 86.4% using a cut-off of 1.7). CONCLUSIONS: CXCL13, BAFF, IL-21, and IL-22 are potential biomarkers of pSS activity and IL-21 and IL-22 are associated with disturbances of lymphocyte subpopulations in pSS. The combination of serum CXCL13, BAFF, and PD-L2 levels allows discrimination between pSS and Sicca syndrome.

Asymptomatic myocardial dysfunction was revealed by feature tracking cardiac magnetic resonance imaging in patients with primary Sjögren's syndrome.

AIM: To evaluate subclinical left ventricular (LV) regional dysfunction in patients with primary Sjögren's syndrome (pSS) using feature tracking cardiac magnetic resonance (FT-CMR) imaging and to identify pSS characteristics independently associated with LV regional dysfunction. METHOD: Fifty patients with pSS and 20 controls without cardiovascular disease underwent non-contrast CMR imaging. Labial gland biopsy was performed in 42 patients (84%). Disease activity was assessed using the European League Against Rheumatism Sjögren's syndrome disease activity index (ESSDAI). LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were measured using FT-CMR. RESULTS: No significant differences in cardiovascular risk factors were found between the pSS group and controls. The pSS group had significantly lower GLS (P = .015) and GCS (P = .008) than the control group. Multiple linear regression analysis indicated that GCS was significantly associated with Raynaud's phenomenon (P = .015), focus score ≥2 (P = .032), and total ESSDAI score ≥8 (P = .029). CONCLUSION: FT-CMR can reveal subclinical LV regional dysfunction in patients with pSS without cardiovascular disease. Furthermore, patients with pSS and Raynaud's phenomenon, a focus score ≥2, or an ESSDAI score ≥8 were considered to be at high risk for myocardial dysfunction.

Increased Indoleamine 2,3-Dioxygenase Levels at the Onset of Sjögren's Syndrome in SATB1-Conditional Knockout Mice.

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by dysfunction of salivary and lacrimal glands, resulting in xerostomia (dry mouth) and keratoconjunctivitis sicca (dry eyes). Autoantibodies, such as anti-SSA and anti-SSB antibodies, are hallmarks and important diagnostic factors for SS. In our previous study, we demonstrated that SS-like xerostomia was observed in SATB1 conditional knockout (SATB1cKO) mice, in which the floxed SATB1 gene was specifically deleted in hematopoietic cells as early as 4 weeks of age. In these mice, autoantibodies were not detected until 8 weeks of age in SATB1cKO mice, although exocrine gland function reached its lowest at this age. Therefore, other markers may be necessary for the diagnosis of SS in the early phase. Here, we found that mRNA expression of the interferonγ (IFN-γ) gene and the IFN-responsive indoleamine 2,3-dioxygenase (IDO) gene is upregulated in the salivary glands of SATB1cKO mice after 3 and 4 weeks of age, respectively. We detected l-kynurenine (l-KYN), an intermediate of l-tryptophan (l-Trp) metabolism mediated by IDO, in the serum of SATB1cKO mice after 4 weeks of age. In addition, the upregulation of IDO expression was significantly suppressed by the administration of IFN-γ neutralizing antibodies in SATB1cKO mice. These results suggest that the induction of IFN-dependent IDO expression is an initial event that occurs immediately after the onset of SS in SATB1cKO mice. These results also imply that serum l-KYN could be used as a marker for SS diagnosis in the early phases of the disease before autoantibodies are detectable.

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.

Sjögren's syndrome complicated with membranous nephropathy, a cause or coincidence?

BACKGROUND: Sjögren's syndrome (SS) has been a well-documented cause of secondary membranous nephropathy (MN); however, the prevalence is quite low. Since primary MN is also a common disease in middle age, whether MN is secondary to SS or just coincidence remains uncertain. The detection of phospholipase A2 receptor (PLA2R), which is most often positive in idiopathic MN, has been rarely reported in such cases. METHODS: We retrospectively studied 13 cases diagnosed with MN and SS in Huashan Hospital between 2009 and 2020, and performed PLA2R detection. We also review the literature by searching in the PubMed database. RESULTS: Among the 13 patients, 8 were found to be PLA2R-positive and 5 were negative. Nine patients were female. All but 1 patients had normal renal function at the time of biopsy. All patients showed positive anti-nuclear antibody and anti-SSA. Two of the 8 PLA2R-positive patients showed positive anti-SSB and 1/8 had mild hypocomplementemia, while all 5 PLA2R-negative patients had positive anti-SSB and 3 showed hypocomplementemia. Renal biopsy revealed focal MN and markedly mesangial hyperplasia in PLA2R-negative patients. Mesangial electron deposits were observed in 1 PLA2R-positive patient in small amounts, and in 3 PLA2R-negative patients with 2 in large amounts. During follow-up, 2 patients in the PLA2R-negative group presented with progressively decreasing serum complement levels, and another one was diagnosed with systemic lupus erythematosus (SLE). CONCLUSIONS: In patients with both MN and SS, PLA2R-negative MN should be considered as a secondary form. Careful screen for SLE is necessary in these patients during follow-up.

Association Between Minor Salivary Gland Biopsy During SjÓ§gren's Syndrome and Serologic Biomarkers: A Systematic Review and Meta-Analysis.

Objective: Patients with primary Sjögren's syndrome (pSS) may develop a potentially severe disease with extra-glandular involvement and lymphoma insurgence. Minor salivary gland biopsy is routinely used in the disease diagnosis, but its potential role as a biomarker for clinical disease presentation and prognosis is still poorly understood. Methods: We performed a systematic review and meta-analysis on clinical presentation and prognosis in pSS patients who underwent minor salivary gland biopsy at diagnosis according to the PRISMA guidelines. Results: We included five retrospective studies and 589 pSS patients. Ectopic GCs presence was not associated with a significant increase in the odds ratio for the clinical variables explored such as salivary gland swelling, arthritis, and Raynaud's phenomenon. As far as serological features are concerned, ectopic GCs presence accounted for an increased ratio of antibodies anti-SSA (OR = 3.13, 95% CI: 1.25-7.85, p = 0.02, I2 = 79%), anti-SSB (OR = 3.94, 95% CI: 1.50-10.37, p = 0.0005, I2 = 80%), and RFs presence (OR = 3.12, 95% CI: 1.94-5.00, p < 0.00001, I2 = 0%). Conclusions: This study showed that the association between ectopic GC in salivary glands identifies a clinical subset characterized by autoantibodies presence, and probably pSS patients affected from a more severe disease.

CD27-CD38lowCD21low B-Cells Are Increased in Axial Spondyloarthritis.

B-cells have received little attention in axial spondyloarthritis (axSpA) and for this reason their role in pathogenesis remains unclear. However, there are indications that B-cells may be involved in the disease process. Our objective was to obtain insights into the composition of the peripheral B-cell compartment of axSpA patients compared to healthy donors (HD) and patients with primary Sjögren's syndrome (pSS), a typical B-cell-associated autoimmune disease. Special emphasis was given to CD27-negative B-cells expressing low levels of CD21 (CD21low B-cells), since this subset is implicated in autoimmune diseases with strong involvement of B-cells. Transitional B-cells (CD38hi) were excluded from the analysis of the CD27-CD21low B-cell compartment. This study included 45 axSpA patients, 20 pSS patients and 30 HDs. Intriguingly, compared to HDs the frequency of CD27-CD38lowCD21low B-cells was significantly elevated in both axSpA and pSS patients (P<0.0001 for both comparisons). The frequency of CD27-CD38lowCD21low B-cells expressing the activation-induced immune markers T-bet and CD11c was decreased in axSpA patients compared to HDs. A higher proportion of CD27-CD38lowCD21low B-cells expressed the chemokine receptor CXCR3 in axSpA compared to HDs, suggestive for active involvement of these cells in an inflammatory process. The frequency of CD27-CD38lowCD21low B-cells in axSpA patients correlated positively with age and erythrocyte sedimentation rate. Furthermore, axSpA patients with extra-skeletal manifestations (ESM) showed increased frequencies of CD27-CD38lowCD21low B-cells compared to patients without ESM. In conclusion, our findings are suggestive of active B-cell involvement in the pathogenesis of axSpA, against prevailing dogma.

Protein-Based Immunome Wide Association Studies (PIWAS) for the Discovery of Significant Disease-Associated Antigens.

Identification of the antigens associated with antibodies is vital to understanding immune responses in the context of infection, autoimmunity, and cancer. Discovering antigens at a proteome scale could enable broader identification of antigens that are responsible for generating an immune response or driving a disease state. Although targeted tests for known antigens can be straightforward, discovering antigens at a proteome scale using protein and peptide arrays is time consuming and expensive. We leverage Serum Epitope Repertoire Analysis (SERA), an assay based on a random bacterial display peptide library coupled with next generation sequencing (NGS), to power the development of Protein-based Immunome Wide Association Study (PIWAS). PIWAS uses proteome-based signals to discover candidate antibody-antigen epitopes that are significantly elevated in a subset of cases compared to controls. After demonstrating statistical power relative to the magnitude and prevalence of effect in synthetic data, we apply PIWAS to systemic lupus erythematosus (SLE, n=31) and observe known autoantigens, Smith and Ribosomal protein P, within the 22 highest scoring candidate protein antigens across the entire human proteome. We validate the magnitude and location of the SLE specific signal against the Smith family of proteins using a cohort of patients who are positive by predicate anti-Sm tests. To test the generalizability of the method in an additional autoimmune disease, we identified and validated autoantigenic signals to SSB, CENPA, and keratin proteins in a cohort of individuals with Sjogren's syndrome (n=91). Collectively, these results suggest that PIWAS provides a powerful new tool to discover disease-associated serological antigens within any known proteome.

A biomarker for lymphoma development in Sjogren's syndrome: Salivary gland focus score.

The aim of this study is to explore the role of labial minor salivary gland (LMSG) focus score (FS) in stratifying Sjögren's Syndrome (SS) patients, lymphoma development prediction and to facilitate early lymphoma diagnosis. Ιn an integrated cohort of 1997 patients, 618 patients with FS ≥ 1 and at least one-year elapsing time interval from SS diagnosis to lymphoma diagnosis or last follow up were identified. Clinical, laboratory and serological features were recorded. A data driven logistic regression model was applied to identify independent lymphoma associated risk factors. Furthermore, a FS threshold maximizing the difference of time interval from SS until lymphoma diagnosis between high and low FS lymphoma subgroups was investigated, to develop a follow up strategy for early lymphoma diagnosis. Of the 618 patients, 560 were non-lymphoma SS patients while the other 58 had SS and lymphoma. FS, cryoglobulinemia and salivary gland enlargement (SGE) were proven to be independent lymphoma associated risk factors. Lymphoma patients with FS ≥ 4 had a statistically significant shorter time interval from SS to lymphoma diagnosis, compared to those with FS < 4 (4 vs 9 years, respectively, p = 0,008). SS patients with FS ≥ 4 had more frequently B cell originated manifestations and lymphoma, while in patients with FS < 4, autoimmune thyroiditis was more prevalent. In the latter group SGE was the only lymphoma independent risk factor. A second LMSG biopsy is patients with a FS ≥ 4, 4 years after SS diagnosis and in those with FS < 4 and a history of SGE, at 9-years, may contribute to an early lymphoma diagnosis. Based on our results we conclude that LMSG FS, evaluated at the time of SS diagnosis, is an independent lymphoma associated risk factor and may serve as a predictive biomarker for the early diagnosis of SS-associated lymphomas.

Deep Phenotyping of CD11c+ B Cells in Systemic Autoimmunity and Controls.

Circulating CD11c+ B cells are a key phenomenon in certain types of autoimmunity but have also been described in the context of regular immune responses (i.e., infections, vaccination). Using mass cytometry to profile 46 different markers on individual immune cells, we systematically initially confirmed the presence of increased CD11c+ B cells in the blood of systemic lupus erythematosus (SLE) patients. Notably, significant differences in the expression of CD21, CD27, and CD38 became apparent between CD11c- and CD11c+ B cells. We observed direct correlation of the frequency of CD21-CD27- B cells and CD21-CD38- B cells with CD11c+ B cells, which were most pronounced in SLE compared to primary Sjögren's syndrome patients (pSS) and healthy donors (HD). Thus, CD11c+ B cells resided mainly within memory subsets and were enriched in CD27-IgD-, CD21-CD27-, and CD21-CD38- B cell phenotypes. CD11c+ B cells from all donor groups (SLE, pSS, and HD) showed enhanced CD69, Ki-67, CD45RO, CD45RA, and CD19 expression, whereas the membrane expression of CXCR5 and CD21 were diminished. Notably, SLE CD11c+ B cells showed enhanced expression of the checkpoint molecules CD86, PD1, PDL1, CD137, VISTA, and CTLA-4 compared to HD. The substantial increase of CD11c+ B cells with a CD21- phenotype co-expressing distinct activation and checkpoint markers, points to a quantitative increased alternate (extrafollicular) B cell activation route possibly related to abnormal immune regulation as seen under the striking inflammatory conditions of SLE which shows a characteristic PD-1/PD-L1 upregulation.

Tissue-specific activation of Myd88-dependent pathways governs disease severity in primary Sjögren's syndrome.

Myd88 activation is an important driver of autoimmunity. Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by exocrine gland dysfunction in combination with serious systemic disease manifestations. Myd88-dependent signaling networks remain incompletely understood in the context of pSS. The objective of this study was to establish the contribution of tissue-specific Myd88 activation to local (exocrine) and systemic pSS manifestations. To this end, we generated two novel conditional knockout pSS mouse models; one lacking Myd88 in hematopoietic cells and a second strain in which Myd88 was deleted in the stromal compartment. Spontaneous production of inflammatory mediators was altered in salivary tissue, and nephritis was diminished in both conditional knockout strains. In contrast, pulmonary inflammation was increased in mice lacking Myd88 in hematopoietic cells and was reduced when Myd88 was ablated in stromal cells. Finally, anti-nuclear autoantibodies (ANAs) were attenuated in pSS mice lacking Myd88 in immune cells. Additionally, the ANA-specific B cell repertoire was skewed in the Myd88-deficient strains. Collectively, these data demonstrate that Myd88 activation in specific cell types is essential for distinct aspects of pSS pathology.

A Proinflammatory Cytokine Network Profile in Th1/Type 1 Effector B Cells Delineates a Common Group of Patients in Four Systemic Autoimmune Diseases.

OBJECTIVE: The effector T cell and B cell cytokine networks have been implicated in the pathogenesis of systemic autoimmune diseases, but the association of these cytokine networks with the heterogeneity of clinical manifestations and immune profiles has not been carefully examined. This study was undertaken to examine whether cytokine profiles can delineate distinct groups of patients in 4 systemic autoimmune diseases (systemic lupus erythematosus, Sjögren's syndrome, rheumatoid arthritis, and systemic sclerosis). METHODS: A total of 179 patients and 48 healthy volunteers were enrolled in the multicenter cross-sectional PRECISE Systemic Autoimmune Diseases (PRECISESADS) study. Multi-low-dimensional omics data (cytokines, autoantibodies, circulating immune cells) were examined. Coculture experiments were performed to test the impact of the cytokine microenvironment on T cell/B cell cross-talk. RESULTS: A proinflammatory cytokine profile defined by high levels of CXCL10, interleukin-6 (IL-6), IL-2, and tumor necrosis factor characterized a distinct group of patients in the 4 systemic autoimmune diseases. In each disease, this proinflammatory cluster was associated with a specific circulating immune cell signature, more severe disease, and higher levels of autoantibodies, suggesting an uncontrolled proinflammatory Th1 immune response. We observed in vitro that B cells reinforce Th1 differentiation and naive T cell proliferation, leading to the induction of type 1 effector B cells and IgG production. This process was associated with an increase in CXCL10, IL-6, IL-2, and interferon-γ production. CONCLUSION: This composite analysis brings new insights into human B cell functional heterogeneity based on T cell/B cell cross-talk, and proposes a better stratification of patients with systemic autoimmune diseases, suggesting that combined biomarkers would be of great value for the design of personalized treatments.

Association between EBV serological patterns and lymphocytic profile of SjS patients support a virally triggered autoimmune epithelitis.

Sjögren's syndrome (SjS) is characterized by lymphocytic infiltration of exocrine glands, i.e. autoimmune epithelitis. Lymphocytes are central in SjS pathogenesis, with B-cell hyperactivity mediated by T-cells. B-cells are main targets of Epstein-Barr virus (EBV) infection, a frequently-suggested trigger for SjS. We aimed to evaluate how the EBV infection modulates B and T-cell subsets in SjS, including as controls Rheumatoid arthritis patients (RA) and healthy participants (HC). SjS patients presented decreased CXCR5+T-cells, although IL21-secreting Tfh and Tfc cells were increased. Tfc were positively correlated with ESSDAI scores, suggesting their relevant role in SjS pathogenesis. As previously described, SjS patients showed expanded circulating naïve B-cell compartments. SjS patients had a higher incidence of EBV-EA-D-IgG+ antibodies, characteristic of recent EBV-infection/reactivation. SjS patients with past infection or recent infection/reactivation showed increased CXCR3+Th1 and CXCR3+Tfh1 cells compared to those without active infection. SjS patients with a recent infection/reactivation profile presented increased transitional B-cells compared to patients with past infection and increased plasmablasts, compared to those without infection. Our results suggest EBV-infection contributes to B and T-cell differentiation towards the effector phenotypes typical of SjS. Local lymphocyte activation at ectopic germinal centres, mediated by Tfh and Tfc, can be EBV-driven, perpetuating autoimmune epithelitis, which leads to gland destruction in SjS.

Primary Sjögren's syndrome manifesting as sclerotic metabolic bone disease.

Primary Sjögren's syndrome (pSS) is a chronic slowly progressive autoimmune disease characterised by lymphocytic infiltration of salivary and lacrimal glands with varying degree of systemic involvement. Renal involvement, a recognised extraglandular manifestation of pSS, is commonly related to tubular dysfunction and generally manifests as distal renal tubular acidosis (RTA), proximal RTA, tubular proteinuria and nephrogenic diabetes insipidus. Untreated long-standing RTA is known to cause metabolic bone disease. Here, we present the report of a patient with sclerotic metabolic bone disease related to pSS with combined distal and proximal RTA and negative workup for other causes of sclerotic bone disease. A significant clinical and biochemical improvement, including recovery of proximal tubular dysfunction, was noted with alkali therapy. This case suggests the need to consider pSS in the diagnostic algorithm of a patient presenting with sclerotic bone disease.

IgA immunoglobulin isotype of rheumatoid factor in primary Sjögren's syndrome.

Primary Sjögren's syndrome (pSS) is an autoimmune disease with autoantibodies overproduction, including rheumatoid factors (RF). RF-IgA, IgG immunoglobulin classes are suggested as potential biomarkers of pSS. We studied 76 patients with pSS (ACR/Eular 2017); laboratory tests included ESR, C-reactive protein, concentrations of gamma globulins, RF, Anti-SS-A/Ro, and anti-SS-B/La. Eye dryness and keratoconjunctivitis sicca were confirmed with Schirmer's test, the ocular staining score (OSS) using lissamine green, fluorescein staining and biopsy of minor salivary gland with the histopathological evaluation. Differences between groups were analyzed with U Mann-Whitney test. Correlations between quantitative variables were assessed with the Spearman correlation coefficient.. The best diagnostic values of immunoglobulin concentration for discriminating pSS patients and healthy individuals are for RF-IgA. With cut-off of 21.5 EU/mL, the sensitivity is 72% and specificity is 100%. Very high specificity (100%) is also obtained for RF-IgM concentration of 74.1 EU/mL. Sensitivity is, however, smaller than that for RF-IgA and amounted to 61%. The RF-IgG is the poorest indicator of pSS with 51% of sensitivity and 95% of specificity. To summarize RF-IgA strongly associate with anti-SS-A and anti-SS-B autoantibodies. Both RF-IgA and RF-IgM may be used as diagnostic tools for pSS. Conclusions: among the three studied rheumatoid factor subtypes, RF-IgA showed the best diagnostic accuracy for pSS. RF-IgA correlated with anti-SS-A/Ro and anti-SS-B antibodies even more closely than RF-IgM. The assessment of the RF-IgA serum concentration may be helpful in the process of establishing pSS diagnosis.

Serological Evidence for the Association Between Epstein-Barr Virus Infection and Sjögren's Syndrome.

Background: Exposure to Epstein-Barr virus (EBV) infection has been hypothesized to be an important risk factor for multiple rheumatic diseases, but the serological evidence so far for its role in Sjögren's syndrome (SjS) is not clearly established yet. This study aimed to assess the seroepidemiological associations of antibodies to EBV with SjS. Methods: A seroepidemiological study containing 119 patients with SjS and 65 healthy controls was first performed, in which the associations of SjS with four commonly studied EBV antibodies including IgM-anti-viral capsid antigen (anti-VCA) antibody, IgG-anti-VCA antibody, IgG-anti-early antigen (anti-EA) antibody, and IgG-anti-EBV nuclear antigen 1 (anti-EBNA1) antibody were evaluated. A systematic review and meta-analysis of eligible seroepidemiological studies was also carried out, and data syntheses were performed using random-effect meta-analysis. Results: In the case-control study, the patients with SjS had both a significantly higher prevalence of IgG-anti-EA antibody positivity (31.9% vs. 3.1%, P < 0.001) and high titers of IgG-anti-EA antibody (P < 0.001) than healthy controls. The titer of IgG-anti-VCA antibody was significantly increased in the patients with SjS compared with healthy controls (P < 0.001). IgG-anti-EA antibody seropositive patients with SjS had lower levels of both C3 (P = 0.002) and C4 (P = 0.02), and the titer of IgG-anti-EA antibody was inversely related to the levels of both C3 (r = -0.31, P < 0.001) and C4 (r = -0.20, P = 0.03). A total of 14 eligible studies on the serological associations between EBV infection and SjS were finally included into the meta-analysis, which suggested obvious associations of SjS with IgM-anti-VCA antibody [Odds ratio (OR) = 5.77, 95%CI 1.73-19.25, P = 0.004] and IgG-anti-EA antibody (OR = 9.97, 95%CI 4.58-21.67, P < 0.00001). Conclusions: The findings from this study provide strong serological evidence for the association between EBV infection and SjS. SjS has obvious associations with IgM-anti-VCA antibody and IgG-anti-EA antibody. IgG-anti-EA antibody is linked to low levels of C3 and C4 in the patients with SjS, the significance of which needs to be addressed in further studies.

LncRNA and mRNA expression profile of peripheral blood mononuclear cells in primary Sjögren's syndrome patients.

The aim of this study was to elucidate the expression profile and the potential role of long non-coding RNA (LncRNA) in the peripheral blood mononuclear cells of primary Sjögren's syndrome (pSS) patients. RNA-seq technology was used to detect the differentially expressed LncRNAs and mRNAs between five age-and sex-matched paired pSS patients and healthy control PBMCs. The selected LncRNAs were detected in the validation study by RT-qPCR in 16 paired pSS patients and healthy controls. The GO, KEGG, co-localization, and co-expression analysis were performed to enrich the potential gene functions and pathways. In this study, 44 out of 1772 LncRNAs and 1034 out of 15,424 mRNAs were expressed differentially in the PBMCs of pSS patients. LINC00426, TPTEP1-202, CYTOR, NRIR, and BISPR were validated as aberrantly expressed, and these LncRNAs strongly correlated with disease activity of pSS. GO and KEGG pathway analysis revealed the significant enrichment of biological processes, cellular components, and molecular function of the up and down-regulated mRNAs, which were mainly concentrated in the immune response and immune system processes. Co-localization and co-expression analysis also revealed that differentially expressed LncRNAs in the PBMCs of pSS were strongly correlated to the mRNA functioning associated with immune response and cell metastasis. Numerous LncRNAs and mRNAs were found differentially expressed in the PBMCs of pSS patients, especially NRIR and BISPR; they interacted with the co-localized and co-expressed mRNAs, which might participate in the pathogenesis of pSS through the NF-κB, JAK-STAT, and other signaling pathways that regulate cell metastasis.