Asociaciones de hallazgos diagnósticos con actividad de la enfermedad en el síndrome de Sjogren primario: un análisis de conglomerados / Associations of diagnostic findings with disease activity in primary Sjogren's syndrome: a cluster analysis

Objective The diagnosis of primary Sjӧgren's syndrome still relies upon a constellation of clinical, laboratory, imaging, and pathological findings. We aimed to evaluate the relation of the disease activity with the results of diagnostic tests for primary Sjӧgren's syndrome. Methods A principal component with cluster analysis was performed to classify 69 patients with primary Sjӧgren's syndrome based on the results of diagnostic evaluations. Results Anti-SSA autoantibody was the most represented feature on the principal components. The anti-SSA and ultrasound score were positively correlated (p=0.001). We identified two distinct clusters of low or high disease activity (p<0.001). Except for disease duration and serum beta2-microglobulin, the clusters were significantly different in salivary flow (p= 0.004), ultrasound findings (p<0.001), IgG (p= 0.001), and salivary beta2-microglobulin (p= 0.048). Also, positive findings were significantly different between the clusters in rheumatoid factor, antinuclear antibody, anti-SSA, and anti-SSB (all p≤0.013). Conclusion Patients with higher syndrome activity were best recognized with serological and ultrasound assessments. However, patients with lower syndrome activity had a longer disease duration, higher stimulated salivary flow rate, and a positive biopsy of minor salivary glands (56%) (AU)

Objetivo El diagnóstico del síndrome de Sjӧgren primario todavía se basa en una constelación de hallazgos clínicos, de laboratorio, de imagen y patológicos. Nuestro objetivo fue evaluar la relación de la actividad de la enfermedad con los resultados de las pruebas diagnósticas para el síndrome de Sjӧgren primario. Métodos Se realizó un análisis de componentes principales mediante conglomerados para clasificar a 69 pacientes con síndrome de Sjӧgren primario en función de los resultados de las evaluaciones de diagnóstico. Resultados El autoanticuerpo anti-SSA fue la característica más representada en los componentes principales. El anti-SSA y la puntuación de ultrasonido se correlacionaron positivamente (p=0,001). Identificamos dos grupos distintos de baja o alta actividad de la enfermedad (p<0,001). Excepto por la duración de la enfermedad y la microglobulina beta2 sérica, los grupos fueron significativamente diferentes en el flujo salival (p=0,004), los hallazgos de ultrasonido (p<0,001), IgG (p=0,001) y microglobulina beta2 salival (p=0,048). Además, los hallazgos positivos fueron significativamente diferentes entre los grupos en factor reumatoide, anticuerpo antinuclear, anti-SSA y anti-SSB (todos p≤0,013). Conclusión Los pacientes con mayor actividad del síndrome se reconocieron mejor con evaluaciones serológicas y ecográficas. Sin embargo, los pacientes con menor actividad del síndrome tenían una mayor duración de la enfermedad, mayor tasa de flujo salival estimulado y una biopsia productiva de glándulas salivales menores (56%) (AU)

CCL5 Release by CCR9+ CD8 T Cells: A Potential Contributor to Immunopathology of Primary Sjögren's Syndrome.

Introduction: Increased CCL5 expression and CD8 T cells have been shown to be pivotal regulators of immunopathology in primary Sjögren's syndrome (pSS) and pSS-like disease. Increased CCL5 expression by CCR9+ CD4 T cells has previously been implicated as a contributor to immunopathology in pSS. The role of CD8 T cells and in particular CCR9+ CD8 T cells and their potential to secrete CCL5 has not previously been studied in pSS. In this study we investigated both CCR9 and CCL5 expression by CD8 T cells in pSS patients compared to healthy controls (HC). Methods: CCR9 expression on CD8 T cells from peripheral blood was compared between patients with pSS and HC by flow cytometry. Intracellular CCL5 expression by naive, memory and effector CCR9- and CCR9+ CD8 T cells was assessed. In addition, the capacity and pace of CCL5 release upon T cell activation was determined for all subsets and compared with CD4 T cells. Results: The frequency of circulating CCR9+ CD8 T cells in pSS patients is increased compared to HC. Antigen-experienced CD8 T cells, especially CCR9+ effector CD8 T cells, express the highest CCL5 levels, and release the highest levels of CCL5 upon activation. Memory and effector CD8 T cells of pSS patients express significantly less CCL5 and subsequently release less CCL5 upon stimulation compared to HC. CCR9+ CD8 T cells rapidly release CCL5 and significantly more than CCR9+ CD4 T cells. Conclusion: CCR9+ CD8 T cells express more CCL5 than CCR9- CD8 T cells. CCL5 is rapidly released upon activation, resulting in reduced intracellular expression. Reduced CCL5 expression by an elevated number of antigen-experienced CCR9-expressing CD8 T cells in pSS patients points towards increased release in vivo. This suggests that CCL5 release by CCR9+ CD8 T cells contributes to immunopathology in pSS.

Salivary free light chains and salivary immunoglobulins as potential non-invasive biomarkers in primary Sjögren's syndrome.

BACKGROUND: B cells contribute significantly to the pathogenesis of primary Sjögren's syndrome (pSS). Free light chains (FLCs) are generated during the production of immunoglobulins (Igs) and are surrogates of B cell activity. We hypothesized that salivary FLCs and salivary Igs could represent salivary gland inflammation and therefore, serve as biomarkers in pSS. METHODS: Patients >18 years old fulfilling the American College of Rheumatology / European League Against Rheumatism (EULAR) 2016 criteria for pSS and age-matched healthy and disease controls (sicca non-pSS, rheumatoid arthritis, systemic lupus erythematosus) were recruited for this cross-sectional study. FLCs in saliva and serum were measured by immunoturbidimetry. Serum and salivary Igs were measured by nephelometry and enzyme-linked immunosorbent assay, respectively. Area under the receiver operator characteristic curve was determined. The factors influencing the serum and salivary FLCs in pSS were determined using backward linear regression. RESULTS: A total of 78 patients with pSS, 76 healthy controls and 62 disease controls were recruited. Median EULAR SS disease activity index (interquartile range) was 1 (3.75). Serum FLCκ and FLCλ, salivary FLCλ, serum and salivary IgG, salivary IgM was significantly higher in the pSS group compared to the controls. Areas under the curve for salivary FLCλ, serum FLCκ, serum and salivary IgG were 0.75, 0.72, 0.78 and 0.77, respectively. Regression analysis showed that salivary FLCκ, salivary FLCλ and salivary IgG were associated with positive salivary gland histopathology. Use of immunosuppressants and glucocorticoids was associated with lower values of salivary parameters. CONCLUSION: Salivary FLCλ and salivary IgG were significantly different between pSS and control groups and could be potential non-invasive biomarkers in pSS. These findings should be confirmed in larger longitudinal studies.

Rheumatoid arthritis, systemic lupus erythematosus and primary Sjögren's syndrome shared megakaryocyte expansion in peripheral blood.

OBJECTIVES: Rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) share many clinical manifestations and serological features. The aim of this study was to identify the common transcriptional profiling and composition of immune cells in peripheral blood in these autoimmune diseases (ADs). METHODS: We analysed bulk RNA-seq data for enrichment of biological processes, transcription factors (TFs) and deconvolution-based immune cell types from peripheral blood mononuclear cells (PBMCs) in 119 treatment-naive patients (41 RA, 38 pSS, 28 SLE and 12 polyautoimmunity) and 20 healthy controls. The single-cell RNA-seq (scRNA-seq) and flow cytometry had been performed to further define the immune cell subsets on PBMCs. RESULTS: Similar transcriptional profiles and common gene expression signatures associated with nucleosome assembly and haemostasis were identified across RA, SLE, pSS and polyautoimmunity. Distinct TF ensembles and gene regulatory network were mainly enriched in haematopoiesis. The upregulated cell-lineage-specific TFs PBX1, GATA1, TAL1 and GFI1B demonstrated a strong gene expression signature of megakaryocyte (MK) expansion. Gene expression-based cell type enrichment revealed elevated MK composition, specifically, CD41b+CD42b+ and CD41b+CD61+ MKs were expanded, further confirmed by flow cytometry in these ADs. In scRNA-seq data, MKs were defined by TFs PBX1/GATA1/TAL1 and pre-T-cell antigen receptor gene, PTCRA. Cellular heterogeneity and a distinct immune subpopulation with functional enrichment of antigen presentation were observed in MKs. CONCLUSIONS: The identification of MK expansion provided new insights into the peripheral immune cell atlas across RA, SLE, pSS and polyautoimmunity. Aberrant regulation of the MK expansion might contribute to the pathogenesis of these ADs.

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.

Trajectory mapping of primary Sjögren's syndrome via transcriptome learning demonstrates limitations of peripheral blood sequencing.

Primary Sjögren's syndrome (pSS) is a complex autoimmune disease characterized by aberrant immune cell action against secretory glands throughout the body. A number of studies have previously identified unique characteristics in the circulating expression profile of white blood cells of pSS patients. However, the molecular progression pattern of pSS is unclear. Through a systematic analysis of pSS transcriptome information, we found that pSS transcriptomes display broad heterogeneity, but cannot be distinguished from the broad range of possible profiles of healthy controls. Instead, only sample learning using a subset of pre-identified signature genes could achieve partial separation through a trajectory governed by interferon activity. Interestingly, this trajectory is correlated with a decrease in dendritic cell counts. Our study thus highlights a major limitation to the utility of broad blood transcriptome analysis in the context of pSS, while also identifying several factors that influence the divergence between patient samples.

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.

Adropin Serum Levels in Patients with Primary Sjögren's Syndrome.

Primary Sjögren's syndrome (pSS) patients have higher prevalence of endothelial dysfunction and premature atherosclerosis. Recent studies investigated adropin, a secretory protein that can regulate lipid metabolism and insulin resistance and protect endothelial cells' function and that has an anti-inflammatory effect. The aim of this study was to determine adropin levels in pSS patients compared to healthy controls. Additional goals were exploring the correlation between adropin and several metabolic and immunological parameters in pSS, including disease specific antibodies, EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI), and Sjögren's Syndrome Disease Damage Index (SSDDI). This research included 52 pSS patients and 52 healthy controls. pSS patients have significantly higher adropin levels compared to the control group (3.76 ± 0.68 vs. 3.14 ± 0.69 ng/mL, p < 0.001). Correlation analysis showed that adropin levels in pSS patients have positive correlation with high-density lipoprotein (HDL) (r = 0.290, p = 0.036) and anti SSA/Ro52 antibodies (r = 0.307, p = 0.026) and negative correlation with SSDDI (r = -0.401, p = 0.003). Multivariant linear regression showed that adropin levels are independently associated with HDL (ß ± SE, 0.903 ± 0.283, p = 0.002) and SSDDI (ß ± SE, -0.202 ± 0.073, p = 0.008). Our findings imply that adropin could be involved in the pathophysiology of pSS, yet it remains to be elucidated in future studies whether adropin has a protective or detrimental role in this setting.

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.

Autoantibody against the Rab6A/Rab6B in primary autoimmune cerebellar ataxia associated with Sjogren's syndrome: A case report.

In the current study we report a novel autoantibody against Purkinje cells in a patient with primary autoimmune cerebellar ataxia (PACA) associated with Sjogren's syndrome (SS). Tissue-based indirect immunofluorescence assay (TBA) of the patient's serum and cerebrospinal fluid (CSF) revealed IgG antibody to Purkinje cells and the granular layer of the rat cerebellum. Rab6A was identified as autoantigen by mass spectrometry (MS) and Western blotting, and the interactions between Rab6A or its homologous Rab6B and autoantibody in patient serum were verified by recombinant cell-based assay (CBA) and neutralization experiments. This autoantibody may represent a novel biomarker in the diagnosis of PACA.

Increased CD4+CD8+ Double-Positive T Cell in Patients with Primary Sjögren's Syndrome Correlated with Disease Activity.

Primary Sjogren's syndrome (pSS) is an autoimmune disease that invades lacrimal glands, salivary glands, and other exocrine glands, but its pathogenic mechanism is still unclear. CD4+CD8+ double-positive T (DPT) cells have been discovered in recent years to play an important role in autoimmune diseases and viral infections, but the frequency and significance of DPT in primary Sjogren's syndrome are still unclear. This study detected the frequency of DPT in the peripheral blood of patients with pSS and detected the clinical indicators and cytokines in patients. We then analyzed the correlation between DPT and clinical indicators, cytokines, and disease activity scores. The results showed that the peripheral DPT frequency of pSS patients was significantly higher than that of healthy controls. The peripheral DPT frequency was negatively correlated with ESR, IgA, and IgG, and peripheral DPT frequency was positively correlated with anti-inflammatory cytokine IL-10. Analysis of DPT and pSS disease activity scores found that DPT frequency had a negative correlation with ESSDAI and SSDAI. This study suggests that peripheral DPT may play a protective role in pSS. The frequency of peripheral DPT cells can be used as an indicator for disease activity. Regulating the expression of peripheral DPT cells is expected to become a new strategy for treatment of pSS.

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.

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.

A new molecular classification to drive precision treatment strategies in primary Sjögren's syndrome.

There is currently no approved treatment for primary Sjögren's syndrome, a disease that primarily affects adult women. The difficulty in developing effective therapies is -in part- because of the heterogeneity in the clinical manifestation and pathophysiology of the disease. Finding common molecular signatures among patient subgroups could improve our understanding of disease etiology, and facilitate the development of targeted therapeutics. Here, we report, in a cross-sectional cohort, a molecular classification scheme for Sjögren's syndrome patients based on the multi-omic profiling of whole blood samples from a European cohort of over 300 patients, and a similar number of age and gender-matched healthy volunteers. Using transcriptomic, genomic, epigenetic, cytokine expression and flow cytometry data, combined with clinical parameters, we identify four groups of patients with distinct patterns of immune dysregulation. The biomarkers we identify can be used by machine learning classifiers to sort future patients into subgroups, allowing the re-evaluation of response to treatments in clinical trials.

Increased Concentrations of Circulating Soluble MHC Class I-Related Chain A (sMICA) and sMICB and Modulation of Plasma Membrane MICA Expression: Potential Mechanisms and Correlation With Natural Killer Cell Activity in Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a severe autoimmune disease of unknown etiology. The major histocompatibility complex (MHC) class I-related chain A (MICA) and B (MICB) are stress-inducible cell surface molecules. MICA and MICB label malfunctioning cells for their recognition by cytotoxic lymphocytes such as natural killer (NK) cells. Alterations in this recognition have been found in SLE. MICA/MICB can be shed from the cell surface, subsequently acting either as a soluble decoy receptor (sMICA/sMICB) or in CD4+ T-cell expansion. Conversely, NK cells are frequently defective in SLE and lower NK cell numbers have been reported in patients with active SLE. However, these cells are also thought to exert regulatory functions and to prevent autoimmunity. We therefore investigated whether, and how, plasma membrane and soluble MICA/B are modulated in SLE and whether they influence NK cell activity, in order to better understand how MICA/B may participate in disease development. We report significantly elevated concentrations of circulating sMICA/B in SLE patients compared with healthy individuals or a control patient group. In SLE patients, sMICA concentrations were significantly higher in patients positive for anti-SSB and anti-RNP autoantibodies. In order to study the mechanism and the potential source of sMICA, we analyzed circulating sMICA concentration in Behcet patients before and after interferon (IFN)-α therapy: no modulation was observed, suggesting that IFN-α is not intrinsically crucial for sMICA release in vivo. We also show that monocytes and neutrophils stimulated in vitro with cytokines or extracellular chromatin up-regulate plasma membrane MICA expression, without releasing sMICA. Importantly, in peripheral blood mononuclear cells from healthy individuals stimulated in vitro by cell-free chromatin, NK cells up-regulate CD69 and CD107 in a monocyte-dependent manner and at least partly via MICA-NKG2D interaction, whereas NK cells were exhausted in SLE patients. In conclusion, sMICA concentrations are elevated in SLE patients, whereas plasma membrane MICA is up-regulated in response to some lupus stimuli and triggers NK cell activation. Those results suggest the requirement for a tight control in vivo and highlight the complex role of the MICA/sMICA system in SLE.

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.

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.

Antigen-driven autoantibody production in lungs of interstitial lung disease with autoimmune disease.

Interstitial lung disease (ILD) sometimes becomes a life-threatening complication of systemic autoimmune diseases; however, little is known about the immune response in lung lesions. We aimed to investigate humoural immunity in ILD associated with rheumatoid arthritis (RA), sjögren's syndrome (SjS), and mixed connective tissue disease (MCTD), using bronchoalveolar fluid (BALF) and serum samples from 15 patients with autoimmune disease associated-ILD. We first showed that BALF contained higher titers of disease-related autoantibodies than serum, suggesting the possibility of autoantibody production in lungs. Next, we produced 326 monoclonal antibodies from antibody-secreting cells in BALF, and the reactivity and their revertants, in which somatic hypermutations were reverted to germline, were analyzed. Among 123 antibodies from RA-ILD, 16 disease-related antibodies (anti-modified protein antibodies and rheumatoid factors) were identified, of which one antibody had both properties. The revertant antibodies changed their target modification in a complicated manner, suggesting that the antibodies were selected against various modifications in lungs. Among 146 antibodies from SjS-ILD and/or MCTD-ILD, seven anti-SSA/Ro60 antibodies and 15 anti-RNP antibodies were identified. Some of the anti-RNP antibodies recognized multiple RNP constituent proteins simultaneously, indicating that epitope spreading may progress in lungs. Our results revealed the existence of an active autoimmunity in the lungs of autoimmune disease associated-ILD.