Classification criteria of Sjögren's syndrome

Sjögren's syndrome (SS) is a chronic, systemic autoimmune disease that affects typically the exocrine glands causing mucosal dryness. Dry eyes and mouth are considered by far the most common and early symptoms of the disease but systemic complications may also occur. In 1993, the preliminary European criteria were proposed and widely accepted, consisting of both subjective and objective criteria. Almost ten years later, these classification criteria were revised by introducing more stringent rules and precise diagnostic procedures leading to the currently used American-European Consensus Group (AECG) criteria. The AECG criteria have been largely employed to conduct epidemiologic and clinical studies of patients with SS and proved to be more specific compared to the preliminary European criteria. The recent American College of Rheumatology/Sjögren's International Collaborative Clinical Alliance (ACR/SICCA) criteria that are based exclusively on objective tests, the stringency of the AECG criteria and the potential therapeutic use of biologic agents in SS clearly set the need for new classification criteria. Whether the new diagnostic approach will further encompass subclinical and early forms of the disease remains to be addressed by the scientific community.

Increased sensitivity of Treg cells from patients with PBC to low dose IL-12 drives their differentiation into IFN-γ secreting cells

IL-12 is a pro-inflammatory cytokine that induces the production of interferon-γ (IFNγ) and favours the differentiation of T helper 1 (Th1) cells. In the presence of IL-12 human Treg cells acquire a Th1-like phenotype with reduced suppressive activity in vitro. Primary biliary cholangitis (PBC) is an autoimmune cholestatic liver disease characterised by high Th1 and Th17 infiltrating cells, reduced frequencies of Treg cells, and a genetic association with IL-12 signalling. Herein, we sought to evaluate the IL-12 signalling pathway in PBC pathology, by studying human samples from patients with PBC, alongside those with primary Sjögren's syndrome (pSS)(autoimmune disease with IL-12 signalling gene association), primary sclerosing cholangitis (PSC) (cholestatic liver disease without IL-12 gene association) and healthy individuals. Our data revealed that TLR stimulation of PBC (n = 17) and pSS monocytes (n = 6) resulted in significant induction of IL12A mRNA (p < 0.05, p < 0.01, respectively) compared to PSC monocytes (n = 13) and at similar levels to HC monocytes (n = 8). PSC monocytes expressed significantly less IL-12p70 (108 pg/ml, mean) and IL-23 (358 pg/ml) compared to HC (458 pg/ml and 951 pg/ml, respectively) (p < 0.01, p < 0.05). Treg cells from patients with PBC (n = 16) and pSS (n = 3) but not PSC (n = 10) and HC (n = 8) responded to low dose (10 ng/ml) IL-12 stimulation by significant upregulation of IFNγ (mean 277 and 254 pg/ml, respectively) compared to PSC and HC Treg cells (mean 22 and 77 pg/ml, respectively)(p < 0.05). This effect was mediated by the rapid and strong phosphorylation of STAT4 on Treg cells from patients with PBC and pSS (p < 0.05) but not PSC and HC. In the liver of patients with PBC (n = 7) a significantly higher proportion of IL-12Rβ2⁺Tregs (16% on average) was detected (p < 0.05) compared to other liver disease controls (5%)(n = 18) which also showed ex vivo high IFNG and TBET expression. CONCLUSION: Our data show an increased sensitivity of PBC and pSS Treg cells to low dose IL-12 stimulation, providing ongoing support for the importance of the IL12-IL-12Rβ2-STAT4 pathway on Treg cells in disease pathogenesis and potentially treatment.

Calcium signaling defects underlying salivary gland dysfunction

Salivary glands secrete saliva, a mixture of proteins and fluids, which plays an extremely important role in the maintenance of oral health. Loss of salivary secretion causes a dry mouth condition, xerostomia, which has numerous deleterious consequences including opportunistic infections within the oral cavity, difficulties in eating and swallowing food, and problems with speech. Saliva secretion is regulated by stimulation of specific signaling mechanisms within the acinar cells of the gland. Neurotransmitter-stimulated increase in cytosolic [Ca²⁺] ([Ca²⁺]_i) in acinar cells is the primary trigger for salivary fluid secretion from salivary glands, the loss of which is a critical factor underlying dry mouth conditions in patients. The increase in [Ca²⁺]_i regulates multiple ion channel and transport activities that together generate the osmotic gradient which drives fluid secretion across the apical membrane. Ca²⁺ entry mediated by the Store-Operated Ca²⁺ Entry (SOCE) mechanism provides the essential [Ca²⁺]_i signals to trigger salivary gland fluid secretion. Under physiological conditions depletion of ER-Ca²⁺ stores is caused by activation of IP3R by IP3 and this provides the stimulus for SOCE. Core components of SOCE in salivary gland acinar cells are the plasma membrane Ca²⁺ channels, Orai1 and TRPC1, and STIM1, a Ca²⁺-sensor protein in the ER, which regulates both channels. In addition, STIM2 likely enhances the sensitivity of cells to ER-Ca²⁺ depletion thereby tuning the cellular response to agonist stimulation. Two major, clinically relevant, conditions which cause irreversible salivary gland dysfunction are radiation treatment for head-and-neck cancers and the autoimmune exocrinopathy, Sjögren's syndrome (pSS). However, the exact mechanism(s) that causes the loss of fluid secretion, in either condition, is not clearly understood. A number of recent studies have identified that defects in critical Ca²⁺ signaling mechanisms underlie salivary gland dysfunction caused by radiation treatment or Sjögren's syndrome (pSS). This chapter will discuss these very interesting and important studies.

Sjögren's syndrome: an update on epidemiology and current insights on pathophysiology

Primary Sjögren's syndrome (pSS) is an autoimmune chronic inflammatory disorder affecting 0.2% to 3.0% of the population, with a 9:1 female to male ratio. Features are oral and ocular dryness, local and systemic autoantibody production, and progressive focal mononuclear cell infiltration in the affected salivary and lacrimal glands. Lymphoma is the most severe complication of pSS, occurring in 4% to 5% of patients. Genetic studies identified an association with HLA and susceptibility genes in cytokine genes and genes involved in B-cell differentiation. Genetic variations may help explain why disease manifestations differ among patients and supports the hypothesis of certain distinct disease phenotypes.

Concomitant Ro/SSA and La/SSB antibodies are biomarkers for the risk of venous thromboembolism and cerebral infarction in primary Sjögren's syndrome

BACKGROUND

To assess the risk of incident cardiovascular disease in patients with primary Sjögren's syndrome, overall and stratified by Ro/SSA and La/SSB autoantibody status.

METHODS

A cohort of patients with primary Sjögren's syndrome in Sweden (n = 960) and matched controls from the general population (n = 9035) were included, and data extracted from the National Patient Register to identify events of myocardial infarction, cerebral infarction and venous thromboembolism. Hazard ratios were estimated using cox proportional hazard regressions.

RESULTS

During a median follow-up of 9.5 years, the overall hazard ratio (HR) was 1.6 (95% CI 1.2-2.1) for myocardial infarction, 1.2 (95% CI 0.9-1.7) for cerebral infarction and 2.1 (95% CI 1.6-2.9) for venous thromboembolism. Patients positive for both Ro/SSA and La/SSB autoantibodies had a substantially higher risk of cerebral infarction (HR 1.7, 95% CI 1.0-2.9) and venous thromboembolism (HR 3.1, 95% CI 1.9-4.8) than the general population. These risks were not significantly increased in Ro/SSA- and La/SSB-negative patients. Among autoantibody-positive patients, the highest HR of cerebral infarction was seen after ≥10 years disease duration (HR 2.8, 95% CI 1.4-5.4), while the HR for venous thromboembolism was highest 0-5 years after disease diagnosis (HR 4.7, 95% CI 2.3-9.3) and remained high throughout disease duration.

CONCLUSIONS

Primary Sjögren's syndrome is associated with a markedly increased risk of cardiovascular disease and the presence of Ro/SSA and La/SSB autoantibodies identify the subgroup of patients carrying the highest risk. These findings suggest that monitoring and prevention of cardiovascular disease in this patient group should be considered.

Salivary Gland Pathology in Sjögren's Syndrome

Primary Sjögren syndrome (pSS) can be considered a systemic autoimmune disease with a strong organ bias. The involvement of the exocrine glands is prevalent and drives the pathognomonic manifestations of dryness that define the sicca syndrome. The salivary glands also represent the hub of pSS pathology. Elements belonging to both innate and acquired immune responses have been described at this site that contribute to disease establishment and progression. The interaction between those elements and their relative contributions to the clinical manifestations and lymphoma progression largely remain to be addressed.

Arthritis in primary Sjögren's syndrome: Characteristics, outcome and treatment from French multicenter retrospective study

OBJECTIVE

To describe the characteristics and the outcome of primary Sjögren Syndrome (pSS) associated arthritis and to compare the efficacy of different therapeutic regimen.

METHODS

We conducted a retrospective study using Club Rhumatisme and Inflammation (CRI) and French Internal Medicine Society (SNFMI) networks. All patients with a diagnosis of pSS and at least one episode of clinical and/or echographic synovitis were included. Patients with synovitis (cases) were compared to pSS patients without synovitis (controls).

RESULTS

57 patients (93% women) were included with a median age of 54 years [45-63]. Patients with synovitis had more frequently lymph node enlargement (12.3% vs. 1.8%, p = .007) and a higher ESSDAI score (8 [6-12] vs. 2 [1-4], p < .0001). There was no difference concerning CRP levels, rheumatoid factor and cyclic citrullinated peptide (CCP)-antibodies positivity. Among 57 patients with synovitis, 101 various treatment courses have been used during the follow-up of 40 [22.5-77] months. First treatment course consisted in steroids alone (3.5%), steroids in association (79%) with hydroxychloroquine (HCQ) (49%), methotrexate (MTX) (35%), rituximab (RTX) (5.3%) or other immunosuppressive drugs (7%). HCQ, MTX, and RTX were associated with a significant reduction of tender and swollen joint count, and a significant steroids-sparing effect. No difference could be shown for the joint response between these treatment regimens.

CONCLUSION

pSS articular manifestations may include synovitis which could mimic rheumatoid arthritis but differ by the absence of structural damage. Even if the use of HCQ, MTX, and RTX seem to be effective for joint involvement, the best regimen remains to be determined.

Immunological profiles determine neurological involvement in Sjögren's syndrome

BACKGROUND

Up to 68% of patients with primary Sjögren's syndrome (pSS) undergo neurological complications, and evidence for distinct immunological subgroups is emerging. We sought to determine systemic and immunological profiles associated with neurological manifestations.

METHODS

420 patients fulfilling the 2002 American-European pSS criteria were retrospectively analyzed. Neurological manifestations were diagnosed through clinical, biological, electrophysiological, and imaging findings. Biographical, clinical, and laboratory data were compared.

RESULTS

Within 93 (22%) patients with neurological manifestations, peripheral and central nervous systems were involved in 66% and 44%, respectively. Raynaud's phenomenon, cutaneous vasculitis, renal involvement, and cryoglobulinemia were associated with sensorimotor neuropathy and mononeuritis multiplex (p<0.05). Conversely, pure sensory neuropathy occurred without extraglandular manifestation, and without anti-Ro/SSA antibodies (p<0.05). All neurological manifestations were associated with increased use of corticosteroids and immunosuppressive drugs (p<0.05).

CONCLUSIONS

In pSS, patients with sensorimotor neuropathies and pure sensory neuropathies have distinct extraglandular and immunological profiles.

The association of Tyro3/Axl/Mer signaling with inflammatory response, disease activity in patients with primary Sjögren's syndrome

OBJECTIVES

Defects in Tyro3/Axl/Mer signaling may lead to impaired phagocytosis of apoptotic cells, eventually contributing to the development of autoimmune disease. The association of TAM signaling with several autoimmune disease has been investigated, but it remains unclear in primary Sjögren's syndrome. Therefore, the aim of this study was to evaluate the level of TAM signaling in primary Sjögren's syndrome with its clinical significance.

METHODS

Real-Time Polymerase Chain Reaction was used to determine the mRNA expression of Mer, Tyro-3, Axl, Gas6, and Protein S in Peripheral Blood Mononuclear Cell from 43 pSS and 46 control. The Enzyme-Linked Immunosorbent Assay method was used to test plasma levels of soluble TAM signaling from those individuals, and the relationship of their levels with clinical characteristic was evaluated.

RESULTS

The mRNA expression levels of Tyro-3, Axl were decreased in pSS patients. When considering the plasma level, increased levels of soluble Mer was observed with statistically significant difference. Soluble Mer levels were positively correlated with IgG levels (r=0.53, P<0.01), Erythrocyte Sedimentation Rate levels (r=0.44, P<0.01) and Sjögren's Syndrome Disease Activity Index (r=0.48, P<0.01). And the levels of soluble Mer in patients with the presence of SSA/SSB were higher than those without SSA/SSB.

CONCLUSIONS

The plasma levels of sMer were increased in pSS patients, which was associated with inflammatory response and disease activity.

Elevated CCL19/CCR7 Expression During the Disease Process of Primary Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a common chronic autoimmune disease characterized by a high prevalence of autoantibodies and lymphocyte-mediated exocrine gland damage. To enhance our understanding of the mechanisms underlying the progression of the disease and to discover potential biomarkers for the early diagnosis of pSS, we applied RNA sequencing to compare the gene expression patterns in minor salivary glands between pSS patients and non-pSS. A total of 293 differentially expressed genes (DEGs) were detected in pSS vs. non-pSS (FDR < 0.05, fold changes > 2). Of these DEGs, 285 (97.26%) were up-regulated, with most being involved in immune system activation, especially in the formation of the immunological synapse. Significantly elevated CCL19/CCR7 expression in the salivary gland was found to be related to anti-Sjögren's syndrome-related antigen A (SSA) antibody and IgG levels in pSS patients, which was further confirmed in a larger cohort. Up-regulated gene expression showed strong discriminatory accuracy in identifying pSS with area under the curve of 0.98 using receiver operating characteristic curve analysis. In conclusion, gene expression changes in pSS include strong markers of immunological activation and have good discriminatory power in identifying patients with pSS.

Diagnostic accuracy of anti-alpha-fodrin antibodies for primary Sjögren's syndrome

OBJECTIVES

To estimate the diagnostic accuracy of anti-alpha-fodrin antibodies for primary Sjögren's syndrome (pSS).

METHODS

Sixty-four pSS subjects and 108 non-pSS patients were prospectively enrolled in this study. Serum anti-alpha-fodrin IgA and IgG were detected by ELISA in a blind fashion. The diagnostic accuracy of anti-alpha-fodrin antibodies was assessed by receiver operating characteristic (ROC) curve analysis. Logistic regression was used to investigate whether anti-alpha-fodrin antibodies could improve the accuracy of pSS diagnosis if used in addition to anti-SSA and anti-SSB.

RESULTS

The areas under the ROC curves for anti-alpha-fodrin IgG and IgA were 0.69 (95% confidence interval (CI): 0.60-0.77) and 0.63 (95% CI: 0.54-0.72), respectively (P < 0.01 for both). The optimal diagnostic thresholds for anti-fodrin IgG and IgA were 11.75 U/ml and 9.75 U/ml, respectively, with a sensitivity of 0.59 and 0.55, and a specificity of 0.75 and 0.73, respectively. Anti-alpha-fodrin IgG and IgA antibodies were associated with pSS after adjustment for anti-SSA and anti-SSB.

CONCLUSIONS

Anti-alpha-fodrin IgG and IgA antibodies are useful diagnostic markers which may improve the accuracy of pSS diagnosis.

Comparison of antibody assays for detection of autoantibodies to Ro 52, Ro 60 and La associated with primary Sjögren's syndrome

Anti-Ro(52/60) and anti-La constitute the hallmark autoantibodies in primary Sjögren's syndrome, being present in 40-70% of sera. Several anti-Ro/La assays exist, but antibody detection appears to be assay-specific, thus the aim of this study was to compare several anti-Ro/La assays. In total, 96 sera from individuals with primary Sjögren's syndrome and 114 healthy controls were tested for anti-Ro 52/60 and anti-La in 17 immunoassays. Especially the immunoassays used for detection of anti-Ro 52 differed in their sensitivity (48-79%), while only small differences in sensitivities were observed for the anti-Ro 60 (69-77%) anti-La (39-44%) assays. Concordances of 65%, 79% and 73% for the anti-Ro 52, anti-Ro 60 and anti-La assays were found, respectively. The majority of the assays yielded high specificities, primarily ranging from 97 to 100%, except from a single anti-Ro 60 assay, which yielded a specificity of 79%. Occasionally, reactivity levels were increased in a few assays, indicating that false-positive results can be obtained when applying assays of reduced specificity. In general, the commercial assays appeared to perform better than the in-house analyses. When correcting the in-house assays for background reactivity, sensitivities were reduced by approximately 7%, 17%, and 19% for anti-Ro 52, anti-Ro 60 and anti-La assays, respectively, illustrating the pitfalls when applying immunoassays for detection of autoantibodies, which in theory may apply to commercial assays as well. Finally, increased total sensitivities were obtained when combining assays. These studies contribute to clarify the clinical utility of immunoassays for detection of autoantibodies of Ro 52, Ro 60 and La and illustrate that the most efficient strategy to maximize antibody sensitivity is to combine several assays.

Cancer incidence in primary Sjögren's syndrome: Data from the French hospitalization database

The relationship between cancer and primary Sjögren's syndrome (pSS) is uncertain. While the increased risk of hematological malignancies is well-known, data on the comparative incidence of solid neoplasms is conflicting. This study aimed to explore the associations between cancer and pSS. This nationwide population-based retrospective study from the French health insurance database (PMSI) evaluated patients hospitalized with new-onset pSS from 2011 to 2018 against age- and sex-matched hospitalized controls (1:10). The incidence of hematological malignancies and solid neoplasms was compared between the two groups. Mortality and multiple cancer incidence were also evaluated. Adjusted Hazard Ratios (aHR) calculations included confounding factors, such as low socioeconomic status. Among 25,661 hospitalized patients with pSS versus 252,543 matched patients (median follow-up of 3.96 years), we observed a higher incidence rate of lymphomas (aHR, 1.97 [95% CI, 1.59-2.43]), Waldenström macroglobulinemia (aHR, 10.8 [6.5-18.0]), and leukemia (aHR, 1.61 [1.1-2.4]). Thyroid cancer incidence was higher (aHR, 1.7 [1.1-2.8]), whereas bladder and breast cancer incidences were lower (aHR, 0.58 [0.37-0.89] and 0.60 [0.49-0.74], respectively). pSS patients with breast cancer exhibited a lower mortality rate. A limitation was that the database only encompasses hospitalized patients, and immunological and histological details are not listed. We confirmed the increased risk of hematological malignancies and thyroid cancers among patients with pSS. The lower risk of breast cancer suggests a role of hormonal factors and raises questions of the concept of immune surveillance within breast tissue. Epidemiological and translational studies are required to elucidate the relationships between pSS and cancer.

[Clinical usefulness of salivary gland ultrasonography in Sjögren's syndrome: Where are we now?]

Salivary gland ultrasonography is a simple, noninvasive and inexpensive procedure, which provides valuable information for the diagnosis of primary Sjögren's syndrome (pSS). The main sonographic characteristic of the major salivary glands (parotid and submandibular) in pSS patients is the heterogeneity of the parenchyma, with the appearance of hypoechoic areas. Numerous studies published over the past 20 years report a sensitivity of 70% and a specificity of more than 90% for the diagnosis of pSS. Before the widespread use of this procedure in daily practice and its integration into classification criteria of the disease, it has yet to be validated in terms of reproducibility and a consensus score should be established. This work is being conducted by an international group of experts. Other ultrasound techniques such as elastography could also be of interest to objectively quantify changes in the glandular tissue that occur during the disease.

Paeoniflorin down-regulates ATP-induced inflammatory cytokine production and P2X7R expression on peripheral blood mononuclear cells from patients with primary Sjögren's syndrome

This study determined the effects of paeoniflorin (PF) on the expression of purinergic receptor P2X ligand-gated ion channel 7 (P2X7R) expressed on peripheral blood mononuclear cells (PBMCs) and production of ATP-induced pro-inflammatory cytokines released by PBMCs in patients with primary Sjögren's syndrome (pSS). The pharmacological functions and cytotoxic effects of PF were dose dependent in PBMCs from 20 newly diagnosed pSS patients and 20 normal individuals. The optimum dose of PF was 100μM. PF significantly down-regulated the production of interleukin (IL)-1β and IL-6 from pSS PBMCs, and significantly inhibited ATP-induced expression of P2X7R, that might contribute to reduced IL-1β and IL-6. mRNA and protein levels of P2X7R on pSS PBMCs were significantly higher than in normal individuals (p=0.03, p<0.001). When PBMCs from subjects were stimulated in vitro with ATP in the presence of PF, P2X7R mRNA and protein levels were decreased significantly (p<0.001, p<0.001, respectively versus ATP group) in the pSS. Supernatant IL-1β and IL-6 levels were significantly lower in the PF group compared with ATP group (p<0.001, p<0.001). We show for the first time that PF-mediated reduction of IL-1β and IL-6 was due in part to the reduced expression and activation of the ATP sensor P2X7R on pSS PBMCs, indicating that PF might be useful for the management of pSS via down-regulating P2X7R expression. Thus, PF may provide a new therapeutic approach to regulate P2X7R-mediated pathologic responses of pSS.

Investigation of autoantibodies to SP-1 in Chinese patients with primary Sjögren's syndrome

In order to evaluate autoantibody to SP-1 as an early biomarker in pSS, we investigated autoantibody to SP-1 in Chinese patients with primary Sjögren's syndrome (pSS). Autoantibodies to SP-1 are significantly increased in pSS patients compared to RA patients, SLE patients, and healthy people without secondary SS. The presence of anti SP-1 antibodies was negatively correlated with the focus score (FS), RF, and salivary gland function. It was positively correlated with FS=0, RF≤20, and normal salivary gland function. In further studies, the autoantigen SP-1 was identified in ductal epithelia of salivary glands in il14α TG mice by IIF. SP-1 mRNAs expression increased with growing age in il14α TG mice. SP-1 mRNA was also identified in labial biopsies of patients with pSS. In conclusion, autoantibody to SP-1 is an early marker in pSS. It is useful to diagnose pSS patients who lack RF or antibodies to Ro/La.

In vitro impact of bisphenol A on maturation and function of monocyte-derived dendritic cells in patients with primary Sjögren's syndrome

Background: Epidemiological studies have shown that environmental factors accelerate the progress of primary Sjögren's syndrome (pSS). Bisphenol A (BPA), a classic endocrine disrupting chemical, affects the immune system. However, the impact of BPA on pSS has not yet been reported. The present study aimed to evaluate the potential relationship between BPA, estrogen receptor (ER), and pSS.Methods: We studied the impact of BPA on monocyte-derived dendritic cells (moDCs) from pSS patients and age-matched healthy controls (HCs). Morphological effects were observed under inverted microscope. Surface markers were analyzed by flow cytometry. ER and cytokine profiles were assessed using real-time polymerase chain reaction. The ability of moDCs to stimulate CD4⁺ T cells activation was assessed by mixed lymphocyte reaction (MLR).Results: moDCs from both pSS patients and HCs expressed ERα as well as ERβ. After BPA-exposure, expression of ERα increased significantly in pSS patients, while that of ERβ remained unchanged. moDCs from BPA-exposed pSS patients showed irregular morphology and reduction in cell aggregation. BPA increased HLA-DR on moDCs of pSS patients via ERα, and promoted the secretion of IL6 and IL12. When co-cultured with BPA-treated moDCs, cytokines (IFN-γ, IL4, IL17, IL10) and transcription factors (T-bet, Gata3, RoR-γt, Foxp3) of CD4⁺ T cells showed imbalance of Th1/Th2/Th17/Treg polarization, with Th1 and Th17 dominating.Conclusions: BPA altered the function of moDCs through ERα, including antigen capture, secretion of inflammatory factors, and ability to stimulate T cells, as well as accelerated the progression and further deterioration of pSS.

Relationships between increased circulating YKL-40, IL-6 and TNF-α levels and phenotypes and disease activity of primary Sjögren's syndrome

BACKGROUND

There is now no single score or marker useful for evaluating disease activity of primary Sjögren's syndrome (pSS). This study was designed to explore the associations of circulating YKL-40, interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) with systemic activity and phenotypes of pSS.

METHODS

This study included 58 pSS patients and 30 healthy controls (HC). The sera were measured by multiplex immunoassay for YKL-40, IL-6 and TNF-α concentrations. The disease activity of pSS patients was evaluated by European league against rheumatism (EULAR) SS disease activity index (ESSDAI). Local severity was assessed in accordance with the Tarpley score.

RESULTS

Serum YKL-40, IL-6 and TNF-α levels significantly elevated in pSS patients compared with those in HC (all P < 0.001). These cytokines correlated with ESSDAI, ESR, CRP, and IgG (all P < 0.05). Serum YKL-40 level correlated markedly with age (r = 0.405, P = 0.002), neutrophil count (r = 0.399, P = 0.002) and neutrophil-to-lymphocyte ratio (NLR) (r = 0.401, P = 0.002), while IL-6 did weakly with NLR (r = 0.296, P = 0.024) and C3 (r = 0.288, 0.036). Serum levels of all three cytokines were substantially lower in patients with eye/mouth dryness vs. those without (all P < 0.05). Additionally, patients with pulmonary, renal involvement or anemia had remarkably higher concentrations of YKL-40 (all P < 0.05), while those with leukocytopenia had lower levels (P = 0.01). Fever or anemia patients showed higher serum concentrations of IL-6 (both P < 0.05), while serum levels of TNF-α were much higher in patients with presence of ANA, anti-SSA or anti-SSB antibodies (All P < 0.05). Serum IL-6 level correlated strongly with YKL-40 (r = 0.452, P < 0.001) and TNF-α (r = 0.743, P < 0.001) in pSS patients. A significant correlation was also found between YKL-40 and TNF-α (r = 0.308, P = 0.022) .

CONCLUSION

The circulating YKL-40, IL-6 and TNF-α levels increase in pSS, and all of them are significantly correlated with indicators (ESSDAI, ESR, CRP, and IgG) for systemic inflammation of pSS. Each cytokine is separately associated with specific pSS phenotype.

Anticentromere antibody-positive primary Sjögren's syndrome: Epitope analysis of a subset of anticentromere antibody-positive patients

OBJECTIVES

Anticentromere antibody (ACA) is generally considered to be a serological marker for systemic sclerosis (SSc). ACA-positive patients with primary Sjögren's syndrome (pSS) have also been reported. ACA often recognizes centromere proteins (CENPs): CENP-A, CENP-B, and CENP-C, and sometimes reacts to heterochromatin protein 1 (HP1)α. We compared the reactivity against six different epitopes for three ACA-positive clinical subgroups: 29 patients with pSS, 36 SSc patients with sicca symptoms, and 28 SSc patients without sicca symptoms.

METHODS

We utilized enzyme-linked immunosorbent assays (ELISAs) with recombinant proteins covering six different epitope regions of ACA (the amino terminus (Nt) of CENP-A, CENP-B, and CENP-C, the carboxyl terminus (Ct) of CENP-B and CENP-C, and HP1α).

RESULTS

The patients with pSS were found to have IgG-class autoantibodies against CENP-C-Nt and HP1α, and IgA-class autoantibodies against CENP-C-Ct with significantly higher frequencies than the SSc patients with or without sicca symptoms. The positive predictive value and the negative predictive value of the combination of these three autoantibodies for pSS were 73% and 82%, respectively, for pSS.

CONCLUSIONS

Based on the result that reactivities against CENP-C and HP1α in patients with pSS differ from those in patients with SSc, we propose ACA-positive pSS as a clinical subset of SS that is independent of SSc.

Association between increased Bcl-2, Fas and FasL levels and inflammation extent in labial salivary glands during primary Sjögren's syndrome

BACKGROUND

Primary Sjögren syndrome (pSS) is a chronic autoimmune disease characterized by epithelial atrophy, mononuclear infiltration in exocrine glands resulting in defective function of these glands. In pSS, atrophy of the epithelium is caused by an increased amount of apoptosis.

OBJECTIVE

The main aim of this study is to investigate the role of the apoptosis-related factors by studying Bcl-2, Fas and FasL expression in relation to the extent of inflammation as well as the effect of therapy on the expression of these mediators.

METHODS

In pSS patients (n=62) documented for their serological and clinical features, Fas, FasL and Bcl-2 plasma levels were assessed using enzyme-linked immunosorbent assays. In the same context, we investigated their expression by immunohistochemistry analysis in the labial salivary glands samples in association with the extent of inflammation.

RESULTS

Interestingly, our results indicated that in pSS patients, the plasmatic Bcl-2, Fas and FasL levels, which appear to be associated with the severity of inflammation and were significantly elevated in comparison to the healthy controls. Moreover, a significant decrease in all these factors was observed in patients after combined corticosteroids-hydroxychloroquine therapy. Importantly, we report a strong positive correlation between Bcl-2 and NO levels. The immunohistochemical staining reveals a strong Bcl-2 expression in infiltrating mononuclear cells and a total absence in the acinar cells. The Bcl-2 level varies according to the severity of the pathology. However, the expression of Fas and FasL was less important and predominantly localized in infiltrating mononuclear cells.

CONCLUSION

Our current study highlights the involvement of Bcl-2, Fas and FasL in pSS glands injury. These factors may act as useful predictor markers of a clinical course in pSS suggesting a novel approach in the pSS patients monitoring.

Autoantibodies to dense-fine-speckled 70 (DFS70) do not necessarily rule out connective tissue diseases

OBJECTIVES

In some patients with antinuclear antibodies (ANA), a pattern called anti-dense-fine-speckled-70 antibody (anti-DFS70) can be detected. Presence of anti-DFS70 is less frequently observed in patients with connective tissue diseases (CTD) and is therefore used as an exclusion criterion by some rheumatologists. To date, however, it is unclear as to what extent the presence of an anti-DFS70 can reliably rule out CTDs.

METHODS

Data of 460 patients who were tested for the presence of anti-DFS70 at University Hospital Bonn, Germany, were analyzed. Patients were examined with regard to clinical symptoms and signs, type of disease, type of CTD, fulfillment of the classification criteria, presence of anti-DFS70, other systemic autoantibodies and ANA titers by indirect immunofluorescence (IIF) assays and line immunoassays. Differences in DFS70 antibody status between patients with CTD were examined. In addition, specificity, sensitivity, and positive predictive values for different ANA titers were calculated.

RESULTS

In 182 of the 460 patients (of whom 79.8% were female), CTD was diagnosed. 354 patients (77.0%) tested negative, 81 (17.6%) positive and 25 (5.4%) borderline for anti-DFS70. Twenty-one patients (25.9%) with a positive result had CTD. No significant differences were observed between anti-DFS70 positive and anti-DFS70 negative patients with CTD concerning age, gender, symptoms, clinical signs, and other disease-specific antibodies. However, of these 21 patients, only one patient showed the monospecific appearance of anti-DFS70. Anti-DFS70 had a sensitivity and a specificity of 26.9% and 86.8%, respectively, with a positive predictive value of 68.2% at an ANA titer of ≥1:160 with respect to the absence of CTD.

CONCLUSIONS

Autoantibodies to DFS70 seem to be prevalent in CTD patients and are thus not a good exclusion criterion. The monospecific occurrence of anti-DFS70 can, however, be helpful in ambiguous situations.

Tear metabolomics highlights new potential biomarkers for differentiating between Sjögren's syndrome and other causes of dry eye

PURPOSE

The lacrimal exocrinopathy of primary Sjögren's syndrome (pSS) is one of the main causes of severe dry eye syndrome and a burden for patients. Early recognition and treatment could prevent irreversible damage to lacrimal glands. The aim of this study was to find biomarkers in tears, using metabolomics and data mining approaches, in patients with newly-diagnosed pSS compared to other causes of dry eye syndrome.

METHODS

A prospective cohort of 40 pSS and 40 non-pSS Sicca patients with dryness was explored through a standardized targeted metabolomic approach using liquid chromatography coupled with mass spectrometry. A metabolomic signature predictive of the pSS status was sought out using linear (logistic regression with elastic-net regularization) and non-linear (random forests) machine learning architectures, after splitting the studied population into training, validation and test sets.

RESULTS

Among the 104 metabolites accurately measured in tears, we identified a discriminant signature composed of nine metabolites (two amino acids: serine, aspartate; one biogenic amine: dopamine; six lipids: Lysophosphatidylcholine C16:1, C18:1, C18:2, sphingomyelin C16:0 and C22:3, and the phoshatidylcholine diacyl PCaa C42:4), with robust performances (ROC-AUC = 0.83) for predicting the pSS status. Adjustment for age, sex and anti-SSA antibodies did not disrupt the link between the metabolomic signature and the pSS status. The non-lipidic components also remained specific for pSS regardless of the dryness severity.

CONCLUSION

Our results reveal a metabolomic signature for tears that distinguishes pSS from other dry eye syndromes and further highlight nine key metabolites of potential interest for early diagnosis and therapeutics of pSS.

Long-term renal prognosis among patients with primary Sjögren's syndrome and renal involvement: A nationwide matched cohort study

BACKGROUND

The long-term renal outcome in patients with primary Sjögren's syndrome (pSS) remains uncertain. We aimed to determine the absolute incidence and relative risk of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in patients with pSS at the general population level.

METHODS

We performed a retrospective cohort study using a national health insurance database in Taiwan from 2000 to 2013. We calculated the cumulative incidence of CKD and ESRD in our pSS and age-, sex- and entry time-matched control cohorts. Cox regression analyses were used to estimate adjusted hazard ratios (aHRs) after adjusting for comorbidities and medications.

RESULTS

Among 17 505 patients with incident pSS, 1008 (5.8%) developed CKD and 38 (0.22%) developed ESRD. Of the 87 525 non-pSS controls, 3173 (3.6%) developed CKD and 256 (0.29%) developed ESRD. The risk of CKD was higher in patients with pSS than in the non-pSS controls (adjusted hazard ratio [HR] 1.49, 95% confidence interval [95% CI] 1.38-1.59). Notably, the risk of ESRD was similar in both pSS and non-pSS cohorts (aHR 0.82, 95% CI 0.58-1.16).

CONCLUSIONS

Renal prognosis among patients with pSS and renal involvement is good. Although the risk of ESRD did not increase in patients with pSS, a significantly increased risk of CKD was observed in these patients, indicating the need for increased vigilance in regular monitoring for renal complications in patients with pSS.

Increased RNA editing sites revealed as potential novel biomarkers for diagnosis in primary Sjögren's syndrome

BACKGROUND

Transcriptome-wide aberrant RNA editing has been shown to contribute to autoimmune diseases, but its extent and significance in primary Sjögren's syndrome (pSS) are currently poorly understood.

METHODS

We systematically characterized the global pattern and clinical relevance of RNA editing in pSS by performing large-scale RNA sequencing of minor salivary gland tissues obtained from 439 pSS patients and 130 non-pSS or healthy controls.

FINDINGS

Compared with controls, pSS patients displayed increased global RNA-editing levels, which were significantly correlated and clinically relevant to various immune features in pSS. The elevated editing levels were likely explained by significantly increased expression of adenosine deaminase acting on RNA 1 (ADAR1) p150 in pSS, which was associated with disease features. In addition, genome-wide differential RNA editing (DRE) analysis between pSS and non-pSS showed that most (249/284) DRE sites were hyper-edited in pSS, especially the top 10 DRE sites dominated by hyper-edited sites and assigned to nine unique genes involved in the inflammatory response or immune system. Interestingly, among all DRE sites, six RNA editing sites were only detected in pSS and resided in three unique genes (NLRC5, IKZF3 and JAK3). Furthermore, these six specific DRE sites with significant clinical relevance in pSS showed a strong capacity to distinguish between pSS and non-pSS, reflecting powerful diagnostic efficacy and accuracy.

CONCLUSION

These findings reveal the potential role of RNA editing in contributing to the risk of pSS and further highlight the important prognostic value and diagnostic potential of RNA editing in pSS.