Current concepts on Sjögren's syndrome - classification criteria and biomarkers

Detection of T Follicular Helper Cells and T Follicular Regulatory Cells in Experimental Sjögren's Syndrome

With the compiling studies on the autoimmune pathogenesis in the developing of Sjögren's syndrome, the functional importance of T follicular helper cells (Tfh) and T follicular regulatory cells (Tfr) was investigated, including our recent findings, among which various techniques for detecting Tfh and Tfr cells in Sjögren's syndrome have been reported. In this chapter, we describe detailed methods for the effective detection of Tfh and Tfr cells in mice with experimental Sjögren's syndrome (ESS), a mouse model with evident salivary hypofunction, increased serum levels of autoantibodies, and histopathological changes in the salivary glands. We provide representative detections of surface markers, cytokines, and transcription factors of Tfh and Tfr cells by flow cytometry and ELISpot assay. Moreover, a detailed protocol for detecting Tfh and Tfr cells in the draining cervical lymph nodes (CLNs) in ESS mice by immunofluorescence microscopy is also described. Together, these techniques of Tfh and Tfr cell detection in ESS mice may facilitate the investigation of autoimmune pathogenesis and enhance the understanding of Tfh and Tfr cell functions in the development of Sjögren's syndrome.

Sjogren's Syndrome: Recent Updates

Primary Sjögren's syndrome (SS) is a chronic systemic autoimmune disorder affecting primarily perimenopausal women [...].

Clinical and laboratory features of childhood-onset primary Sjögren's syndrome: A retrospective study from China

INTRODUCTION

The initial presentations of childhood-onset primary Sjögren's syndrome (C-pSS) vary, making diagnosis challenging. We aimed to improve the diagnosis and evaluation of C-pSS by summarizing its clinical and laboratory features.

METHODS

A total of 49 patients with C-pSS between July 2015 and August 2022 in the Department of Rheumatology and Immunology of Shanghai Children's Medical Centre were enrolled in this study. Their clinical manifestations and laboratory examinations of these patients were compared based on the presence or absence of thrombocytopenia and parotitis and whether the immunological markers, including anti-nuclear antibodies (ANA), rheumatoid factor (RF), anti-Ro52/SSA antibodies (anti-SSA/Ro52), anti-Ro60/SSA antibodies (anti-SSA/Ro60), and anti-Ro/SSB antibodies (anti-SSB), were positive.

RESULTS

The mean age at C-pSS diagnosis was 10.34 ± 3.45 years, and the ratio of boys to girls was 1:6. In the thrombocytopenia group, parotitis (P = 0.044), organ involvement except for hematology (P = 0.002), positive anti-SSB (P = 0.004), and positive RF (P = 0.001) were less frequently observed. Complement C4 (P = 0.038) and white blood cells (P = 0.002) levels decreased and increased significantly, respectively. Anti-SSB (P = 0.010) and RF (P = 0.004) positivity were independent potential protective factors against thrombocytopenia in patients with C-pSS. In the parotitis group, higher ANA titers (P = 0.027), higher focus scores on labial gland biopsy (P = 0.024), and positive RF (P = 0.001), anti-SSA/Ro60 (P = 0.003), and anti-SSB (P = 0.001) were observed more frequently. Furthermore, positive anti-SSB (P = 0.012) and positive RF (P = 0.028) were independent risk factors for parotitis in patients with C-pSS. The hemoglobin level was significantly lower in patients with positive anti-SSA/Ro52 and positive anti-SSA/Ro60 results (P = 0.022 and P = 0.029, respectively), while immunoglobulin G level was significantly higher in patients in the same group (P = 0.048 and P = 0.007, respectively).

CONCLUSIONS

Positive anti-SSB and positive RF values may be independent potential protective factors of thrombocytopenia in patients with C-pSS. In contrast, positive anti-SSB and positive RF were independent risk factors of parotitis in patients with C-pSS. More studies are needed to reveal the diagnostic role and pathogenic mechanism of immunological markers in C-pSS.

Comparison of salivary gland MRI and ultrasonography findings among patients with Sjögren's syndrome over a wide age range

Objectives

This retrospective study compared MRI and US findings among patients with SS over a wide age range.

Methods

Ninety patients with SS aged 8–84 years who had undergone both MRI and US examinations were divided into four groups according to age, as follows: <18 years (juvenile SS, JSS), 9 patients; 18–39 years, 12 patients; 40–69 years, 53 patients; >69 years, 16 patients. Imaging findings of parotid glands (PGs) and submandibular glands (SMGs) were compared among the four groups. Furthermore, the relationships within and between imaging findings and various clinical findings were examined.

Results

On MRI, patients with JSS commonly exhibited multiple high-intensity spots in the PGs on MR sialography and fat-suppressed T2-weighted imaging. With increasing SS group age, the frequencies and numbers of the high-intensity spots were lower. Fat areas on MRI and hyperechoic bands on US were rarely observed in the PGs and SMGs of patients with JSS, whereas they were more common in patients with adult SS. In addition, the presence of hyperechoic bands on US, the presence of fat areas on MRI, and decreased salivary flow were associated with one another.

Conclusion

Salivary gland imaging findings in patients with JSS were characterized by punctate sialectasis, whereas those findings in patients with adult SS were characterized by fatty degeneration. Distinct findings in patients with JSS and adult SS are likely to reflect differences in glandular lesion stage. MRI and US are presumably useful for evaluation of glandular lesion severity during follow-up.

Diagnostic performance of serology against histologic assessment to diagnose Sjogren's syndrome: a systematic review

The objective of this review was to assess and evaluate whether the published diagnostic accuracy studies provide evidence to sustain the current diagnostic guidelines put forth by ACR/EULAR used for patients with suspected Sjögren's syndrome (SS). Literature databases, including Medline, Embase, and EBM Reviews, were searched for relevant studies on the correlation between ACR/EULAR criteria, particularly those with a direct comparison between their accuracy in diagnosing Sjögren's syndrome. We followed Cochrane, QUADAS-2, and STARD guidelines and the four-phase flow diagram by the PRISMA Statement. Reports in several languages, but only human studies were considered. Three studies assessed the accuracy of the current diagnostic tests, and these did not present adequate designs that would allow a well-supported conclusion with a high level of certainty. Due to significant clinical and methodological heterogeneity, a meta-analysis was not performed. A qualitative review of the papers was undertaken. Neither the comparative nor the non-comparative study designs permit conclusive recommendations regarding an alternative diagnostic pathway for SS. Well-designed studies of the diagnostic accuracy of SS tests are needed to validate current guidelines or to suggest changes to the current guidelines.

Ultrasonography predicts the results of labial salivary gland biopsy in patients with suspected Sjögren's syndrome: a matrix risk model

Objective:

Although a positive result of labial salivary gland biopsy (LSGB) is critical for the diagnosis of Sjögren’s syndrome, rheumatologists prefer assessing the non-invasive objective items and hope to learn the predicted probability of positive LSGB before referring patients with suspected Sjögren’s syndrome to receive biopsy. This study aimed to explore the predictive value of combined B-mode ultrasonography (US) and shear-wave elastography (SWE) examination on LSGB results.

Methods:

A derivation cohort and later a validation cohort of patients with suspected Sjögren’s syndrome were recruited. All participants received clinical assessments, B-mode US and SWE examination on bilateral parotid and submandibular glands before LSGB. Positive LSGB was defined by a focus score ⩾1 per 4 mm² of glandular tissue.

Results:

In the derivation cohort of 91 participants, either the total US scores or the total SWE values of four glands significantly distinguished patients with positive LSGB from those with negative results (area under the curve (AUC) = 0.956, 0.825, both p < 0.001). The positive predictive value (PPV) was 100% in patients with total US scores ⩾9 or with total SWE values ⩾33 kPa. The negative predictive value (NPV) was 100% in patients with total US scores <5, but 68% in patients with total SWE values <27 kPa. A matrix risk model was derived based on the combination of total US scores and total SWE values. Patients can be stratified into high, moderate, and low risk of positive LSGB. In the validation cohort of 52 participants, the PPV was 94% in the high-risk subpopulation and the NPV was 93% in the low-risk subpopulation.

Conclusion:

A novel matrix risk model based on the combined B-mode US and SWE examination can help rheumatologists to make a shared decision with suspected Sjögren’s syndrome patients on whether the invasive procedure of LSGB should be performed.

Musculoskeletal Manifestations in Sjogren's Syndrome: An Orthopedic Point of View

Sjogren's syndrome (SS) is a frequent entity with a broad symptomatology spectrum, mainly affecting the salivary and lachrymal glands. The disease also affects the musculoskeletal system targeting bones, specific joints, muscles, and the peripheral nerve system. Disease related clinical manifestations canhave an accumulative impact, as the syndrome is commonly associated with other rheumatic diseases. A literature review was performed with the aim to assess the in-depth association of Sjogren's syndrome and its treatment agents with the musculoskeletal system and further investigate its potential relevance with common orthopedic postoperative complications.

A case of Sjögren's syndrome with worsening of pleural effusion due to steroid discontinuation

The etiology of Sjögren's syndrome (SS) remains unclear and is associated with many other autoimmune diseases. In particular, symptoms of SS are not apparent when steroids are already being administered for other autoimmune diseases. This report documents a case of autoimmune hepatitis with SS, which was diagnosed on the basis of the worsening of unilateral pleural effusion after the discontinuation of steroids as well as the manifestation of symptoms, such as dry mouth. Adrenal insufficiency due to the discontinuation of steroids was assumed to be the cause of the worsening, rather than infection stress, because no indicators of infectious diseases were observed. The diagnosis of SS was confirmed via lip biopsy examination and anti-SS antibody positivity. Re-administration of steroids rather than antibiotics drastically reduced the pleural effusion and improved the dry mouth symptom. SS with pleural effusion in a case of autoimmune disease was reported to show both unilateral and bilateral pleural effusion predominantly containing lymphocytes. SS with pleural effusion may be more common than expected and should be differentiated from traditional SS. Moreover, biopsy examination should be considered if necessary because the condition might remain latent when steroids are administered.

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Sjögren's syndrome might be masked by steroid treatment for other conditions.

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Pleural effusion after steroid discontinuation might indicate Sjögren's syndrome.

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Lip biopsy examination and anti-SS antibody tests help confirm Sjögren's syndrome.

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Re-administration of steroids helps reverse the condition and improve symptoms.

Anti-Ro/SSA Antibodies May Be Responsible for Cerebellar Degeneration in Sjogren's Syndrome

Background

Neurological disorders have been identified to be a common extraglandular manifestation of Sjogren's syndrome (SjS). Central nervous system (CNS) symptoms appear in about 5% of patients with SjS. However, so far, only a few incidences of cerebellar degeneration have been reported, and the clinical features and pathological mechanisms associated with SjS remain to be unclear. Intramedullary production of anti-Ro/anti-SjS-related antigen A (SSA) has been observed in some patients with SjS patients who have CNS involvement, suggesting the involvement of anti- Ro/SSA antibodies as antineuronal antibodies in previous studies.

Methods

We recently treated cerebellar degeneration in a patient with SjS. We analyzed the serum and cerebrospinal fluid (CSF) in order to detect anti-Ro/SSA and anti-La/anti-SjS-related antigen B (SSB) antibodies. We also searched the literature for previous case reports to evaluate the characteristics of cerebellar degeneration in patients with SjS. First, we have studied in mouse brain tissue and examined whether the Ro/SSA (Ro52/tripartite motif protein (TRIM)21) protein was expressed in the cerebellum of mice using immunohistochemistry.

Results

Although all patients that we found in the literature review and our patient 1 were positive for anti-Ro/SSA antibodies, some patients were also negative for anti-La/SSB antibodies. Anti-Ro/SSA antibodies were observed in both serum and CSF; however, anti-Ro/SSA antibodies were negative in the CSF of patients with SjS without CNS involvement. Cerebellar atrophy was observed, and sequelae remained in the majority of patients. Autopsy findings indicated a selective loss of Purkinje cells. Ro52/TRIM21 expression was also detected throughout murine brains, including the hippocampus, cerebral cortex and cerebellum. High Ro52/TRIM21 expression was observed in the Purkinje cells.

Conclusions

We described the characteristics of cerebellar degeneration in patients with SjS and Ro52/TRIM21 expression in the Purkinje cells of murine cerebellar tissue sections. These outcomes indicate that anti-Ro/SSA antibodies were likely responsible for cerebellar degeneration in patients suffering from SjS.

Ophthalmologic Manifestations of Primary Sjögren's Syndrome

Sjögren’s syndrome (SS) is a chronic, progressive, inflammatory, autoimmune disease, characterized by the lymphocyte infiltration of exocrine glands, especially the lacrimal and salivary, with their consequent destruction. The onset of primary SS (pSS) may remain misunderstood for several years. It usually presents with different types of severity, e.g., dry eye and dry mouth symptoms, due to early involvement of the lacrimal and salivary glands, which may be associated with parotid enlargement and dry eye; keratoconjunctivitis sicca (KCS) is its most common ocular manifestation. It is still doubtful if the extent ocular surface manifestations are secondary to lacrimal or meibomian gland involvement or to the targeting of corneal and conjunctival autoantigens. SS is the most representative cause of aqueous deficient dry eye, and the primary role of the inflammatory process was evidenced. Recent scientific progress in understanding the numerous factors involved in the pathogenesis of pSS was registered, but the exact mechanisms involved still need to be clarified. The unquestionable role of both the innate and adaptive immune system, participating actively in the induction and evolution of the disease, was recognized. The ocular surface inflammation is a central mechanism in pSS leading to the decrease of lacrimal secretion and keratoconjunctival alterations. However, there are controversies about whether the ocular surface involvement is a direct autoimmune target or secondary to the inflammatory process in the lacrimal gland. In this review, we aimed to present actual knowledge relative to the pathogenesis of the pSS, considering the role of innate immunity, adaptive immunity, and genetics.

Identification of a Novel Serum Proteomic Signature for Primary Sjögren's Syndrome

Context

Primary Sjögren's syndrome (pSS) is a complex heterogeneous autoimmune disease (AID) which can mimic rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE). Our exploratory study investigated serum biomarkers that may discriminate pSS from RA and SLE.

Methods

Serum concentrations of 63 biomarkers involved in immune cell trafficking, inflammatory response, cellular movement, and cell-to-cell signaling were measured in AID patients, included prospectively into the study at the Montpellier University Hospital. A multivariate analysis by multiple logistic regression was performed, and discriminative power assessed using logistic regression adjusted on significant demographic factors.

Results

Among the 95 patients enrolled, 42 suffered from pSS, 28 from RA, and 25 from SLE. Statistical analysis showed that concentrations of BDNF (OR = 0.493 with 95% CI [0.273-0.891]; p = 0.0193) and I-TAC/CXCL11 (OR = 1.344 with 95% CI [1.027-1.76]; p = 0.0314) can significantly discriminate pSS from RA. Similarly, greater concentrations of sCD163 (OR = 0.803 with 95% CI [0.649-0.994]; p = 0.0436), Fractalkine/CX3CL1 (OR = 0.534 with 95% CI [0.287-0. 991]; p = 0.0466), MCP-1/CCL2 (OR = 0.839 with 95% CI [0.732-0.962]; p = 0.0121), and TNFa (OR = 0.479 with 95% CI [0.247-0.928]; p = 0.0292) were associated with SLE diagnosis compared to pSS. In addition, the combination of low concentrations of BDNF and Fractalkine/CX3CL1 was highly specific for pSS (specificity 96.2%; positive predictive value 80%) compared to RA and SLE, as well as the combination of high concentrations of I-TAC/CXCL11 and low concentrations of sCD163 (specificity 98.1%; positive predictive value 75%).

Conclusion

Our study highlights biomarkers potentially involved in pSS, RA, and SLE pathophysiology that could be useful for developing a pSS-specific diagnostic tool.

A distinguishing profile of chemokines, cytokines, and biomarkers in the saliva of children with Sjögren's syndrome

Objective

SS is an autoimmune disease most commonly diagnosed in adults but can occur in children. Our objective was to assess the presence of chemokines, cytokines and biomarkers (CCBMs) in saliva from these children that were associated with lymphocyte and mononuclear cell functions.

Methods

Saliva was collected from 11 children diagnosed with SS prior to age 18 years and 16 normal healthy children. A total of 105 CCBMs were detected in multiplex microparticle-based immunoassays. ANOVA and t test (0.05 level) were used to detect differences. Ingenuity Pathway Analysis (IPA) was used to assess whether elevated CCBMs were in annotations associated with immune system diseases and select leukocyte activities and functions. Machine learning methods were used to evaluate the predictive power of these CCBMs for SS and were measured by receiver operating characteristic (ROC) curve and area under curve (AUC).

Results

Of the 105 CCBMs detected, 43 (40.9%) differed in children with SS from those in healthy study controls (P < 0.05) and could differentiate the two groups (P < 0.05). Elevated CCBMs in IPA annotations were associated with autoimmune diseases and with leukocyte chemotaxis, migration, proliferation, and regulation of T cell activation. The best AUC value in ROC analysis was 0.93, indicating that there are small numbers of CCBMs that may be useful for diagnosis of SS.

Conclusion

While 35 of these 43 CCBMs have been previously reported in SS, 8 CCBMs had not. Additional studies focusing on these CCBMs may provide further insight into disease pathogenesis and may contribute to diagnosis of SS in children.

Recognize Yourself-Innate Sensing of Non-LTR Retrotransposons

Although mobile genetic elements, or transposons, have played an important role in genome evolution, excess activity of mobile elements can have detrimental consequences. Already, the enhanced expression of transposons-derived nucleic acids can trigger autoimmune reactions that may result in severe autoinflammatory disorders. Thus, cells contain several layers of protective measures to restrict transposons and to sense the enhanced activity of these “intragenomic pathogens”. This review focuses on our current understanding of immunogenic patterns derived from the most active elements in humans, the retrotransposons long interspersed element (LINE)-1 and Alu. We describe the role of known pattern recognition receptors in nucleic acid sensing of LINE-1 and Alu and the possible consequences for autoimmune diseases.

Immunology of IL-12: An update on functional activities and implications for disease

As its first identified member, Interleukin-12 (IL-12) named a whole family of cytokines. In response to pathogens, the heterodimeric protein, consisting of the two subunits p35 and p40, is secreted by phagocytic cells. Binding of IL-12 to the IL-12 receptor (IL-12R) on T and natural killer (NK) cells leads to signaling via signal transducer and activator of transcription 4 (STAT4) and subsequent interferon gamma (IFN-γ) production and secretion. Signaling downstream of IFN-γ includes activation of T-box transcription factor TBX21 (Tbet) and induces pro-inflammatory functions of T helper 1 (T_H1) cells, thereby linking innate and adaptive immune responses. Initial views on the role of IL-12 and clinical efforts to translate them into therapeutic approaches had to be re-interpreted following the discovery of other members of the IL-12 family, such as IL-23, sharing a subunit with IL-12. However, the importance of IL-12 with regard to immune processes in the context of infection and (auto-) inflammation is still beyond doubt. In this review, we will provide an update on functional activities of IL-12 and their implications for disease. We will begin with a summary on structure and function of the cytokine itself as well as its receptor and outline the signal transduction and the transcriptional regulation of IL-12 secretion. In the second part of the review, we will depict the involvement of IL-12 in immune-mediated diseases and relevant experimental disease models, while also providing an outlook on potential translational approaches.

Association of a dysbiotic oral microbiota with the development of focal lymphocytic sialadenitis in IκB-ζ-deficient mice

Mice lacking IκB-ζ, a protein encoded by the Nfkbiz gene, spontaneously develop a Sjögren’s syndrome-like disease involving the lachrymal glands, but no salivary gland symptoms have been reported. We found that Nfkbiz^−/− female mice presented a significantly reduced salivary flow rate, focal lymphocytic sialadenitis (FLS), and a dysbiotic oral microbiota at week 24. To dissect the contributions of genetic and environmental factors to the salivary gland phenotype, Nfkbiz^+/+ and Nfkbiz^−/− mice were cohoused after weaning and evaluated at week 20. Cohousing alleviated the salivary gland phenotype of Nfkbiz^−/− mice but did not induce any disease phenotype in Nfkbiz^+/+ mice. Additionally, the oral microbiota in the cohoused mice was synchronized toward that in Nfkbiz^+/+ mice. In conclusion, IκB-ζ-deficient mice developed hyposalivation and FLS, in which a dysbiotic oral microbiota played an important role. This finding suggests that the dysbiotic oral microbiota could be a therapeutic target.

Value of multilevel sectioning of labial salivary gland biopsies in the diagnosis of Sjögren's syndrome

OBJECTIVES

The objective of this study was to examine the diagnostic value of cutting labial salivary gland (LSG) biopsies at 2 levels in the histological evaluation for Sjögren's syndrome (SS).

STUDY DESIGN

This retrospective study included LSG biopsy specimens from 112 consecutive patients evaluated for SS from 2007 to 2019. Three observers, blinded with regard to patient data, independently scored the degree of focal lymphocytic infiltration (foci) and calculated the focus score in specimens cut at 2 levels 60 µm apart.

RESULTS

Unblinded analysis revealed that the LSG specimens derived from 107 women and 5 men, aged 49.2 ± 22.3 years. Seventy-six patients had SS (70 primary SS and 6 secondary SS) according to the American-European Consensus Group and American College of Rheumatology/European League Against Rheumatism criteria. The average number of LSGs was 5.0 ± 1.4 and the focus scoring area was 16.1 ± 7.6 mm². Compared to baseline, the average number of foci (4.4 vs 5.1, P < .001), focus score (1.7 vs 1.9, P = .01), and cases with focus score >1.0 (61 vs 74%; P = .03) were higher in the second level. Subsequently, an additional 11 cases of SS were confirmed (14%), and 8 non-SS cases were reclassified as SS (22%).

CONCLUSIONS

Histological assessment of an additional section level improves the diagnostic accuracy of the labial salivary gland biopsy to detect histopathological changes consistent with the diagnosis of SS.

A Tutorial on Saliva's Role in Swallowing With a Focus on Sjögren's Syndrome

Purpose Saliva is integral to swallowing and necessary for oral health. Understanding saliva's origin and properties is important for swallowing assessment and management. Diseases such as Sjögren's syndrome (SS) can affect saliva negatively, often contributing to dysphagia. Our objectives are to (a) highlight saliva's fundamental role in swallowing, (b) provide a bibliometric overview of literature pertaining to SS pathophysiology and effects on saliva, (c) explore implications of salivary changes on swallowing and quality of life in SS and other populations, and (d) provide suggestions for systematic saliva assessment in practice. Method This tutorial reviews saliva production, composition, and involvement in swallowing within health and disease. Using rapid review methodology, we outline the effect of SS on saliva and describe SS etiology, diagnosis, and treatment. We discuss formal saliva assessments and a multidisciplinary approach. Results Saliva plays a vital role in swallowing, particularly lubrication, bolus formation, and oral health. SS affects the salivary glands altering salivary flow rate and composition. We identified 55 studies (N) measuring salivary changes, grouping them according to four strata demarcated by SS classification criteria updates. For some, xerostomia, dysphagia, and reduced life quality result. Formal saliva assessments include the Clinical Oral Dryness Score, Xerostomia Inventory, and Secretion Rating Scale. Multidisciplinary care is optimal for patients with salivary changes. Conclusion Understanding salivary changes in disease may enhance understanding of swallowing and inform dysphagia practice. Expanding swallowing assessments with formal saliva evaluations, and patient perspectives thereof, may aid in developing bespoke treatments, ultimately improving outcomes and quality of life. Supplemental Material https://doi.org/10.23641/asha.12456449.

Mesenchymal stem cells inhibited the differentiation of MDSCs via COX2/PGE2 in experimental sialadenitis

Background

Mesenchymal stem cells (MSCs) can regulate innate and adaptive immune systems through interacting with immune cells directly and secreting multiple soluble factors. Due to their immunosuppressive properties, MSC transplantation has been applied to treat many clinical and experimental autoimmune diseases. However, the therapeutic effects and mechanisms by which MSCs regulate myeloid cells in Sjögren’s syndrome (SS) still remain elusive.

Methods

The number and immune-suppressive activity of myeloid-derived suppressor cells (MDSCs), polymorphonuclear MDSCs (PMN-MDSCs), and monocytic MDSCs (M-MDSCs) were determined in non-obese diabetic (NOD) mice with sialadenitis and in NOD mice with human umbilical cord-derived MSC (UC-MSC) transplantation. Bone marrow cells were cultured with MSC-conditioned medium (MSC-CM) for 4 days. The number and immune-suppressive gene of MDSCs were detected by flow cytometry or qRT-PCR.

Results

The results showed that the number of MDSCs and PMN-MDSCs was higher and M-MDSCs were lower in NOD mice with sialadenitis. UC-MSCs ameliorated SS-like syndrome by reducing MDSCs, PMN-MDSCs, and M-MDSCs and promoting the suppressive ability of MDSCs significantly in NOD mice. UC-MSCs inhibited the differentiation of MDSCs. In addition, UC-MSCs enhanced the suppressive ability of MDSCs in vitro. Mechanistically, MSCs inhibited the differentiation of MDSCs and PMN-MDSCs via secreting prostaglandin E2 (PGE2) and inhibited the differentiation of M-MDSCs through secreting interferon-β (IFN-β).

Conclusions

Our findings suggested that MSCs alleviated SS-like symptoms by suppressing the aberrant accumulation and improving the suppressive function of MDSCs in NOD mice with sialadenitis.

A Novel Proposal of Salivary Lymphocyte Detection and Phenotyping in Patients Affected by Sjogren's Syndrome

A preliminary evaluation of the parotid secretion cellular composition in patients with Sjogren’s Syndrome (SS) and a diagnostic accuracy assessment of salivary lymphocyte detection and immunophenotyping in Sjogren’s Syndrome diagnosis and prognosis were performed. The study included 40 consecutive patients, aged 19–60 years, with parenchymal sialadenitis associated with Sjogren’s Syndrome, and 20 healthy donors. The exclusion criteria were exacerbation of sialadenitis, chronic infections, malignant neoplasms, and lymphoproliferative diseases. The standard diagnostic tests were minor salivary gland biopsy and parotid sialography. Immunophenotyping of parotid secretion lymphocytes was performed by multicolor flow cytometry. Lymphocytes were detectable in parotid secretion of patients affected by Sjogren’s Syndrome, both primary (pSS) and secondary (sSS) form, but not in that from healthy donors. Sensitivity, specificity, positive, and negative predictive values of lymphocytes detection in parotid saliva were 77.5%, 100%, 100%, and 69%, respectively. The mean numbers of the total T-cell population, T-helper cells, and T-cytotoxic cells were 71.7%, 41.6%, and 53%, respectively. The immunophenotype of lymphocytes obtained by patients’ parotid flow resembles the immunophenotypes of glandular biopsies currently known. Our preliminary data suggest the use of saliva as an alternative and non-invasive method for evaluating the prognosis of Sjogren’s Syndrome.

Salivary Redox Biomarkers in Selected Neurodegenerative Diseases

Neurodegenerative diseases (NDDs), such as Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, are disorders, which cause irreversible and progressive deterioration of the central nervous system. The pathophysiology of NDDs is still not fully explained; nevertheless, oxidative stress is considered as a critical mediator of cerebral degeneration, brain inflammation, as well as neuronal apoptosis. Therefore, it is not surprising that redox biomarkers are increasingly used in the diagnosis of neurodegenerative diseases. As saliva is a very easy to obtain bioliquid, it seems promising to use this biomaterial in the diagnosis of NDDs. Saliva collection is easy, cheap, stress-free, and non-infectious, and it does not require the help of a specialised medical personnel. Additionally, the concentrations of many salivary redox biomarkers correlate with their content in blood serum as well as the degree of disease progression, which makes them non-invasive indicators of NDDs. This paper reviews the latest knowledge concerning the use of salivary redox biomarkers in the diagnosis and prognosis of selected neurodegenerative diseases.

Saliva and Oral Diseases

Saliva is a fascinating biological fluid which has all the features of a perfect diagnostic tool. In fact, its collection is rapid, simple, and noninvasive. Thanks to several transport mechanisms and its intimate contact with crevicular fluid, saliva contains hundreds of proteins deriving from plasma. Advances in analytical techniques have opened a new era-called "salivaomics"-that investigates the salivary proteome, transcriptome, microRNAs, metabolome, and microbiome. In recent years, researchers have tried to find salivary biomarkers for oral and systemic diseases with various protocols and technologies. The review aspires to provide an overall perspective of salivary biomarkers concerning oral diseases such as lichen planus, oral cancer, blistering diseases, and psoriasis. Saliva has proved to be a promising substrate for the early detection of oral diseases and the evaluation of therapeutic response. However, the wide variation in sampling, processing, and measuring of salivary elements still represents a limit for the application in clinical practice.

Human umbilical cord mesenchymal stem cells confer potent immunosuppressive effects in Sjögren's syndrome by inducing regulatory T cells

BACKGROUND

Primary Sjögren's syndrome (SS) is a lymphoproliferative disease with a chronic autoimmune disorder characterized by mononuclear cell (MNC) infiltration of notably the lacrimal and salivary glands. As mesenchymal stem cells (MSCs) regulate series of immunological responses partially by regulating proportion of CD4⁺ T cells and inducing an immunosuppressive local milieu, umbilical cord MSCs (UC-MSCs) are being considered as a novel source for cell-based therapies against primary SS. This study aimed to investigate the feasibility of UC-MSCs in treatment of SS and to explore the possible mechanism(s) with the special emphasis on regulatory T cells (Tregs).

METHODS

Potent immunosuppressive effects of human UC-MSCs on SS were explored in vivo and in vitro. To study the effects of human UC-MSCs on the development and progression of SS, human UC-MSCs were administered before disease onset (preventive protocol) and after disease occurrence (therapeutic protocol) in non-obese diabetic (NOD) mice. In human study, the effect of human UC-MSCs on T cells from SS patients was studied.

RESULTS

In both protocols, the histopathology of submandibular and sublingual salivary glands showed decreased inflammatory infiltrates. In vitro, human UC-MSCs exhibited potent suppressive effects on responses of MNCs in NOD mice and T cells in SS patients. Such inhibitory effects were coupled with decreased production of proinflammtory cytokines interferon-γ, interleukin (IL)-6, tumor necrosis factor-α and increased production of IL-10 (n = 10, p < .01). The frequency of CD4⁺Foxp3⁺T cells in the spleen of NOD recipients was elevated (n = 6, p < .05).

CONCLUSION

Human UC-MSCs are capable of inducing CD4⁺Foxp3⁺ T cells in both NOD mice and human in vitro. Human UC-MSCs effectively interfere with the autoimmune attack in the course of SS by inducing an in vivo state of T cell unresponsiveness and the upregulation of Tregs.

Primary Sjögren's syndrome and the eye

Primary Sjögren syndrome is an autoimmune disease that mainly affects exocrine glands such as the salivary and lacrimal glands. In addition, systemic involvement is common. Primary Sjögren syndrome is of particular interest to ophthalmologists as it constitutes an important differential diagnosis in conditions with dry eye disease. In addition, ocular tests for more precisely diagnosing and monitoring primary Sjögren syndrome have become increasingly important, and new therapeutics for local and systemic treatment evolve as a result of increased understanding of immunological mechanisms and molecular pathways in the pathogenesis of primary Sjögren syndrome. We provide an update of interest to ophthalmologists regarding pathogenesis, diagnosis, investigative procedures, and treatment options.

Single Cell Based Phosphorylation Profiling Identifies Alterations in Toll-Like Receptor 7 and 9 Signaling in Patients With Primary Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is associated with polymorphisms and mRNA expression profiles that are indicative of an exaggerated innate and type I IFN immune response. Excessive activation potential of signaling pathways may play a role in this profile, but the intracellular signaling profile of the disease is not well characterized. To gain insights into potentially dysfunctional intracellular signaling profiles of pSS patients we conducted an exploratory analysis of MAPK/ERK and JAK/STAT signaling networks in peripheral blood mononuclear cells (PBMC) from 25 female pSS patients and 25 female age-matched healthy donors using phospho-specific flow cytometry. We analyzed unstimulated samples, as well as samples during a 4 h time period following activation of Toll-like receptor (TLR) 7 and 9. Expression levels of MxA, IFI44, OAS1, GBP1, and GBP2 in PBMC were analyzed by real-time PCR. Cytokine levels in plasma were determined using a 25-plex Luminex-assay. Principal component analysis (PCA) showed that basal phosphorylation profiles could be used to differentiate pSS patients from healthy donor samples by stronger intracellular signaling pathway activation in NK and T cells relative to B cells. Stimulation of PBMC with TLR7 and -9 ligands showed significant differences in the phosphorylation profiles between samples from pSS patients and healthy donors. Including clinical parameters such as extraglandular manifestations (EGM), we observed stronger responses of NF-κB and STAT3 S727 in B cells from EGM-negative patients compared to EGM-positive patients and healthy controls. Plasma cytokine levels were correlated to the basal phosphorylation levels in these patients. In addition, 70% of the patients had a positive IFN score. These patients differed from the IFN score negative patients regarding their phosphorylation profiles and their plasma cytokine levels. In conclusion, we here report increased signaling potentials in peripheral B cells of pSS patients in response to TLR7 and -9 stimulation through STAT3 S727 and NF-κB that correlate with a type I IFN signature. Induction of these pathways could contribute to the generation of a type I IFN signature in pSS. Patients displaying elevated potentiation of STAT3 S727 and NF-κB signaling could therefore benefit from therapies targeting these pathways.

Current concepts on Sjögren's syndrome - classification criteria and biomarkers

Sjögren's syndrome is a lymphoproliferative disease with autoimmune features characterized by mononuclear cell infiltration of exocrine glands, notably the lacrimal and salivary glands. These lymphoid infiltrations lead to dryness of the eyes (keratoconjunctivitis sicca), dryness of the mouth (xerostomia), and, frequently, dryness of other surfaces connected to exocrine glands. Sjögren's syndrome is associated with the production of autoantibodies because B-cell activation is a consistent immunoregulatory abnormality. The spectrum of the disease extends from an organ-specific autoimmune disorder to a systemic process and is also associated with an increased risk of B-cell lymphoma. Current treatments are mainly symptomatic. As a result of the diverse presentation of the syndrome, a major challenge remains to improve diagnosis and therapy. For this purpose an international set of classification criteria for primary Sjögren's syndrome has recently been developed and validated and seems well suited for enrolment in clinical trials. Salivary gland biopsies have been examined and histopathology standards have been developed, to be used in clinical trials and patient stratification. Finally, ultrasonography and saliva meet the need of non-invasive imaging and sampling methods for discovery and validation of disease biomarkers in Sjögren's syndrome.