Prevalence of Novel Candidate Sjögren Syndrome Autoantibodies in the Penn Sjögren's International Collaborative Clinical Alliance Cohort

[Diagnostic values of anti-salivary gland protein-1 antibody combined with anti-parotid secretory protein antibody for Sjögren's syndrome]

OBJECTIVE

To assess the diagnostic value of anti-salivary gland protein-1 (SP1) antibody combined with anti-parotid secretory protein (PSP) antibody for Sjögren's syndrome (SS).

METHODS

A total of 60 patients with primary SS (pSS) who were treated in the outpatient and inpatient department of Department of Rheumatology and Immunology of the Second Hospital of Hebei Medical University from January 2020 to December 2022 were collected. Thirty patients with other autoimmune diseases accompanied by dry mouth and/or dry eyes were collected as disease control group. Thirty healthy subjects from the physical examination center were collected for healthy control group, serum samples were obtained from all of them. Their general features and clinical information including clinical manifestations, laboratory examinations and other examinations were recorded. The 2016 American College of Rheumatology (ACR)/European League against Rheumatism (EULAR) classification criteria were adopted as the diagnostic standard of pSS. Immunoglobulin G (IgG) subtype of anti-SP1 antibody and anti-PSP antibody were detected by chemiluminescence immunoassay. The receiver operating characteristic (ROC) curve was used to evaluate the accuracy of anti-SP1 antibody and anti-PSP antibody in diagnosing pSS.The cli-nical characteristics of anti-SP1 antibody and anti-PSP antibody positive patients and negative patients in pSS group were further compared. Independent samples t test, Mann-Whitney U test, variance analysis, Kruskal-Wallis test, Chi-square test or Fisher's exact test and Spearman correlation analysis were used for statistical analysis.

RESULTS

There was no significant difference in age (F=1.406, P=0.495) and gender (χ2=2.105, P=0.349) among pSS group, disease control group and healthy control group. The expression levels of anti-SP1 antibody (H=16.73, P < 0.001) and anti-PSP antibody (H=26.09, P < 0.001) were statistically different among the three groups. An intergroup comparison of anti-SP1 antibody expression levels showed that there was a statistically significant difference between pSS and healthy control group (P < 0.001), but no statistically significant difference between the other groups. Comparison of anti-PSP antibody expression levels between the groups showed that there were statistically significant differences between pSS and healthy control group (P < 0.001), and between disease control group and healthy control group (P=0.009), while no statistically significant differences between the other groups. The positive rate of anti-SP1 antibody in pSS group was significantly higher than that in disease control group and healthy control group (58.33% vs. 40.00% vs. 13.33%, P < 0.001). The positive rate of anti-PSP antibody in pSS group was significantly higher than that in disease control group and healthy control group (75.00% vs. 56.17% vs. 16.67%, P < 0.001). The area under the curve for anti-SP1 antibody was 0.688 (P < 0.001). The sensitivity and specificity of anti-SP1 antibody were 58.33% (35/60) and 70.00% (42/60) respectively, the positive predictive value was 66.04% (35/53) and the negative predictive value was 54.55% (42/77) of anti-SP1 antibody.The area under the curve of anti-PSP antibody was 0.720 (P < 0.001), with a sensitivity was 75.00% (45/60), and specificity was 63.33% (38/60).The positive predictive value and negative predictive value of anti-PSP antibody were 67.16% (45/67) and 71.70% (38/53) respectively. All the 13 pSS patients were negative for anti-Sjögren's syndrome A (SSA, including SSA52 and SSA60) antibody and anti- Sjögren's syndrome B (SSB) antibody. Among them, 11 patients were positive for both anti-SP1 antibody and anti-PSP antibody, 1 patient was positive for anti-SP1 antibody and 1 patient was positive for anti-PSP antibody. The clinical features of anti-SP1 antibody and anti-PSP antibody positive and negative groups were compared in pSS patients. The duration of disease in anti-SP1 antibody positive group was shorter (Z=-2.277, P=0.023) when compared with the negative patients. The patients with positive anti-PSP antibody were younger than those in the negative group (t=2.598, P < 0.05), the positive rate of rheumatoid factor (P=0.002) and the serum level of IgG (t=3.806, P=0.003) in anti-PSP antibody positive group were higher than in the negative group. Analysis of the correlation between anti-SP1 antibody and anti-PSP antibody in the pSS patients showed that there was significant correlation between them (r=0.801, P < 0.001).

CONCLUSION

Both anti-SP1 antibody and anti-PSP antibody are valuable in the diagnosis of SS, and anti-SP1 antibody is helpful for the early diagnosis of pSS. The combined detection of anti-SP1 antibody and anti-PSP antibody is helpful for the early diagnosis of pSS patients with negative anti-SSA antibody and anti-SSB antibody.

Diagnostic and therapeutic potentials of extracellular vesicles for primary Sjögren's Syndrome: A review

Primary Sjögren syndrome (pSS) is a chronic autoimmune disease mainly affecting salivary and lacrimal glands. The current pSS biomarkers, serum autoantibodies, are negative in many pSS patients diagnosed with histopathology changes, indicating the need of novel biomarkers. The current therapies of pSS are merely short-term symptomatic relief and can't provide effective long-term remedy. Extracellular vehicles (EVs) are nano-sized lipid bilayer-delimited particles spontaneously released by almost all types of cells and carrying various bioactive molecules to mediate inter-cellular communications. Recent studies found that EVs from salivary gland epithelial cells and immune cells play essential roles in pSS pathogenesis. Correspondingly, EVs and their cargos in plasma and saliva are promising candidate biomarkers for pSS diagnosis. Moreover, EVs from mesenchymal stem cells have shown promises to improve pSS treatment by modulating immune responses. This review summarizes recent findings in roles of EVs in pSS pathogenesis, diagnosis, and treatment of pSS, as well as related challenges and future research directions.

Novel autoantibodies help diagnose anti-SSA antibody negative Sjögren disease and predict abnormal labial salivary gland pathology

OBJECTIVES

Sjögren disease (SjD) diagnosis often requires either positive anti-SSA antibodies or a labial salivary gland biopsy with a positive focus score (FS). One-third of patients with SjD lack anti-SSA antibodies (SSA-), requiring a positive FS for diagnosis. Our objective was to identify novel autoantibodies to diagnose 'seronegative' SjD.

METHODS

IgG binding to a high-density whole human peptidome array was quantified using sera from SSA- SjD cases and matched non-autoimmune controls. We identified the highest bound peptides using empirical Bayesian statistical filters, which we confirmed in an independent cohort comprising SSA- SjD (n=76), sicca-controls without autoimmunity (n=75) and autoimmune-feature controls (SjD features but not meeting SjD criteria; n=41). In this external validation, we used non-parametric methods for binding abundance and controlled false discovery rate in group comparisons. For predictive modelling, we used logistic regression, model selection methods and cross-validation to identify clinical and peptide variables that predict SSA- SjD and FS positivity.

RESULTS

IgG against a peptide from D-aminoacyl-tRNA deacylase (DTD2) bound more in SSA- SjD than sicca-controls (p=0.004) and combined controls (sicca-controls and autoimmune-feature controls combined; p=0.003). IgG against peptides from retroelement silencing factor-1 and DTD2 were bound more in FS-positive than FS-negative participants (p=0.010; p=0.012). A predictive model incorporating clinical variables showed good discrimination between SjD versus control (area under the curve (AUC) 74%) and between FS-positive versus FS-negative (AUC 72%).

CONCLUSION

We present novel autoantibodies in SSA- SjD that have good predictive value for SSA- SjD and FS positivity.

Updates in diagnostics, treatments, and correlations between oral and ocular manifestations of Sjogren's syndrome

Sjogren's syndrome (SS) is characterized as an autoimmune disorder targeting secretory glands, including the lacrimal and salivary glands, causing dry eye and dry mouth predominantly in women over the age of 40. In this review, we summarize recent advancements in SS diagnostics, treatments, and our understanding of correlations between oral and ocular manifestations of SS. Google Scholar and PubMed databases were utilized to search peer-reviewed papers since 2016 on SS diagnosis, treatment, and correlations between oral and ocular manifestations. For diagnostics, we discuss the updated SS classification criteria by the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR), new biomarkers, and compare studies of current diagnostic methods with alternative technologies. For treatments, we discuss topical, systemic, and surgical treatment developments in the management of oral and ocular symptoms of SS as there is still no cure for the disorder. Finally, we report studies that directly suggest correlations between the ocular surface disease and oral disease in SS, as well as shared abnormalities in the microbiome and cytokine expression that may be correlated. We conclude by stating limitations to our review as well as paths moving forward. Elucidating correlations between oral and ocular manifestations may be the key to furthering our understanding of SS pathogenesis as well as defining new standards for diagnosis and treatment.

Dry eye in Sjögren's syndrome - characteristics and therapy

BACKGROUND

Sjögren's syndrome is an autoimmune disease, and its important feature is the lymphocyte infiltration of exocrine glands, including lacrimal glands. It contributes to defects of their activity and causes that one of the main manifestation of Sjögren's syndrome is dry eye. Unfortunately, the discrimination between dry eye related and non-related to Sjögren's syndrome is difficult at the initial stages of diseases. In addition, the available agents for the treatment of Sjögren's syndrome-related dry eye have limited efficacy.

AIM

The purpose of this study was to describe and emphasize differences between Sjögren's Syndrome-related dry eye and non-Sjögren's Syndrome-related dry eye together with the determination of novel therapeutic options for Sjögren's Syndrome-related dry eye.

METHOD

A review of the relevant papers describing characteristics of Sjögren's Syndrome-related dry eye and its therapy was conducted. This article is based on both pre-clinical and clinical evidences.

RESULTS

On the basis of our analysis, we indicated differences between Sjögren's Syndrome-related dry eye and non-Sjögren's Syndrome-related dry eye. Moreover, there are some novel markers that could be used in the diagnosis of Sjögren's Syndrome-related dry eye. In addition, expect artificial tear, other agents e.g. hydroxychloroquine can be effective in therapy of disease.

CONCLUSIONS

Sjögren's Syndrome-related dry eye is a disorder, whose diagnosis may be difficult and mistaken for non-Sjögren's Syndrome-related dry eye. However, Sjögren's Syndrome-related dry eye has some specific features. In addition, the development of newer and safer therapeutic agents for Sjögren's syndrome-related dry eye is needed, and therefore further clinical, randomized studies are necessary.

Dry eye disease, a prominent manifestation of systemic autoimmune disorders

OBJECTIVES

Dry eye disease (DED) is arguably the most frequent ocular disease encountered in ophthalmic clinical practice. DED is frequently an underestimated condition causing a significant impact on visual function and quality of life. Many systemic autoimmune diseases (SAIDs) are related to moderate to severe DED. The main objective of this review is to enhance the awareness among ophthalmologists of the potential association of an underlying SAID in a high-risk patient with DED.

METHODS

An exhaustive literature search was performed in the National Library of Medicine's Pubmed, Scopus, Web of Science, and Google Scholar databases for all English language articles published until November 2021. The main keywords included "dry eye disease" associated with autoimmune, connective tissue, endocrine, gastrointestinal, hematopoietic, vascular, and pulmonary diseases. Case reports, series, letters to the editor, reviews, and original articles were included.

RESULTS

Although DED is frequently associated with SAIDs, its diagnosis is commonly delayed or missed, producing significant complications, including corneal ulceration, melting, scleritis, uveitis, and optic neuritis resulting in severe complications detrimental to visual function and quality of life. SAID should be suspected in a woman, 30 to 60 years old with a family history of autoimmunity, presenting with DED symptoms and extraocular manifestations including arthralgias, dry mouth, unexplained weight and hair loss, chronic fatigue, heat or cold intolerance, insomnia, and mood disorders.

CONCLUSIONS

Establishing the correct diagnosis and treatment of DED associated with SAIDs is crucial to avoid its significant burden and severe ocular complications.

The Diagnostic Performance of Early Sjögren's Syndrome Autoantibodies in Juvenile Sjögren's Syndrome: The University of Florida Pediatric Cohort Study

Objectives

The aim of this study was to evaluate the clinical validity of early Sjögren's syndrome (SS) autoantibodies (eSjA), which were originally marketed for early diagnosis of SS, for juvenile SS (JSS) in a recently identified pediatric cohort.

Methods

A total of 105 symptomatic subjects with eSjA results available were evaluated at the Center for Orphaned Autoimmune Disorders at the University of Florida and enrolled for this study. JSS diagnosis was based on the 2016 ACR/EULAR SS criteria. Demographic/clinical/laboratory parameters were compared between JSS (n = 27) and non-JSS (n = 78) for % positivity, sensitivity, and specificity of eSjA (SP1, anti-salivary protein; CA6, anti-carbonic anhydrase VI; PSP, anti-parotid secretory protein) and classic SS-autoantibodies (cSjA; ANA, SSA/SSB, RF, and others) either alone or in combination. Associations between eSjA and diagnostic/glandular parameters were also determined by Fisher's exact test.

Results

Compared to non-JSS, JSS patients exhibited sicca symptoms demonstrating reduced unstimulated salivary flow rate (USFR) and abnormal glandular features revealed by salivary gland ultrasound (SGUS). Among cSjA, ANA demonstrated the highest sensitivity of 69.2%, while SSA, SSB, and RF showed around 95% specificities for JSS diagnosis. The % positive-SSA was notably higher in JSS than non-JSS (56% vs. 5%). Of eSjA, anti-CA6 IgG was the most prevalent without differentiating JSS (37%) from non-JSS (32%). Sensitivity and specificity of eSjA were 55.6 and 26.9%, respectively. Autoantibodies with potentially applicable specificity/sensitivity for JSS were seen only in cSjA without a single eSjA included. There were no associations detected between eSjA and focus score (FS), USFR, SSA, SGUS, and parotitis/glandular swelling analyzed in the entire cohort, JSS, and non-JSS. However, a negative association between anti-PSP and parotitis/glandular swelling was found in a small group of positive-SSA (n = 19, p = 0.02) whereas no such association was found between anti-PSP-positive compared to anti-PSP-negative. JSS and non-JSS groups differed in FS, USFR, and EULAR SS Patient Reported Index Dryness/Mean in CA6/PSP/ANA, SP1, and SSA-positive groups, respectively. Additionally, a higher FS was found in RF-positive than RF-negative individuals.

Conclusions

eSjA underperformed cSjS in differentiating JSS from non-JSS. The discovery of clinical impact of eSjA on early diagnosis of JSS necessitates a longitudinal study.

Epithelial-immune cell interplay in primary Sjögren syndrome salivary gland pathogenesis

In primary Sjögren syndrome (pSS), the function of the salivary glands is often considerably reduced. Multiple innate immune pathways are likely dysregulated in the salivary gland epithelium in pSS, including the nuclear factor-κB pathway, the inflammasome and interferon signalling. The ductal cells of the salivary gland in pSS are characteristically surrounded by a CD4⁺ T cell-rich and B cell-rich infiltrate, implying a degree of communication between epithelial cells and immune cells. B cell infiltrates within the ducts can initiate the development of lymphoepithelial lesions, including basal ductal cell hyperplasia. Vice versa, the epithelium provides chronic activation signals to the glandular B cell fraction. This continuous stimulation might ultimately drive the development of mucosa-associated lymphoid tissue lymphoma. This Review discusses changes in the cells of the salivary gland epithelium in pSS (including acinar, ductal and progenitor cells), and the proposed interplay of these cells with environmental stimuli and the immune system. Current therapeutic options are insufficient to address both lymphocytic infiltration and salivary gland dysfunction. Successful rescue of salivary gland function in pSS will probably demand a multimodal therapeutic approach and an appreciation of the complicity of the salivary gland epithelium in the development of pSS.

Ocular Pathophysiology of Sjögren's Syndrome

The purpose of this review is to delve into the clinical and research understanding of the pathophysiology and presentation of Sjögren's-related keratoconjunctivitis sicca in order address the diagnostic and management challenge that it represents, as well as to provide a basis for appreciating the pharmacotherapies designed to treat the ophthalmic symptoms of Sjögren's disease.