Development of new extra-glandular manifestations or associated auto-immune diseases after establishing the diagnosis of primary Sjögren’s syndrome: A long-term study of the Antonius Nieuwegein Sjögren (ANS) cohort

Anti-SSA/SSB antibody double-negative Sjögren's disease patients: a comprehensive clinical study and immune profile

INTRODUCTION/OBJECTIVES

Anti-Sjögren's syndrome A (SSA/Ro60) and anti-Sjögren's syndrome B (SSB/La) antibodies are not present in up to 25% of patients with primary Sjögren's disease (SjD). Our observational study aims to provide a clinical perspective on the presentation, extra-glandular manifestations, as well as the immune profile of anti-SSA/SSB antibody double-negative SjD patients.

METHOD

A total of 615 SjD patients of age 53.21 (± 0.59) were enrolled without acute infection or ongoing treatment that could affect the immune system. Of our participants, 254 (41.3%) were seronegative for both SSA (Ro60) and SSB (La) autoantibodies (SSA/SSB double-negative). A 1:1 propensity score matching was performed to balance age at diagnosis, disease duration, and gender for extra-glandular involvement analyses and immune profiling. Peripheral blood mononuclear cells (PBMCs) were derived from all patients. Flow cytometry was performed to further define the immune cell subsets.

RESULTS

Our study revealed that anti-SSA/SSB seronegative patients had a delayed onset by an average of 7.43 years and exhibited a lower prevalence of parotid gland enlargement compared to the seropositive group (50.8% vs. 59%, p < 0.05). In terms of extra-glandular involvement, seronegative patients exhibited a lower prevalence of white blood cell (WBC), hemoglobin (HGB), and platelet (PLT) reduction (OR 0.406, 95% CI 0.314-0.523; OR 0.751, 95% CI 0.587-0.959; OR 0.56, 95% CI 0.383-0.818, respectively) compared to anti-SSA/SSB antibody-positive group. Additionally, the double-negative group tended to hold higher CD4 + T helper cells and lower CD8 + T cell proportions compared with the anti-SSA/SSB-positive group (40.52% vs. 37.38%, p < 0.001; 28.25% vs. 32.55%, p < 0.001 respectively). Higher proportions of NK cells (13.05% vs. 10.32%, p < 0.001) and CD161 + Treg cells (13.69% vs. 12.03%, p < 0.001) were found in the double-negative group.

CONCLUSION

The observed higher frequency of CD161 + Tregs and NK cells, as well as the lower frequency of CD8 + T cells and B cells, in anti-SSA/SSB antibody double-negative patients suggests a potential role of innate immunity in this subgroup of Sjögren's syndrome. Our findings hint at the importance of serological and immune profiles in tailoring personalized management strategies for these patients. Key Points • Our analyses suggested a potential role of innate immunity in anti-SSA/SSB antibody double-negative SjD patients in comparison to seropositive counterparts. • Higher frequencies of CD4 + T cells, CD161 + Tregs, and NK cells were observed in the peripheral blood of double-negative patients, alongside lower proportions of CD8 + T cells and B cell subsets. • Double-negative patients exhibited a lower prevalence of reductions in white blood cell counts, hemoglobin level, and platelet level.

Recommendations on neurologic, cognitive, and psychiatric manifestations in patients with Sjögren's disease by the Brazilian Society of Rheumatology

BACKGROUND

Neurological and psychiatric manifestations occur in patients with primary Sjogren's disease (SjD) with a wide-ranging clinical presentation, affecting quality of life, social participation, and prognosis. Despite this, neither central nor peripheral neurological symptoms are systematically evaluated in the context of autoimmunity or identified as manifestations of SjD. The EULAR Sjogren's Syndrome Disease Activity Index (ESSDAI) covers only part of them in the neurological domain.

METHODS

We performed a systematic review of the diagnosis and prevalence of central, peripheral, and autonomic nervous system manifestations in primary SjD, following the recommendations proposed by the Cochrane Collaboration Handbook. Observational studies were included when their main issue was the diagnosis and the prevalence of the manifestations individually. We employed a generalized linear mixed model (GLMM) method with a random-effects model, and the results were computed using logit transformation, implemented through the 'meta' and 'metafor' packages in the R software (version 3.6.1). To present these recommendations, agreement among experts was investigated using the Delphi method in in-person meetings.

RESULTS

We propose ten recommendations regarding the investigation and management of neurological involvement in SjD that had 100% agreement among participants.

CONCLUSION

These recommendations add to the literature on the clinical care of patients with SjD.

Association Between Quantitative Sialoscintigraphy and Antibody Profiles in Patients With Sjögren or Sicca Syndrome

PURPOSE

This study analyzed the association between anti-Ro/SSA and anti-La/SSB antibody levels with quantitative and visual sialoscintigraphy patterns in patients suspected of having Sjögren or sicca syndrome.

PATIENTS AND METHODS

Medical records of patients who underwent sialoscintigraphy between April 2020 and May 2022 were reviewed. Associations between antibody levels and sialoscintigraphy parameters were evaluated using linear regression. Receiver operating characteristic curve analysis was used to identify antibody cutoff values for predicting flat-type patterns and the risk of Sjögren or sicca syndrome.

RESULTS

Of the 170 patients (mean age, 56.6 years; 78.8% female), 95.3% had dry mouth and eyes, 30% experienced polyarthralgia, and 66.5% were prescribed hydroxychloroquine. The most common sialoscintigraphy finding was the median-type time-activity curve (TAC) pattern. Anti-Ro/SSA and anti-La/SSB levels were significantly correlated with maximum accumulation or maximum secretion in the salivary glands. Receiver operating characteristic analysis for anti-Ro/SSA predicting a flat-type TAC pattern showed an area under the curve (AUC) of 0.659 to 0.780, with specificity between 82.1% and 86.3% for antibody levels greater than 85.2 units. Anti-Ro/SSA levels greater than 49.75 units predicted a higher risk of Sjögren or sicca syndrome, with an AUC of 0.622 and 83.9% specificity. Anti-La/SSB levels had no significant predictive value, with an AUC of 0.554.

CONCLUSIONS

Anti-Ro/SSA levels greater than 85.2 units were strong predictors of flat-type TAC patterns, indicating near-total salivary gland dysfunction and supporting their diagnostic utility in Sjögren or sicca syndrome.

CXCL9 may serve as a potential biomarker for primary Sjögren's syndrome with extra-glandular manifestations

BACKGROUND

Primary Sjögren's syndrome (pSS) is an autoimmune condition that causes harm to exocrine glands and also has extra-glandular manifestations (EGM). pSS patients with EGM have a worse prognosis than those with only sicca symptoms. Previous studies have shown that the minor salivary glands (MSG) of pSS patients exhibit a unique profile of cytokines and chemokines compared to healthy controls. However, there is a lack of research comparing pSS with EGM (pSS-EGM) and pSS without EGM (pSS-non-EGM). This study aims to explore potential biomarkers associated with pSS, particularly pSS with EGM.

METHODS

By utilizing RNA sequencing, we conducted an analysis on the gene expression profiles of MSG in 63 patients diagnosed with pSS, as well as 12 non-pSS individuals. Furthermore, we also investigated the MSG of pSS patients, both with and without EGM. Through bioinformatics analysis, we identified genes with differential expression (DEGs) and determined the core hub genes using PPI network. We then analyzed the top 20 DEGs and their correlation with the patients' clinical characteristics, and validated our findings using peripheral blood plasma.

RESULTS

A total of 725 differentially expressed genes (DEGs) were identified in the comparison between pSS and non-pSS groups, and 727 DEGs were observed between pSS-EGM and pSS-non-EGM. It is noteworthy that the expression levels of CXCL9 were higher in both pSS patients and pSS-EGM when compared to the control group. Taking into consideration the significance of the top 20 DEGs in relation to clinical parameters and the central hub genes, we ultimately chose CXCL9. In comparison to the non-pSS group, pSS patients exhibited notably greater expression of the CXCL9 gene in the MSG, as well as higher levels of CXCL9 protein in their plasma (p < 0.001). Furthermore, the expression of the CXCL9 gene and levels of CXCL9 protein were notably higher in pSS patients accompanied by EGM and those with SSA antibodies. Additionally, a correlation was found between the expression of the CXCL9 gene and the EULAR Sjogren's Syndrome Disease Activity Index (ESSDAI), as well as with immunoglobulin G (IgG) levels and erythrocyte sedimentation rate (ESR). Meanwhile, the protein levels of CXCL9 were found to be correlated with IgG levels and ESSDAI.

CONCLUSION

CXCL9 proves to be a valuable biomarker in pSS, specifically due to its strong ability to differentiate between pSS patients with EGM and those without EGM. There is a significant correlation between CXCL9 and various clinical parameters both at the gene and protein level. Therefore, CXCL9 could be a potential target for future treatment of pSS.

Chronological interplay, clinical features, and treatments among patients with cancer and primary Sjögren's syndrome

OBJECTIVE

While the incidence and type of blood malignancies are well documented amid primary Sjögren's syndrome patients (pSS), data focusing on solid neoplasms are more conflicting. We aimed to describe clinical, pathological, and immunological characteristics of pSS patients with cancers, along with the chronological interplay between the two conditions.

METHODS

Outcomes concerning both pSS and cancer were retrospectively collected from Montpellier University Hospital (tertiary center) between 2019 and 2020. pSS characteristics were compared to a control group of pSS patients without cancer.

RESULTS

A total of 165 patients with pSS were included: 55 patients with cancer (52 female, mean age 58.4 ± 10.4 years at pSS diagnosis; mean follow-up 10.5 ± 10.1 years, 12 patients had multiple cancers) and 110 controls without cancer. Characteristics of pSS patients with cancers were different from controls mostly for lymphoma prognosis factors. Among the 70 cancers, we recorded 55 solid neoplasms (whom 27 breast cancers and 8 lung cancers, and 82% of adenocarcinomas), with no evidence of disease at the end of follow-up in 85% of them. Among the 15 recorded blood malignancies, ten were lymphomas with an excellent prognosis. Regarding chronological interplay between cancer and pSS, most cancers (43%) were diagnosed close (± 5 years) to pSS diagnosis. Breast cancers were diagnosed before or close to pSS diagnosis (mean delay - 1.8 ± 13.0 years), at an early stage, with only two relapses (no cancer-related death), while lung cancers were diagnosed late after.

CONCLUSIONS

The tight chronological interplay between breast cancer and pSS and the intriguing pathological and immunological pattern of pSS in these patients suggest a hypothesis of immune control of cancer.

Anti-SSA/SSB-negative primary Sjögren's syndrome showing different clinical phenotypes: a retrospective study of 934 cases

BACKGROUND

Currently, only a few studies have described the general characteristics of patients with primary Sjögren's syndrome (pSS) who tested negatives for anti-SSA and anti-SSB antibodies. We aimed to further investigate the clinical characteristics of these patients in a large sample.

METHODS

Data from patients with pSS who were treated at a tertiary hospital in China between 2013 and 2022 were retrospectively analyzed. Clinical characteristics of the patients were compared between those with and without anti-SSA and anti-SSB antibody negativity. Factors associated with anti-SSA and anti-SSB negativity were identified by logistic regression analysis.

RESULTS

Overall, 934 patients with pSS were included in this study, among whom 299 (32.0%) tested negative for anti-SSA and anti-SSB antibodies. Compared with patients testing positive for anti-SSA or anti-SSB antibodies, that testing negative for the two antibodies had a lower proportion of females (75.3% vs. 90.6%, p < 0.001) and thrombocytopenia (6.7% vs. 13.6%, p = 0.002), but a higher proportion of abnormal Schirmer I tests (96.0% vs. 89.1%, p = 0.001) and interstitial lung disease (ILD) (59.2% vs. 28.8%, p = 0.001). Anti-SSA and anti-SSB negativity was positively associated with male sex (odds ratio [OR] = 1.86, 95% confidence interval [CI]: 1.05, 3.31), abnormal Schirmer I tests (OR = 2.85, 95% CI: 1.24, 6.53), and ILD (OR = 2.54, 95% CI: 1.67, 3.85). However, it was negatively related to thrombocytopenia (OR = 0.47, 95% CI: 0.24, 0.95).

CONCLUSION

Approximately one third of pSS patients had anti-SSA and anti-SSB negativity. pSS patients testing negative for anti-SSA and anti-SSB showed a higher risk of abnormal Schirmer I tests and ILD, but a lower risk of thrombocytopenia.

Interstitial Lung Disease and Pulmonary Damage in Primary Sjögren's Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Pulmonary lung involvement is the most common extra-glandular manifestation in patients with primary Sjögren's syndrome (pSS), leading to a worsening of the patient's prognosis. To date, different studies have assessed the prevalence of pulmonary involvement and interstitial lung disease (ILD) in pSS patients with different results.

METHODS

We performed a systematic literature review and meta-analysis on ILD pooled prevalence in pSS according to the PRISMA and MOOSE guidelines. Furthermore, we explored the pooled prevalence of the two main presentations of pSS-ILD, nonspecific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP).

RESULTS

We analysed the pSS-ILD prevalence in 30 studies including 8255 pSS patients. The pSS-ILD pooled prevalence was 23% (95% CI: 16-30). For NSIP, we found a pooled prevalence of 52% (CI 41-64), and for UIP we found a pooled prevalence of 44% (CI: 32-55). Regarding the meta-regression analysis, male gender, DLco value, country, and HRCT seem to contribute to the ILD presence.

CONCLUSIONS

At least 20% of pSS patients have a comorbid ILD, usually NSIP. Male gender and alteration in DLco value may be considered the most important independent factors supporting an active search of lung complications during the clinical history of pSS patients.

Elevated Kynurenine Levels in Patients with Primary Sjögren's Syndrome

OBJECTIVE

We aimed to investigate the plasma levels of tryptophan (Trp) and its metabolites in patients with primary Sjögren's syndrome (pSS).

METHODS

The study included 34 pSS patients and 42 healthy individuals, and serum Trp and kynurenine (Kyn) concentrations were measured by liquid chromatography with tandem mass spectrometry. Trp degradation was predicted using the ratio of Kyn and Trp concentrations (Kyn/Trp).

RESULTS

In our study, the mean serum Trp concentration was found to be considerably lower in the pSS group than in the control group (P = .001). The levels of Kyn (P = .019) and the Kyn/Trp ratio (P < .001) were significantly higher in the pSS group than in the control group. The Kyn/Trp ratio was negatively correlated with C-reactive protein (r = -0.369, P = .032).

CONCLUSION

We found that Kyn pathway metabolism was altered in patients with pSS. This suggests that Trp metabolism may be closely linked to the disease pathogenesis of pSS.

Primary Sjögren syndrome-related peripheral neuropathy: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Primary Sjögren syndrome (pSS) is a chronic, systemic, autoimmune disorder characterized by lymphocytic infiltrates of the exocrine organs, leading to sicca symptoms and parotid enlargement. pSS has been linked to various neurological manifestations, including peripheral neuropathy (PN). We aimed to provide a comprehensive analysis of the currently available evidence regarding pSS-related PN.

METHODS

A literature search in the PubMed database was performed, and 49 papers were eligible to be included in this systematic review and meta-analysis.

RESULTS

The pooled prevalence of PN in pSS is estimated to be 15.0% (95% confidence interval = 10.7%-20.7%). The mean age of pSS patients at PN diagnosis is 59 years. Among the patients with pSS and PN, 83% are females. Neuropathic symptoms usually precede or lead to the pSS diagnosis at a 2:1 ratio in patients with pSS-related PN. The commonest type of pSS-related PN is distal axonal polyneuropathy (80% of patients with pSS-related PN), followed by sensory ganglionopathy. Peripheral and cranial mononeuropathies-particularly trigeminal-are also frequent. Risk factors for developing PN include increasing age and presence of vasculitis. Immune-mediated pathogenetic mechanisms are discussed. Glucocorticoids are the most commonly used treatment option for managing pSS-related PN, when associated with vasculitis, followed by the use of intravenous immunoglobulin.

CONCLUSIONS

PN is very common in pSS patients. Evidence on long-term prognosis of PN in pSS is limited, and further research is needed. Research into the use of immunosuppressive medication in nonvasculitic neuropathies in the context of pSS merits further consideration.

N6-Methyladenosine Regulator-Mediated RNA Methylation Is Involved in Primary Sjögren's Syndrome Immunoinfiltration

The crucial role of epigenetic regulation, especially the modifications of RNA N6-methyladenosine (m6A), in immunity is a current research hotspot. However, the m6A modifications in primary Sjögren's syndrome (pSS) and the immune infiltration pattern they govern remain unknown. Thus, the patterns of 23 m6A regulator-mediated RNA modifications in parotid or blood samples from pSS patients were evaluated by bioinformatics analysis in the current study. Comparing m6A regulators between control and pSS patients showed that m6A regulators are associated with pSS, and regulators also had differential correlations. Further clustering analysis and comparison of gene expression and immune cell infiltration between m6A modification patterns revealed that each modification pattern had its own unique genetic and immune profile. Multiple immune cell infiltrations were differentially expressed between the patterns. The enrichment of gene ontology between the two patterns in parotid was concentrated on RNA metabolism and processing. The KEGG pathway enrichment and weighted correlation network analysis further showed that the autophagy pathway might be involved in the m6A modification patterns in pSS. Together, these findings suggest that m6A regulators play a certain role in the immune cell infiltration of parotid tissue in pSS.

Disease phenotype and diagnostic delay in Saudi patients with primary Sjögren's syndrome: An exploratory cross-sectional study

Objectives:

To describe primary Sjögren’s syndrome (pSS) cohort in Saudi Arabiain view in of clinical/serological/histopathological phentotype, and, diagnostic delay.

Methods:

A cross-sectional study conducted between October 2018 and May 2019. Diagnostic delay was calculated from symptoms onset to clinical diagnosis. The European League Against Rheumatism (EULAR) Sjögren’s Syndrome Disease Activity Index (ESSDAI) and EULAR Sjogren’s Syndrome Patient Reported Index (ESSPRI) were calculated.

Results:

Forty-one patients were included in the study. There were predominantly females (78%) with a mean (±SD) age of 58.76±12.7 and disease duration of 4.6±2.28 years. The mean diagnostic delay was 2.2±2.4 (range 1-11) years. Minor salivary gland biopsy was performed on 38 (92.7%) patients with a mean focus score of 2.3± 1.2 points. Interstitial lung disease and arthritis were the most common extra-glandular manifestations (EGM) affecting 27 (65.9%) patients for both. The mean ESSDAI was 9.95±7.73 and ESSPRI was 5.17±2.4.

Conclusion:

Saudi primary Sjogren’s syndrome patients have a high prevalence of EGM predominantly arthritis and ILD. The diagnostic delay is variable in our cohort.

The management of Sjögren's syndrome: British Society for Rheumatology guideline scope

The guideline will be developed using the methods and processes outlined in Creating Clinical Guidelines: Our Protocol [1]. This development process to produce guidance, advice and recommendations for practice has National Institute for Health and Care Excellence (NICE) accreditation.

Epidemiology of cutaneous involvement in Sjögren syndrome: Data from three French pSS populations (TEARS, ASSESS, diapSS)

OBJECTIVE

To determine the prevalence and significance of dermatological disorders in primary Sjögren syndrome (pSS).

METHODS

We used 2 pSS French cohorts (ASSESS, in which prevalence of skin disorders in 395 patients was evaluated; and diapSS, in which 76 on 139 pSS patients had an examination by a dermatologist) and baseline data of the TEARS randomized trial (110 patients with recent or active pSS treated with rituximab or placebo and evaluated for skin dryness using a visual analogue scale (VAS) out of 100).

RESULTS

Skin manifestations included in the EULAR Sjögren syndrome disease activity index (ESSDAI) were rare in the ASSESS cohort (n=16/395, 4.1%, mainly purpuras; only 3 had high activity), but they were associated with activity in the other ESSDAI domains (peripheral neurological (P<0.001), muscular (P<0.01), haematological (P<0.05), biological (P<0.05), history of arthritis (P<0.01), splenomegaly (P<0.05) and higher gamma globulin levels (P<0.01)). In the diapSS cohort, compared to pSS patients not receiving a dermatological consultation, the pSS patients who had a dermatological consultation had significantly more dermatological involvement outside the ESSDAI score [38.2% (29/76) versus 15.9% (10/63); P<0.01]. The TEARS study showed a high prevalence of cutaneous dryness (VAS>50; 48.2%) and found that patients with dry skin had higher VAS pain (P<0.01) and drought (P<0.01) scores.

CONCLUSION

ESSDAI skin activity is rare and associated with hypergammaglobulinemia and ESSDAI activity. Systematic dermatological examination is informative for non-specific lesions. The most common skin disorder is skin dryness, which is associated with a higher pain and overall subjective dryness.

Current State of Knowledge on Primary Sjögren's Syndrome, an Autoimmune Exocrinopathy

Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune rheumatic disease characterized by lymphoplasmacytic infiltration of the salivary and lacrimal glands, whereby sicca syndrome and/or systemic manifestations are the clinical hallmarks, associated with a particular autoantibody profile. pSS is the most frequent connective tissue disease after rheumatoid arthritis, affecting 0.3-3% of the population. Women are more prone to develop pSS than men, with a sex ratio of 9:1. Considered in the past as innocent collateral passive victims of autoimmunity, the epithelial cells of the salivary glands are now known to play an active role in the pathogenesis of the disease. The aetiology of the "autoimmune epithelitis" still remains unknown, but certainly involves genetic, environmental and hormonal factors. Later during the disease evolution, the subsequent chronic activation of B cells can lead to the development of systemic manifestations or non-Hodgkin's lymphoma. The aim of the present comprehensive review is to provide the current state of knowledge on pSS. The review addresses the clinical manifestations and complications of the disease, the diagnostic workup, the pathogenic mechanisms and the therapeutic approaches.

Prevalence and risk factors of interstitial lung disease in patients with primary Sjögren's syndrome: A systematic review and meta-analysis

OBJECTIVE

To systematically review the prevalence and risk factors for interstitial lung disease (ILD) in patients with primary Sjögren's syndrome (pSS).

METHODS

We searched PubMed, Embase, and Cochrane Library from inception to December 2019. Two investigators reviewed records according to predefined criteria. We calculated the pooled prevalence, weighted mean differences (WMDs), odds ratio (OR) and 95% confidence intervals (CIs) using a random effects model, and performed subgroup analysis, sensitivity analysis, and Egger's test.

RESULTS

In 23 studies with 6157 pSS patients, the pooled prevalence of ILD in pSS patients was 13% (95% CI: 9-19). The pSS-ILD prevalence was higher in Asia (20%) than that in Europe (10%). Male gender (OR = 1.92, 95% CI: 1.26-2.95), elder age (WMD = 9.25 years, 95% CI: 2.78-15.72) and higher C-reactive protein (CRP) (WMD = 3.92 mg/L, 95% CI: 0.27-1.61) was associated with ILD in pSS patients.

CONCLUSION

Interstitial lung disease was prevalent in pSS patients. Elder age, male gender and higher CRP were risk factors for pSS-ILD. Our data highlighted the importance of screening for ILD in high-risk pSS patients.

Toward better outcomes in Sjögren's syndrome: The promise of a stratified medicine approach

Sjögren's syndrome is a systemic autoimmune disease defined by its targeted inflammation of the salivary and lacrimal glands, resulting in dry mouth and eyes in the majority and persistent or recurrent salivary gland enlargement in a minority of those affected. Involvement of major organs, an increased risk of lymphoma, and autoantibodies against ubiquitous cellular ribonucleoproteins define some of its systemic features. Those affected have a high symptom burden and the development of disease-modifying therapies is thus an urgent need. A stratified medicine approach offers promise as a means of targeting specific therapies to patients for whom the mechanism of action is most relevant. Implementation of this approach will require an understanding of the pathophysiological processes underlying different patient subsets, and then identifying or developing a drug that targets this pathway. Such therapies would be most effective if implemented early in the disease course before the advent of adverse outcomes or glandular damage. This review will provide a disease overview followed by an analysis of the feasibility of a stratified medicine approach, focusing on the disease heterogeneity, predictors of disease progression and adverse outcomes, and recent advances in the development of relevant outcome measures and new therapies.

Can artificial intelligence replace manual search for systematic literature? Review on cutaneous manifestations in primary Sjögren’s syndrome

Objectives

Manual systematic literature reviews are becoming increasingly challenging due to the sharp rise in publications. The primary objective of this literature review was to compare manual and computer software using artificial intelligence retrieval of publications on the cutaneous manifestations of primary SS, but we also evaluated the prevalence of cutaneous manifestations in primary SS.

Methods

We compared manual searching and searching with the in-house computer software BIbliography BOT (BIBOT) designed for article retrieval and analysis. Both methods were used for a systematic literature review on a complex topic, i.e. the cutaneous manifestations of primary SS. Reproducibility was estimated by computing Cohen’s κ coefficients and was interpreted as follows: slight, 0–0.20; fair, 0.21–0.40; moderate, 0.41–0.60; substantial, 0.61–0.80; and almost perfect, 0.81–1.

Results

The manual search retrieved 855 articles and BIBOT 1042 articles. In all, 202 articles were then selected by applying exclusion criteria. Among them, 155 were retrieved by both methods, 33 by manual search only, and 14 by BIBOT only. Reliability (κ = 0.84) was almost perfect. Further selection was performed by reading the 202 articles. Cohort sizes and the nature and prevalence of cutaneous manifestations varied across publications. In all, we found 52 cutaneous manifestations reported in primary SS patients. The most described ones were cutaneous vasculitis (561 patients), xerosis (651 patients) and annular erythema (215 patients).

Conclusion

Among the final selection of 202 articles, 155/202 (77%) were found by the two methods but BIBOT was faster and automatically classified the articles in a chart. Combining the two methods retrieved the largest number of publications.

Neurological and Inflammatory Manifestations in Sjögren's Syndrome: The Role of the Kynurenine Metabolic Pathway

For decades, neurological, psychological, and cognitive alterations, as well as other glandular manifestations (EGM), have been described and are being considered to be part of Sjögren's syndrome (SS). Dry eye and dry mouth are major findings in SS. The lacrimal glands (LG), ocular surface (OS), and salivary glands (SG) are linked to the central nervous system (CNS) at the brainstem and hippocampus. Once compromised, these CNS sites may be responsible for autonomic and functional disturbances that are related to major and EGM in SS. Recent studies have confirmed that the kynurenine metabolic pathway (KP) can be stimulated by interferon-γ (IFN-γ) and other cytokines, activating indoleamine 2,3-dioxygenase (IDO) in SS. This pathway interferes with serotonergic and glutamatergic neurotransmission, mostly in the hippocampus and other structures of the CNS. Therefore, it is plausible that KP induces neurological manifestations and contributes to the discrepancy between symptoms and signs, including manifestations of hyperalgesia and depression in SS patients with weaker signs of sicca, for example. Observations from clinical studies in acquired immune deficiency syndrome (AIDS), graft-versus-host disease, and lupus, as well as from experimental studies, support this hypothesis. However, the obtained results for SS are controversial, as discussed in this study. Therapeutic strategies have been reexamined and new options designed and tested to regulate the KP. In the future, the confirmation and application of this concept may help to elucidate the mosaic of SS manifestations.

Prognostic value of Sjögren's syndrome autoantibodies

Sjögren's syndrome is in part considered an autoimmune disease because patient sera contain antibodies binding self-structures. In fact, in addition to anti-Ro (or SSA) and anti-La (or SSB), which are included in the classification criteria, there are a wide variety of autoantibodies found among these patients. We reviewed English-language MEDLINE sources. Anti-Ro and anti-La found among healthy individuals, including mothers giving birth to infants with neonatal lupus, predicts future connective tissue disease. Those with Sjögren's syndrome can be divided into two groups; patients with only exocrine gland involvement and those with systemic disease. The presence of anti-Ro/La is associated with systemic, extraglandular disease. Rheumatoid factor is also associated with extraglandular disease while anti-cyclic citrullinated peptide (CCP) is likely associated with inflammatory arthritis and progression to rheumatoid arthritis. Anti-mitochondrial antibodies are uncommon but predict progression to primary biliary cirrhosis. Cryoglobulinemia is found in excess among those with non-Hodgkin's lymphoma. Determination of autoantibodies on the sera of Sjögren's syndrome patients has prognostic implications for Sjögren's syndrome itself as well as associated diseases.