Extraglandular Manifestations Research Articles

Polyarthritis in Sjögren's Syndrome: Difficulties in Distinguishing Extraglandular Manifestation and Associated Rheumatoid Arthritis.

Aim of the study was to investigate the demographic data and disease course characteristics of patients with Sjögren's syndrome (SS) and inflammatory joint pain of various origins and to search for factors that might help with the distinction of polyarthritis as an extraglandular manifestation and rheumatoid arthritis as an associated systemic autoimmune disorder. A total of 355 patients were retrospectively analyzed, 128 of whom served as controls (SS-C), while 159 had polyarthritis as an extraglandular symptom of Sjögren's syndrome (SS-pa) and 68 were diagnosed as having associated rheumatoid arthritis (SS-RA). The patients without any inflammatory joint manifestations were significantly older than the SS-pa patients, while, for the SS-RA group, the difference was not significant. The onset of joint pain appeared significantly earlier in the SS-RA patients. Regarding either extraglandular manifestations or associated autoimmune disorders, there were significant differences between the controls and both SS-pa and SS-RA groups, while no significant difference was found between the SS-pa and SS-RA groups. Thus, laboratory and imaging methods should be used to differentiate between the two conditions, but laboratory biomarkers are even more important for early diagnosis. A ROC curve analysis showed an acceptable diagnostic accuracy in differentiating between SS-pa and SS-RA patients using a binary logistic regression model, where highly positive rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) values, kidney involvement, and anti-Ro/SS-A positivity were shown to significantly raise the odds of having RA, whereas anti-La/SS-B positivity seemed to have a protective role, since it significantly decreased the odds of having it. Further biomarkers are needed to better classify SS patient cohorts with inflammatory joint pain of different origins and, consequently, different management requirements.

Recommendations on cutaneous and hematological manifestations of Sjögren’s disease by the Brazilian Society of Rheumatology

Sjogren’s disease (SjD) is an autoimmune disease that is characterized not only by the sicca symptoms it causes but also by its systemic nature, which is capable of several and not yet fully understood extraglandular manifestations. To gain a clearer understanding of these manifestations as well as a better practical approach, a panel of experts from the Brazilian Society of Rheumatology conducted a systematic review and meta-analysis on the identification of epidemiologic and clinical features of the extraglandular manifestations present in ESSDAI (EULAR Sjogren´s syndrome disease activity index), followed by a voting panel with recommendations for clinical practice. This publication is complementary to others already published and covers cutaneous and hematological manifestations, with prevalence data generated by a meta-analysis of 13 clinical or laboratory manifestations and 6 clinical management recommendations.

Recommendations on cutaneous and hematological manifestations of Sjögren’s disease by the Brazilian Society of Rheumatology

Sjogren’s disease (SjD) is an autoimmune disease that is characterized not only by the sicca symptoms it causes but also by its systemic nature, which is capable of several and not yet fully understood extraglandular manifestations. To gain a clearer understanding of these manifestations as well as a better practical approach, a panel of experts from the Brazilian Society of Rheumatology conducted a systematic review and meta-analysis on the identification of epidemiologic and clinical features of the extraglandular manifestations present in ESSDAI (EULAR Sjogren´s syndrome disease activity index), followed by a voting panel with recommendations for clinical practice. This publication is complementary to others already published and covers cutaneous and hematological manifestations, with prevalence data generated by a meta-analysis of 13 clinical or laboratory manifestations and 6 clinical management recommendations.

Association of focus score and extraglandular involvement in Sjögren's syndrome: A study on antinuclear antibodies and minor salivary gland pathology

Objectives: This study aimed to investigate the relationship between patients with and without extraglandular involvement in Sjögren's syndrome (SS) by analyzing ANA (antinuclear antibody) and ENA (extractable nuclear antigen) results and minor salivary gland pathology findings. Patients and methods: A total of 265 (245 females; 20 males; mean age: 50.4±12.4; range, 19 to 79 years) patients diagnosed with SS were included in the retrospective cohort study between March 1, 2011, and December 1, 2021. Detailed documentation was performed, capturing demographic characteristics, clinical information, laboratory findings, medication usage, and manifestations of the syndrome. The patients were divided into two groups, with (78 females; 8 males; mean age: 52.7±11.5; range, 22 to 78 years or without (167 females; 12 males; mean age: 49.3±12.8; range, 19 to 79 years extraglandular involvement. Results: The mean follow-up duration was 63.1±31.9 months. Extraganular involvement, including joint involvement, lung involvement, central nervous system involvement, hematological involvement, hepatitis, and lymphoma, was observed in 32.5% of the patients. Patients with extraglandular involvement required multiple medications, while those with only glandular involvement predominantly used hydroxychloroquine. The mean duration from SS diagnosis to extraglandular involvement was 15.2±27.8 months. The comparison between patients with and without extraglandular involvement revealed a significant association between higher focus scores (FS) and extraglandular manifestations. However, no significant differences were observed in terms of ANA positivity, ANA titers, or ENA positivity. Regression analysis indicated that age and FS were linked to systemic involvement. Conclusion: This study highlights the importance of FS as a predictive indicator for extraglandular manifestations in SS. Advanced age was found to be associated with an increased likelihood of extraglandular involvement. Assessing FS and age can aid in predicting extraglandular manifestations.

Hypocitraturia as a biomarker of renal tubular acidosis in patients with Sjögren’s disease

IntroductionSjögren’s disease (SD) is an immune-mediated chronic inflammatory disease that affects epithelial tissues, mainly salivary and lacrimal glands. It also presents extraglandular manifestations. The main renal manifestation is tubulointerstitial nephritis (TIN), which can manifest as renal tubular acidosis (RTA). Urinary citrate may be a biomarker of RTA in these patients. The objective of this study was to evaluate whether hypocitraturia is a predictive biomarker of RTA in a sample of patients with SD in a tertiary hospital in southern Brazil.MethodsAll patients with SD who met the inclusion criteria and who participated in the rheumatology outpatient clinic of the Irmandade Santa Casa de Misericórdia de Porto Alegre were included. Demographic, SD, serological and urinary data were obtained. RTA was considered in those patients who persistently presented urinary pH above 5.5 and serum pH below 7.35. Patients who persistently had urinary pH above 5.5 underwent a urinary acidification test with furosemide and fludrocortisone. These patients received 1 mg of fludrocortisone and 40 mg of furosemide and had their urine samples tested 2, 4 and 6 h after taking the medications. The test was stopped at any urine sample with pH 5.5 or less. The variables were expressed as mean and standard deviation or interquartile range. The association between hypocitraturia and RTA was assessed using the chi-square.ResultsForty-two patients were included, 95.2% female with a median age of 61.73 years. The prevalence of complete distal RTA was 4.88%. Twenty-eight patients underwent urine acidification testing. Five patients had hypocitraturia, and two of them had complete distal RTA. The association between hypocitraturia and RTA was statistically significant (p < 0.012), with a sensitivity of 100%, specificity of 91.2% and accuracy of 91.7%. The negative predictive value was 100%. The global renal assessment of the population demonstrated two patients with RTA, one patient with decreased renal function and six patients with proteinuria greater than 0.5 g/24 h.ConclusionThe prevalence of RTA in the studied population was 4.88%. Hypocitraturia had high sensitivity and accuracy for the diagnosis of RTA.

Primary Sjögren’s syndrome: Autoantibodies and their relationship to clinical manifestations and histology of minor salivary glands

IntroductionTo evaluate the association between autoantibodies with clinical manifestations (extraglandular and glandular) and histopathological findings of minor salivary gland biopsy in primary Sjögren’s syndrome. Materials and methodsObservational, descriptive, and cross-sectional study. Forty-seven patients with pSS according to the ACR/EULAR 2016 criteria were included. A face-to-face survey, a review of medical records, and the measurement of autoantibodies (Ab) anti-Ro 52, anti-Ro 60, anti-La, antinuclear antibodies (ANA), rheumatoid factor (RF) IgA, IgG and IgM, and anti-alpha fodrin IgA and IgG were done. Characterization of the population and analysis of the association between clinical characteristics, autoantibodies, and histopathology were performed. ResultsAssociation of anti-alpha fodrin IgA and anti-Ro 52 Ab was found with pulmonary involvement (P = .014 and P = .031 respectively) and anti-La antibodies with haematological manifestations, specifically leukopenia (P = .011), lymphopenia (P = .023), and anaemia (P = .09). We found no association between the histopathological findings of the minor salivary gland biopsy and extraglandular manifestations. ConclusionsThe activation of B cells, reflected in the increased production of autoantibodies, is related to extraglandular manifestations in pSS, which is observed more frequently in patients with earlier diagnosis.

Comprehensive analysis of the clinical manifestations and hematological parameters associated with secondary immune thrombocytopenia in patients with primary Sjögren syndrome: An observational study.

Primary Sjögren Syndrome (pSS) is a chronic autoimmune disease that primarily affects exocrine glands and can lead to various extraglandular manifestations, including secondary immune thrombocytopenia (ITP). Understanding the clinical and hematological differences in pSS patients with and without secondary ITP is crucial for improved patient management and treatment strategies. This retrospective study, conducted from January 2020 to December 2023, involved a cohort of pSS patients, dividing them into 2 groups: those with secondary ITP and those without. Patients were evaluated using the European League Against Rheumatism Sjögren Syndrome Disease Activity Index (ESSDAI), EULAR Sjögren Syndrome Patient-Reported Index (ESSPRI), Health Assessment Questionnaire, and other hematological parameters. Inclusion criteria were based on the American-European Consensus Group or ACR/EULAR classification criteria for pSS. Exclusion criteria included other autoimmune or hematological disorders, prior splenectomy, recent blood transfusions, and lack of informed consent. Statistical analysis was performed using SPSS software, with various tests applied to analyze the data, including logistic regression to identify risk factors for secondary ITP. Significant differences were noted in fatigue, lymphadenopathy, arthritis, mean age, and ESSDAI scores between the secondary ITP and non-secondary ITP groups. Patients with secondary ITP exhibited higher platelet counts, more prevalent lymphopenia, higher immunoglobulin G (IgG) levels, lower complement 3 levels, and reduced white blood cell and hemoglobin levels. Logistic regression analysis identified lymphadenopathy as a risk factor and arthritis as a protective factor for the development of secondary ITP. The study reveals distinct clinical and hematological characteristics in pSS patients with secondary ITP, suggesting a higher disease activity in this subset. These findings underscore the need for further exploration of these associations to develop more precise treatment approaches for pSS, focusing on preventing secondary ITP and improving patient outcomes.

Long Non-Coding RNAs in Sjögren's Disease.

Sjögren's disease (SjD) is a heterogeneous autoimmune disease characterized by severe dryness of mucosal surfaces, particularly the mouth and eyes; fatigue; and chronic pain. Chronic inflammation of the salivary and lacrimal glands, auto-antibody formation, and extra-glandular manifestations occur in subsets of patients with SjD. An aberrant expression of long, non-coding RNAs (lncRNAs) has been described in many autoimmune diseases, including SjD. Here, we review the current literature on lncRNAs in SjD and their role in regulating X chromosome inactivation, immune modulatory functions, and their potential as biomarkers.

Primary Sjögren’s Syndrome Presenting with Dyskinesia

Sjögren’s syndrome (SS) is an autoimmune disease in which lymphocytes invade salivary and tear glands, leading to dry mouth and dry eyes. It is also associated with extraglandular manifestations. The most frequently reported neurological extraglandular manifestations are sensory polyneuropathies. Movement disorders have been reported in only 2% of primary SS patients. In this case, we present a case of primary SS initially manifesting as generalized chorea, which was initially misdiagnosed as tardive dyskinesia.

The diagnosis and misdiagnosis of Sjögren disease.

Although one of the most common systemic autoimmune disorders, Sjögren disease (SjD) may be overlooked in patients presenting with non-specific symptoms or no complaints of sicca symptoms. SjD is not a condition to be missed as patients could present with serious extra-glandular manifestations, including lymphomas. In this article, we discuss the diagnostic pitfalls of this disorder and encourage physicians to consider carefully the 'non-textbook' presentations.

A case report on Sjogren syndrome with autoimmune liver disorder

Background: Primary Sjogren’s syndrome (pSS) is a chronic systemic and autoimmune disorder characterized by inflammation and dysfunction of exocrine glands. Liver involvement was the first extraglandular manifestations to be reported in patients with pSS. Tubulointerstitial nephritis (TIN) is the main renal involvement associated with pSS and manifest as distal renal tubular acidosis (RTA), and others, of which RTA is the main clinical presentation. RTA has been reported in 4.3 to 9% of pSS patients. In this case, patient experiences RTA. Case Presentation: A 19 year old female patient was presented with complaints of abdominal pain, fatigue for 2 months and loose stools. She had history of autoimmune hepatitis and decompensated liver cirrhosis with portal hypertension (autoimmune), bilateral peroneal axonal neuropathy, grade II hepatic encephalopathy resolved and recurrent pustular lesion for past 2 years which rupture spontaneously and heals with scary. She also presented with recurrent hypokalemia which was corrected. No history of similar complaints among the family members. Conclusion: This case explains the autoimmune liver disorder with newly diagnosed primary sjogren’s syndrome associated with recurrent hypokalemia.

Male patients with primary Sjögren's syndrome have unique clinical manifestations and circulating lymphocyte profiles.

We aimed to explore the relationship between clinical characteristics and circulating lymphocyte profiles in Chinese male patients with primary Sjögren's syndrome (pSS). Data from 397 patients with pSS were analyzed retrospectively. 37 were male, which is a prevalence of 9.3%. The clinical, laboratory, and immunophenotypic profiles of peripheral blood lymphocyte subsets were compared between male and female pSS patients. Male patients with primary Sjögren's syndrome have unique clinical manifestations and circulating lymphocyte profiles. Male patients complained more about xerophthalmia and presented with more extra-glandular manifestations as compared with female patients. The CD4+/CD8+ ratio (P = 0.030), the prevalence of CD4-CD8- T cells in lymphocytes (P = 0.020), the absolute number of CD4-CD8- T cells (P = 0.035), the prevalence of CD4+ T cells in lymphocytes (P < 0.001), and the absolute number of CD4+ T cells (P = 0.023) were significantly lower in male patients compared to female patients. On the other hand, the prevalence of CD8+CD28+ T cells (P = 0.030) and CD4+CD25high T cells (P = 0.040) in lymphocytes was significantly higher in male patients than in female patients. Moreover, compared to females with pSS, an elevated serum IgG level, low C3 and C4 levels, anti-SSB positivity, and ANA titers of ≥ 1:160 positivity were more frequent in male with pSS. Male patients with pSS have distinctive peripheral blood lymphocyte subpopulations, present with more severe clinical symptoms and immunological features, and have an unfavorable prognosis. Key Points • Male patients with pSS have more severe clinical symptoms and specific characteristics of peripheral blood lymphocyte subsets. • Male pSS patients exhibit a higher intensity of the disease (as evaluated by ESSDAI). • Male patients with pSS require individualized treatment regimens and closer follow-up.

Intracranial Hypertension as a rare presentation of Sjögren's Syndrome: a case report

Introduction. A rare extraglandular manifestation of Sjögren's syndrome is presented, mimicking idiopathic intracranial hypertension. Case Report. A young eutrophic female, complained of persistent headache, followed by diplopia and bilateral sixth nerve paresis. Neuroimaging investigation showed classic signs of intracranial hypertension. As the patient had a normal weight, prompted evaluation of secondary causes, which revealed positive anti-SSA/Ro and anti-La/SSB antibodies. A salivary gland biopsy later confirmed the diagnosis of Sjögren's syndrome. Xerostomia and dysphagia developed weeks later. Conclusion. This case report is important to raise awareness about an atypical neurological manifestation of Sjögren's syndrome.

Update on Sjögren's syndrome : Diagnostics, treatment, and challenges

Sjögren's syndrome (SjS) is the most common connective tissue disease with aprevalence of 1:200. Predominantly affecting women, SjS is associated with destruction of the exocrine glands, leading to xerophthalmia and xerostomia. In over 50% of patients, there are also extraglandular manifestations, leading to multiple organ manifestations including polyneuropathies and interstitial lung disease as well as symptoms such as fatigue and arthralgia. Diagnostic procedures include biomarkers, in particular anti-SS-A/Ro antibodies, histology of salivary glands, and salivary gland sonography. There are currently no licensed immunosuppressive drugs for SjS, so current treatment is often based on off-label use of drugs. The European League Against Rheumatism (EULAR) has recently published treatment recommendations based on the prevailing organ manifestations. Several promising controlled trials with novel compounds and concepts are currently in progress.

Anti-centromere antibody positivity is an independent variable associated with salivary gland ultrasonography score in Sjögren’s syndrome

Sjögren’s syndrome (SS) is an autoimmune disease characterized by periductal lymphocytic infiltration of the salivary and lacrimal glands. SS also exhibits extra-glandular manifestations and specific autoantibodies. Salivary gland ultrasonography (SGUS) is a common procedure used to assess the severity of glandular involvement. However, the association between SGUS and extra-glandular lesions remains poorly understood. This study aimed to identify clinical indices, including disease activity, associated with glandular involvement using SGUS in patients with SS. We included 115 patients with SS and 90 without SS. Patients with SS had significantly higher ultrasonography (US) score than patients without SS. Multivariate analysis revealed focus score, Saxon test positivity, and anti-centromere antibody (ACA) positivity as independent variables associated with the US score in patients with SS. In addition, these results were similar to those obtained in patients with primary SS. Patients with SS and ACA positivity had higher US score and an increased prevalence of hyperechoic bands in the parotid glands and submandibular glands. In conclusion, this study indicated that ACA positivity is associated with the US score in patients with SS. These results suggest that US findings in patients with ACA positivity might show specific changes in the salivary glands, especially fibrosis.

Inclusion-body myositis associated with Sjögren's disease: clinical characteristics and comparison with other Sjögren-associated myositis.

To describe the characteristics of patients with Sjögren's disease (SjD) and inclusion-body myositis (IBM), and how they compare to SjD patients with other inflammatory myopathies (IM). Patients were retrospectively recruited from 13 French centers and included if they met the ACR/EULAR criteria for SjD and for IM. They were categorized as SjD-IBM if sub-criteria for IBM were met, or as SjD-other IM if not. SjD-IBM patients (n = 22) were mostly females (86%), with a median [Q1; Q3] age of 54 [38.5; 64] years at SjD diagnosis, and 62 [46.5; 70] years at first IBM symptoms. Although most patients displayed glandular and immunological abnormalities, additional extra-glandular manifestations were uncommon, resulting in moderate disease activity at SjD diagnosis (ESSDAI 5.5 [1; 7.8]). Classic IBM features were frequent, such as progressive symptom onset (59%), asymmetrical (27%) and distal (32%) involvements, dysphagia (41%), low CPK (386.5 [221.8; 670.5] UI/l) and CRP (3.0 [3; 8.5] mg/l) levels. Immunosuppressants were reported as efficient in 55% of cases.Compared with SjD-IBM patients, SjD patients with other IM (n = 50) were significantly younger, displayed more frequent additional extra-glandular disease, higher ESSDAI score (11 [3; 30]), shorter delay between SjD diagnosis and myositis onset (0 [-0.5; 26]), more frequent CPK values over 1000 UI/l (36%), and less frequent classic IBM features. IBM can occur in SjD patients, with muscle features reminiscent of classic sporadic IBM characteristics, but mostly affecting women. In SjD patients with muscle involvement, extra-glandular manifestations, high ESSDAI score, elevated CPK values, and shorter delay after SjD diagnosis plead against IBM.

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

BackgroundPrimary 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.MethodsBy 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.ResultsA 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.ConclusionCXCL9 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.

Thymic mucosa-associated lymphoid tissue lymphoma in a patient with Sjögren’s syndrome with cutaneous vasculitis

Introduction. The association between Sj?gren?s syndrome (SS) and the development of lymphoma is well known. The prevalence of lymphoma in patients with SS is 5%. Mucosa-associated lymphoid tissue (MALT) lymphoma is the most common lymphoma type in patients with SS. It is common for MALT lymphoma to develop in the stomach, while it is extremely rare in the thymus. Case report. We present a 61-year-old Caucasian male patient with primary SS, cutaneous vasculitis, and thymic MALT lymphoma. The patient had a two-year history of diffuse cutaneous palpable purpura on legs, intermittently enlarged left parotid gland, and dry mouth. The results of Schirmer?s test were positive, labial salivary glands biopsy revealed a focus score ? 1, serology testing showed positive anti-Ro/SS-A and anti-La/SS-B antibodies, while skin biopsy findings revealed leukocytoclastic vasculitis. Diagnosis of primary SS with extraglandular cutaneous manifestations was confirmed. Cryoglobulinemia (Cg) and monoclonal gammopathy (MG) were detected, which increased the suspicion of hematological malignancy, and additional diagnostic procedures were performed. Computed tomography of the chest revealed an enlarged, multicystically altered anterior mediastinal mass. A thymectomy was performed through video-assisted thoracic surgery. Histological findings of the tissue confirmed the presence of tumor tissue consistent with MALT lymphoma in the thymus. Induction therapy with pulse doses of glucocorticoids was applied for three days, which was continued with medium doses of the drug. The doses were gradually reduced, and hydroxychloroquine was introduced. This has shown to be an effective therapy against features of SS. Postoperative local radiotherapy was performed. Conclusion. In SS patients with CV and in the presence of Cg and MG, attention should also be paid to the eventual development of MALT lymphoma, including the rare localization in the thymus.

Sjögren's syndrome: one year in review 2023.

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disorder characterised by the T-cell-mediated hyperactivation of B-cells and cytokine production. The condition may evolve from an asymptomatic, indolent course, with glandular involvement, to extra-glandular systemic manifestations up to lymphoma development. On tissue level, the typical feature is the lymphocytic infiltration of the salivary gland by B-, T- and antigen presenting cells, as mirrored by the diagnostic cornerstone role of minor salivary gland (MSG) biopsy. Recently, increasing research focused on the investigation of mechanisms underlying the complex pathogenesis of the disease and highlighted the multi-factorial nature of SS consisting of concomitant involvement of environmental, genetic, neuroendocrine and immune factors. In particular, many aspects have been investigated regarding genetic and epigenetics, the role of specific B- and T-cell phenotypes and the investigation of disease-specific biomarkers as predictors of disease development, activity, and lymphomagenesis. Surely, a deeper understanding of these multiple mechanisms may facilitate earlier diagnosis, enable subphenotyping of patients and open novel therapeutic possibilities to address the unmet needs of the disease in the upcoming years.In this review, following the others of this series, we will summarise the most recent literature on pSS pathogenesis and clinical features focusing in particular on new insights into pSS molecular stratification and therapeutic advances in the era of precision medicine.

Epidemiology of Sjögren syndrome.

Sjögren syndrome is a phenotypically varied autoimmune disorder that can occur alone in primary Sjögren syndrome or in association with other connective tissue diseases (CTDs), including rheumatoid arthritis, systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). The estimation of the prevalence and incidence of Sjögren syndrome varies depending on diagnostic criteria and study design, making it difficult to estimate geographical and temporal trends. Nonetheless, disease phenotype is influenced by geographical origin, which is a risk factor for systemic activity. Whether mortality in primary Sjögren syndrome is increased compared with that ofthe general population is not yet known, but extra-glandular manifestations, in particular lymphomas, are clear risk factors for mortality. In CTDs associated with Sjögren syndrome, lymphoma risk seems higher than that of patients with CTD alone, and there is potentially lower disease activity in SLE with Sjögren syndrome and in SSc with Sjögren syndrome than in SLE or SSc alone.