Home-Based Telemedicine in Rheumatology-A Scoping Review.

OBJECTIVE: We performed a scoping review of the relevant literature on home-based telehealth in rheumatology to understand its appropriate application in rheumatology practice. METHODS: We searched the Cochrane Library, PubMed, Web of Science, and scientific meeting abstracts to identify articles that specifically addressed telehealth suitability, barriers to telehealth, patient-reported outcomes (PROs) collected in telehealth settings, and telehealth satisfaction. From the initial search of 4,882 studies, 23 reports were included. In addition, 10 abstracts were also eligible for analysis, resulting in a total of 33 articles: 2 randomized clinical trials, 9 prospective cohort studies, and 22 retrospective studies. RESULTS: We found that triage appointments or predictive models could be helpful in selecting patients for telehealth and that telehealth interventions were appropriate for follow-up of patients with systemic lupus erythematosus and inflammatory arthritis, but that conducting new patient visits over telehealth was not ideal. Barriers to telehealth include patient factors (age, technology access) and need for physician/process factors (eg, physical examinations). PROs collected in regular practice can be incorporated into telehealth. Several small, single-center studies suggest that telehealth does not lead to negative outcomes compared with in-person visits, and overall, patients report high patient satisfaction with telehealth. In several scenarios, home-based telehealth was equivalent to in-person visits with regard to patient outcomes and satisfaction. CONCLUSION: The widespread potential of telehealth to manage and deliver care for people with rheumatic disease is significant. As such, further research in the form of randomized controlled trials can help contribute to growing evidence that shapes telehealth implementation for patients with rheumatic diseases.

The Importance of Ultrasound-Guided Synovial Biopsy in the Workup of Seronegative Inflammatory Arthritis: A Case Report.

We report a case of a 74-year-old male who presented with typical clinical features of rheumatoid arthritis (RA), as well as elevated markers of inflammation. However, the patient did not respond to multiple RA treatments, and an ultrasound-guided synovial biopsy (UGSB) of the right wrist was performed, which established the diagnosis of amyloidosis. A variety of inflammatory conditions sometimes get misdiagnosed as seronegative RA due to similarities in clinical presentation. This case report highlights the importance of a thorough workup in patients who appear to have seronegative RA. Given the wide availability of ultrasound-guided, minimally invasive synovial biopsies, these procedures should be employed more often to detect rare conditions that may mimic seronegative RA, such as amyloidosis.

α-Ketoglutarate-Dependent KDM6 Histone Demethylases and Interferon-Stimulated Gene Expression in Lupus.

OBJECTIVE: We aimed to investigate the hypothesis that interferon (IFN)-stimulated gene (ISG) expression in systemic lupus erythematosus (SLE) monocytes is linked to changes in metabolic reprogramming and epigenetic regulation of ISG expression. METHODS: Monocytes from healthy volunteers and patients with SLE at baseline or following IFNα treatment were analyzed by extracellular flux analysis, proteomics, metabolomics, chromatin immunoprecipitation, and gene expression. The histone demethylases KDM6A/B were inhibited using glycogen synthase kinase J4 (GSK-J4). GSK-J4 was tested in pristane and resiquimod (R848) models of IFN-driven SLE. RESULTS: SLE monocytes had enhanced rates of glycolysis and oxidative phosphorylation compared to healthy control monocytes, as well as increased levels of isocitrate dehydrogenase and its product, α-ketoglutarate (α-KG). Because α-KG is a required cofactor for histone demethylases KDM6A and KDM6B, we hypothesized that IFNα may be driving "trained immune" responses through altering histone methylation. IFNα priming (day 1) resulted in a sustained increase in the expression of ISGs in primed cells (day 5) and enhanced expression on restimulation with IFNα. Importantly, decreased H3K27 trimethylation was observed at the promoters of ISGs following IFNα priming. Finally, GSK-J4 (KDM6A/B inhibitor) resulted in decreased ISG expression in SLE patient monocytes, as well as reduced autoantibody production, ISG expression, and kidney pathology in R848-treated BALB/c mice. CONCLUSION: Our study suggests long-term IFNα exposure alters the epigenetic regulation of ISG expression in SLE monocytes via changes in immunometabolism, a mechanism reflecting trained immunity to type I IFN. Importantly, it opens the possibility that targeting histone-modifying enzymes, such as KDM6A/B, may reduce IFN responses in SLE.

Macrophage fumarate hydratase restrains mtRNA-mediated interferon production.

Metabolic rewiring underlies the effector functions of macrophages1-3, but the mechanisms involved remain incompletely defined. Here, using unbiased metabolomics and stable isotope-assisted tracing, we show that an inflammatory aspartate-argininosuccinate shunt is induced following lipopolysaccharide stimulation. The shunt, supported by increased argininosuccinate synthase (ASS1) expression, also leads to increased cytosolic fumarate levels and fumarate-mediated protein succination. Pharmacological inhibition and genetic ablation of the tricarboxylic acid cycle enzyme fumarate hydratase (FH) further increases intracellular fumarate levels. Mitochondrial respiration is also suppressed and mitochondrial membrane potential increased. RNA sequencing and proteomics analyses demonstrate that there are strong inflammatory effects resulting from FH inhibition. Notably, acute FH inhibition suppresses interleukin-10 expression, which leads to increased tumour necrosis factor secretion, an effect recapitulated by fumarate esters. Moreover, FH inhibition, but not fumarate esters, increases interferon-ß production through mechanisms that are driven by mitochondrial RNA (mtRNA) release and activation of the RNA sensors TLR7, RIG-I and MDA5. This effect is recapitulated endogenously when FH is suppressed following prolonged lipopolysaccharide stimulation. Furthermore, cells from patients with systemic lupus erythematosus also exhibit FH suppression, which indicates a potential pathogenic role for this process in human disease. We therefore identify a protective role for FH in maintaining appropriate macrophage cytokine and interferon responses.

Using Patient-Reported Health Data From Social Media to Identify Diverse Lupus Patients and Assess Their Symptom and Medication Expressions: A Feasibility Study.

OBJECTIVE: Patient communities use social media for peer support and information seeking. This study assessed the feasibility of using public patient-generated health data from the social network Twitter to identify diverse lupus patients and gather their perspectives about disease symptoms and medications. METHODS: We extracted public lupus-related Twitter messages (n = 47,715 tweets) in English posted by users (n = 8,446) in the US between September 1, 2017 and October 31, 2018. We analyzed the data to describe lupus patients and the expressed themes (symptoms and medications). Two independent coders analyzed the data; Cohen's kappa coefficient was used to ensure interrater reliability. Differences in symptom and medication expressions were analyzed using 2-tailed Z tests and a combination of 1-way analysis of variance tests and unpaired t-tests. RESULTS: We found that lupus patients on Twitter are diverse in gender and race: approximately one-third (34.64%, 62 of 179) were persons of color (POCs), and 85.47% were female. The expressed disease symptoms and medications varied significantly by gender and race. Most of our findings correlated with documented clinical observations, e.g., expressions of general pain (8.39%, 709 of 8,446), flares (6.05%, 511 of 8,446), and fatigue (4.18%, 353 of 8,446). However, our data also revealed less well-known patient observations, e.g., possible racial disparities within ocular manifestations of lupus. CONCLUSION: Our results indicate that social media surveillance can provide valuable data of clinical relevance from the perspective of lupus patients. The medical community has the opportunity to harness this information to inform the patient-centered care within underrepresented patient groups, such as POCs.

Genome-wide association study identifies Sjögren's risk loci with functional implications in immune and glandular cells.

Sjögren's disease is a complex autoimmune disease with twelve established susceptibility loci. This genome-wide association study (GWAS) identifies ten novel genome-wide significant (GWS) regions in Sjögren's cases of European ancestry: CD247, NAB1, PTTG1-MIR146A, PRDM1-ATG5, TNFAIP3, XKR6, MAPT-CRHR1, RPTOR-CHMP6-BAIAP6, TYK2, SYNGR1. Polygenic risk scores yield predictability (AUROC = 0.71) and relative risk of 12.08. Interrogation of bioinformatics databases refine the associations, define local regulatory networks of GWS SNPs from the 95% credible set, and expand the implicated gene list to >40. Many GWS SNPs are eQTLs for genes within topologically associated domains in immune cells and/or eQTLs in the main target tissue, salivary glands.

Neutrophils Contribute to ER Stress in Lung Epithelial Cells in the Pristane-Induced Diffuse Alveolar Hemorrhage Mouse Model.

Diffuse alveolar hemorrhage (DAH), although rare, is a life-threatening complication of systemic lupus erythematosus (SLE). Little is known about the pathophysiology of DAH in humans, although increasingly neutrophils, NETosis and inflammatory monocytes have been shown to play an important role in the pristane-induced model of SLE which develops lung hemorrhage and recapitulates many of the pathologic features of human DAH. Using this experimental model, we asked whether endoplasmic reticulum (ER) stress played a role in driving the pathology of pulmonary hemorrhage and what role infiltrating neutrophils had in this process. Analysis of lung tissue from pristane-treated mice showed genes associated with ER stress and NETosis were increased in a time-dependent manner and reflected the timing of CD11b+Ly6G+ neutrophil accumulation in the lung. Using precision cut lung slices from untreated mice we observed that neutrophils isolated from the peritoneal cavity of pristane-treated mice could directly induce the expression of genes associated with ER stress, namely Chop and Bip. Mice which had myeloid-specific deletion of PAD4 were generated and treated with pristane to assess the involvement of PAD4 and PAD4-dependent NET formation in pristane-induced lung inflammation. Specific deletion of PAD4 in myeloid cells resulted in decreased expression of ER stress genes in the pristane model, with accompanying reduction in IFN-driven genes and pathology. Lastly, coculture experiments of human neutrophils and human lung epithelial cell line (BEAS-2b) showed neutrophils from SLE patients induced significantly more ER stress and interferon-stimulated genes in epithelial cells compared to healthy control neutrophils. These results support a pathogenic role of neutrophils and NETs in lung injury during pristane-induced DAH through the induction of ER stress response and suggest that overactivation of neutrophils in SLE and NETosis may underlie development of DAH.

Home-based virtual reality for chronic pain: protocol for an NIH-supported randomised-controlled trial.

INTRODUCTION: Chronic pain is highly prevalent and associated with a large burden of illness; there is a pressing need for safe, home-based, non-pharmacological, interventions. Virtual reality (VR) is a digital therapeutic known to be effective for acute pain, but its role in chronic pain is not yet fully elucidated. Here we present a protocol for the National Institute of Health (NIH) Back Pain Consortium (BACPAC) VR trial that evaluates the effectiveness of three forms of VR for patients with chronic lower back pain (cLBP), a highly prevalent form of chronic pain. METHODS AND ANALYSIS: The NIH BACPAC VR trial will randomise 360 patients with cLBP into one of three arms, each administered through a head-mounted display: 1) skills-based VR, a program incorporating principles of cognitive behavioural therapy, mindful meditation and physiological biofeedback therapy using embedded biometric sensors; 2) distraction-based VR, a program using 360-degree immersive videos designed to distract users from pain; and 3) sham VR, a non-immersive program using two-dimensional videos within a VR headset. Research participants will be monitored for 12 weeks using a combination of patient-reported outcomes administered via REDCap (Research Electronic Data Capture), wearable sensor data collected via Fitbit Charge 4 and electronic health record data. The primary outcome will be the NIH Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference scale. Secondary outcomes will include PROMIS Anxiety, PROMIS Sleep Disturbance, opioid prescription data and Pain Catastrophizing Scale Short Form. A subgroup analysis will explore patient level predictors for VR efficacy. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Institutional Review Board of Cedars-Sinai Health System in April 2020. The results will be disseminated in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT04409353.

Expressed Symptoms and Attitudes Toward Using Twitter for Health Care Engagement Among Patients With Lupus on Social Media: Protocol for a Mixed Methods Study.

BACKGROUND: Lupus is a complex autoimmune disease that is difficult to diagnose and treat. It is estimated that at least 5 million Americans have lupus, with more than 16,000 new cases of lupus being reported annually in the United States. Social media provides a platform for patients to find rheumatologists and peers and build awareness of the condition. Researchers have suggested that the social network Twitter may serve as a rich avenue for exploring how patients communicate about their health issues. However, there is a lack of research about the characteristics of lupus patients on Twitter and their attitudes toward using Twitter for engaging them with their health care. OBJECTIVE: This study has two objectives: (1) to conduct a content analysis of Twitter data published by users (in English) in the United States between September 1, 2017 and October 31, 2018 to identify patients who publicly discuss their lupus condition and to assess their expressed health themes and (2) to conduct a cross-sectional survey among these lupus patients on Twitter to study their attitudes toward using Twitter for engaging them with their health care. METHODS: This is a mixed methods study that analyzes retrospective Twitter data and conducts a cross-sectional survey among lupus patients on Twitter. We used Symplur Signals, a health care social media analytics platform, to access the Twitter data and analyze user-generated posts that include keywords related to lupus. We will use descriptive statistics to analyze the data and identify the most prevalent topics in the Twitter content among lupus patients. We will further conduct self-report surveys via Twitter by inviting all identified lupus patients who discuss their lupus condition on Twitter. The goal of the survey is to collect data about the characteristics of lupus patients (eg, gender, race/ethnicity, educational level) and their attitudes toward using Twitter for engaging them with their health care. RESULTS: This study has been funded by the National Center for Advancing Translational Science through a Clinical and Translational Science Award. The institutional review board at the University of Southern California (HS-19-00048) approved the study. Data extraction and cleaning are complete. We obtained 47,715 Twitter posts containing terms related to "lupus" from users in the United States published in English between September 1, 2017 and October 31, 2018. We included 40,885 posts in the analysis. Data analysis was completed in Fall 2020. CONCLUSIONS: The data obtained in this pilot study will shed light on whether Twitter provides a promising data source for garnering health-related attitudes among lupus patients. The data will also help to determine whether Twitter might serve as a potential outreach platform for raising awareness of lupus among patients and implementing related health education interventions. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/15716.

American Indians Have a Higher Risk of Sjögren's Syndrome and More Disease Activity Than European Americans and African Americans.

OBJECTIVE: To describe the clinical and serologic manifestations of Sjögren's syndrome (SS) in ethnic groups of the US. METHODS: This was a cross-sectional study of 648 patients with primary SS: 20 African American (AA), 164 American Indian (AI), 426 European American (EA), and 38 patients of other races evaluated in a multidisciplinary Sjögren's International Collaborative Clinical Alliance research clinic. RESULTS: AA subjects comprised 3.1% of the SS cohort, much lower than the percentage of AA in the state of Oklahoma (P = 3.01 × E - 05), the US (P = 2.24E - 13), or a systemic lupus erythematosus (SLE) cohort at the same institution (P = 4.26 × 10E - 27). In contrast, the percentage of AI in the SS cohort (25.3%) was much higher than expected (P = 3.17E - 09 versus SLE cohort, P = 6.36 - 26 versus Oklahoma, and P = 8.14E - 96 versus US population). The SS classification criteria were similar between AA and EA, but subjects of AI ancestry had lower rates of abnormal tear and salivary flow, as well as anti-Ro/SSA and anti-La/SSB antibodies. Paradoxically, AI had higher levels of disease activity (mean ± SD European League Against Rheumatism Sjögren's Syndrome Disease Activity Index score 3.77 ± 4.78) in comparison to EA (2.90 ± 4.12; P = 0.011) and more extraglandular manifestations affecting mainly the articular and glandular domains. Meanwhile, AA patients were characterized by higher rates of hypergammaglobulinemia (odds ratio [OR] 1.39 [95% confidence interval (95% CI) 1.39-8.65]; P = 0.01), elevated erythrocyte sedimentation rate (ESR) (OR 3.95 [95% CI 1.46-9.95]; P = 0.009), and parotid enlargement (OR 4.40 [95% CI 1.49-13.07]; P = 0.02). CONCLUSION: AI are affected at high rates with SS but present with few classical features, potentially preventing timely diagnosis. In contrast to SLE, SS is infrequent and not more severe among AA, but the triad of hypergammaglobulinemia, increased ESR, and parotid enlargement warrants extra vigilance for lymphomagenesis.

Reproducibility of Ocular Surface Staining in the Assessment of Sjögren Syndrome-Related Keratoconjunctivitis Sicca: Implications on Disease Classification.

OBJECTIVE: The objective of this study was to assess the performance and reproducibility of the two currently used ocular surface staining scores in the assessment of keratoconjunctivitis sicca in Sjögren syndrome (SS) research classification. METHODS: In a multidisciplinary clinic for the evaluation of sicca, we performed all tests for the American European Consensus Group (AECG) and the American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria, including the van Bijsterveld score (vBS) and the Ocular Staining Score (OSS), in 994 participants with SS or with non-SS sicca. We analyzed the concordance between the scores, the diagnostic accuracy and correlation with clinical variables, and interrater and intrasubject reproducibility. RESULTS: A total of 308 (31.1%) participants had a discordant vBS and OSS that was due to extra corneal staining points in the OSS. The presence of one or more of the additional points was highly predictive of SS classification (odds ratio = 3.66; P = 1.65 × 10e-20) and was associated with abnormal results of all measures of autoimmunity and glandular dysfunction. Receiver operating characteristic curves showed optimal cutoff values of four for the vBS (sensitivity = 0.62; specificity = 0.71; Youden's J = 0.33) and five for the OSS (sensitivity = 0.56; specificity = 0.75; Youden's J = 0.31). Notably, there was very poor consistency in interobserver mean scores and distributions (P < 0.0001) and in intrasubject scores after a median of 5.5 years (35% changed status of the ocular criterion). CONCLUSION: Ocular surface staining scores are useful for SS research classification; however, they are subject to significant interrater and intrasubject variability, which could result in changes in classification in 5%-10% of all subjects. These results highlight the need for objective and reproducible markers of disease that have thus far remained elusive for SS.

IL-16/miR-125a axis controls neutrophil recruitment in pristane-induced lung inflammation.

Severe lung inflammation and alveolar hemorrhage can be life-threatening in systemic lupus erythematosus (SLE) patients if not treated early and aggressively. Neutrophil influx is the driver key of this pathology, but little is known regarding the molecular events regulating this recruitment. Here, we uncover a role for IL-16/mir-125a in this pathology and show not only that IL-16 is a target for miR-125a but that reduced miR-125a expression in SLE patients associates with lung involvement. Furthermore, in the pristane model of acute "SLE-like" lung inflammation and alveolar hemorrhage, we observed reduced pulmonary miR-125a and enhanced IL-16 expression. Neutrophil infiltration was markedly reduced in the peritoneal lavage of pristane-treated IL-16-deficient mice and elevated following i.n. delivery of IL-16. Moreover, a miR-125a mimic reduced pristane-induced IL-16 expression and neutrophil recruitment and rescued lung pathology. Mechanistically, IL-16 acts directly on the pulmonary epithelium and markedly enhances neutrophil chemoattractant expression both in vitro and in vivo, while the miR-125a mimic can prevent this. Our results reveal a role for miR-125a/IL-16 in regulating lung inflammation and suggest this axis may be a therapeutic target for management of acute lung injury in SLE.

Rare X Chromosome Abnormalities in Systemic Lupus Erythematosus and Sjögren's Syndrome.

OBJECTIVE: Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE) are related by clinical and serologic manifestations as well as genetic risks. Both diseases are more commonly found in women than in men, at a ratio of ~10 to 1. Common X chromosome aneuploidies, 47,XXY and 47,XXX, are enriched among men and women, respectively, in either disease, suggesting a dose effect on the X chromosome. METHODS: We examined cohorts of SS and SLE patients by constructing intensity plots of X chromosome single-nucleotide polymorphism alleles, along with determining the karyotype of selected patients. RESULTS: Among ~2,500 women with SLE, we found 3 patients with a triple mosaic, consisting of 45,X/46,XX/47,XXX. Among ~2,100 women with SS, 1 patient had 45,X/46,XX/47,XXX, with a triplication of the distal p arm of the X chromosome in the 47,XXX cells. Neither the triple mosaic nor the partial triplication was found among the controls. In another SS cohort, we found a mother/daughter pair with partial triplication of this same region of the X chromosome. The triple mosaic occurs in ~1 in 25,000-50,000 live female births, while partial triplications are even rarer. CONCLUSION: Very rare X chromosome abnormalities are present among patients with either SS or SLE and may inform the location of a gene(s) that mediates an X dose effect, as well as critical cell types in which such an effect is operative.

Identification of a Sjögren's syndrome susceptibility locus at OAS1 that influences isoform switching, protein expression, and responsiveness to type I interferons.

Sjögren's syndrome (SS) is a common, autoimmune exocrinopathy distinguished by keratoconjunctivitis sicca and xerostomia. Patients frequently develop serious complications including lymphoma, pulmonary dysfunction, neuropathy, vasculitis, and debilitating fatigue. Dysregulation of type I interferon (IFN) pathway is a prominent feature of SS and is correlated with increased autoantibody titers and disease severity. To identify genetic determinants of IFN pathway dysregulation in SS, we performed cis-expression quantitative trait locus (eQTL) analyses focusing on differentially expressed type I IFN-inducible transcripts identified through a transcriptome profiling study. Multiple cis-eQTLs were associated with transcript levels of 2'-5'-oligoadenylate synthetase 1 (OAS1) peaking at rs10774671 (PeQTL = 6.05 × 10-14). Association of rs10774671 with SS susceptibility was identified and confirmed through meta-analysis of two independent cohorts (Pmeta = 2.59 × 10-9; odds ratio = 0.75; 95% confidence interval = 0.66-0.86). The risk allele of rs10774671 shifts splicing of OAS1 from production of the p46 isoform to multiple alternative transcripts, including p42, p48, and p44. We found that the isoforms were differentially expressed within each genotype in controls and patients with and without autoantibodies. Furthermore, our results showed that the three alternatively spliced isoforms lacked translational response to type I IFN stimulation. The p48 and p44 isoforms also had impaired protein expression governed by the 3' end of the transcripts. The SS risk allele of rs10774671 has been shown by others to be associated with reduced OAS1 enzymatic activity and ability to clear viral infections, as well as reduced responsiveness to IFN treatment. Our results establish OAS1 as a risk locus for SS and support a potential role for defective viral clearance due to altered IFN response as a genetic pathophysiological basis of this complex autoimmune disease.

Immune Mechanisms and Novel Targets in Rheumatoid Arthritis.

Significant progress has been made in understanding the pathophysiology of rheumatoid arthritis. It is widely recognized that early institution of treatment is one of the best predictive factors for response to therapy. Several novel approaches are currently being investigated and several novel biologics are in various stages of development. With advances in the fields of proteomics, genomics, and metabolomics, specific phenotypes of the disease can be better identified and specific therapies for particular phases of the disease and specific patients will allow for improved control of this condition.

MicroRNA-302d targets IRF9 to regulate the IFN-induced gene expression in SLE.

Systemic lupus erythematosus (SLE) is a complex disease targeting multiple organs as a result of overactivation of the type I interferon (IFN) system, a feature currently being targeted by multiple biologic therapies against IFN-α. We have identified an estrogen-regulated microRNA, miR-302d, whose expression is decreased in SLE patient monocytes and identify its target as interferon regulatory factor (IRF)-9, a critical component of the transcriptional complex that regulates expression of interferon-stimulated genes (ISGs). In keeping with the reduced expression of miR-302d in SLE patient monocytes, IRF9 levels were increased, as was expression of a number of ISGs including MX1 and OAS1. In vivo evaluation revealed that miR-302d protects against pristane-induced inflammation in mice by targeting IRF9 and hence ISG expression. Importantly, patients with enhanced disease activity have markedly reduced expression of miR-302d and enhanced IRF9 and ISG expression, with miR-302d negatively correlating with IFN score. Together these findings identify miR-302d as a key regulator of type I IFN driven gene expression via its ability to target IRF9 and regulate ISG expression, underscoring the importance of non-coding RNA in regulating the IFN pathway in SLE.

Effect of Tobacco Smoking on The Clinical, Histopathological, and Serological Manifestations of Sjögren's Syndrome.

OBJECTIVES: To assess the association of smoking habits with the clinical, serological, and histopathological manifestations of Sjögren's syndrome (SS) and non-Sjögren's sicca (non-SS sicca). METHODS: Cross-sectional case-control study of 1288 patients with sicca symptoms (587 SS and 701 non-SS sicca) evaluated in a multi-disciplinary research clinic. Smoking patterns were obtained from questionnaire data and disease-related clinical and laboratory data were compared between current, past, ever, and never smokers. RESULTS: Current smoking rates were 4.6% for SS patients compared to 14.1% in non-SS sicca (p = 5.17x10E-09), 18% in a local lupus cohort (p = 1.13x10E-14) and 16.8% in the community (p = 4.12x10E-15). Current smoking was protective against SS classification (OR 0.35, 95%CI 0.22-0.56, FDR q = 1.9E10-05), focal lymphocytic sialadenitis (OR 0.26, 95%CI 0.15-0.44, FDR q = 1.52x10E-06), focus score ≥1 (OR 0.22, 95%CI 0.13-0.39, FDR q = 1.43x10E-07), and anti-Ro/SSA(+) (OR 0.36, 95%CI 0.2-0.64, FDR q = 0.0009); ever smoking was protective against the same features and against anti-La/SSB(+) (OR 0.52, 95%CI 0.39-0.70, FDR q = 5.82x10E-05). Duration of smoking was inversely correlated with SS even after controlling for socioeconomic status, BMI, alcohol and caffeine consumption. CONCLUSIONS: Current tobacco smoking is negatively and independently associated with SS, protecting against disease-associated humoral and cellular autoimmunity. The overall smoking rate amongst SS patients is significantly lower than in matched populations and the effects of smoking are proportional to exposure duration. In spite of the protective effects of tobacco on SS manifestations, it is associated with other serious comorbidities such as lung disease, cardiovascular risk and malignancy, and should thus be strongly discouraged in patients with sicca.