Inflammatory cytokines and their potential role in Sjogren's syndrome risk: insights from a mendelian randomization study

AIM

This study aimed to investigate the causal impact of inflammatory cytokines on Sjogren's Syndrome (SS) and to identify potential biomarkers for SS clinical management using Mendelian Randomization (MR).

MATERIALS AND METHODS

Leveraging GWAS summary data of inflammatory cytokines and SS, we executed the first two-sample MR analysis. Genetic variants from prior GWASs associated with circulating inflammatory cytokines served as instrumental variables (IVs). Data regarding cytokines were analyzed using the Olink Target-96 Inflammation panel, synthesizing data from 14,824 participants. GWAS summary statistics for SS were procured from the UK Biobank, focusing on samples of European ancestry. To discern the causal relationship between inflammatory cytokines and SS, several MR methodologies, including inverse variance weighted (IVW) and MR-Egger regression, were applied.

RESULTS

After rigorous IV quality control, 91 cytokines were incorporated into the MR analysis. The IVW analysis identified 8 cytokines with a positive association to SS: Axin-1 (OR 2.56, 95% CI 1.07-6.10), T-cell surface glycoprotein CD5 (OR 1.81, 95% CI 1.08-3.02), CUDP1 (OR 1.61, 95% CI 1.00-2.58), CXCL10 (OR 1.92, 95% CI 1.25-2.95), IL-4 (OR 2.18, 95% CI 1.22-3.91), IL-7 (OR 2.35, 95% CI 1.27-4.33), MCP-2 (OR 1.27, 95% CI 1.05-1.54), and TNFRSF9 (OR 1.83, 95% CI 1.03-3.24), suggesting their potential in increasing SS risk.

CONCLUSION

Our study conducted through MR, identified various inflammatory cytokines associated with SS risk, validating some previous research results and offering some new potential biomarkers for SS. However, these findings necessitate further research for validation and exploration of their precise role in the onset and progression of SS.

Screening biomarkers for Sjogren's Syndrome by computer analysis and evaluating the expression correlations with the levels of immune cells

Background

Sjögren's syndrome (SS) is a systemic autoimmune disease that affects about 0.04-0.1% of the general population. SS diagnosis depends on symptoms, clinical signs, autoimmune serology, and even invasive histopathological examination. This study explored biomarkers for SS diagnosis.

Methods

We downloaded three datasets of SS patients' and healthy pepole's whole blood (GSE51092, GSE66795, and GSE140161) from the Gene Expression Omnibus (GEO) database. We used machine learning algorithm to mine possible diagnostic biomarkers for SS patients. Additionally, we assessed the biomarkers' diagnostic value using the receiver operating characteristic (ROC) curve. Moreover, we confirmed the expression of the biomarkers through the reverse transcription quantitative polymerase chain reaction (RT-qPCR) using our own Chinese cohort. Eventually, the proportions of 22 immune cells in SS patients were calculated by CIBERSORT, and connections between the expression of the biomarkers and immune cell ratios were studied.

Results

We obtained 43 DEGs that were mainly involved in immune-related pathways. Next, 11 candidate biomarkers were selected and validated by the validation cohort data set. Besides, the area under curves (AUC) of XAF1, STAT1, IFI27, HES4, TTC21A, and OTOF in the discovery and validation datasets were 0.903 and 0.877, respectively. Subsequently, eight genes, including HES4, IFI27, LY6E, OTOF, STAT1, TTC21A, XAF1, and ZCCHC2, were selected as prospective biomarkers and verified by RT-qPCR. Finally, we revealed the most relevant immune cells with the expression of HES4, IFI27, LY6E, OTOF, TTC21A, XAF1, and ZCCHC2.

Conclusion

In this paper, we identified seven key biomarkers that have potential value for diagnosing Chinese SS patients.

Cardiac damage in autoimmune diseases: Target organ involvement that cannot be ignored

Autoimmune diseases are diseases that cause damage to the body's own tissues as a result of immune dysfunction, often involving multiple organs and systems. The heart is one of the common target organs of autoimmune diseases. The whole structure of the heart can be affected, causing microcirculatory disorders, arrhythmias, pericardial damage, myocarditis, myocardial fibrosis, and impaired valvular function. However, early clinical manifestations of autoimmune heart damage are often overlooked because they are insidious or have no typical features. The damage is often severe and irreversible when symptoms are apparent, even life-threatening. Therefore, early detection and treatment of heart damage in autoimmune diseases is particularly important. Herein, we review the clinical features and mechanisms of cardiac damage in common rheumatic diseases.

Systemic Autoimmune Diseases in Patients Hospitalized with COVID-19 in Spain: A Nation-Wide Registry Study

We aimed to evaluate the clinical outcome of Systemic Autoimmune Diseases (SADs) patients hospitalized with COVID-19 in Spain, before the introduction of SARS-CoV-2 vaccines. A nationwide, retrospective and observational analysis of the patients admitted during 2020, based on the ICD10 codes in the National Registry of Hospital Discharges, was performed. Among 117,694 patients, only 892 (0.8%) presented any type of SAD before COVID-19-related admission: Sjogren’s Syndrome constituted 25%, Systemic Vasculitides 21%, Systemic Lupus Erythematosus 19%, Sarcoidosis 17%, Systemic Sclerosis 11%, Mixed and Undifferentiated Connective Tissue Disease 4%, Behçet’s Disease 4% and Inflammatory Myopathies 2%. The in-hospital mortality rate was higher in SAD individuals (20% vs. 16%, p < 0.001). After adjustment by baseline conditions, SADs were not associated with a higher mortality risk (OR = 0.93, 95% CI 0.78−1.11). Mortality in the SADs patients was determined by age (OR = 1.05, 95% CI 1.04−1.07), heart failure (OR = 1.67, 95% CI 1.10−2.49), chronic kidney disease (OR = 1.29, 95% CI 1.05−1.59) and liver disease (OR = 1.97, 95% CI 1.13−3.44). In conclusion, the higher COVID-19 mortality rate seen in SADs patients hospitalized in Spain in 2020 was related to the higher burden of comorbidities, secondary to direct organ damage and sequelae of their condition. Whilst further studies should evaluate the impact of baseline immunosuppression on COVID-19 outcomes in this population, efforts should be focused on the optimal management of SAD to minimize the impact of the organ damage that has been shown to determine COVID-19 prognosis.

Cigarette smoking patterns preceding primary Sjögren's syndrome

BACKGROUND

Cigarette smoking is a well-established risk factor for several autoimmune diseases, but its role in primary Sjögren's syndrome (pSS) remains unclear. Here, we investigated the association between cigarette smoking and subsequent development of pSS.

METHODS

Information on smoking habits was collected from lifestyle habit questionnaires of patients with pSS (n=815) and a matched control group (n=4425) for a case-control study. Differences in smoking exposure were analysed by conditional logistic regression. Potential interactions between smoking and risk-associated human leucocyte antigens (HLA) were assessed by multivariate regression.

RESULTS

The fraction of patients with pSS having ever smoked prior to diagnosis was lower than in controls (OR 0.67, 95% CI 0.55 to 0.81). Current smoking at diagnosis was also less prevalent in cases (OR 0.37, 95% CI 0.26 to 0.53). However, period prevalence of smoking during early adulthood was not statistically different from controls (OR 0.89, 95% CI 0.66 to 1.22) but markedly decreased over time. This was partly due to patients being more prone to stop smoking, starting already 30 years prior to diagnosis (OR 2.01, 95% CI 1.22 to 3.30). Smoking patterns were also stratified by autoantibody status, yielding similar estimates. No interaction effects between HLA-DRB1 haplotypes and smoking were observed.

CONCLUSION

The observed smoking patterns indicate that individuals who develop pSS smoke equally much as the general population during early life but are then more prone to stop. The data can be interpreted as smoking conferring protective effects, or reflecting early symptoms of pSS that affect smoking habits, emphasising the slow, progressive development of the disease.

Rheumatology practice amidst the COVID-19 pandemic: a pragmatic view

The coronavirus disease 2019 (COVID-19) pandemic has come with many challenges for healthcare providers and patients alike. In addition to the direct burden it has placed on societies and health systems, it had a significant impact in the care of patients with chronic diseases, as healthcare resources were deployed to fight the crisis, and major travel and social restrictions were adopted. In the field of rheumatology, this has required notable efforts from departments and clinicians to adapt to the novel status quo and assure the follow-up of patients with rheumatic and musculoskeletal diseases. In the present viewpoint, we provide a practical approach to tackle this reality. Key measures include setting up preventive team management strategies, optimising communication with patients and reorganising patient care in all its dimensions. We then anticipate the nuances of rheumatology practice as restrictive measures are progressively lifted, while an effective vaccine is still pending. This includes the need to reimpose the same strategy as further waves unfold. Finally, we look ahead and address the lessons we can incorporate into post-COVID-19 rheumatology.

A Case Report of Mikulicz Syndrome

Mikulicz Syndrome (MS) is a rare chronic condition characterized by the abnormal enlargement of glandular tissue in the head and neck. Patients usually present with enlarged lacrimal and parotid glands. While this can be a benign self-limiting condition, other complex systemic diseases, such as sarcoidosis, may represent other underlying etiologies. We present a case of MS in a patient with a history of Crohn's disease.

The Frequency of Primary Sjogren's Syndrome and Fibromyalgia in Irritable Bowel Syndrome

OBJECTIVE

To determine the frequency of sicca complex, Sjogren's Syndrome (SS) and Fibromyalgia (FM) in patients with Irritable Bowel Syndrome (IBS).

METHODS

Seventy seven IBS patients who fulfilled the Rome-III criteria were included in the study. All patients were assessed for FM according to the American College of Rheumatology (ACR) 2010 criteria. After examination for objective evidence of sicca complex by Schirmer test, TBUT and Ocular Staining Score (OSS), serological tests were performed. And the diagnosis of SS was made according to the American College of Rheumatology (ACR) classification criteria for SS - 2012.

RESULTS

Thirteen (16.9%) of IBS patients had FM. Dry eye was detected in 20(26.0%), 7(9.1%) and 29(37.7%) patients by OSS, Schirmer test and TBUT, respectively. Of 77 patients with IBS, the diagnosis of SS was established in two patients (2.6%).

CONCLUSION

The frequency of Sjogren's Syndrome among patients with IBS is relatively higher than the general population. All IBS patients should be questioned for dryness of the mouth and eyes, and if necessary, should be evaluated for SS.

Artificial tears potpourri: a literature review

Numerous brands and types of artificial tears are available on the market for the treatment of dysfunctional tear syndrome. Past literature has focused on comparing the components of these products on patient’s clinical improvement. The wide array of products on the market presents challenges to both clinicians and patients when trying to choose between available tear replacement therapies. Different formulations affect patients based on etiology and severity of disease. In order to provide an unbiased comparison between available tear replacement therapies, we conducted a literature review of existing studies and National Institutes of Health clinical trials on commercially available, brand name artificial tears. Outcomes evaluated in each study, as well as the percent of patients showing clinical and symptomatic improvement, were analyzed. Fifty-one studies evaluating different brands of artificial tears, and their efficacy were identified. Out of the 51 studies, 18 were comparison studies testing brand name artificial tears directly against each other. Nearly all formulations of artificial tears provided significant benefit to patients with dysfunctional tear syndrome, but some proved superior to others. From the study data, a recommended treatment flowchart was derived.