Activation of Toll-Like Receptor 7 Signaling Pathway in Primary Sjögren's Syndrome-Associated Thrombocytopenia

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.

Ocular Surface Allostasis-When Homeostasis Is Lost: Challenging Coping Potential, Stress Tolerance, and Resilience

The loss of ocular surface (OS) homeostasis characterizes the onset of dry eye disease. Resilience defines the ability to withstand this threat, reflecting the ability of the ocular surface to cope with and bounce back after challenging events. The coping capacity of the OS defines the ability to successfully manage cellular stress. Cellular stress, which is central to the outcome of the pathophysiology of dry eye disease, is characterized by intensity, continuity, and receptivity, which lead to the loss of homeostasis, resulting in a phase of autocatalytic dysregulation, an event that is not well-defined. To better define this event, here, we present a model providing a potential approach when homeostasis is challenged and the coping capacities have reached their limits, resulting in the stage of heterostasis, in which the dysregulated cellular stress mechanisms take over, leading to dry eye disease. The main feature of the proposed model is the concept that, prior to the initiation of the events leading to cellular stress, there is a period of intense activation of all available coping mechanisms preventing the imminent dysregulation of ocular surface homeostasis. When the remaining coping mechanisms and resilience potential have been maximally exploited and have, finally, been exceeded, there will be a transition to manifest disease with all the well-known signs and symptoms, with a shift to allostasis, reflecting the establishment of another state of balance. The intention of this review was to show that it is possibly the phase of heterostasis preceding the establishment of allostasis that offers a better chance for therapeutic intervention and optimized recovery. Once allostasis has been established, as a new steady-state of balance at a higher level of constant cell stress and inflammation, treatment may be far more difficult, and the potential for reversal is drastically decreased. Homeostasis, once lost, can possibly not be fully recovered. The processes established during heterostasis and allostasis require different approaches and treatments for their control, indicating that the current treatment options for homeostasis need to be adapted to a more-demanding situation. The loss of homeostasis necessarily implies the establishment of a new balance; here, we refer to such a state as allostasis.

Nomogram Based on Inflammatory Factor to Predict Therapeutic Response of Thrombocytopenia in Patients with Primary Sjögren's Syndrome

Objective

Thrombocytopenia is a common manifestation of blood system involvement in primary Sjögren's syndrome (pSS) patients, and the treatment approach involves glucocorticoids and immune agents. However, a proportion of patients do not respond well to this therapy and failed to achieve remission. Accurate prediction of therapeutic response in pSS patients with thrombocytopenia is of great significance for improving the prognosis. This study aims to analyze the influencing factors of no remission to treatment in pSS patients with thrombocytopenia and establish an individualized nomogram to predict the treatment response of patients.

Materials and Methods

The demographic data, clinical manifestations and laboratory examinations of 119 patients with thrombocytopenia pSS in our hospital were retrospectively analyzed. According to the 30-day treatment response, patients were divided into remission group and non-remission group. Logistic regression was used to analyze the influencing factors related to the treatment response of patients, and then a nomogram was further established. The discriminative ability and clinical benefit of the nomogram were evaluated by receiver operating characteristic (ROC) curve, calibration chart and decision curve analysis (DCA).

Results

After treatment, there were 80 patients in the remission group and 39 in the non-remission group. Comparative analysis and multivariate logistic regression analysis identified hemoglobin (P=0.023), C3 level (P=0.027), IgG level (P=0.040), and bone marrow megakaryocyte counts (P=0.001) as independent predictors of treatment response. The nomogram was constructed based on the above four factors, and the C-index of the model was 0.882 (95% CI 0.810-0.934). The calibration curve and DCA proved that the model has better performance.

Conclusion

The nomogram incorporating hemoglobin, C3 level, IgG level, and bone marrow megakaryocyte counts could be used as an auxiliary tool to predict the risk of treatment non-remission in pSS patients with thrombocytopenia.

Nucleic acid-sensing toll-like receptors: Important players in Sjögren’s syndrome

Sjögren’s syndrome (SS) is a chronic systemic autoimmune disease that affects the salivary and lacrimal glands, as well as other organ systems like the lungs, kidneys and nervous system. SS can occur alone or in combination with another autoimmune disease, such as systemic lupus erythematosus (SLE) or rheumatoid arthritis. The etiology of SS is unknown but recent studies have revealed the implication of the activation of innate immune receptors, including Toll-like receptors (TLRs), mainly through the detection of endogenous nucleic acids, in the pathogenesis of systemic autoimmune diseases. Studies on SS mouse models suggest that TLRs and especially TLR7 that detects single-stranded RNA of microbial or endogenous origin can drive the development of SS and findings in SS patients corroborate those in mouse models. In this review, we will give an overview of the function and signaling of nucleic acid-sensing TLRs, the interplay of TLR7 with TLR8 and TLR9 in the context of autoimmunity, summarize the evidence for the critical role of TLR7 in the pathogenesis of SS and present a possible connection between SARS-CoV-2 and SS.

Thromboelastography Parameters in Urosepsis: A Retrospective Study

Thromboelastography (TEG) is usually used to monitor coagulation disorder clinically. It is unclear whether TEG has association with urosepsis and sepsis-induced coagulopathy (SIC). The purpose of this study was to investigate the clinical significance of TEG parameters in urosepsis. 90 patients who were admitted to the Emergency Ward and Emergency Intensive Care Unit (EICU) of Ren Ji Hospital affiliated to Shanghai Jiao Tong University School of Medicine due to urinary infection from February 2014 to February 2022 were retrospectively studied. Urosepsis patients and non-sepsis patients were separately investigated according to the final discharge diagnosis and Sepsis 3.0. At the same time, patients with urosepsis were further divided into groups of SIC and non-SIC based on the definition of SIC. The data of clinical features, laboratory biomarkers, and TEG parameters were collected and analyzed. There were significant differences in white blood cell count, C-reactive protein (CRP), platelet count, procalcitonin (PCT), fibrinogen (FIB), international normalized ratio (INR), prothrombin time (PT), D-dimer, and incidence of urinary tract obstruction between the urosepsis group and non-sepsis group (P < 0.05). In the comparison with non-sepsis group, K value was significantly lower (P = 0.006), while α-angle (P = 0.003) and clot index (CI) (P = 0.048) were significantly higher in urosepsis group. The area under the K value curve excluding urosepsis was 0.667. The areas under CI and α-angle curves for diagnosing urosepsis were 0.682 and 0.621, respectively. The patients in SIC group had significantly higher K value, lower α-angle, and maximum amplitude (MA) than those in non-SIC group (P < 0.05). Coagulopathy is prone to occur in patients with urosepsis. TEG is helpful for assessment of hypercoagulable state in urosepsis and prediction of hypocoagulability in SIC patients implying the dynamic process of DIC.

Clinical and laboratory features of childhood-onset primary Sjögren's syndrome: A retrospective study from China

INTRODUCTION

The initial presentations of childhood-onset primary Sjögren's syndrome (C-pSS) vary, making diagnosis challenging. We aimed to improve the diagnosis and evaluation of C-pSS by summarizing its clinical and laboratory features.

METHODS

A total of 49 patients with C-pSS between July 2015 and August 2022 in the Department of Rheumatology and Immunology of Shanghai Children's Medical Centre were enrolled in this study. Their clinical manifestations and laboratory examinations of these patients were compared based on the presence or absence of thrombocytopenia and parotitis and whether the immunological markers, including anti-nuclear antibodies (ANA), rheumatoid factor (RF), anti-Ro52/SSA antibodies (anti-SSA/Ro52), anti-Ro60/SSA antibodies (anti-SSA/Ro60), and anti-Ro/SSB antibodies (anti-SSB), were positive.

RESULTS

The mean age at C-pSS diagnosis was 10.34 ± 3.45 years, and the ratio of boys to girls was 1:6. In the thrombocytopenia group, parotitis (P = 0.044), organ involvement except for hematology (P = 0.002), positive anti-SSB (P = 0.004), and positive RF (P = 0.001) were less frequently observed. Complement C4 (P = 0.038) and white blood cells (P = 0.002) levels decreased and increased significantly, respectively. Anti-SSB (P = 0.010) and RF (P = 0.004) positivity were independent potential protective factors against thrombocytopenia in patients with C-pSS. In the parotitis group, higher ANA titers (P = 0.027), higher focus scores on labial gland biopsy (P = 0.024), and positive RF (P = 0.001), anti-SSA/Ro60 (P = 0.003), and anti-SSB (P = 0.001) were observed more frequently. Furthermore, positive anti-SSB (P = 0.012) and positive RF (P = 0.028) were independent risk factors for parotitis in patients with C-pSS. The hemoglobin level was significantly lower in patients with positive anti-SSA/Ro52 and positive anti-SSA/Ro60 results (P = 0.022 and P = 0.029, respectively), while immunoglobulin G level was significantly higher in patients in the same group (P = 0.048 and P = 0.007, respectively).

CONCLUSIONS

Positive anti-SSB and positive RF values may be independent potential protective factors of thrombocytopenia in patients with C-pSS. In contrast, positive anti-SSB and positive RF were independent risk factors of parotitis in patients with C-pSS. More studies are needed to reveal the diagnostic role and pathogenic mechanism of immunological markers in C-pSS.

Advances in Pathogenesis of Sjögren's Syndrome

Sjögren's syndrome (SS) is a chronic autoimmune disease of unknown etiology that mainly involves exocrine glands. Patients present with dry mouth and eyes, fever, arthralgia, and other systemic symptoms. In severe cases, the quality of life of patients is affected. At present, there is no cure for SS, and the treatment options are extremely limited. In recent years, studies of patients and animal models have identified abnormalities of immune cell function and cytokines to be involved in SS. A systematic review of the literature may clarify the etiology and pathogenesis of SS, as well as provide a theoretical basis for the development of new drugs for the treatment of SS.