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Abstract Background Minor salivary gland (MSG) biopsy is a critical but invasive method for the classification of primary Sjögren’s disease (pSjD). Here we aimed to identify salivary proteins as potential biomarkers and to establish a non-invasive prediction model for pSjD. Methods Liquid chromatography-tandem mass spectrometry was conducted on whole saliva samples from patients with pSjD and non-Sjögren control subjects (non-pSjD). Proteins involved in immune processes were upregulated in the pSjD group, such as complement C3 (C3), complement factor B (CFB), clusterin (CLU), calreticulin (CALR), and neutrophil elastase (NE), which were further confirmed by ELISA. Multivariate logistic regression analyses were performed to identify markers that differentiated pSjD from non-pSjD; receiver operating characteristic (ROC) curves were constructed. A diagnostic model based on the combination of salivary biomarkers (CFB, CLU, and NE), serum autoantibodies (anti-SSA /Ro60 and anti-SSA/Ro52), and Schirmer’s test was evaluated in 186 patients (derivation cohort) with replication in 72 patients (validation cohort). Results In multivariate analyses, CFB, CLU, and NE were independent predictors of pSS. A model based on the combination of salivary biomarkers (CFB, CLU, and NE), serum autoantibodies (anti-SSA and anti-Ro52), and Schirmer’s test achieved significant discrimination of pSS. In the derivation cohort, the area under curve (AUC) of the ROC was 0.930 (95% CI 0.877–0.965, P

Summary: Lupus nephritis (LN), a severe complication of systemic lupus erythematosus (SLE), exhibits significant heterogeneity. Recent evidence suggests that non-immune factors contribute to end-organ damage, challenging the traditional view of LN solely arising from immune dysregulation. To investigate this, we employed autoimmune-prone Gnaq+/− mice receiving intraperitoneal pristane injections. Bone marrow transfer (BMT) distinguished the roles of immune versus non-immune cells. We observed that: (1) BMT from wild-type (WT) mice to Gnaq+/− recipients resulted in severe proteinuria and diffuse proliferative nephritis after pristane exposure; (2) GNAQ knockdown increased the expression of IFI16/Ifi202b and activated the NF-κB pathway in endothelial cells; and (3) increased IFI16 expression in human kidney biopsies correlated with proliferative LN. Taken together, these findings suggest that GNAQ acts as an inflammatory regulator in kidney endothelial cells via the IFI16/NF-κB pathway, potentially linking it to the development of LN in humans.