a Salivary Cell-free RNA Liquid Biopsy Model for Non-invasive Diagnosis in Sjögren's Disease

Overview

The goal of this observational study is to learn whether salivary cell-free RNA (cfRNA) can be used as a non-invasive liquid biopsy test to help diagnose Sjögren's disease (SjD) and understand disease-related changes in the salivary glands. The main questions it aims to answer are: * Can salivary cfRNA distinguish patients with SjD from people with sicca symptoms who do not have SjD? * Are salivary cfRNA signals associated with clinical features of SjD, such as autoantibody-related immune activity and salivary gland pathology? * Can salivary cfRNA signals be linked to specific cell types and tissue regions in the salivary glands? Participants will provide saliva samples, and clinical information from routine medical evaluation will be collected. Some available salivary gland tissue transcriptomic data will also be analyzed to explore the possible tissue sources of salivary cfRNA signals.

This observational study will evaluate SjoTrace, a salivary cell-free RNA (cfRNA)-based liquid biopsy approach for Sjögren's disease (SjD). SjD is an autoimmune disease that often affects the salivary glands and causes dryness symptoms, but diagnosis can be challenging because sicca symptoms may also occur in people without SjD. In this study, saliva samples will be collected from participants with SjD and from non-SjD sicca control participants as part of an observational research protocol. Salivary cfRNA profiles will be analyzed to identify RNA features associated with SjD. Machine-learning methods will be used to develop and evaluate a cfRNA-based diagnostic score. The study will also explore whether salivary cfRNA signals are related to clinical features of SjD, including immune-related laboratory findings and salivary gland pathology. In addition, transcriptomic datasets from salivary gland tissue, including bulk RNA sequencing, single-cell RNA sequencing, and spatial transcriptomic data, will be analyzed to investigate the possible tissue and cellular sources of disease-associated cfRNA signals. This study does not assign participants to any treatment or intervention. All clinical care decisions will be made by the participants' regular health care providers. The research is intended to assess the diagnostic and biological value of salivary cfRNA as a non-invasive tool for SjD evaluation.