Clinical Research Directory

Inclusion Criteria: SjD group: * Aged 18-65 years * Fulfilled the 2016 ACR/EULAR classification criteria for Sjögren's disease * Newly diagnosed or previously diagnosed with complete diagnostic evidence available * Willing to provide clinical data and saliva samples * Provided written informed consent Non-SjD sicca control group: * Aged 18-65 years * Frequency-matched with the case group by sex and age * No personal or family history of autoimmune diseases * No persistent symptoms suggestive of SjD (e.g., dry mouth or dry eyes), with physical examination and necessary laboratory test results within normal limits * Willing to provide clinical data and saliva samples * Provided written informed consent Exclusion Criteria: * Malignant tumors or severe active infections * Pregnancy or lactation * Use of biologics or potent immunosuppressive therapy within the past 3 months that could significantly alter study indicators (patients included due to strict clinical necessity will be recorded and utilized for sensitivity analysis) * Severe hepatic or renal impairment, or other diseases that significantly interfere with cfRNA detection * Failure to meet the standardized oral status, fasting, or sampling timing requirements prior to collection, with resampling being impossible * Incomplete clinical data * Substandard collection, preservation, or quality control of saliva or labial gland tissue samples * Any other conditions deemed unsuitable for participation by the investigator