Comprehensive Clinical, Serological, and Molecular Biomarker Profiling of Primary Sjögren's Syndrome: A Single-Center Cohort Study in Northeastern Romania.

Primary Sjögren's syndrome (pSS) exhibits considerable clinical and immunological heterogeneity, complicating personalized management. We aimed to delineate the demographic, functional, serological, histopathological, and therapeutic features of a Romanian pSS cohort and to identify biomarker-treatment correlations that could inform patient-oriented strategies. Thirty-two patients meeting the 2016 ACR/EULAR classification criteria for pSS were retrospectively analyzed. Data collected included demographics, autoantibody profiles (Anti-Ro/SSA, Anti-La/SSB, ANA, RF, Anti-CCP), immunoglobulin levels, complement consumption (C3/C4), minor salivary gland biopsy (focus score), salivary flow tests, and systemic inflammation markers (CRP). Pearson correlation matrices were constructed to explore the associations between serological markers and prescribed therapies. The cohort was predominantly female (87.5%) with a mean age of 52.8 ± 9.9 years. Seropositivity rates were 50% for Anti-Ro/SSA, 77% for Anti-La/SSB, and 40% for ANA. Clinically significant glandular dysfunction was evident in 65% of patients (unstimulated flow ≤ 0.1 mL/min), and all biopsies demonstrated focus scores > 1. Methotrexate use correlated strongly with Anti-Ro/SSA and Anti-La/SSB positivity ( ≤ 0.05), indicating its targeted application in seropositive sub-phenotypes. Conclusion: These findings underscore the immunologic and clinical diversity of pSS and support a biomarker-driven, multidisciplinary framework for personalized treatment. Larger prospective and multicenter studies are warranted to validate these correlations and to refine precision medicine approaches in pSS.