Foster Olivia¹, Anderson Henry², Bailey Ella³, Robinson Olivia⁴, Reed Isla⁵, Foster Jack⁶, Walker Liam⁷
ABSTRACT:
Systemic autoimmune diseases (SADs), including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Sjögren’s syndrome, are characterized by dysregulated immune responses and multi-organ involvement. Early diagnosis and monitoring remain challenging due to heterogeneous clinical presentations. This review provides a comparative analysis of salivary, plasma, and urinary biomarkers in SADs, highlighting their translational potential for non-invasive diagnostics and personalized medicine. We evaluate the clinical utility of cytokines (e.g., IL-6, TNF-α), autoantibodies (e.g., anti-CCP, anti-dsDNA), and novel omics-derived markers across biofluids. Salivary biomarkers offer advantages in accessibility and cost, while plasma provides systemic immune profiles, and urine reflects renal involvement. Challenges in standardization, biomarker specificity, and integration with multi-modal data are discussed. The review concludes with future directions, including point-of-care technologies and AI-driven biomarker panels for precision rheumatology.