TNFSF11 and rheumatoid arthritis: While our biomarkers demonstrate high diagnostic accuracy for OA, distinguishing early OA from rheumatoid arthritis (RA) or traumatic synovitis requires combinatorial approaches: Unlike RA, which shows systemic autoimmunity (e.g., anti-CCP antibodies), OA synovium exhibits unique TNFSF11 elevation unaltered by IL-17 inhibition.