The role of presepsin and Maresin-1 levels in blood and synovial fluid in early diagnosis of septic arthritis

Objective: Early and accurate diagnosis of septic arthritis is essential to prevent irreversible joint damage and systemic complications. This study aimed to evaluate the diagnostic performance of serum and synovial fluid presepsin and Maresin-1 levels in adult patients with suspected native knee septic arthritis. Methods: This prospective study included 70 adult patients presenting with acute knee monoarthritis who underwent synovial fluid aspiration. Patients were enrolled based on clinical suspicion of septic arthritis and subsequently classified into septic arthritis (n = 25) and control (n = 45) groups according to the Newman criteria. Serum and synovial fluid samples were analyzed for routine inflammatory markers, presepsin, and Maresin-1 levels. Diagnostic performance was assessed using receiver-operating characteristic (ROC) analysis. Results: Serum white blood cell count (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin (PCT), and presepsin levels were significantly higher in the septic arthritis group (WBC: P = .001; ESR: P = .001; CRP: P < .001; PCT: P < .001; presepsin: P = .001). Synovial fluid WBC, lactate dehydrogenase, glucose, and presepsin levels also differed significantly between groups (all P < .001). Serum and synovial Maresin-1 levels did not differ significantly between groups (serum: P = .76; synovial: P = .98). The ROC analysis showed that CRP had the highest diagnostic accuracy (AUC: 0.91), followed by PCT (0.81), synovial presepsin (0.78), ESR (0.74), and serum presepsin (0.73). Conclusion: Synovial presepsin demonstrated moderate diagnostic accuracy in distinguishing native joint septic arthritis from noninfectious effusions and performed better than traditional biomarkers other than CRP. Maresin-1 did not show diagnostic utility in the acute phase. Synovial presepsin may be considered a complementary biomarker in the evaluation of suspected septic arthritis. Cite this article as: Aydın C, Tartar AS, Aydın O, Kazez M. The role of presepsin and maresin-1 levels in blood and synovial fluid in early diagnosis of septic arthritis. Acta Orthop Traumatol Turc., 2026; 60(3), 0523, doi: 10.5152/j.aott.2026.25523.