Synovial fluid presepsin as a novel biomarker for the rapid differential diagnosis of native joint septic arthritis from crystal arthritis.

OBJECTIVE

To investigate whether presepsin can be used as a novel biomarker to differentiate between native joint septic arthritis (NJSA) and crystal arthritis (CA).

METHODS

This study included 75 patients diagnosed with either NJSA (n = 21) or CA (n = 54). Presepsin in synovial fluid and blood, C-reactive protein, and procalcitonin were measured and compared between the NJSA and CA groups. Receiver operating characteristic (ROC) curve analyses were performed to differentiate between the two groups.

RESULTS

Synovial fluid and blood presepsin were significantly higher in the NJSA group than in the CA group (p < 0.0001 and p < 0.01, respectively). The area under the ROC curve for synovial fluid presepsin in the NJSA group compared with the CA group was 0.93 (sensitivity 85.7%, specificity 85.2%, positive predictive value 69.2%, negative predictive value 93.9%, positive likelihood ratio 5.79, negative likelihood ratio 0.17). Among the tests, synovial fluid presepsin was the most accurate.

CONCLUSIONS

Measurement of synovial fluid presepsin is reliable for the early diagnosis of NJSA, and synovial fluid presepsin could be used as a novel biomarker for differentiating between NJSA and CA.