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Diagnostic Utility of a Rapid Myeloperoxidase Test in Synovial Fluid for Chronic Periprosthetic Joint Infection
Shinsuke Ikeda1,2, Katsufumi Uchiyama1,3, Yojiro Minegishi1,4
1Department of Orthopaedic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
Background:
Numerous biomarkers have been identified for the diagnosis of periprosthetic joint infection (PJI), but no single biomarker has been proven to have definitive accuracy. Alpha-defensin is an excellent biomarker that is included as a minor criterion in the 2nd International Consensus Meeting (ICM) PJI diagnostic criteria; however, its high cost limits its accessibility at many general medical facilities. Consequently, alternative biomarkers for PJI diagnosis are under investigation. Myeloperoxidase (MPO), an enzyme with microbicidal properties through the catalysis of hypochlorous acid production, has emerged as a promising alternative. MPO has previously been reported as an effective biomarker for PJI. In the present study, we conducted a rapid MPO test as a point-of-care test (POCT) and evaluated its diagnostic utility.
Methods:
Patients with a suspected infection after total joint arthroplasty were categorized into the PJI or aseptic failure groups according to the 2nd ICM PJI diagnostic criteria. MPO and alpha-defensin levels in synovial fluid that was collected during surgery were quantified using an enzyme-linked immunosorbent assay (ELISA), and their diagnostic accuracy was compared. Additionally, an MPO POCT was conducted, and its diagnostic accuracy was assessed.
Results:
The investigation included 23 patients with PJI and 23 with aseptic failure. All were Japanese. MPO and alpha-defensin ELISAs exhibited a strong correlation, and, at the optimal cutoff, both tests demonstrated a sensitivity of 0.957 and a specificity of 0.957. The MPO POCT produced results in just 10 minutes and achieved a sensitivity of 1.00 and a specificity of 0.913.
Conclusions:
The MPO ELISA demonstrated high diagnostic accuracy for PJI, equivalent to that of the alpha-defensin test. Furthermore, the MPO POCT showed similarly high diagnostic accuracy. The MPO POCT is a promising and rapid tool for diagnosing PJI and could serve as an alternative to the alpha-defensin test.
Level Of Evidence:
Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.
Insights
A rapid myeloperoxidase (MPO) point-of-care test (POCT) shows high accuracy for diagnosing periprosthetic joint infection (PJI). This MPO POCT is a promising, accessible alternative to the costly alpha-defensin test for PJI diagnosis.
Area of Science:
- Orthopedics
- Infectious Diseases
- Biomarker Discovery
Background:
- Accurate diagnosis of periprosthetic joint infection (PJI) remains challenging.
- Alpha-defensin is a reliable PJI biomarker but is limited by cost.
- Myeloperoxidase (MPO) is investigated as a cost-effective alternative biomarker.
Purpose of the Study:
- To evaluate the diagnostic utility of a rapid myeloperoxidase (MPO) point-of-care test (POCT) for PJI.
- To compare the diagnostic accuracy of MPO and alpha-defensin tests in synovial fluid.
Main Methods:
- Synovial fluid samples from PJI and aseptic failure patients were analyzed.
- Myeloperoxidase (MPO) and alpha-defensin levels were quantified using ELISA.
- Diagnostic accuracy of MPO ELISA and a rapid MPO POCT was assessed.
Main Results:
- MPO and alpha-defensin ELISAs showed high diagnostic accuracy (sensitivity 0.957, specificity 0.957).
- The MPO POCT yielded results in 10 minutes with high accuracy (sensitivity 1.00, specificity 0.913).
- MPO and alpha-defensin levels correlated strongly.
Conclusions:
- MPO ELISA demonstrates diagnostic accuracy comparable to alpha-defensin for PJI.
- The MPO POCT is a rapid and accurate tool for PJI diagnosis.
- MPO POCT presents a viable, cost-effective alternative to alpha-defensin testing.
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