Alpha-defensin does not provide additional benefit over leukocyte esterase in the diagnosis of periprosthetic joint infection

ABSTRACT

Background: Leukocyte esterase (LE) and α-defensin (AD) are two synovial biomarkers that are used for the diagnosis of periprosthetic joint infection (PJI), however, the superiority of one over the other remains unknown. We aimed to compare their diagnostic value.

Methods: In this retrospective study, we evaluated patients who underwent revision total hip and knee arthroplasty at a single institution between 2013 and 2019 for whom both LE and AD were available. PJI was defined by the 2018 International Consensus Meeting criteria. The diagnostic performance of AD and LE was compared.

Results: Overall, 122 patients (28 PJI and 94 aseptic revisions) were included. The area under the curve was 0.905 (95% confidence interval[CI]:0.820–0.991) and 0.913 [95%CI:0.834–0.992] for LE and AD, respectively. Positive and negative predictive values were 95.8% (95%CI:76.5%-99.4%) and 94.9% (95%CI:89.4%-97.6%) for LE and 89.0% (95%CI:72.2%-96.1%) and 96.0% (95%CI:90.5%-98.3%) for AD. While both tests were useful in 18 cases that were inconclusive based on preoperative findings, AD had no benefit over LE.

Conclusion: Both LE and AD are valuable markers in patients with suspected PJI. Since LE is very inexpensive and readily available point-of-care test, we believe it offers more value in the work up of suspected PJI.

KEYWORDS:

• Leukocyte esterase
• alpha-defensin
• synovial biomarkers
• diagnosis
• periprosthetic joint infection
• total joint arthroplasty

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.