Laboratory-based versus qualitative assessment of α-defensin in periprosthetic hip and knee infections: a systematic review and meta-analysis
Two methods are currently available for the assay of α-defensin: the enzyme-linked immunosorbent assay (ELISA) and the lateral flow test. We aimed to assess the diagnostic accuracy of synovial fluid α-defensin and to compare the accuracy of the laboratory-based test and the qualitative assessment for the diagnosis of hip and knee prosthetic infection.
Materials and methods
We searched (from inception to May 2018) MEDLINE, Scopus, EMBASE, Web of Science, and Cochrane for studies on α-defensin in the diagnosis of periprosthetic joint infection (PJI). Sensitivity, specificity, positive and negative likelihood ratio (LR), and diagnostic odds ratio were analyzed using the bivariate diagnostic random-effects model. The receiver-operating curve for each method was calculated.
We included 13 articles in our meta-analysis, including 1170 patients who underwent total hip and knee arthroplasties revision; 368 (31%) had a joint infection according to MSIS and MSIS-modified criteria. Considering the false-positive result rate of 8% and false-negative result rate of 3%, pooled sensitivity and specificity were 0.90 (95% CI 0.83–0.94) and 0.95 (0.92–0.96), respectively. The area under the curve (AUC) was 0.94 (0.92–0.94). No statistical differences in terms of sensitivity and specificity were found between the laboratory-based and qualitative test. The pooled sensitivity and specificity of the two alpha-defensin assessment methods were: laboratory-based test 0.97 (95% CI 0.93–0.99) and 0.96 (95% CI 0.94–0.98), respectively; qualitative test 0.83 (95% CI 0.73–0.91) and 0.94 (95% CI 0.89–0.97), respectively.
The diagnostic odds ratio of the α-defensin laboratory based was superior to that of the qualitative test (1126.085, 95% CI 352.172–3600.702 versus 100.9, 95% CI 30.1–338.41; p < 0.001). The AUC for immunoassay and qualitative tests was 0.97 (0.95–0.99) and 0.91 (0.88–0.99), respectively.
Detection of α-defensin is an accurate test for diagnosis of hip and knee prosthetic infections. The diagnostic accuracy of the two alpha-defensin assessment methods is comparable. The lateral flow assay is a valid, rapid, and more available diagnostic tool, particularly to rule out PJI.
Keywordsα-Defensin Prosthetic joint infection Hip Knee
The authors received no funding for this project.
Compliance with ethical standards
Conflict of interest
One author of this paper have disclosed potential or pertinent conflicts of interest, which may include receipt of payment, either direct or indirect, or association with an entity in the biomedical field which may be perceived to have potential conflict of interest with this work. The others authors have no conflict of interest to declare.
This article does not contain any studies with human participants or animals performed by any of the authors.
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