2025 ISAKOS Biennial Congress ePoster
Albumin To Globulin Ratio In Periprosthetic Knee Infections Diagnostic Work-Up. Have We Found A New Screening Tool?
Domenico De Mauro, MD ITALY
Giovanni Balato, Prof. ITALY
Tiziana Ascione, MD, Naples ITALY
Lucrezia Marasco, MD, Naples ITALY
Filippo Leggieri, MD, Florence, Florence ITALY
Matteo Innocenti, MD, Florence ITALY
Enrico Festa, MD, Naples ITALY
Donato Di Gennaro, MD, Naples ITALY
Federico II University, Naples, ITALY
FDA Status Not Applicable
Summary
This study aimed to assess the most appropriate thresholds for Albumin to Globulin ratio (AGR) in patients who had a suspected periprosthetic knee infection. Furthermore, we evaluated the diagnostic accuracy of our proposed threshold.
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Abstract
Aims. This study aimed to assess the most appropriate thresholds for Albumin to Globulin ratio (AGR) in patients who had a suspected periprosthetic knee infection. Furthermore, we evaluated the diagnostic accuracy of our proposed threshold.
Patients and Methods. Between January 2020 and April 2022, we analysed patients with failed or painful knee arthroplasty admitted to a tertiary referral institution to undergo the standardized diagnostic protocol to identify those with a PJI. The 2018 International Consensus Meeting (ICM) criteria were used to classify patients with PJIs and aseptic joints. Sensitivity, specificity, positive predictive value, negative predictive value, and the Area under the ROC curve (AUC) of AGR were calculated to define the test diagnostic accuracy.
Results. ROC curve showed that the optimal cut-off value of AGR was 1.43. AGR registered a sensitivity of 95% (95% CI 91 to 197), a specificity of 63% (95% CI 56 to 69), a positive predictive value of 75% (95% CI 69 to 81) and a negative predictive value of 91% (95% CI 86 to 94). Receiver operator curve analysis demonstrated an AUC of 0.85 (95% CI 0.77 to 0.88). Although BMI, uremia, GOT, INR, and alkaline phosphatase showed significant differences between the false positive cases and those cases affected by aseptic failure with AGR higher than 1.43, indicating potential confounding effects (p<0.05), no parameter was found to be a significant predictor of false positives cases (p>0.05).
Conclusions. For its high sensitivity, AGR showed potential as a screening tool for detecting infections in PJI diagnostics.