CRP/Albumin Has a Promising Prospect as a New Biomarker for the Diagnosis of Periprosthetic Joint Infection

Purpose: In the present study, we aimed to identify more effective biomarkers for the diagnosis of periprosthetic joint infection (PJI) by comparing the diagnostic ability of C-reactive protein (CRP)/albumin, systemic immune-inflammation index (SII), and existing biomarkers. Methods: In this single-center retrospective analysis, 216 patients who underwent revision knee or hip arthroplasty from June 2013 to June 2021 and met the inclusion and exclusion criteria were analyzed, including 80 patients in the PJI group and 136 patients in the non-PJI group. The following information was collected for analysis, including CRP, fibrinogen, erythrocyte sedimentation rate (ESR), D-dimer, platelet count (PC), neutrophil count (N), lymphocyte count (Lym), and albumin count on the second day of admission. The receiver operating characteristic (ROC) curve was used to compare the diagnostic ability of various biomarkers, and further subgroup analysis was carried out in the PJI group. Results: Compared with the non-PJI group, CRP, fibrinogen, D-dimer, ESR, CRP/albumin, and SII in the PJI group were significantly increased (P < 0.001), and their area under the curve (AUC) was 0.937, 0.878, 0.777, 0.914, 0.941, and 0.765, respectively. In the three subgroup analyses, there was no significant difference in appeal biomarker (P > 0.05) based on PJI culture results, infection time, and infection site. Conclusion: CRP/albumin had a promising prospect as a new biomarker for the diagnosis of PJI, while it had insufficient predictive ability in the PJI subgroup analysis. However, SII had insufficient ability to diagnose PJI. Therefore, SII was not suitable to be used as a diagnostic biomarker.

Automated summary

This study aimed to identify more effective biomarkers for the diagnosis of PJI, with CRP/albumin showing promising prospects but insufficient predictive ability in the PJI subgroup analysis, while SII was found to be unsuitable as a diagnostic biomarker for PJI.