Diagnosis of periprosthetic joint infection based on semi-quantitative detection of synovial fluid calprotectin by MALDI-TOF MS / 中华检验医学杂志

ABSTRACT

Objective:To explore the clinical value of synovial fluid calprotectin for the diagnosis of periprosthetic joint infection (PJI).Methods:Based on prospective cohort study design, a total of 82 patients suspected of PJI after hip and knee arthroplasty in the First Medical Center of the PLA General Hospital from July 2021 to June 2022 were selected. Patients were divided into infection group (PJI, n=39) and non-infection group (non-PJI, n=43) according to the diagnostic criteria proposed by the Second International Consensus Conference in 2018. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used for double-blind detection of calprotectin and internal reference standard (IRS) in synovial fluid of patients. The peaks of target protein and IRS were recorded for further analysis. Mann-Whitney U test was used to compare the concentrations of S100A8 and S100A9 between the two groups, and receiver operating characteristic curve (ROC) was used to analyze the diagnostic efficacy of S100A8 and S100A9 for PJI. Results:Calprotectin was detected as monomers S100A8 and S100A9. Synovial fluid S100A8 was significantly higher in the PJI group than that in the non-PJI group [1.57 (0.48, 4.17) vs 0.00 (0.00, 0.05), Z=?7.221, P<0.05]. Synovial fluid S100A9 was also significantly higher in the PJI group than that in the non-PJI group [0.74 (0.29, 1.70) vs 0.06 (0.00, 0.10), Z=?6.255, P<0.05]. When using S100A8 and S100A9 to diagnose PJI, the sensitivity were 97.4% and 87.2%, the specificity were 86.0% and 88.4%, and the area under the ROC were 0.964 (95% CI 0.929-0.998) and 0.902 (95% CI 0.924-0.996), respectively. Conclusion:The detection of synovial fluid S100A8 and S100A9 by MALDI-TOF MS can make a satisfactory diagnosis for PJI.