Grassi Marco, Salari Paolo, Farinelli Luca, D'Anzeo Marco, Onori Nicoletta, Gigante Antonio
Clinical Orthopedics, Department of Clinical and Molecular Science, School of Medicine, Università Politecnica delle Marche, Ancona, Italy.
Institute for Complex Arthroplasty and Revisions (ICAR), Villa Ulivella Clinic, Florence, Italy.
J Arthroplasty. 2022 Apr;37(4):781-786. doi: 10.1016/j.arth.2021.12.040. Epub 2022 Jan 6.
Periprosthetic joint infection (PJI) is a devastating complication after joint replacement surgery, and making diagnosis is often far from obvious. Calprotectin was recently proposed as a promising synovial biomarker to detect PJI. To our knowledge, no comparative study exists between enzyme-linked immunosorbent assay (ELISA) and rapid calprotectin test (CalFAST). Our purpose was to compare these methods with leukocyte esterase (LE) test from synovial fluid of painful knee arthroplasty subjected to infectious workup.
Ninety-three patients were included in this prospective observational study. They underwent synovial fluid aspiration that was analyzed for cell count, microbiological culture, LE test, calprotectin rapid test, and calprotectin immunoassay dosage. The 2018 Consensus Statements criteria for PJI were used to diagnose PJI. Sensitivity, specificity, positive and negative likelihood ratio, and receiver operating characteristic were calculated for detection methods and compared.
We categorized 39 patients as infected and 50 patients as not infected. The sensitivity comparing the ELISA test and CalFAST test was similar, 92.3% and 97.4%, respectively. LE rapid test showed 46% of sensitivity and 94% of specificity. The highest specificity was found with ELISA test (100%). Comparing the receiver operating characteristic curves by z-test, there were statistically significant differences between LE strip test and the other two methods. Otherwise, no statistically significant differences were present between ELISA and CalFAST test.
Synovial calprotectin detection has high accuracy in knee PJI diagnosis, both ELISA and rapid test. LE strip test remains a good test to confirm the diagnosis of PJI in case of positivity. In clinical practice, the calprotectin rapid test can be considered an excellent point-of-care test.
人工关节周围感染（PJI）是关节置换术后一种严重的并发症，其诊断往往并不明确。钙卫蛋白最近被认为是一种有前景的用于检测PJI的滑膜生物标志物。据我们所知，酶联免疫吸附测定（ELISA）和快速钙卫蛋白检测（CalFAST）之间尚无比较研究。我们的目的是将这些方法与对接受感染性检查的疼痛性膝关节置换术患者的滑液进行的白细胞酯酶（LE）检测进行比较。
93例患者纳入了这项前瞻性观察研究。他们接受了滑液抽吸，对其进行细胞计数、微生物培养、LE检测、钙卫蛋白快速检测和钙卫蛋白免疫测定定量分析。采用2018年PJI共识声明标准诊断PJI。计算检测方法的敏感性、特异性、阳性和阴性似然比以及受试者工作特征曲线，并进行比较。
我们将39例患者分类为感染，50例患者分类为未感染。ELISA检测和CalFAST检测的敏感性相似，分别为92.3%和97.4%。LE快速检测显示敏感性为46%，特异性为94%。ELISA检测的特异性最高（100%）。通过z检验比较受试者工作特征曲线，LE试纸条检测与其他两种方法之间存在统计学显著差异。否则，ELISA和CalFAST检测之间不存在统计学显著差异。
滑膜钙卫蛋白检测在膝关节PJI诊断中具有较高准确性，ELISA和快速检测均如此。LE试纸条检测在阳性时仍是确认PJI诊断的良好检测方法。在临床实践中，钙卫蛋白快速检测可被视为一种出色的即时检测方法。
