Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Center for Musculoskeletal Surgery (CMSC), Augustenburger Platz 1, D-13353 Berlin, Germany.
Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Center for Musculoskeletal Surgery (CMSC), Augustenburger Platz 1, D-13353 Berlin, Germany; Berlin-Brandenburg Center for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Germany.
J Infect. 2019 Aug;79(2):123-129. doi: 10.1016/j.jinf.2019.05.015. Epub 2019 May 21.
Synovial fluid leukocyte count is the current standard test for diagnosing periprosthetic joint infection (PJI). As D-lactate is almost exclusively produced by bacteria, it represents a useful biomarker for bacterial infection. We evaluated the performance of synovial fluid D-lactate for the diagnosis of PJI and compared it with the synovial fluid leukocyte count.
Consecutive patients with joint aspiration of a prosthetic hip, knee or shoulder joint were prospectively included. PJI was diagnosed according to the working criteria of the European Bone and Joint Infection Society (EBJIS). The synovial fluid D-lactate was determined spectrophotometrically at 570 nm, synovial fluid leukocytes were counted by flow cytometry. The receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of investigated parameters.
Of 148 patients, 44 (30%) were diagnosed with PJI and 104 (70%) with aseptic failure. For diagnosis of PJI, the sensitivity of synovial fluid D-lactate (at cut-off 1.263 mmol/l) was 86.4% [95% CI, 75.0-95.5%] and the specificity was 80.8% [95% CI, 73.1-88.5%]. The AUCs of D-lactate concentration and leukocyte count were 90.3% [95% CI 85.7-95.0%] and 91.0% [95% CI 85.1-96.8%], respectively (p = 0.8). Virulence of the pathogen did not influence the D-lactate concentration (p = 0.123). The synovial fluid erythrocyte concentration correlated with D-lactate in patients with aseptic failure (ρ = 0.339, p <0.01).
Synovial fluid D-lactate showed similar performance to the leukocyte count for diagnosis of PJI. Advantages of D-lactate test are requirement of low synovial fluid volume, short turnaround time and low cost.
滑液白细胞计数是目前诊断人工关节假体周围感染（PJI）的标准检测方法。由于 D-乳酸几乎完全由细菌产生，因此它是一种有用的细菌感染生物标志物。我们评估了滑液 D-乳酸对 PJI 的诊断性能，并将其与滑液白细胞计数进行了比较。
前瞻性纳入连续接受髋关节、膝关节或肩关节关节抽吸术的患者。PJI 根据欧洲骨与关节感染学会（EBJIS）的工作标准进行诊断。通过 570nm 分光光度法测定滑液 D-乳酸，通过流式细胞术计数滑液白细胞。采用受试者工作特征（ROC）分析评估研究参数的诊断性能。
在 148 名患者中，44 名（30%）被诊断为 PJI，104 名（70%）为无菌性失败。对于 PJI 的诊断，滑液 D-乳酸（在截止值 1.263mmol/l 时）的灵敏度为 86.4%[95%置信区间，75.0-95.5%]，特异性为 80.8%[95%置信区间，73.1-88.5%]。D-乳酸浓度和白细胞计数的 AUC 分别为 90.3%[95%置信区间 85.7-95.0%]和 91.0%[95%置信区间 85.1-96.8%]（p=0.8）。病原体的毒力不影响 D-乳酸浓度（p=0.123）。在无菌性失败患者中，滑液红细胞浓度与 D-乳酸呈正相关（ρ=0.339，p<0.01）。
滑液 D-乳酸在诊断 PJI 方面的表现与白细胞计数相似。D-乳酸检测的优点是需要的滑液量少、周转时间短、成本低。
