Department of Companion Animals and Horses, Equine Surgery Unit, University of Veterinary Medicine Vienna, Vienna, Austria.
Qualizyme Diagnostics GmbH & Co KG, Neue Stiftingtalstraße 2, Graz, Austria.
Equine Vet J. 2022 May;54(3):513-522. doi: 10.1111/evj.13459. Epub 2021 Jun 15.
Synovial sepsis is a commonly occurring, potentially career-ending or even life-threatening orthopaedic emergency. Diagnosis of synovial sepsis is currently primarily based on synovial fluid analysis, which often leaves diagnostic ambiguity due to overlap of clinicopathological parameters between septic and aseptic inflammatory synovitis.
To evaluate the reliability of lysozyme (LYS), myeloperoxidase (MPO) and elastase (ELT) as biomarkers for synovial sepsis in horses using a photometric assay to measure increased enzyme activity.
Prospective, single-blinded, analytical, clinical study.
Equine synovial samples were assigned to one of three groups: (1) healthy controls (n = 10), (2) aseptic (n = 27) and (3) septic synovitis (n = 30). The enzyme activity assays (LYS, MPO and ELT) were compared with standard synovial fluid parameters and broad-range bacterial 16S rDNA PCR.
LYS and MPO activities were significantly different between septic synovial samples, and both aseptic and control samples (P < .001, LYS: confidence interval [CI]: 2.25-3.41, resp., 2.21-3.8, MPO: CI 0.752-1.6, resp., 0.639-1.81). LYS achieved a 100% sensitivity and 100% specificity in differentiating between septic and aseptic (cut-off value 751.4) or control (cut-off: 484.6) samples (P < .001). MPO reached 93.33% sensitivity, 100% specificity for distinguishing septic from control (cut-off value: 0.1254) synovial samples and 93.33% sensitivity, 81.48% specificity for discriminating between septic and aseptic (cut-off value: 0.1305) synovial samples (P < .001). ELT activity could not be measured in any synovial sample. Both the LYS and the MPO measurements showed a highly significant correlation with PCR (LYS r = .79, MPO r = .69), synovial leukocyte count (LYS r = .752, MPO r = .571), % neutrophils (LYS r = .751, MPO r = 0.663) and each other (r = .744, all P < .001).
Variation in horses' signalment, affected synovial structures and synovial fluid freezing times may have affected the discriminative power of this study.
Increased MPO and LYS activities allow reliable, rapid diagnosis of synovial sepsis with high sensitivity and specificity.
滑液脓毒症是一种常见的、潜在的危及职业生涯甚至危及生命的骨科急症。滑液脓毒症的诊断目前主要基于滑液分析，但由于脓毒性和无菌性炎症性滑膜炎之间的临床病理参数重叠，诊断仍存在不确定性。
使用光密度测定法测量酶活性增加，评估溶菌酶（LYS）、髓过氧化物酶（MPO）和弹性蛋白酶（ELT）作为马滑膜脓毒症生物标志物的可靠性。
前瞻性、单盲、分析性、临床研究。
将马的滑膜样本分为三组：（1）健康对照组（n=10）、（2）无菌性（n=27）和（3）化脓性滑膜炎（n=30）。比较酶活性测定（LYS、MPO 和 ELT）与标准滑液参数和广谱细菌 16S rDNA PCR。
LYS 和 MPO 活性在化脓性滑膜样本之间以及无菌性和对照组样本之间存在显著差异（P<0.001，LYS：置信区间[CI]：2.25-3.41，分别为 2.21-3.8，MPO：CI 0.752-1.6，分别为 0.639-1.81）。LYS 在区分化脓性和无菌性（临界值 751.4）或对照组（临界值：484.6）样本方面达到 100%的灵敏度和 100%的特异性（P<0.001）。MPO 对化脓性与对照组（临界值：0.1254）滑膜样本的区分达到 93.33%的灵敏度和 100%的特异性，对化脓性与无菌性（临界值：0.1305）滑膜样本的区分达到 93.33%的灵敏度和 81.48%的特异性（P<0.001）。ELT 活性在任何滑膜样本中均无法测量。LYS 和 MPO 测量均与 PCR 高度相关（LYS r=0.79，MPO r=0.69）、滑膜白细胞计数（LYS r=0.752，MPO r=0.571）、%中性粒细胞（LYS r=0.751，MPO r=0.663）和彼此之间（r=0.744，均 P<0.001）。
马的特征、受影响的滑膜结构和滑液冷冻时间的变化可能影响了本研究的判别能力。
MPO 和 LYS 活性升高可可靠、快速诊断滑液脓毒症，具有高灵敏度和特异性。
