新型免疫层析技术在关节假体周围感染（PJI）诊断中的应用

Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty and is associated with substantial cost and burden to the patient and the health care system, with current reports showing a rise in failure rates for these procedures. Unfortunately, there is no single test or finding that is 100% accurate, sensitive, rapid and simple for the diagnosis of PJI. The diagnosis of PJI is based upon a combination of clinical findings, laboratory results from peripheral blood and synovial fluid, microbiological data, histological evaluation of periprosthetic tissue. While this MSIS definition provides a standard for definitive retrospective diagnosis and research, it also has higher rate of false negative than othermethods and has a complexity that makes it difficult to execute in daily clinical practice. The leukocyte esterase colorimetric strip test has been used widely in clinical practice, with the advantages of providing real-time results, being simple and inexpensive, having higher sensitivity and specificity, and having the ability to both rule out and confirm periprosthetic joint infection. In this study, as signal marker, superparamagnetic particles (SMPs) are using to replace colloidal gold for determination of α-defensin, neutrophil elastase 2, bactericidal/permeability-increasing protein, neutrophil gelatinase-associated lipocalin and lactoferrin. SMPs could be used as color marker for qualitative detection, and magnetic marker for quantitative detection. In summary, the study of colorimetric strip tests based on the magnetic immuno-chromatographic system provides new theoretical support for diagnosis of PJI and rapid detection technologies.

人工关节假体周围感染是人工关节置换术后灾难性的并发症，随着其发生率的增加，给病人和医疗系统都带来了巨大的经济负担。尽管如此，仍然没有一种灵敏、准确、快速、简便的方法诊断假体周围感染。目前较常用的MSIS诊断标准主要是基于临床表现，外周血及关节液的实验室检查，组织病理学检查，但是依旧存在“假阴性”率高且复杂不简便的缺点。近些年来，白细胞酯酶试纸因其快速准确的特点已应用于临床，且已证实在髋、膝关节假体周围诊断中都有着良好的敏感性和特异性。本研究拟用超顺磁颗粒替代胶体金标记物应用于免疫层析技术中，以关节液中的α防御素、中心粒细胞弹性蛋白酶-2、杀菌/渗透增强蛋白、中性粒细胞明胶酶相关载质蛋白和乳铁蛋白为检测对象，研究基于超顺磁性颗粒的免疫层析理论并研发以上五种生物标记物检测试纸。综上，基于磁性免疫层析系统研发的试纸，为假体关节周围感染快速检测技术的发展提供了新的手段。

人工关节假体周围感染是人工关节置换术后灾难性的并发症，随着其发生率的增加， 给病人和医疗系统都带来了巨大的经济负担。目前，仍缺乏一种灵敏、准确、快速 、简便的方法诊断假体周围感染。本研究通过1）候选关节液标记物的验证；2）关节液前处理方法研究；3）标记物、目标物的研究、抗体制备、生物桥的研究以及快速检测试纸在临床样本中的验证。研发出基于彩色乳胶微粒的免疫层析技术，开发针对α-防御素的快速检测试纸。将试纸的检测结果与ELSIA结果比对，比较两种方法的一致性。使用α-防御素快速诊断试纸可在20min左右完成检测，其诊断PJI的敏感度、特异度、阳性预测值、阴性预测值分别为0.857，0.933，0.857以及0.933。而使用ELSIA法检测时，其曲线下面积AUC为0.969。当取15.44μg/ml为阳性阈值时，其敏感度、特异度、阳性预测值、阴性预测值分别为1.000、0.900、0.824以及1.000。两种检测方法有相对较好的一致性（Kappa=0.752）。尽管反应条件还需进一步优化，但基于免疫层析技术的α-防御素快速检测试纸已可在20min左右完成检测，且结果与ELSIA检测相似，有望日后用于临床。