白细胞酯酶试纸对115例腹腔积液感染判断的初步研究

A preliminary study of diagnosing the presence of infection by leucocyte esterase reagent strips in 115 ascites samples

目的探索白细胞酯酶试纸对感染性腹腔积液的快速床边诊断价值。方法自2010年11月—2011年8月收集来自该院消化内科102名住院病人的腹水标本115例,其中包括肝硬化腹水80例,其他原因的腹水35例,使用Multistix10 SG白细胞酯酶试纸检测腹水标本是否为感染性腹水,将结果与腹水多形核白细胞计数进行比较。为了设定最佳临界值,本研究绘制ROC曲线并分析了以不同色度作为临界值的敏感度、特异度、阳性预测值、阴性预测值。结果共30例腹水标本PMN≥250/mm3,其中29例由白细胞酯酶试纸正确检测。白细胞酯酶试纸的色度1为最佳临界值,其敏感度96.67%,特异度94.80%,阳性预测值与阴性预测值分别为87.88%及98.65%。但白细胞酯酶试纸难以用于血性腹水、乳糜性腹水等颜色深染标本的检测。结论初步研究发现,白细胞酯酶试纸能快速准确地诊断感染性腹腔积液,可进一步扩大样本量研究。

Objective To explore the value of leucocyte esterase reagent strips in the rapid and bedside diagnosis of infectious ascites. Methods From November 2010 to August 2011, 115 ascitic fluid samples were collected from 102 consecutive patients, including 80 cases from cirrhotic patients and 35 cases for other reasons. Abdominal paracentesis was performed and the Multistix 10 SG was tested, then we compared the results with PMN count. A ROC curve was elaborated to define which cut-off point was more reliable to be used as a positive result of the reagent strip for the diagnosis of spontaneous bacterial peritonitis. We also calculated the sensitivity, specificity, positive predictive value （PPV） and negative predictive value （NPV） of the reagent strip at different positive cut-off points （ I〉 1, ≥2 and ≥3）. Results PMN was no less than 250 in 30 ascitic fluid samples, 29 samples of which were correctly diagnosed by leucocyte esterase reagent strips. We defined degree 1 ＋ in the colormetric scale as the cutoff point for the diagnosis of infectious ascites. Muhistix 10 SG showed a sensitivity of 96.67%, specificity of 94.80%, NPV of 87.88% and PPV of 98.65%. But leucocyte esterase reagent strips can not be applied to deep dyeing ascities like bloody ascites or chylous ascites. Conclusion According to our preciminarg research , the application of leucocyte esterase reagent strips is a rapid, accurate tool for the diagnosis of ascitic fluid infection, worthing more research on it.