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Abstract：
BACKGROUND: Numerous immunoassays have been commercialized to determine pancreatic elastase (PE) in feces in screening for exocrine pancreatic insufficiency (EPI), but how the different assays compare to one another is controversial, especially in the context that all methods use the same cut-off values for interpreting the results obtained on the presence or absence of EPI or the degree of insufficiency if it is present. Our aim was to analytically verify a new method for determining PE, compare the results with a previous method, and verify the declared cut-off values for interpretation of the results.
METHODS: PE in the stool was assayed using a previous monoclonal enzyme-linked immunosorbent assay (\"ScheBo ELISA\") and a new polyclonal particle-enhanced turbidimetric immunoassay (\"Bühlmann PETIA\"). The direct method comparison of two immunoassays was performed in 40 samples. Clinical comparisons were conducted against each other for the binary determination of \"abnormal/normal\" elastase levels and the three-way determination of \"severe/moderate/no\" EPI in 56 samples. The indirect comparison method used external quality assessment (EQA) data to compare the monoclonal and polyclonal immunoassays for PE, and additionally compare the monoclonal ScheBo ELISA to a monoclonal chemiluminescence immunoassay (\"DiaSorin CLIA\").
RESULTS: Precision in the series and intra-laboratory precision for Bühlmann PETIA met the manufacturer\'s specifications for the concentration range of limit/lower values and the range of normal values. The Bühlmann PETIA immunoassay on different analytical platforms yielded comparable results and nearly perfect agreement in the case of three-way classification (kappa = 0.89 with 95%CI from 0.79 to 1.00. ScheBo ELISA tends to generate higher values of pancreatic elastase than the Bühlmann PETIA; agreement between the methods was moderate in the case of binary classification (kappa = 0.43; 95% CI 0.25 to 0.62), and substantial in the case of three-way classification (kappa = 0.62; 95% CI 0.50 to 0.75). EQA data analysis showed a statistically significant difference between ScheBo ELISA and Bühlmann PETIA peer groups (p = 0.031), as well as the DiaSorin CLIA and ScheBo ELISA peer groups (p = 0.010).
CONCLUSIONS: The ScheBo ELISA and Bühlmann PETIA do not appear to be commutable in the analytical and clinical context. Our data address a discordance between different mono- and polyclonal immunoassays for pancreatic elastase and the potential of misclassification using its universal cut-off values in screening suspected patients for exocrine pancreatic insufficiency.
METHODS: PE in the stool was assayed using a previous monoclonal enzyme-linked immunosorbent assay (\"ScheBo ELISA\") and a new polyclonal particle-enhanced turbidimetric immunoassay (\"Bühlmann PETIA\"). The direct method comparison of two immunoassays was performed in 40 samples. Clinical comparisons were conducted against each other for the binary determination of \"abnormal/normal\" elastase levels and the three-way determination of \"severe/moderate/no\" EPI in 56 samples. The indirect comparison method used external quality assessment (EQA) data to compare the monoclonal and polyclonal immunoassays for PE, and additionally compare the monoclonal ScheBo ELISA to a monoclonal chemiluminescence immunoassay (\"DiaSorin CLIA\").
RESULTS: Precision in the series and intra-laboratory precision for Bühlmann PETIA met the manufacturer\'s specifications for the concentration range of limit/lower values and the range of normal values. The Bühlmann PETIA immunoassay on different analytical platforms yielded comparable results and nearly perfect agreement in the case of three-way classification (kappa = 0.89 with 95%CI from 0.79 to 1.00. ScheBo ELISA tends to generate higher values of pancreatic elastase than the Bühlmann PETIA; agreement between the methods was moderate in the case of binary classification (kappa = 0.43; 95% CI 0.25 to 0.62), and substantial in the case of three-way classification (kappa = 0.62; 95% CI 0.50 to 0.75). EQA data analysis showed a statistically significant difference between ScheBo ELISA and Bühlmann PETIA peer groups (p = 0.031), as well as the DiaSorin CLIA and ScheBo ELISA peer groups (p = 0.010).
CONCLUSIONS: The ScheBo ELISA and Bühlmann PETIA do not appear to be commutable in the analytical and clinical context. Our data address a discordance between different mono- and polyclonal immunoassays for pancreatic elastase and the potential of misclassification using its universal cut-off values in screening suspected patients for exocrine pancreatic insufficiency.
摘要：
背景：许多免疫测定法已经商业化，以确定粪便中的胰腺弹性蛋白酶（PE），以筛查胰腺外分泌功能不全（EPI），但是不同的检测方法如何相互比较是有争议的，特别是在所有方法都使用相同的临界值来解释在存在或不存在EPI或存在不足的程度上获得的结果的情况下。我们的目的是分析验证一种测定PE的新方法，将结果与以前的方法进行比较，并验证声明的截止值，以解释结果。
方法：使用先前的单克隆酶联免疫吸附试验（\"ScheBoELISA\"）和新的多克隆颗粒增强比浊法免疫测定（\"BühlmannPETIA\"）来测定粪便中的PE。在40个样品中进行了两种免疫测定的直接方法比较。在56个样品中进行了相互临床比较，以二元确定“异常/正常”弹性蛋白酶水平和“严重/中度/无”EPI的三向确定。间接比较方法使用外部质量评估（EQA）数据来比较PE的单克隆和多克隆免疫测定，并将单克隆ScheBoELISA与单克隆化学发光免疫测定法（“DiaSorinCLIA”）进行了比较。
结果：BühlmannPETIA系列精密度和实验室内精密度符合制造商关于浓度限值/下限范围和正常值范围的规范。在不同分析平台上的BühlmannPETIA免疫测定在三向分类的情况下产生了可比的结果和几乎完美的一致性（kappa=0.89，95CI从0.79到1.00。ScheBoELISA倾向于产生比BühlmannPETIA更高的胰腺弹性蛋白酶值；在二元分类的情况下，方法之间的一致性中等（κ=0.43；95％CI0.25至0.62），并且在三向分类的情况下是实质性的(κ=0.62；95%CI0.50至0.75)。EQA数据分析显示，ScheBoELISA和BühlmannPETIA同行之间存在统计学上的显着差异（p=0.031），以及DiaSorinCLIA和ScheBoELISA对等组（p=0.010）。
结论：ScheBoELISA和BühlmannPETIA在分析和临床背景下似乎不可改变。我们的数据解决了胰腺弹性蛋白酶的不同单克隆和多克隆免疫测定之间的不一致，以及在筛查可疑患者的胰腺外分泌功能不全时使用其通用临界值进行错误分类的可能性。
方法：使用先前的单克隆酶联免疫吸附试验（\"ScheBoELISA\"）和新的多克隆颗粒增强比浊法免疫测定（\"BühlmannPETIA\"）来测定粪便中的PE。在40个样品中进行了两种免疫测定的直接方法比较。在56个样品中进行了相互临床比较，以二元确定“异常/正常”弹性蛋白酶水平和“严重/中度/无”EPI的三向确定。间接比较方法使用外部质量评估（EQA）数据来比较PE的单克隆和多克隆免疫测定，并将单克隆ScheBoELISA与单克隆化学发光免疫测定法（“DiaSorinCLIA”）进行了比较。
结果：BühlmannPETIA系列精密度和实验室内精密度符合制造商关于浓度限值/下限范围和正常值范围的规范。在不同分析平台上的BühlmannPETIA免疫测定在三向分类的情况下产生了可比的结果和几乎完美的一致性（kappa=0.89，95CI从0.79到1.00。ScheBoELISA倾向于产生比BühlmannPETIA更高的胰腺弹性蛋白酶值；在二元分类的情况下，方法之间的一致性中等（κ=0.43；95％CI0.25至0.62），并且在三向分类的情况下是实质性的(κ=0.62；95%CI0.50至0.75)。EQA数据分析显示，ScheBoELISA和BühlmannPETIA同行之间存在统计学上的显着差异（p=0.031），以及DiaSorinCLIA和ScheBoELISA对等组（p=0.010）。
结论：ScheBoELISA和BühlmannPETIA在分析和临床背景下似乎不可改变。我们的数据解决了胰腺弹性蛋白酶的不同单克隆和多克隆免疫测定之间的不一致，以及在筛查可疑患者的胰腺外分泌功能不全时使用其通用临界值进行错误分类的可能性。
