Clq-coated ELISA법을 이용한 정맥용 면역글로불린제제의 항보체성 측정

Clq-Coated Microtitre Enzyme-linked Immunosorbent Assay for Measuring the Anticomplementary Activity of Intravenous Immunoglobulin Preparations

The quality of an intravenous immunoglobulin preparation (IVIG) is reflected by the degree of nonspecific activation of complements, the so-called anticomplementary activity (ACA). ACA of aggregates in IVIG was investigated using method by the European Pharmacopoeia and Clq-coated microtiter enzyme-linked immunosorbent assay (ELISA). Both the EP method and the ELISA method showed a dose response curve with the amount of complements bound increasing with the percentage content of aggiegates in immunoglobulin standard. The correlation between the two tests was good (r=0.96, r=0.99). However the correlation was not found when the ACA (EP method) of IVIG product was compared with its aggregate percentage. These results emphasize that the method of aggregate formation affects ACA and that estimation of the percentage distribution of aggregates by HPLC may not reflect ACA. In analysing IVIG product for Clq binding activity test with the ELISA, the result by using Protein A-HRP correlated with aggregate percentage (r=0.84). But the correlation decreased (r=0.48) when the result used Protein A-AP(having poorer sensitivity than HRP) was compared with aggregate percentage. As a result, some variation between the two methods, due to differences in assay principles, is to be expected. However ELISA technique has the advantage in that it is easier to perform, more precise and less subject to reagent variability and is the more suitable screening method than HPLC analysis.