新しいＥｎｚｙｍｅ Ｉｍｍｕｎｏａｓｓａｙ Ｓｙｓｔｅｍによる血清中ジゴキシン測度測定の評価

Abstract

A concentration of digoxin and apparent one of methyldigoxin in serum were measured by using the cloned enzyme donor immunoassay (CEDIA) method and the digoxin-NXT (NXT) method, and compared these new enzyme immunoassay systems with the fluorescence polarization immunoassay (FPIA) method.There was a significant correlation between FPIA and NXT methods in the serum concentration of digoxin, and a significant correlation between FPIA and CEDIA methods in the serum concentration of digoxin or apparent one of methyldigoxin was also found, respectively.However, in the serum concentration of digoxin, the mean value of the NXT method was significantly higher than that of the FPIA method.In contrast, the level determined by the CEDIA method was significantly smaller than that by the FPIA method.At the subtherapeutic range measured with the FPIA method (<0.8ng/ml), the value by NXT method shows 1.7-fold higher than that by the CEDIA method.Cross-reactivities among these three methods were compared by using the serum samples of 15 patients, not administered digitalis.It was found that the determinations of NXT and CEDIA methods were interfered with substances other than digitalis, such as the FPIA method.These results indicate that the specificity of reaction differs from one another in these three methods.