Abstract
We have developed and evaluated an ELISA method which can specifically detect Troponin I (TnI) derived from cardiac muscle in serum, without showing cross-immunoreaction with TnI derived from skeletal muscle. The proposed method is not affected by the presence of hemoglobin, unlike conventional Troponin T (TnT) measurement. The mean serum TnI concentration in 87 healthy subjects undergoing a group medical examination obtained using the ELISA method was 0.271±0.087μg/l (mean±SD). The change as a function of time of serum TnI concentration paralleled that of serum CK-MB concentration in patients with cardiac infarction, and the maximum serum TnI concentration in the same patients was approximately 120 times the reference level (mean+2SD). The correlation coefficient between serum TnI and CK concentrations was r=-0.081 (n=46), that between serum TnI and CK-MB concentrations was r=0.214 (n=51), and that between serum TnI and TnT concentrations was r=0.687 (n=55). Our findings indicate that the serum TnI concentration can be used as a new marker for cardiac diseases and lesions.
