COMPARISON OF THE TROPONIN-T AND TROPONIN-I ELISA TESTS, AS MEASURED BY MICROPLATE IMMUNOASSAY TECHNIQUES, IN DIAGNOSING ACUTE MYOCARDIAL-INFARCTION

We describe an improved procedure using a standard microplate immunoas say reader to measure the concentration of troponin T in human serum. We also describe an immunoassay for troponin I in serum. Only 160 mu l of serum are needed for a single analysis of each troponin. For compa rison, creatine kinase MB mass analysis in serum was performed with a commercial luminometric method. From 95 apparently healthy people the following values were obtained: creatine kinase MB mass 2.6 +/- 1.2 mu g/l, troponin T 0.027 +/- 0.025 mu g/l and troponin I 0.03 +/- 0.031 mu g/l. We compared the results of troponin T and troponin I methods w ith each other, as well as with those of creatine kinase MB mass measu red in 48 patients with verified acute myocardial infarction and in 60 control patients with non-cardiac chest pain. The correlation between troponin T and troponin I values was 0.91 for the total material and 0.94 for 48 patients with acute myocardial infarction. Troponin I show ed better earlier sensitivity than troponin T (p = 0.043). In nine pat ients in the control group, creatine kinase MB mass exceeded the refer ence limit of 5.0 mu g/l, while in two patients the cut-off limit of 1 0.0 mu g/l was also surpassed, pointing to non-specificity. In the gro up of infarct patients, the highest serum creatinine value was 193 mu mol/l, whereas in the control group it was 406 mu mol/l. The sera of p atients with impaired renal function without any cardiac failure showe d no increase in troponin T and troponin I values. In conclusion, seru m creatine kinase MB mass and troponin I seem to confirm an acute myoc ardial infarction more rapidly than does troponin T; troponin I has th e highest cardiac specificity.