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Troponin I in the blood
Last reviewed: 20.11.2021
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The reference values (norm) of troponin I in serum are 0-1 ng / ml.
Troponin I is a structural protein of the troponin complex of muscles with a molecular weight of 26,500 Da. Troponins I, like troponins T, cardiac and skeletal muscles, differ significantly in their amino acid sequence. This allowed the creation of diagnostic kits for cardiac isoforms of these troponins. For troponin I, the difference in amino acid sequence between the cardiac and skeletal isoforms is approximately 40%. Troponin I and troponin T are the components of the contractile apparatus, that is, the structurally related proteins of the cardiomyocytes; while the proteins dissolved in the cytosol (myoglobin) are relatively quickly washed out of the necrosis zone, the destruction of the cardiomyocyte contractile apparatus is more prolonged, therefore, the increase in the concentration of troponins persists up to 8-10 days after the onset of myocardial infarction. Troponin I is a highly specific marker of myocardial infarction. The increase in the concentration of troponin I in the blood occurs 4-6 hours after the onset of myocardial infarction (in 50% of patients), reaches a maximum on the 2nd day and comes to a normal value between 6 and 8 days. Mean values of troponin I concentration in the blood on the second day of myocardial infarction are 80-100 ng / ml. When evaluating the results of the study of troponin I, it must be remembered that the clipping values of its concentration (myocardial infarction and myocardial infarction) are 2.5 ng / ml. The content of troponin I increases in patients with unstable angina in the development of micronecrosis. With stable angina, no increase in troponin I is noted.
Unlike troponin T, the concentration of troponin I does not increase in patients with renal insufficiency, with massive injuries and muscle diseases.