Cardiac-specific immunoenzymometric assay of troponin I in the early phase of acute myocardial infarction

Abstract

The screening by immunoenzymometric assay (IEMA) of 784 monoclonal antibody (MAb) combinations resulted in the selection of an optimal pair of MAbs for measuring human cardiac troponin I (TnI). Using a one-step IEMA described here, we were able to detect TnI within the range of 0.2-20 micrograms/L in 30 min at room temperature. No cross-reactivity was observed with the skeletal isoforms of troponin up to a concentration of 500 micrograms/L. This assay was used to measure cardiac TnI in the plasma of 43 patients with acute myocardial infarction (AMI). TnI was detected relatively early after the onset of chest pain (4.3 +/- 2.1 h, mean +/- SD); the peak occurred after 12.2 +/- 4.6 h in a population that had undergone fibrinolysis. TnI disappearance was generally observed between 5 and 9 days after the onset of chest pain. No cardiac TnI could be detected in 145 healthy donors or in a control group of 6 patients (with skeletal damage or rhabdomyolysis). This assay allows a specific diagnosis of AMI in its early acute phase, with a high diagnostic specificity and sensitivity.

Cardiac troponin I concentrations in neonates with hypoxic‐ischaemic encephalopathy

“…Asphyxiated neonates have higher cardiac troponin I (cTnI) concentrations than controls (4). In adults, cTnI appears in serum within a few hours of myocardial injury and peaks at 12-18 h (5).…”

Perioperative catecholamine changes in cardiac risk patients

“…Post-operative ischaemia seems to correlate with adverse outcome, and prolonged subendocardial ischaemia rather than acute coronary artery occlusion precedes cardiac complications [1,6]. Cardiac troponins (TNs) -troponin T (TNT) and troponin I (TNI) -have been established as a sensitive marker for detection of major and minor myocardial cell injury, avoiding the high incidence of false-positive results by the use of creatine kinase (CK)-MB [7][8][9][10][11][12]. Metzler et al [13] found that in cardiac risk patients undergoing non-cardiac surgery high postoperative levels of TNT and TNI were correlated with post-operative cardiac complications, whereas patients with no or only slightly increased concentrations of both troponins had a good outcome.…”

Elevated circulating cardiac troponin I in patients with cirrhosis

“…14 Elevated cardiac troponin I is known to be a marker of myocyte injury and is therefore a valuable tool for the diagnosis of myocardial infarction. 7,13,15,16 Elevated cardiac troponin I concentrations have also been observed in other clinical conditions such as reperfusion therapy monitoring, 17 myocarditis, and in patients with cardiac contusions, 18,19 thus confirming its cardiospecificity.…”