Monoclonal antibodies specific to epitopes between amino acid residues 23-36 and 126-196 recognized 80% to 90% of cardiac troponin I in patient blood within 36 hours after acute myocardial infarction.
Observational
Antibodies targeting the central part of cTnI (aar 34-126) and adjacent epitopes (aar 23-36 and 126-196) are optimal for AMI diagnostic assays as they recognize the vast majority of circulating cTnI fragments.
BACKGROUND: In the blood of patients with acute myocardial infarction (AMI), cardiac troponin I (cTnI) presents as an intact molecule with a repertoire of proteolytic fragments. The degradation of cTnI might negatively influence its precise immunodetection. In this study we identified cTnI fragments and calculated their ratio in the blood of patients at different times after AMI to discriminate the most stable part(s) of cTnI. METHODS: Serial serum samples were collected from AMI patients within 1 to 36 h after the onset of chest pain both before and after stenting. cTnI and its fragments were immunoextracted from serum samples and analyzed by Western blotting with monoclonal antibodies (mAbs) specific to the different epitopes of cTnI and by 2 in-house immunoassays specific to the central and terminal portions of cTnI. RESULTS: Intact cTnI and its 11 major fragments were detected in blood of AMI patients. The ratio of the fragments in serial samples did not show large changes in the period 1-36 h after AMI. mAbs specific to the epitopes located approximately between amino acid residues (aar) 34 and 126 stained all extracted cTnI. mAbs specific to aar 23-36 and 126-196 recognized approximately 80% to 90% (by abundance) of cTnI. CONCLUSIONS: In addition to mAbs specific to the central part of cTnI (approximately aar 34-126), antibodies specific to the adjacent epitopes (approximately aar 23-36 and 126-196) could be used in assays because they recognize ≥80% of cTnI in patients' blood samples within the first 36 h after AMI.
Katrukha et al. (Mon,) conducted a observational in Acute Myocardial Infarction. Monoclonal antibodies specific to different epitopes of cTnI was evaluated on Detection and ratio of intact cTnI and its proteolytic fragments. Monoclonal antibodies specific to epitopes between amino acid residues 23-36 and 126-196 recognized 80% to 90% of cardiac troponin I in patient blood within 36 hours after acute myocardial infarction.