Investigation of release and degradation of cardiac troponin T in patients with acute myocardial infarction.
OBJECTIVE
Cardiac troponin T (cTnT) degradation after tissue release is still under debate. Because degradation of cTnT might have consequences on clearance of the molecule from the circulation, but also on the assay performance, the aim of this study was to investigate cTnT release and degradation in serum of AMI patients.


METHODS
Serum samples were collected from 20 patients with AMI diagnosis undergoing rapid revascularization. Intact cTnT and fragments were detected using a combination of immunoprecipitation, SDS-PAGE and Western blotting.


RESULTS
The intact cTnT protein was detected only during the first 12 h after the cTnT concentration started to increase above the AMI cut-off value of 0.03 microg/L. Thereafter only fragments with molecular weights ranging from 10 to 30 kDa were detected, with two fragments being most prominent (15 and 25 kDa).


CONCLUSIONS
Intact cTnT rapidly disappears from the circulation during the early hours after AMI, but immunoreactive fragments remain present longer. The current cTnT immunoassay detects both intact cTnT and fragments.
Michielsen
Etienne C H J
EC
Department of Clinical Chemistry, University Hospital Maastricht, P Debyelaan 25, 6229 HX, PO box 5800, NL-6202 AZ, Maastricht, The Netherlands.
Diris
Jart H C
JH
Kleijnen
Vincent W V C
VW
Wodzig
Will K W H
WK
Van Dieijen-Visser
Marja P
MP
D006801:Humans; D008970:Molecular Weight; D009203:Myocardial Infarction / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D020107:Troponin T / Q000097:blood / Q000378:metabolism*
D010446:Peptide Fragments; D020107:Troponin T