Impaired renal clearance explains elevated troponin T fragments in hemodialysis patients.
BACKGROUND
Patients with severe renal dysfunction often have unexplained elevated serum concentrations of cardiac troponin T (cTnT). We investigated whether in vivo fragmentation of cTnT could explain these increases.


RESULTS
cTnT, creatine kinase isoenzyme MB, and myoglobin serum concentrations were measured in all 63 dialysis patients of our in-hospital dialysis department. A highly sensitive immunoprecipitation assay, followed by electrophoresis and Western blotting, was used to extract and concentrate cTnT and its possible fragments from serum of these 63 hemodialysis patients. Although creatine kinase isoenzyme MB values excluded recent ischemic myocardial events in 55 of the 63 cases, cTnT fragments ranging in size from 8 to 25 kDa were present in the serum samples of all dialysis patients.


CONCLUSIONS
cTnT is fragmented into molecules small enough to be cleared by the kidneys of healthy subjects. Impaired renal function causes accumulation of these cTnT fragments and is very likely the cause of the unexplained elevations of serum cTnT found in patients with severe renal failure.
Diris
Jart H C
JH
Department of Clinical Chemistry, University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands. Diris@klinchem.azm.nl
Hackeng
Christian M
CM
Kooman
Jeroen P
JP
Pinto
Yigal M
YM
Hermens
Wim T
WT
van Dieijen-Visser
Marja P
MP
D000368:Aged; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D009202:Cardiomyopathies / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D047468:Immunoprecipitation; D007527:Isoenzymes / Q000097:blood; D007668:Kidney / Q000378:metabolism*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009211:Myoglobin / Q000097:blood; D010446:Peptide Fragments / Q000097:blood / Q000378:metabolism; D006435:Renal Dialysis; D020107:Troponin T / Q000097:blood* / Q000378:metabolism
D015415:Biomarkers; D007527:Isoenzymes; D009211:Myoglobin; D010446:Peptide Fragments; D020107:Troponin T; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form