Differentialdiagnostische Bedeutung von Troponin T im Serum: Myokardinfarkt, Rhabdomyolyse oder Niereninsuffizienz?

Anamnese und Befunde: Bei einem 30jahrigen Patienten mit Niereninsuffizienz bei fokal-sklerosierender Glomerulonephritis fiel nach einem Krampfanfall mit konsekutiver Rhabdomyolyse neben einer auf > 100 000 U/l erhohten Kreatinkinaseaktivitat eine Erhohung des kardialen Troponin T (cTnT) im Serum auf (13 µg/l, Normwert  100 000 U/l) but also of cardiac troponin T (cTnT) concentration in serum (13 µg/1; normal: < 0.1 µg/l), in the absence of any cardiac symptoms. Course: Raised concentration of cTnT is known to occur in patients with renal failure but no cardiac symptoms. In our patient, despite increased creatinine levels, serum cTnT gradually fell to normal within 3 weeks, i.e. the raised creatinine played no part in the elevation of cTnT, which in this patient was probably due to crossreaction between cardiac and skeletal TnT, or transient fresh synthesis of cTnT in regenerating skeletal musculature. Conclusions: In patients with extensive rhabdomyolysis and renal failure the assessment of the clinical status and the ECG, to exclude myocardial infarction, are of crucial importance. The cTnT level by itself is of only limited value in such cases.