The influence of hemolysis, turbidity and icterus on the measurements of CK-MB, troponin I and myoglobin.

To decide on the acceptability of a specimen for the measurement of serum CK-MB, troponin I and myoglobin, we investigated the influence of hemolysis, turbidity, and icterus on those tests by adding arbitrarily made interferents. A total of 16 cases each for CK-MB and troponin I, and 18 cases for myoglobin tests were studied to verify the effects of hemolysis, turbidity, and unconjugated hyperbilirubinemia. A total of 16 cases were studied to clarify the effects of the conjugated hyperbilirubinemia. We graded the severity of hemolysis, turbidity, and icterus as mild, moderate, and severe after adding hemolysate, Intralipos (20% soybean oil), and unconjugated or conjugated bilirubin to sera. ACS180SE automated chemiluminescence system was used to measure CK-MB, troponin I, and myoglobin. CK-MB and troponin I were affected by any degree of hemolysis, turbidity, unconjugated hyperbilirubinemia, and conjugated hyperbilirubinemia, while myoglobin was affected only by severe unconjugated hyperbilirubinemia and conjugated hyperbilirubinemia in the samples with concentration higher than reference range, resulting in concentration level lower than baseline. In conclusion, the results of cardiac markers should be carefully interpreted when the specimens are hemolyzed, turbid or icteric.