Abstract
Cardiac troponin I is a marker for diagnosis of myocardial damage. Several immunoassays are currently available for determination of concentrations of troponin I in serum. We evaluated a chemiluminescent assay for troponin I using ACS:180 automated analyzer (Bayer Diagnostics). We compared our results with two other immunoassays using the OPUS Magnum (OPUS troponin I assay, Dade Behring) and AxSYM (microparticle enzyme immunoassay, Abbott) analyzers. The within‐run and between‐run CVs were less than 5% for all three levels of controls. The chemiluminescent assay for troponin I was linear up to a serum troponin I concentration of 50 ng/mL and the detection limit was 0.1 ng/mL of troponin. A good correlation between troponin I concentration measured by the chemiluminescent assay (y axis) and the microparticle enzyme immunoassay (MEIA) (x axis) was observed, although the concentrations of troponin I in individual specimens were approximately four times higher, when measured by the MEIA assay, than those measured by chemiluminescent assay. The correlation coefficient was 0.98 with the regression equation y = 0.22x + 1.125. We also observed a good correlation in troponin I concentrations obtained by the chemiluminescent assay (y axis) and OPUS troponin I assay (x axis). The correlation coefficient was 0.96 and the regression equation was y = 0.79x – 0.52. The correlation coefficient was 0.93 when we compared troponin I concentrations obtained by the OPUS assay (x axis) with the corresponding concentrations obtained by the MEIA assay (y axis). The corresponding regression equation was y = 0.25x + 3.5. We conclude that the chemiluminescent troponin I assay showed good analytical performance. J. Clin. Lab. Anal. 14:224–229, 2000. © 2000 Wiley‐Liss, Inc.
Keywords: troponin I, chemiluminescent, MEIA
REFERENCES
- 1. Dorogy ME, Hooks GS, Cameron RW, Davis RC. 1995. Clinical and angiographic correlates of normal creatinine kinase with increased MB isoenzymes in possible acute myocardial infarction. Am Heart J 130:211–217. [DOI] [PubMed] [Google Scholar]
- 2. Hong RA, Litch JD, Wei Y, et al. 1986. Elevated CK‐MB with normal total creatinine kinase in suspected myocardial infarction: associated clinical findings and early prognosis. Am Heart J 111:1041–1046. [DOI] [PubMed] [Google Scholar]
- 3. Osborn LA, Rossum A, Standefer J, et al. 1995. Evaluation of CK and CK‐MB in alcohol abuse subjects with heavy consumption. Cardiology 86:130–134. [DOI] [PubMed] [Google Scholar]
- 4. Shen CC, Hung CJ, Wu CC, Huang HW, Ho WM. 1999. Rhabdomyolysis‐induced acute renal failure after morphine overdose—a case report. Acta Anaesthesoil Sin 37:159–162. [PubMed] [Google Scholar]
- 5. Leszyk J, Dumaswala R, Porter JD, et al. 1988. Amino acid sequence of bovine cardiac troponin I. Biochemistry 27:2821–2827. [DOI] [PubMed] [Google Scholar]
- 6. Vallins WJ, Brand NJ, Dabhade N, et al. 1990. Molecular cloning of human cardiac troponin I using polymerase chain reaction. FEBS Lett 270:57–61. [DOI] [PubMed] [Google Scholar]
- 7. Guest TG, Ramanathan AV, Tuteur PG, et al. 1995. Myocardial injury in critically ill patients: a frequently unrecognized complication. JAMA 273:1945–1949. [PubMed] [Google Scholar]
- 8. Cohen LF, Mohabeer AJ, Keffer JH, Jialal I. 1996. Troponin I in hypothyroidism. Clin Chem 42:305–320. [PubMed] [Google Scholar]
- 9. Bodor GS, Porterfield D, Voss EM, Smith S, Apple FS. 1995. Cardiac troponin I is not expressed in fetal and healthy or diseased adult human skeletal muscle tissue. Clin Chem 41:1710–1715. [PubMed] [Google Scholar]
- 10. Beck SR. 1995. Myocardial injury in critically ill patients. JAMA (letter) 274:1672–1673. [DOI] [PubMed] [Google Scholar]
- 11. Li D, Keffer J, Jialal I. 1996. Greater frequency of increased cardiac troponin I than increased cardiac troponin T in patients with chronic renal failure. Clin Chem (letter) 42:114–115. [PubMed] [Google Scholar]
- 12. Keffer JH. 1997. The cardiac profile and proposed practice guideline for acute ischemic heart disease. Am J Clin Pathol 107:398–409. [DOI] [PubMed] [Google Scholar]
- 13. Bodor GS. 1994. Cardiac troponin I: a highly specific biochemical marker for myocardial infarction. J Clin Immunoassay 17:40–44. [Google Scholar]