Proficiency testing of creatine kinase and creatine kinase-2: the experience of the Ontario Laboratory Proficiency Testing Program

¹ Laboratory Proficiency Testing Program, 250 Bloor St. East, Suite 501, Toronto, ON, Canada M4W 1E6.

² Department of Biochemistry, University of Western Ontario, London, ON, Canada.

³ Department of Laboratory Medicine, The Credit Valley Hospital, Mississauga, ON, Canada.

⁴ Department of Laboratory Medicine, Sunnybrook Health Science Centre, North York, ON, Canada.

⁵ Department of Laboratory Medicine, University of Toronto, Toronto, ON, Canada.

⁶ Department of Clinical Chemistry, Hamilton General Campus, Hamilton Health Sciences Corporation, Hamilton, ON, Canada.

⁷ Department of Pathology, McMaster University, Hamilton, ON, Canada.

⁸ Analyzer types and manufacturers are: aca, Dimension, Paramax, and Stratus systems (Dade International); Access (Sanofi Diagnostics Pasteur); ACS 180 (Chiron); Beckman CX systems (Beckman Instruments); Cobas Mira systems (Roche Diagnostic Systems); Hitachi systems (Boehringer Mannheim); ICON (Hybritech); RA systems and Immuno I (Bayer Corp.); Spectrum, IMx, and AxSYM (Abbott Labs.); Vitros DT, 250, 500, and 700 (Johnson and Johnson Clinical Diagnostics).

⁹ LPTP requires that proficiency testing challenges are processed as patient specimens. Accordingly, outliers reported in these surveys have not been subjected to statistical trimming.
^a Address correspondence to this author at: 19 Linksgate Rd., London, ON, Canada N6G 2A6. E-mail ahenders{at}julian.uwo.ca.

The Ontario Laboratory Proficiency Testing Program has regularly monitored the analytical performance of total creatine kinase (CK) (230 participants) and CK isoenzyme-2 (CK-MB) (160 participants) throughout the entire province. Consistently, a wide dispersion of results has been observed not only between different analyzer systems but also among identical analyzers. Accordingly, the results of the last three proficiency surveys for these analytes were examined statistically to establish both the extent of these variations and the range of values reported for the male upper reference ranges. The results of many of the analyzer systems were significantly different from each other, as were many of the reference ranges. This unsatisfactory situation may only be remedied by the use of reference materials as shown by others. The consequences of these findings also effect the reliability of epidemiological surveys such as the WHO MONICA Project (Circulation 1994;90:583–612), which monitors deaths due to heart disease and includes cardiac enzyme results in its criteria.

The following articles in journals at HighWire Press have cited this article:

				A. Halkin, G. W. Stone, C. L. Grines, D. A. Cox, B. D. Rutherford, P. Esente, C. M. Meils, P. Albertsson, A. Farah, J. E. Tcheng, et al. Prognostic Implications of Creatine Kinase Elevation After Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction J. Am. Coll. Cardiol., March 7, 2006; 47(5): 951 - 961. [Abstract] [Full Text] [PDF]

				R. H. Christenson, H. Vaidya, Y. Landt, R. S. Bauer, S. F. Green, F. A. Apple, A. Jacob, G. R. Magneson, S. Nag, A. H.B. Wu, et al. Standardization of Creatine Kinase-MB (CK-MB) Mass Assays: The Use of Recombinant CK-MB as a Reference Material Clin. Chem., September 1, 1999; 45(9): 1414 - 1423. [Abstract] [Full Text] [PDF]