Creatine kinase MB measured by fluorometric enzyme immunoassay and immunochemiluminescence.
Creatine kinase MB (CK-MB) was measured in serum by a fluorometric enzyme immunoassay on the Stratus analyzer and by an immunochemiluminometric assay using the Ciba Corning Magic Lite System. Both methods were standardized against purified CK-MB, with Stratus underestimating by 20 percent and Magic Lite overestimating by 28 percent. The assays proved sensitive and linear; however, at a CK-MB concentration of 7.0 micrograms per L, Stratus gave unacceptable inter-assay precision. No cross-reactivity was observed with CK-MM or CK-BB and elevated triglycerides, bilirubin, and hemoglobin did not interfere. Correlations with an immunoradiometric assay (Embria), using 522 samples, gave: Stratus = 0.999 (Embria) -3.3; r = 0.969, and Magic Lite = 1.225 (Embria) -3.03; r = 0.971. When using Magic Lite, results from 40 acute myocardial infarction (AMI) patients gave a mean CK-MB value of 93.8 micrograms per L (range: 9.2 to 428 micrograms per L) at the peak of enzyme release and a mean value of 69.6 micrograms per L (range: 6.7 to 319 micrograms per L) when using Stratus. Both methods proved to be highly sensitive and specific in the diagnosis of AMI; however, the need for standardization of CK-MB assays is stressed.
McBride
J H
JH
Department of Pathology and Laboratory Medicine, University of California, Los Angeles 90024-1732.
Rodgerson
D O
DO
Ota
M K
MK
Maruya
M
M
McEveney
S
S
D003402:Creatine Kinase / Q000097:blood* / Q000276:immunology; D003429:Cross Reactions; D005455:Fluorescent Antibody Technique / Q000592:standards; D006801:Humans; D007124:Immunoenzyme Techniques / Q000592:standards; D007527:Isoenzymes; D008163:Luminescent Measurements; D009203:Myocardial Infarction / Q000145:classification / Q000175:diagnosis / Q000201:enzymology; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007527:Isoenzymes; D003402:Creatine Kinase