A two-tube immunochemical method for determination of CK-MB isoenzyme in serum evaluated.
A new commercial kit (Impres-MB; International Immunoassay Labs.) recently was introduced for measuring the MB isoenzyme of creatine kinase (CK-MB) based on the use of monoclonal antibodies. After antibodies to CK-MM isoenzyme are added to precipitate the CK-MM, antibodies to CK-M monomer are added to precipitate the M-subunit isoenzymes of CK. Subtracting the enzymatic activity of the second supernate from the residual activity in the first yields the activity of CK-MB. Results are not affected by CK-BB, mitochondrial CK, or adenylate kinase. However, the anti-CK-MM antibodies precipitated only about 98% of serum CK-MM and may have partly precipitated CK-MB isoenzyme (average analytical recovery of CK-MB, 86.6%). Comparison between Impres-MB (y) and electrophoresis (x) yielded the following linear-regression equation: y = 0.79x + 3 (r = 0.982, n = 97). Data for CK-MB temporal kinetics, obtained from patients with myocardial infarction, correlated significantly in both methods; however, peak activity values of CK-MB were significantly different, confirming that the difference between the new method and the electrophoretic method average 20%.
Panteghini
M
M
Laboratorio Analisi Chimico-Cliniche, Spedali Civili, Brescia, Italy.
Bonora
R
R
Pagani
F
F
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D003402:Creatine Kinase / Q000097:blood*; D004586:Electrophoresis; D006801:Humans; D007163:Immunosorbent Techniques; D007527:Isoenzymes; D008875:Middle Aged; D009203:Myocardial Infarction / Q000201:enzymology*; D011786:Quality Control; D012016:Reference Values
D000911:Antibodies, Monoclonal; D007527:Isoenzymes; D003402:Creatine Kinase