title: Radioimmunoassay of creatine kinase-B isoenzyme in human sera: results in patients with acute myocardial infarction.
abstract: A radioimmunoassay was developed to measure serum levels of the B isoenzyme of creatine kinase(ATP: creatine N-phosphotransferase, EC 2.7.3.2) (CPK) in order to evaluate the time course and frequency of MB isoenzyme elevation in patients with acute myocardial infarction. The method can identify as little as 0.2 ng of the B portion of the CPK-MB isoenzyme, does not significantly crossreact with CPK-MM isoenzyme, and is not affected by storage of serum at --20 degrees CPK isoenzyme containing B subunits was detected in 48 out of 51 sera from normal adults; serum levels in these individuals ranged between 1.2 and 12.5 ng/ml [mean +/- SEM was 2.7 +/- 0.30 ng/ml]. The mean serum level of CPK-B isoenzyme in a pool of sera obtained from 100 normal subjects was 2.9 +/- 0.35 ng/ml; two patients with rhabdomyolysis that were studied had serum CPK-B isoenzyme levels of 2.5 and 3.5 ng/ml, respectively. In contrast, serum levels of the CPK-B isoenzyme were markedly elevated in sera from 18 patients with acute myocardial infarcts when obtained within 12 hr after hospital admission; the mean +/- SEM concentration was 56 +/- 7.8 ng/ml. We performed serial determinations on 14 patients with acute myocardial infarcts and demonstrated that maximal serum CPK-B levels occurred within the first 12 hr after admission and were lower thereafter. The serum concentration of B-containing CPK isoenzyme in 19 additional patients admitted with chest pain but without acute myocardial infarction was 3.4 +/- 0.50 ng/ml. Thus, radioimmunoassay measurement of CPK-B isoenzyme appears to be a useful and sensitive test for the detection of acute myocardial infarcts in patients.
mesh_terms: D000208:Acute Disease; D003402:Creatine Kinase / Q000097:blood* / Q000276:immunology; D006801:Humans; D007527:Isoenzymes / Q000097:blood* / Q000276:immunology; D009203:Myocardial Infarction / Q000201:enzymology*; D011863:Radioimmunoassay / Q000379:methods; D013997:Time Factors
chemical_list: D007527:Isoenzymes; D003402:Creatine Kinase
references.citation: Ann N Y Acad Sci. 1964 Dec 28;121:404-27
references.pmid: 14240539
references.citation: J Biol Chem. 1951 Nov;193(1):265-75
references.pmid: 14907713
references.citation: Science. 1976 Nov 19;194(4267):855-7
references.pmid: 982049
references.citation: Circulation. 1973 Feb;47(2):263-9
references.pmid: 4684926
references.citation: Arch Biochem Biophys. 1972 Jun;150(2):648-78
references.pmid: 5044047
references.citation: Circulation. 1972 Oct;46(4):640-8
references.pmid: 5072765
references.citation: Ann Intern Med. 1973 Nov;79(5):741-3
references.pmid: 4148054
references.citation: J Lab Clin Med. 1967 Apr;69(4):696-705
references.pmid: 4381359
references.citation: J Biol Chem. 1976 Mar 10;251(5):1476-80
references.pmid: 1254579
references.citation: Circulation. 1975 Jun;51(6):1046-52
references.pmid: 165909
references.citation: Biochem J. 1973 Jul;133(3):529-39
references.pmid: 4733239
references.citation: J Mol Cell Cardiol. 1976 Feb;8(2):159-67
references.pmid: 1255738
references.citation: J Clin Invest. 1975 Nov;56(5):1334-9
references.pmid: 1184754
references.citation: Clin Chem. 1975 Jun;21(7):844-9
references.pmid: 1132135
references.citation: J Clin Invest. 1971 Dec;50(12):2614-25
references.pmid: 5129313
references.citation: J Biol Chem. 1969 Aug 25;244(16):4406-12
references.pmid: 5806584
references.citation: J Biol Chem. 1967 Oct 25;242(20):4824-33
references.pmid: 6061423