Comparison of Two Immunoinhibitory Methods with Agarose Gel-Electrophoresis for Measuring the MB Isoenzyme of Creatine Kinase in Serum from Cases of Suspected Myocardial Infarction

Abstract

Summary:Two immunoinhibitory methods for measuring creatine kinase-MB (a dry chemical and a wet chemical method) were compared with the commonly used agarose gel electrophoretic method, using 563 serum samples from 235 patients with suspected acute myocardial infarction. Comparison of the electrophoretic and the dry chemistry methods showed the linear relationship: electrophoretic method = -6.5 U/l + 1.22 χ dry chemistry method, r = 0.943. For the wet chemistry method the relationship was: electrophoretic method = -7.2 U/l + 1.19 x wet chemistry method, r = 0.854. Parallel determinations of total creatine kinase were also done and the methods were virtually identical in performance.Compared with the electrophoretic method (which showed a 15% prevalence of acute myocardial infarction), these classifications showed sensitivities of 0.92 and 0.67 and specificities of 0.94 and 0.99 (dry and wet chemistry, respectively; using methods recommended by the manufacturers). After optimization of discriminators the sensitivity was increased to 0.94/0.92 and the specificity to 0.99/0.99. Introduction." ., ,. . , specific antibodies against the subumt M. The antiAcute myocardial infarction is one of the commonest bodies have either been used in radioimmunoassays causes of hospitalization and death in the western or for specific inhibition of the enzymatic activity of industrialized countries. It is therefore of great im-the subunit M, followed by measurement of the reportance to have a fast, inexpensive, sensitive, and maining enzymatic activity (2, 5). The aim of this specific diagnostic test. The most widely used single study is to compare two different immunoinhibition laboratory test is electrophoretic determination of the methods (a dry and a wet chemistry method) with the MB isoenzyme of creatine kinase (EC 2.7.3.2) 1 ) (crea-commonly used but laborious electrophoretic method, tine kinase-MB) (1, 2). This method is very specific and reasonably sensitive, but it is rather tedious and expensive (3, 4). The last decade has seen the devel-Materials and Methods opment of easier analytical methods, which utilize Samples

Immunoreactive Creatine Kinase-MB and Creatine Kinase Isozyme Concentrations During Treatment of Hypothyroid Patients

“…tfais confirme d that serum creatine kinasetion; the BB form is found in the brain, the MB form in MB levels st l rema i ned hj g h, even though serum conthe heart, and the MM form in the skeletal muscles (l, een trations of thyroid stimulating hormone and thyroid 2). Isozyme, creatine kinase-MB, is easily released from hormones, and the serum catalytic activity concentracardiac muscle after acute myocardial infarction (3)(4)(5). tions of total crea tine kinase and creatine kinase-MB Hypothyroidism induces the elevation of serum creatine mea sured by the routine method were normalized.…”