Uwe Dr. Würzburg

Bestimmung der Aktivität von Creatinkinase MB im Serum unter Verwendung inhibierender Antikörper

SummaryA new method for the determination of creatine kinase-MB activity in the serum is presented. The principle of this method is the direct measurement of the activity of creatine kinase M subunits by inhibiting antibodies. The total test procedure takes 15 min. In the sera of all the 83 patients tested, who have clinically proven myocard infarction, creatine kinase-MB activity can be measured between the 6th and 28th hour after infarction. At the time of maximum total creatine kinase activity the percentage of creatine kinase-MB activity is between 6 and 17%, the mean value being 8%. In cases of emergency this method can be used for the differential diagnosis of elevated total creatine kinase activities of unknown origin.ZusammenfassungEs wird über eine neue Methode zur quantitativen Bestimmung der Creatinkinase MB-Aktivität im Serum berichtet. Die Methode beruht auf einer direkten Messung der Aktivität der Creatin-kinase-Untereinheit B nach Hemmung der Aktivität der Creatinkinase-Untereinheit M durch inhibierende Antikörper und benötigt zur Durchführung 15 min. Bei allen 83 untersuchten Patienten mit klinisch gesichertem Myokardinfarkt konnten zwischen der 6. und 28. Stunde nach Infarkteintritt Creatinkinase MB-Aktivität gemessen werden. Der Creatinkinase MB-Anteil zum Zeitpunkt der höchsten Creatinkinase-Gesamtaktivität betrug 6–17%, im Mittel 8%. Diese Methode ermöglicht daher in der Notfalldiagnostik eine Differentialdiagnose unklarer Creatinkinase-Gesamtaktivitäts-Erhöhungen.A new method for the determination of creatine kinase-MB activity in the serum is presented. The principle of this method is the direct measurement of the activity of creatine kinase M subunits by inhibiting antibodies. The total test procedure takes 15 min. In the sera of all the 83 patients tested, who have clinically proven myocard infarction, creatine kinase-MB activity can be measured between the 6th and 28th hour after infarction. At the time of maximum total creatine kinase activity the percentage of creatine kinase-MB activity is between 6 and 17%, the mean value being 8%. In cases of emergency this method can be used for the differential diagnosis of elevated total creatine kinase activities of unknown origin.

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.

[Determination of creatine phosphokinase-MB in the serum of patients with myocardial infarction by an immunological method (author's transl)].

SummaryThe immunological method of determining creatine phosphokinase-MB in the serum of patients with myocardial infarction described here is based on the differential measurements of CK-activities before and after a specific immuno-precipitation of the CK-MB-type. The minimum activity of the CK-MB-type which it is possible to determine with this method is 4% of the total activity. In patients with clinically confirmed myocardial infarctions 1–15% (mean 7.8%) of the total activity can be calculated as CK-activity of the MB-type on the first/second day(s) after the infarction. In patients with increased total CK-activity and without verified infarction the CK-MB content does not differ significantly from zero. The differences between the two groups are statistically significant. In patients with myocardial reinfarction the CK-MB-activity is higher than that after the first infarction. The immunological method to determine creatine-phosphokinase isoenzyme MB is of differential-diagnostic value in myocardial infarction.ZusammenfassungEs wird über den Nachweis von Creatinkinase-MB im Serum beim Myokardinfarkt mit einer immunologischen Methode berichtet. Die Methode beruht auf der differentiellen Bestimmung der Creatinkinase-Aktivitäten vor und nach spezifischer Immunpräcipitation von Creatinkinase-MB. Die Nachweisgrenze der Creatinkinase-MB-Aktivität mit dieser Methode liegt bei 4% der Creatinkinase-Gesamtaktivität. Bei Patienten mit klinisch gesichertem Myokardinfarkt kann am 1./2. Tag nach dem Infarkt 1–15% (Mittel 7,8%) der Creatinkinase-Gesamtaktivität als CK-MB-Aktivität nachgewiesen werden. Bei Patienten mit erhöhter CK-Gesamtaktivität ohne gesicherten Infarkt ist der CK-MB-Anteil nicht signifikant von Null unterschieden. Die Unterschiede der beiden Gruppen sind statistisch signifikant. Bei Patienten mit Reinfarkt findet sich ein höherer Anteil von CK-MB-Aktivität als nach Erstinfarkt. Die immunologische Nachweismethode für Creatinkinase-MB hat differentialdiagnostische Bedeutung beim Myokardinfarkt.

Creatinkinase — Isoenzyme: Idiopathisches Auftreten von Creatinkinase-BB-Aktivitäten im Serum von Patienten

SummaryBy differentiation of creatine kinase isoenzyme activities in sera using immunological methods the published data about occurrence of creatine kinase BB activities in patients with different diseases or after surgical treatment, respectively, cannot be verified in general. With a frequency in the order of magnitude of 1:1000 in the serum of old patients (age 57 to 85 years with one exception), however, creatine kinase BB activities can be measured. The range of activities is 15 to 234 U/l, or 19 to 94% of total creatine kinase activities, respectively. At the present time there is no possibility to correlate this phenomenon to any specific disease. These cases are detected by abnormally high results of CK-MB activity measurements with the immunoinhibition test (range 60 to 202% of total creatine kinase activities) which lead to a repeated analysis using immunoprecipitation. The results of all CK-BB patients investigated till now are presented and discussed.ZusammenfassungBei der Differenzierung der Aktivitäten von Creatinkinase-Isoenzymen im Serum von Patienten mit immunologischen Methoden kann das in der Literatur beschriebene Vorkommen von Creatinkinase-BB-Aktivitäten bei verschiedenen Krankheiten bzw. Operationen im allgemeinen nicht bestätigt werden. Jedoch wird bei Patienten höheren Lebensalters (57–85 Jahre mit einer Ausnahme) mit einer Frequenz von größenordnungsmäßigl:1000 Creatinkinase-BB-Aktivität gefunden. Die Aktivitäten betragen 15–234 U/l bzw. 19–94% der Gesamt-Creatinkinase-Aktivitäten. Bisher kann kein Zusammenhang mit einer bestimmten Krankheit hergestellt werden. Diese Fälle werden dadurch erkannt, daß die Bestimmung von CK-MB-Aktivitäten mit dem Immun-Inhibitionstest abnorm hohe Werte ergibt (60–202% der Gesamt-Creatinkinase-Aktivität), die zu einer Nachprüfung mit dem Immun-Präcipitationstest führen. Die bisher untersuchten Fälle werden vorgestellt und diskutiert.

Activity of creatine kinase isoenzyme MB in serum and red cell acetylcholinesterase variants in patients with Duchenne muscular dystrophy.

ZusammenfassungDie Aktivitäten der Creatinkinase und des Creatinkinase Isoenzyms MB im Serum sowie Varianten der Erythrozyten-Acetylcholinesterase wurden bei Patienten mit Muskeldystrophie Typ Duchenne (DMD) und anderen Formen sowie bei den Verwandten und gesunden Kontrollpersonen bestimmt. Nur bei Fällen von DMD konnten Creatinkinase-Isoenzyme MB wie auch Varianten der Acetylcholinesterase der Erythrozyten nachgewiesen werden.SummaryActivity of creatine kinase isoenzyme MB in serum and variants of red cell acetylcholinesterase were determined in patients with Duchenne muscular dystrophy, in other forms of Dystrophy and in family members of Duchenne patients and healthy controls. Creatine kinase isoenzyme MB was observed only in all cases of DMD as well as variants of red cell acetylcholinesterase characterized by so-called inhibitor numbers. Carriers of Duchenne muscular dystrophy can be distinguished from Duchenne patients and healthy controls by estimation of Acetylcholinesterase variants.

Immunologischer Schnelltest zur Bestimmung der Kreatinkinase MB-Aktivität im Serum

A rapid and sensitive method for the quantitative determination of creatine kinase (ATP: creatine phosphotransferase, EC 2.7.3.2, short term CK) isoenzyme MB activity is presented. This method utilises inhibiting anti-CK-MM, which is produced by immunisation of goats with reactivated human CK-MM isoenzyme. The resulting antiserum completely inhibits the activity of CK-M subunits without affecting the activity of CK-B subunits. Complete inhibition of CK-M activity is achieved within a few minutes and persists over a prolonged time. Table I shows, that in accord with the specificity of the antibodies for M subunits, within experimental error the activity of CK-MM is inhibited to 100 ~o, the activity of CK-MB to 50 ~o, and the activity of CK-BB to 0 ~. The effect can be reproduced in a CK activity range from less than 100 to 1000 U/l, Data from experiments with purified human CK isoenzymes are presented, which show the activity inhibiting action of anti-CK-MM in dependence from reaction time, from different CK substrates, and from different CK activators. These inhibiting anti-CK-MM sera can be utilised in a quantitative test for measurement of CK-MB Table 1. Inhibition of creatine kinase isoenzyme activity by inhibiting anti-CK-MM. Inactivated human sera with addition of purified CK isoenzymes. Mean values + 1 s from 5 fold measurements