Atypical Serum Creatine Kinase Isoenzyme Pattern Caused by Complexing of Creatine Kinase-BB with Immunoglobulins G and A

Abstract

In commemoration of Professor Dr. Gabor SzaszSummary: 12 cases are described, which show high serum creatine kinase-BB levels, as well as atypical creatine kinase activity band located between normally migrating creatine kinase-MM and creatine kinase-MB. It is shown that the altered properties of the serum creatine kinase-BB, namely its molecular size, heat resistance, electrophoretic mobility, but not its immunological behavior, are caused by complexing with kappa-chains of immunoglobulins G or A. The complex occurring in vivo could also be produced in vitro by using purified patients' IgG and human creatine kinase-BB.The interaction of creatine kinase-BB with immunoglobulins possibly protects the enzyme against intravascular degradation in vivo, and may therefore account for the high creatine kinase-BB levels observed in these patients. Atypisches Isoenzymmuster von Kreatinkinase im Serum infolge Komplexbildung von Kreatinkinase-BB mit Immun· globulin G und AZusammenfassung: Es werden 12 Falle beschrieben, die eine erhöhte Kreatinkinase-BB-Aktivität im Serum als auch eine atypische Kreatinkinase-Bande zwischen Kreatinkinase-MM und Kreatinkinase-MB aufweisen. Es wird gezeigt, daß die veränderten Eigenschaften der Serum-Kreatinkinase-BB, nämlich Molekulargewicht, Hitzestabilität, elektrophoretische Mobilität, aber nicht das immunologische Verhalten, auf die Bindung des Enzyms an kappa-Ketten der Immunpglobuline G und A zurückzuführen sind. Der in vivo auftretende Komplex konnte auch in vitro reproduziert werden und zwar mit gereinigtem Patienten-IgG und humaner Kreatinkinase-BB.Die Bindung zwischen Kreatinkinase-BB und Immunoglobulinen schützt möglicherweise das Enzym in vivo gegen intraväsale Degradation und könnte somit die bei diesen Patienten auftretende erhöhte Kreatinkinase-BB-Aktivität hervorrufen.

Macro-Creatine Kinase-BB: Observations on 6 Patients

“…The atypical migration of the enzyme activity is obviously due to its high molecular weight (M T = 250,000) compared to the molecular weight of native creatine kinase isoenzymes (M T = 80,000, (15,16) (8), this is also the case for 5 of the six reported patients. The alteredM/c/zae//s constants of the creatine kinase-BB enzyme thus could be explained by steric hindrance.…”

“…The cause of the , cathodic location is assumed to be an elevated molecular In the last three years repeated reports have appeared on rf ^^ ^^ ßß as g ^ rf aeodatton atypical isoenzyme distribution of creatine kinase immunoglobulins G and A (5,8). At present there is | (EC.…”

“…At present there is | (EC. 2.7.3.2) (1)(2)(3)(4)(5)(6)(7)(8). Electrophoretic investigations (3,4, no izab , e connection with uniform etiological 5,7) show an-enzyme activity located between creatine patients manifested a regularly detectable and anamnestically inexplicable increase in total creatine kinase activity.…”

Stability of Macro Creatine Kinases and Creatine Kinase Isoenzymes Compared: Heat Inactivation Test for Determination of Thermostable Creatine Kinases

“…One form of macromolecular creatine kinase demonstrated in patients' sera was identified as a complex between creatine kinase BB and immunoglobulins (4)(5)(6)(7)(8).…”

“…In contrast to uncoupled creatine kinase BB, the immunoglobulin-linked BB was described as strikingly thermostable (4,7).…”