Mitochondrial creatine kinase. A poor prognostic sign

Area of Science:

• Biochemistry
• Clinical Chemistry
• Pathophysiology

Background:

• Creatine kinase (CK) is an enzyme crucial for cellular energy homeostasis.
• CK exists in different isoenzyme forms, including MM, MB, and mitochondrial CK (MtCK).
• Elevated serum CK levels are indicative of muscle damage, but specific isoenzyme analysis can provide further diagnostic information.

Purpose of the Study:

• To investigate the presence and significance of a specific CK isoenzyme band in patients experiencing shock.
• To determine the clinical implications and diagnostic value of this unusual CK isoenzyme in critical illness.

Main Methods:

• Serum samples were analyzed for creatine kinase (CK) isoenzyme patterns using electrophoresis.
• Patients presenting with shock were specifically monitored for the presence of a CK isoenzyme band cathodic to MM.

Main Results:

• A distinct CK isoenzyme band, migrating cathodically to the MM band and presumed to be mitochondrial CK (MtCK), was identified in eight patients in shock.
• Six out of these eight patients (75%) experienced fatal outcomes within 12 days of the isoenzyme detection.
• The detection of this MtCK isoenzyme in serum correlated with severe tissue damage.

Conclusions:

• The presence of a serum CK isoenzyme band cathodic to MM (likely MtCK) is a significant indicator in patients with shock.
• Severe tissue damage is a prerequisite for the release of this specific mitochondrial CK isoenzyme into the bloodstream at detectable levels.
• This finding suggests that serum MtCK may serve as a prognostic biomarker for severe tissue injury and mortality in critically ill patients.