Clinically effective CK-MB reporting: how to do it?

Area of Science:

• Biochemistry
• Clinical Diagnostics
• Cardiology

Background:

• The Muscle Brain (MB) isoenzyme of creatine kinase (CK) is a key biomarker for myocardial injury.
• Current practice often involves measuring CK-MB in absolute units, which can lead to diagnostic inaccuracies.
• The immunoinhibition assay, common in India, is prone to falsely elevated CK-MB results in specific conditions.

Purpose of the Study:

• To evaluate the diagnostic utility of reporting %CK-MB compared to absolute CK-MB values.
• To highlight the limitations of absolute CK-MB measurements in specific clinical scenarios.
• To demonstrate how %CK-MB reporting aids in identifying macroCK variants and related pathologies.

Main Methods:

• Review of clinical utility of CK-MB measurements.
• Analysis of circumstances leading to falsely elevated absolute CK-MB results with immunoinhibition assays.
• Comparison of diagnostic implications of reporting absolute CK-MB versus %CK-MB.

Main Results:

• Absolute CK-MB measurements can be falsely elevated due to central nervous system damage, childbirth, macro CK-immunoglobulin complexes, and various carcinomas.
• %CK-MB reporting effectively detects macroCK (CK variants) and associated proliferative and autoimmune conditions.
• Reporting %CK-MB offers a more accurate assessment in the presence of these interfering factors.

Conclusions:

• Reporting %CK-MB provides a more reliable diagnostic approach for myocardial injury compared to absolute CK-MB values.
• %CK-MB analysis is essential for identifying macroCK variants and understanding their prognostic implications.
• Shifting from absolute to relative CK-MB reporting enhances diagnostic specificity and aids in managing complex pathologies.