Macrotroponins cause discrepancy in high-sensitivity examination

Area of Science:

• Clinical Chemistry
• Biomarker Analysis
• Immunochemistry

Background:

• Cardiac troponins (cTnI and cTnT) are critical biomarkers for diagnosing myocardial infarction.
• Discrepancies between clinical findings and troponin levels necessitate further investigation.

Observation:

• Two cases presented with significantly elevated cardiac troponin I (cTnI) and normal cardiac troponin T (cTnT) concentrations, conflicting with clinical presentation.
• Initial assays suggested macro-troponin I as a potential cause for the discrepant results.

Findings:

• Laboratory analysis, including polyethylene glycol precipitation and Sephadex G-100 gel filtration, confirmed the presence of macro-troponin I in both cases.
• Macro-troponin I significantly interfered with cTnI assays, leading to falsely elevated results.

Implications:

• Recognition of macro-troponin interference is crucial to avoid misdiagnosis and unnecessary patient management.
• Close collaboration between clinicians and laboratory staff is essential for accurate interpretation of complex biomarker results.