[False positive on macrotroponin].

Area of Science:

• Clinical Biochemistry
• Cardiology
• Immunology

Background:

• Cardiac troponin (cTn) isoforms I and T are established biomarkers for myocardial injury.
• Highly sensitive assays improve acute coronary syndrome (ACS) diagnosis but increase complexity and susceptibility to interference.
• Elevated cTn levels necessitate careful interpretation to avoid misdiagnosis.

Purpose of the Study:

• To present a case of macrotroponinemia, specifically IgG-troponin T immunocomplexes.
• To enhance awareness among healthcare providers regarding the critical interpretation of persistently high cardiac troponin values.
• To highlight potential analytical interferences in troponin testing.

Main Methods:

• Case report detailing a patient with macrotroponinemia.
• Characterization of circulating IgG-troponin T immunocomplexes.
• Review of diagnostic challenges associated with high-sensitivity troponin assays.

Main Results:

• Identification of macrotroponinemia due to IgG-troponin T immunocomplexes.
• Demonstration of how immunocomplexes can lead to falsely elevated troponin measurements.
• Underscores the importance of considering analytical interferences in troponin testing.

Conclusions:

• Macrotroponinemia is a rare but significant cause of elevated cardiac troponin.
• Prescribers must critically evaluate persistently high troponin values, considering potential interfering factors like immunocomplexes.
• Accurate interpretation of troponin assays is vital for appropriate patient management and diagnosis of cardiac conditions.