A 53-year-old man with chest pain and persistently elevated cardiac troponin T was found to have a false-positive elevation secondary to an immunoglobulin-troponin bound complex (macrotroponin T).
Case Report (n=1)
Macrotroponin should be considered as a differential diagnosis for persistently elevated troponin when clinical and imaging findings do not suggest acute coronary syndrome or structural heart disease.
BACKGROUND: Troponin is a crucial biomarker for the diagnosis of an acute coronary syndrome (ACS). It rises in response to myocardial injury from significant acute myocardial ischaemia caused by obstructive coronary artery disease 'classical' myocardial infarction (MI). However, raised levels have also been noted in conditions not recognized as classical ACS. This may include MI with non-obstructed coronary arteries such as takotsubo cardiomyopathy and other acute or chronic conditions such as pulmonary embolus or chronic kidney disease. This is commonly labelled as a 'falsely elevated' troponin although there is some myocardial strain to explain the rise, such as an increase in cardiac oxygen demand. True 'falsely elevated' troponin, characterized by a persistent elevation in the absence of cardiac injury does occur and thought to be secondary to an immunoglobulin-troponin complex (macrotroponin). CASE SUMMARY: A 53-year-old gentleman with a background of diabetes, hypertension, hypercholesterolaemia, and hepatitis B was admitted with chest pain and persistently elevated cardiac troponin T (cTnT) levels. Investigations revealed unobstructed coronary arteries and a structurally normal, well-functioning heart. Subsequent biochemical analysis found the persistently elevated cTnT secondary to macrotroponin T. DISCUSSION: Macrotroponin, an immunoglobulin-troponin bound complex should be considered as a differential diagnosis when the biochemistry is not reflective of the clinical picture. Early recognition requires effective collaboration with the biochemistry laboratory for accurate diagnosis.
Akhtar et al. (Sun,) conducted a case report in False-positive troponin elevation (Macrotroponin) (n=1). A 53-year-old man with chest pain and persistently elevated cardiac troponin T was found to have a false-positive elevation secondary to an immunoglobulin-troponin bound complex (macrotroponin T).