High sensitive troponin T elevation in an oncology patient on treatment with Pembrolizumab

Abstract Objectives Troponins are a complex of three proteins that play a key role in the contraction of striated muscles. Currently, cardiac troponins T (cTnT) and I (cTnI) are the best biomarkers for acute myocardial infarction (AMI) diagnostic. Case presentation Immune-mediated toxicity due to Pembrolizumab was suspected in a 70-year-old male patient with gastric adenocarcinoma. To confirm this, creatine kinase (CK) and high sensitivity troponin T (hs-cTnT) analysis was carried out, giving values above the reference range. While CK normalized over time, hs-cTnT levels remained high. Before opting to perform an endomyocardial biopsy, high-sensitive troponin I (hs-cTnI) was measured, yielding a normal value. Due to discrepancies in troponin levels, a standard protocol was followed to confirm the presence of analytical interferences, that was negative. Conclusions The discrepancy observed between both troponin levels, and the absence of analytical interference, led us to exclude cardiac damage in our patient. So, the most probable cause of elevated cTnT was muscle involvement. This case highlights the importance of confirming troponin results using an alternative assay to rule out limited specificity and emphasizes the need for accessible tools to identify potential analytical interferences.