Diseased Skeletal Muscle Can Raise Levels of Troponin T

Cardiac troponins such as T (cTnT) and I (cTnI) are considered to be quite specific for cardiac muscle damage. In this study from Mayo Clinic's neuromuscular clinic, researchers documented a potential cause for rare false-positives seen on the cTnT assay. Eighteen highly selected patients with myopathies who were undergoing skeletal muscle biopsy for clinical reasons were screened for elevated cTnT concentrations. If cTnT level was elevated, a cTnI assay also was performed.

Sixteen patients had elevated cTnT but normal cTnI levels. In one additional patient who had elevations in both cTnT and cTnI levels, the eventual diagnosis was cardiomyopathy in the setting of vacuolar myopathy. Among the 16 patients with isolated cTnT elevations, 4 had …