Is it heart or skeletal muscle?

We present a case where the laboratory was asked to investigate suspected interference in our troponin T assay. The patient 29-year-old male with schizophrenia on long term clozapine. Hs-Troponin (Roche), performed routine monitoring chronically elevated between 40 100 ng/L (RI <14 ng/L), multiple cardiac investigations being normal. Creatine kinase similarly 400 700 U/L <250 U/L) over same time period. Initial studies did not show evidence of macrotroponin or heterophile antibody interference. Measurement three alternative platforms all showed undetectable/normal concentration Troponin I, suggesting that more likely from skeletal muscle. CK and LDH isoenzyme measurement confirmed this finding, supporting diagnosis asymptomatic myopathy, clozapine statin probable causes. Skeletal myopathy is well described adverse effect both therapy. be such settings compared I which specific. Knowledge differences muscle expression troponins enzymes as can assist optimal management patients.