Clinical chemistry
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Adrenal insufficiency is a complication of transsphenoidal surgery (TSS) for pituitary adenoma, and correct identification of patients requiring glucocorticoid replacement is important. Controversy exists over which early postoperative 9 AM cortisol concentration reliably predicts hypothalamic-pituitary-adrenal (HPA) axis reserve, as defined by the insulin tolerance test (ITT). ⋯ A day 5 post-TSS 9 AM serum cortisol <111 nmol/L reliably detects secondary adrenal insufficiency, and concentrations >392 nmol/L support intact HPA function. Because concentrations of 111-392 nmol/L are poorly predictive of HPA function, glucocorticoid replacement should continue in such cases until definitive testing is performed using an ITT.
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Cardiac troponin (cTn) is an established marker of myocardial infarction. Pronounced heterogeneity and the minute amounts released into the circulation constitute significant challenges for cTn detection. Recently, autoantibody formation to cTn was shown to be common and to interfere with immunoassay performance. In this study, we investigated cTn autoantibodies and cardiac troponin I (cTnI) in acute coronary syndrome (ACS) patients over a 1-year period after the index event. ⋯ During ACS, patients with cTn autoantibodies have higher cTnI release and therefore larger myocardial damage than patients without autoantibodies. Their cTnI release also lasts longer, at least months. The possible prognostic impact of these observations must be evaluated in larger clinical cohorts.
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We sought to determine the diagnostic accuracy of the cardiac troponin I (cTnI) VITROS(R) Troponin I-ES assay for early detection of acute myocardial infarction (AMI) and for risk prediction of adverse events in patients with symptoms of acute coronary syndrome (ACS). ⋯ Admission cTnI measured by the VITROS ES assay is a sensitive biomarker for detection of AMI. Utilizing >30% cTnI delta in addition to either the baseline or follow-up concentration improved both specificity and risk assessment in patients presenting with symptoms of ACS.