Clinical chemistry
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Circulating Epstein-Barr viral (EBV) DNA and anti-EBV capsid antigen IgA (IgA VCA) represent two of the most sensitive peripheral blood markers of nasopharyngeal carcinoma (NPC), but direct comparative studies of these two markers are lacking. ⋯ For diagnosis of NPC, EBV DNA identifies almost all false-negative IgA-VCA cases and gives a 99% diagnostic sensitivity when combined with IgA-VCA. In the screening setting, EBV DNA identifies three-fourths of false-positive IgA-VCA cases. The selective application of EBV DNA in an IgA-VCA-based screening protocol could improve screening accuracy with only moderate increases in cost.
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Cardiac troponin I (cTnI) is a more specific and sensitive biomarker than creatine kinase MB (CKMB) for detection of myocardial damage. We report the prevalence of positive cTnI and CKMB mass among patients hospitalized with suspected acute coronary syndrome (ACS) and the potential impact of use of different reference cutoffs, particularly those proposed by European Society of Cardiology/American College of Cardiology (ESC/ACC) consensus guidelines, on rates of diagnosis of acute myocardial infarction (AMI). ⋯ Use of lower reference cutoffs for plasma biomarkers, as recommended by ESC/ACC guidelines, markedly increases the rates of cTnI-positive cases overall. A substantial proportion of the increase in total cTnI-positive cases was derived from the creation of additional cTnI-positive/CKMB-negative cases. CKMB-positive/cTnI-negative cases are likely false positive for myocardial injury.