title: Glycogen phosphorylase BB in acute coronary syndromes.
abstract: The diagnosis of myocardial damage is preferably based on measurement of the cardiac-specific troponins. However, there is an emerging need for early, specific cardiac markers. One potential candidate is the glycogen phosphorylase BB isoenzyme (GPBB). We investigated the use of a new, commercially available GPBB ELISA assay in 61 patients presenting with an acute coronary syndrome (37 acute myocardial infarction, 24 unstable angina pectoris) in comparison to established cardiac markers such as troponin T, creatine kinase isoenzyme MB (CKMB) mass, and myoglobin. Blood samples were obtained on arrival, as well as 1, 2, 3, 4, 8, 12 and 24 h later. GPBB plasma concentrations were elevated in 90.9% of patients 1 h after onset of chest pain and increased to 100% at 4-5 h. Within the first 6 h, GPBB showed the highest sensitivity (95.5-100%) and high specificity (94-96%) compared to myoglobin (85-95% sensitivity) and CKMB mass (71.4-91.3% sensitivity). As expected, troponin T showed high specificity (100%) and sensitivity >95% later in the time course (>or=3 h). In un-stable angina pectoris patients, a very high rate of elevated GPBB was observed (93.9% at 3 h) compared to myoglobin (66.7%). Cardiac troponin T and CKMB were only elevated in 33.8% and 55.0% of these patients, respectively. In conclusion, GPBB is a promising marker for the early diagnosis of acute coronary syndromes and could probably act as a marker of ischemia. However, further studies on specificity and development of a fast, automated assay are necessary before GPBB can be recommended as a routine diagnostic tool.
authors.affiliation: Institute of Clinical Chemistry and Laboratory Medicine, Department of Internal Medicine, Johannes Gutenberg-University, Mainz, Germany. peetz@zentrallabor.klinik.uni-mainz.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Peetz
authors.forename: Felix
authors.initials: F
authors.lastname: Post
authors.forename: Helmut
authors.initials: H
authors.lastname: Schinzel
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Schweigert
authors.forename: Caroline
authors.initials: C
authors.lastname: Schollmayer
authors.forename: Katrin
authors.initials: K
authors.lastname: Steinbach
authors.forename: Francesco
authors.initials: F
authors.lastname: Dati
authors.forename: Franz
authors.initials: F
authors.lastname: Noll
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Lackner
mesh_terms: D000208:Acute Disease; D000328:Adult; D000787:Angina Pectoris / Q000097:blood* / Q000175:diagnosis / Q000201:enzymology; D015415:Biomarkers; D003327:Coronary Disease / Q000097:blood*; D052279:Creatine Kinase, MB Form / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis / Q000201:enzymology; D009211:Myoglobin / Q000097:blood; D010763:Phosphorylase b / Q000097:blood*; D012680:Sensitivity and Specificity; D013997:Time Factors; D020107:Troponin T / Q000097:blood
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D009211:Myoglobin; D020107:Troponin T; D010763:Phosphorylase b; D052279:Creatine Kinase, MB Form