A novel assay for cobalt-albumin binding and its potential as a marker for myocardial ischemia-a preliminary report.
We initially observed a phenomenon of reduced in vitro binding of exogenous cobalt [Co(II)] to the N-terminus of human serum albumin (HSA) in emergency chest pain patients with early onset unstable angina and myocardial infarction. We then developed a colorimetric assay to measure cobalt-HSA binding and record the results in absorbance units (ABSU). In a preliminary clinical study of 139 emergency patients with acute chest pain, 99 patients with evidence of myocardial ischemia (Group 1) had elevated assay levels (mean ABSU +/- SD; 0.519 +/- 0.086) compared to 40 patients (Group 2) with no evidence of ischemia (0.316 +/- 0.092) (p < 0.00001). In Group 1, 95 of 99 (96.0%) patients had levels higher than a decision threshold of 0.400 ABSU and in Group 2, 37 of 40 (92.5%) samples had higher cobalt binding capacity (ABSU </= 0.400). Further studies are warranted to determine if an assay measuring altered cobalt-HSA binding is a clinically useful diagnostic test to rule out myocardial ischemia.
Bar-Or
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D
Department of Trauma Research, Swedish Medical Center, Englewood, Colorado 80110, USA.
Lau
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Winkler
J V
JV
D000368:Aged; D001665:Binding Sites; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002637:Chest Pain / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D003035:Cobalt / Q000378:metabolism; D003124:Colorimetry / Q000379:methods*; D003663:Decision Trees; D004638:Emergency Treatment / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000150:complications / Q000175:diagnosis*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012709:Serum Albumin; D013997:Time Factors
D015415:Biomarkers; D012709:Serum Albumin; D003035:Cobalt