title: Assessment of the nickel-albumin binding assay for diagnosis of acute coronary syndrome.
abstract: BACKGROUND
  Myocardial ischemia may alter the metal binding capacity of circulating serum albumin. Thus, the aim of this study was to describe an automated method to measure ischemia-induced alterations in the binding capacity of serum albumin for exogenous nickel, and to evaluate the diagnostic characteristics of this assay for the assessment of acute coronary syndrome (ACS) in patients presenting to the emergency room (ER) with acute chest pain.
  
  
  METHODS
  We assessed the concentrations of cardiac troponin I (cTnI), serum albumin, ischemia-modified albumin (IMA) measured by the cobalt-albumin binding assay (CABA), and by an automated nickel-albumin binding assay (NABA) in the following groups: ACS (n=63) and non-ischemic chest pain (NICP, n=26). Biochemical markers were determined in blood samples obtained from patients within 3 h of ER admission.
  
  
  RESULTS
  cTnI, CABA and NABA concentrations were higher in ACS group in comparison to the NICP group. A significant correlation between NABA and CABA was observed (r=0.5387, p<0.001). Areas under the curve for CABA and NABA were 0.7289 and 0.7582, respectively. Both CABA and NABA have the ability to discriminate patients with ACS. However, NABA has a slightly higher ability to discriminate ACS compared with CABA.
  
  
  CONCLUSIONS
  Patients with ACS have reduced nickel binding to human serum albumin, and NABA may have an important role as an early marker of myocardial ischemia, particularly in patients presenting to the ER with acute chest pain.
authors.affiliation: Laboratório de Bioquímica Clínica, Departamento de Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Sandra Huber
authors.initials: SH
authors.lastname: da Silva
authors.forename: Renata da Silva
authors.initials: Rda S
authors.lastname: Pereira
authors.forename: Bruna dos Santos
authors.initials: Bdos S
authors.lastname: Hausen
authors.forename: Cristiane
authors.initials: C
authors.lastname: Signor
authors.forename: Patrícia
authors.initials: P
authors.lastname: Gomes
authors.forename: Marli Matiko Anraku
authors.initials: MM
authors.lastname: de Campos
authors.forename: Rafael Noal
authors.initials: RN
authors.lastname: Moresco
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000175:diagnosis*; D000368:Aged; D001665:Binding Sites; D003035:Cobalt / Q000097:blood / Q000737:chemistry; D006801:Humans; D008875:Middle Aged; D009532:Nickel / Q000097:blood / Q000737:chemistry*; D012372:ROC Curve; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000032:analysis / Q000737:chemistry*
chemical_list: D012709:Serum Albumin; D003035:Cobalt; D009532:Nickel