title: Verification of an immunoturbidimetric assay for heart-type fatty acid-binding protein (H-FABP) on a clinical chemistry platform and establishment of the upper reference limit.
abstract: BACKGROUND
  Heart-type fatty acid-binding protein (H-FABP) is an early biomarker of cardiac injury. Randox Laboratories developed an immunoturbidimetric H-FABP assay for non-proprietary automated clinical chemistry analysers that could be useful in the emergency department. We verified the analytical performances claimed by Randox Laboratories on Roche Cobas 6000 clinical chemistry platform in use in our laboratory, and we defined our own 99th percentile upper reference limit for H-FABP.
  
  
  METHODS
  For the verification of method performances, we used pools of spared patient samples from routine and two levels of quality control material, while samples for the reference value study were collected from 545 blood donors. Following CLSI guidelines we verified limit of blank (LOB), limit of detection (LOD), limit of quantitation (LOQ), repeatability and within-laboratory precision, trueness, linearity, and the stability of H-FABP in EDTA over 24h.
  
  
  CONCLUSIONS
  The LOQ (3.19 μg/L) was verified with a CV% of 10.4. The precision was verified for the low (mean 5.88 μg/L, CV=6.7%), the medium (mean 45.28 μg/L, CV=3.0%), and the high concentration (mean 88.81 μg/L, CV=4.0%). The trueness was verified as well as the linearity over the indicated measurement interval of 0.747-120 μg/L. The H-FABP in EDTA samples is stable throughout 24h both at room temperature and at 4 °C. The H-FABP 99th percentile upper reference limit for all subjects (3.60 μg/L, 95% CI 3.51-3.77) is more appropriate than gender-specific ones that are not statistically different.
authors.affiliation: Department of Laboratory Medicine, University Milano-Bicocca, Vimercate Hospital, Vimercate, MB, Italy. Electronic address: simona.damolin@gmail.com.
authors.forename: Simona
authors.initials: S
authors.lastname: Da Molin
authors.affiliation: Department of Laboratory Medicine, University Milano-Bicocca, Desio Hospital, Desio, MB, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Cappellini
authors.affiliation: Department of Laboratory Medicine, University Milano-Bicocca, Desio Hospital, Desio, MB, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Falbo
authors.affiliation: Department of Laboratory Medicine, University Milano-Bicocca, Desio Hospital, Desio, MB, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Signorini
authors.affiliation: Department of Laboratory Medicine, University Milano-Bicocca, Desio Hospital, Desio, MB, Italy; Department of Experimental Medicine, School of Medicine, University Milano-Bicocca, Milano, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Brambilla
mesh_terms: D015415:Biomarkers / Q000097:blood*; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; C493408:FABP3 protein, human; D000074026:Fatty Acid Binding Protein 3; D050556:Fatty Acid-Binding Proteins
keywords: 99th percentile upper reference limit; Acute myocardial infarction (AMI); Analytical evaluation; Heart-type fatty acid-binding protein (H-FABP); Immunoturbidimetric assay