title: Measurement of plasminogen activator inhibitor type 1 antigen: comparison of Tintelize and Imubind methods.
abstract: Our specific aim was to compare three plasminogen activator-inhibitor type 1 (PAI-1) antigen ELISA kit assays (the Biopool AB, Ltd, TintElize PAI-1 Strip-Well Format; the American Diagnostica, Inc., Imubind 822/1; and the second generation Imubind 822/1S). Within-run coefficients of variation (n = 6) for the TintElize, Imubind 822/1 and Imubind 822/1S methods were 5.5%, 5.9% and 6.8%, respectively. Between-run coefficients of variation for six aliquots per run were 2.9% for TintElize, 3.8% for Imubind 822/1, and 3.5% for Imubind 822/1S. Comparison of the average of duplicate aliquots from hyperlipidaemic patients demonstrated intraclass correlations of 0.75, 0.79 and 0.95 for TintElize vs Imubind 822/1 (n = 39), TintElize vs Imubind 822/1S (n = 39), and Imubind 822/1 vs 822/1S (n = 84), respectively. Lower 95% confidence interval limits of the intraclass correlation were 0.55, 0.48 and 0.93, respectively. Mean PAI-1 antigen values (n = 39) were 12.1, 15.8, 15.8 and 16.0 ng/ml, respectively, for TintElize, TintElize without using the quenching well, Imubind 822/1, and Imubind 822/1S. All three methods were easily performed and exhibited high correlation and reproducibility. A significant systematic bias (P < 0.006) existed between TintElize and TintElize without using the quenching well, Imubind 822/1, and Imubind 822/1S. However, there was no significant bias when TintElize without using the quenching well is compared with Imubind 822/1 (P > 0.8) and to 822/1S (P > 0.8) nor is there significant systematic bias between Imubind 822/1 and 822/1S (P > 0.3). By convention, interchangeability between assay methods suggests that the lower limit of the 95% intraclass correlation confidence interval be greater than 0.75.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Ohio.
authors.forename: D M
authors.initials: DM
authors.lastname: Stroop
authors.forename: C J
authors.initials: CJ
authors.lastname: Glueck
authors.forename: T M
authors.initials: TM
authors.lastname: Tracy
authors.forename: H R
authors.initials: HR
authors.lastname: Schumacher
mesh_terms: D003365:Costs and Cost Analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000191:economics / Q000592:standards / Q000706:statistics & numerical data*; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D011933:Reagent Kits, Diagnostic / Q000706:statistics & numerical data; D012016:Reference Values; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D011933:Reagent Kits, Diagnostic