title: Validation of commercial assays for measurements of trefoil factor family peptides in serum.
abstract: BACKGROUND
  Trefoil peptides (TFF1, TFF2 and TFF3) are 7-12 kDa molecules, secreted by mucin-producing epithelial cells. Increased serum concentrations have been reported in a number of pathological conditions, which warrants the need for validated commercially available assays.
  
  
  METHODS
  We validated commercial assays for TFF1-3 and compared results obtained with our in-house assays, using serum from blood donors.
  
  
  RESULTS
  Level of detection was: ≤ 0.008 nmol/L. Measuring ranges were: 0.032-0.51 (TFF1), 0.038-0.76 (TFF2) and 0.019-0.15 (TFF3) nmol/L. Imprecision (CV), judged from the measurement of serum pools in two levels, was below 9% (TFF2 and TFF3) but up to 18% (mean 0.41 nmol/L) for TFF1. No cross reactivity between the TFFs (concentrations > 100 nmol/L) was observed. The 95% non-parametric reference intervals were: <0.0032-0.53 (TFF1), 0.099-1.4 (TFF2) and 0.086-0.87 (TFF3) nmol/L. Comparing commercial to in-house assays (n=132), showed biases explained by differences in the calibrators (TFF1 and TFF2). A number of samples showed markedly different results.
  
  
  CONCLUSIONS
  The commercial assays for TFF2 and TFF3 are acceptable for use on serum samples, while the TFF1 assay revealed a poor imprecision and a too narrow measuring range. Results obtained with the commercial and the in-house assays differed, partly because of differences in the calibrators employed.
authors.affiliation: Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark. mie.samson@dadlnet.dk
authors.forename: Mie H
authors.initials: MH
authors.lastname: Samson
authors.forename: Ebba
authors.initials: E
authors.lastname: Nexo
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D010455:Peptides / Q000097:blood*; D011933:Reagent Kits, Diagnostic; D000071163:Trefoil Factor-1; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3; D025521:Tumor Suppressor Proteins / Q000097:blood*
chemical_list: D010455:Peptides; D011933:Reagent Kits, Diagnostic; C051838:TFF1 protein, human; C082495:TFF3 protein, human; D000071163:Trefoil Factor-1; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3; D025521:Tumor Suppressor Proteins