title: A technical and clinical evaluation of a new assay for inhibin A and its use in second trimester Down syndrome screening.
abstract: BACKGROUND
  The objective of the study was to compare a new AutoDELFIA® Inhibin A kit (B064-102) with the Access Inhibin A kit (A36097) using clinical specimens and to evaluate the AutoDELFIA® Inhibin A assay performance in screening for Down syndrome in the second trimester of pregnancy.
  
  
  METHODS
  Using clinical samples, we performed a method comparison between new and existing inhibin A kits and assessed AutoDELFIA® Inhibin A kit precision performance. Normal median values for the second trimester of pregnancy were also determined. Finally, we evaluated the screening performance of the AutoDELFIA® Inhibin A kit together with other second trimester biomarkers for the detection of Down syndrome.
  
  
  RESULTS
  The two methods showed a high degree of correlation (r=0.99, Pearson and Spearman correlation), and the average relative level difference between the methods at a concentration range of 41.7-1925 pg/mL was 19.6% [95% confidence interval (CI) from 17.6% to 21.5%]. The acceptable precision of the AutoDELFIA® Inhibin A kit was demonstrated: the within-lot CV% varied from 1.9% to 3.9%. The screening performance results show that AutoDELFIA® Inhibin A when added to a combination of other second trimester serum markers [human alpha foetoprotein (hAFP), free beta subunit of human chorionic gonadotropin (free hCGβ) and unconjugated estriol (uE3) or hAFP and free hCGβ] improves the detection rate of screening in both combinations.
  
  
  CONCLUSIONS
  The performance of the AutoDELFIA® Inhibin A assay is highly acceptable for routine laboratory use for screening Down syndrome in the second trimester of pregnancy.
authors.forename: Georgina
authors.initials: G
authors.lastname: Wilson
authors.forename: Päivi
authors.initials: P
authors.lastname: Liitti
authors.forename: Tuukka
authors.initials: T
authors.lastname: Pölönen
authors.forename: Mikko
authors.initials: M
authors.lastname: Sairanen
authors.forename: Kevin
authors.initials: K
authors.lastname: Spencer
mesh_terms: D000293:Adolescent; D000328:Adult; D004314:Down Syndrome / Q000097:blood* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007265:Inhibins / Q000097:blood*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000097:blood*; D011296:Prenatal Diagnosis
chemical_list: C422362:inhibin A; D007265:Inhibins