title: Is the determination of specific IgE against components using ISAC 112 a reproducible technique?
abstract: BACKGROUND
  The ImmunoCAP ISAC 112 is a fluoro-immunoassay that allows detection of specific IgE to 112 molecular components from 51 allergenic sources. We studied the reliability of this technique intra- and inter- assay, as well as inter-batch- and inter-laboratory-assay.
  
  
  METHODS
  Twenty samples were studied, nineteen sera from polysensitized allergic patients, and the technique calibrator provided by the manufacturer (CTR02). We measured the sIgE from CTR02 and three patients' sera ten times in the same and in different assays. Furthermore, all samples were tested in two laboratories and with two batches of ISAC kit. To evaluate the accuracy of ISAC 112, we contrasted the determinations of CTR02 calibrator with their expected values by T Student test. To analyse the precision, we calculated the coefficient of variation (CV) of the 15 allergens that generate the calibration curve, and to analyse the repeatability and the reproducibility, we calculated the intraclass coefficient correlation (ICC) to each allergen.
  
  
  RESULTS
  The results obtained for CTR02 were similar to those expected in 7 of 15 allergens that generate the calibration curve, whereas in 8 allergens the results showed significant differences. The mean CV obtained in the CTR02 determinations was of 9.4%, and the variability of sera from patients was of 22.9%. The agreement in the intra- and inter-assay analysis was very good to 94 allergens and good to one. In the inter-batch analyse, we obtained a very good agreement to 82 allergens, good to 14, moderate to 5 allergens, poor to one, and bad to 1 allergen. In the inter-laboratory analyse, we obtained a very good agreement to 73 allergens, good to 22, moderate to 6 and poor to two allergens.
  
  
  CONCLUSIONS
  The allergen microarray immunoassay, ISAC 112, is a repeatable and reproducible in vitro diagnostic tool for determination of sIgE beyond the own laboratory.
authors: Department of Allergology and Clinical Immunology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: Rubén
authors: R
authors: Martínez-Aranguren
authors: Allergology Service, Complejo Hospitalario de Navarra, Pamplona, Spain.
authors: María T
authors: MT
authors: Lizaso
authors: Department of Allergology and Clinical Immunology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: María J
authors: MJ
authors: Goikoetxea
authors: Allergology Service, Complejo Hospitalario de Navarra, Pamplona, Spain.
authors: Blanca E
authors: BE
authors: García
authors: Department of Allergology and Clinical Immunology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: Paula
authors: P
authors: Cabrera-Freitag
authors: Department of Computer Architecture, Universidad de Málaga, Málaga, Spain.
authors: Oswaldo
authors: O
authors: Trellez
authors: Department of Allergology and Clinical Immunology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: María L
authors: ML
authors: Sanz
mesh_terms: D002138:Calibration; D015200:Fluoroimmunoassay / Q000379:methods*; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: D007073:Immunoglobulin E