Five commercially available insulin-like growth factor I (IGF-I) assays in comparison to the former Nichols Advantage IGF-I in a growth hormone treated population.
Krebs, Alexander Wallaschofski, Henri Spilcke-Liss, Elisabeth Kohlmann, Thomas Brabant, Georg E Völzke, Henry Nauck, Matthias
Krebs, Alexander
Wallaschofski, Henri
Spilcke-Liss, Elisabeth
Kohlmann, Thomas
Brabant, Georg E
Völzke, Henry
Nauck, Matthias
Citations
Altmetric:
Abstract
BACKGROUND: The serum insulin-like growth factor I (IGF-I) level is accepted to diagnose the growth hormone (GH) status. Here, we evaluated the DRG IGF-I 600 ELISA, DSL IGF-I ELISA, IDS OCTEIA IGF-I, Mediagnost IGF-I-ELISA, and the Siemens Immulite 2500 IGF-I in comparison to the former Nichols Advantage IGF-I assay. METHODS: Imprecision was determined by use of a serum pool and commercial control materials. Accuracy was evaluated by means of a method comparison to Nichols in 173 serum samples of GH deficient patients. RESULTS: The Siemens and the IDS IGF-I assays showed the lowest imprecision with coefficients of variation up to 3.6% and 6.9%, respectively. Both correlated best to Nichols (Siemens: y=0.667X+8.8 microg/L, r=0.950; IDS: y=0.527 X+4.6 microg/L, r=0.927) with the lowest dispersion of residuals from a linear equation. The DSL assay had the highest comparability to Nichols (y=1.000 X+35.5 microg/L, r=0.864), but with a considerable scattering. CONCLUSIONS: To yield IGF-I determination comparable to the former Nichols IGF-I, either the Siemens or the IDS assay should be applied, and the results should be converted by a linear method transformation. Where a conversion factor is not desired, the DSL assay should be selected.
Description
Date
2008
Publisher
Collections
Keywords
Evaluation
Growth Hormone Deficiency
Sensitivity
Specificity
Growth Hormone Deficiency
Sensitivity
Specificity
Type
Article
Citation
Five commercially available insulin-like growth factor I (IGF-I) assays in comparison to the former Nichols Advantage IGF-I in a growth hormone treated population. 2008, 46 (12):1776-83 Clin. Chem. Lab. Med.