The development of decision limits for the implementation of the GH-2000 detection methodology using current commercial insulin-like growth factor-I and amino-terminal pro-peptide of type III collagen assays

Erotokritou-Mulligan, Ioulietta, Guha, Nishan, Stow, Michael, Bassett, E. Eryl, Bartlett, Christiaan, Cowan, David A., Sonksen, Peter H. and Holt, Richard I. G. (2012) The development of decision limits for the implementation of the GH-2000 detection methodology using current commercial insulin-like growth factor-I and amino-terminal pro-peptide of type III collagen assays. Growth Hormone and IGF Research, 22 (2), 53-58. (doi:10.1016/j.ghir.2011.12.005). (PMID:22305721)

Abstract

Background: The GH-2000 project developed a method for detecting GH misuse based on the measurement of insulin-like growth factor-I (IGF-I) and the amino-terminal pro-peptide of type III collagen (P-III-NP). The objective
of this study was to develop decision limits for the GH-2000 score to detect GH misuse in elite athletes using two currently available commercial assays for each analyte.

Study design: Subjects: 404 male (mean age 23.9 yrs, range 12–37 yrs) and 94 female elite athletes (mean age 24.5 yrs, range 18–34 yrs) participated. Blood samples were collected according to World Anti-Doping Agency (WADA) guidelines at various sporting events including 238 samples collected as part of the UK Anti- Doping Testing Programme.

Laboratory analysis: IGF-I was measured by Siemens Immulite IGF-I assay and Immunotech A15729 IGF-IIRMA. P-III-NP was measured by RIA-gnost P-III-P and the UniQ™ PIIINP RIA.

Statistical analysis: The GH-2000 score decision limits were developed through the analysis of the elite athlete samples.

Results: For males and females separately, the distributions of GH-2000 scores were consistent with Normal distributions. Using a specificity of 99.99% new decision limits were determined which included an allowance for uncertainty associated with calculations based on a finite sample size. One outlier was identified with results incompatible with normal physiology and tested positive with the current isoform GH test.

Conclusions: We have developed decision limits using currently available commercial assays to measure IGF-I and P-III-NP in elite athletes. This should allow the introduction of a test for GH misuse based on the measurement of these GH sensitive biomarkers.

This record has no associated files available for download.

Contributors

Author: Richard I. G. Holt

Download statistics