title: The harmonisation of growth hormone measurements: taking the next steps.
abstract: For over 20 years differences in results of growth hormone (GH) measurement have been recognised as being significant enough to lead to misdiagnosis and inappropriate management of patients with GH-related disorders. Whilst issues of method standardisation, variable antibody specificity, use of different reporting units with different conversion factors, and interference from GH binding protein have been acknowledged as contributing to the discrepancies, inconsistent approaches to method harmonisation have hampered opportunities to enhance the evidence base for GH measurements. Amongst the first steps to be taken, international collaboratives recommended the universal adoption of the International Standard 98/547 and the reporting of results in mass units. Whilst inter-method variability may have improved over the last 10 years, clinically significant differences remain. A more recently recognised issue contributing to the discrepancies may be the differences in the matrix materials used by kit manufacturers to assign values to their calibrants. The establishment of an international harmonisation oversight group is recommended: its key roles to include identification of a commutable matrix reference material, assessing the clinical significance of assay interferents, the evaluation of liquid chromatography-mass spectrometry as a reference measurement procedure and the provision of acceptance criteria for the clinical application of GH methods.
authors: Department of Biochemistry, Bolton NHS Foundation Trust, Minerva Road, Farnworth, Bolton BL4 0JR, UK. Electronic address: gilbert.wieringa@boltonft.nhs.uk.
authors: Gilbert E
authors: GE
authors: Wieringa
authors: UK NEQAS [Edinburgh], Department of Laboratory Medicine, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK.
authors: Catharine M
authors: CM
authors: Sturgeon
authors: Department of Endocrinology, The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, UK.
authors: Peter J
authors: PJ
authors: Trainer
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods* / Q000592:standards*; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D012015:Reference Standards
chemical_list: D019382:Human Growth Hormone
keywords: Growth hormone; Harmonisation collaboratives; Method differences