July 27, 2017
Growth hormone standardisation Minimize

Growth hormone standardisation

The diagnosis of disorders of growth hormone (GH) secretion is based on the measurement of GH before and after dynamic tests. Over the years, specific cut-off values have been proposed without reference to the considerable variation in results due to different methods for analysing GH. These analytical factors were reported in a meeting held at the National Institute for Biological Standards and Control (NIBSC) in 2000. One of the conclusions was that the recombinant DNA derived standard (IS 98/574) should replace the pituitary derived standard IS 80/505.

The key issue with IS 80/505 is that it is defined in IU but has no assigned mass value. This has led to factors between 2 and 3 being used to convert mass to U. The lack of transparency in this conversion has clearly contributed to the confusion over definitions of GH deficiency.

The more recent IS 98/574 is a recombinant preparation with defined physico-chemical characteristics and an assigned value of 3.0 U/mg. This will enable reporting of GH results in μg/L or mU/L of IS 98/574; such that values expressed in μg/L will be one third of the same value expressed in mU/L.

In 2006, major clinical endocrinology journals advised submitting authors that they would only accept GH data submitted in μg/L of IS 98/574.

References

  • Standardisation of human growth hormone (hGH) assays. http://www.birminghamquality.org.uk/DLopen/nibscgh.pdf  accessed 17 July 2008
  • Sheppard MC. Growth hormone assay standardization: an important clinical advance. Clin Endocrinol 2007;66:157–161.
  • Wieringa, JH Barth, P Trainer. Growth hormone assay standardisation: a biased view? Clin Endocrinol 2004;60:538-539.
  • Barth JH, Sibley PE. Standardisation of the IMMULITE systems Growth Hormone assay standardised with the recombinant IS 98/574. Ann Clin Biochem 2008; in press

JHB 17 July 2008

  

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