Andrew Ellis1, John Seth, Ruth Al-Sadie, Julian H Barth. 1. United Kingdom National Quality Assessment Scheme for Peptide Hormones, Department of Clinical Biochemistry, Royal Infirmary, Edinburgh EH3 9YW, UK. ukneqas@ed.ac.uk
Abstract
INTRODUCTION: Measurement of serum growth hormone (GH) concentration in response to insulin-induced hypoglycaemia remains an important investigation in the assessment of pituitary disease. METHODS: In this audit, laboratories were presented with aliquots of sera with GH concentrations likely to be found in an insulin stress test (IST). They were invited to analyse the specimens for GH and comment on their results. RESULTS AND DISCUSSION: A number of laboratories appeared to be using out-of-consensus cut-off concentrations that sometimes were unrelated to the bias of their GH assay. The specimens were chosen to mimic those seen in an IST that was clearly not indicative of GH deficiency, so there was reasonable consensus in the interpretation of results. However, five laboratories (9.6%) did indicate that their results were equivocal.
INTRODUCTION: Measurement of serum growth hormone (GH) concentration in response to insulin-induced hypoglycaemia remains an important investigation in the assessment of pituitary disease. METHODS: In this audit, laboratories were presented with aliquots of sera with GH concentrations likely to be found in an insulin stress test (IST). They were invited to analyse the specimens for GH and comment on their results. RESULTS AND DISCUSSION: A number of laboratories appeared to be using out-of-consensus cut-off concentrations that sometimes were unrelated to the bias of their GH assay. The specimens were chosen to mimic those seen in an IST that was clearly not indicative of GH deficiency, so there was reasonable consensus in the interpretation of results. However, five laboratories (9.6%) did indicate that their results were equivocal.