Endocrine Abstracts

Introduction: Plasma metanephrines (PMETS) are widely used as a first-line investigation for phaeochromocytoma/paraganglioma owing to the high diagnostic sensitivity of the test. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become the methodology of choice for measuring PMETS due to the high analytical specificity of the technique. However, there have been recent reports of interference in LC-MS/MS PMETS assays by the α1-recept...

Introduction: Plasma metanephrines (PMETS) are widely used as a first-line investigation for phaeochromocytoma/paraganglioma owing to the high diagnostic sensitivity of the test. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become the methodology of choice for measuring PMETS due to the high analytical specificity of the technique. However, there have been recent reports of interference in LC-MS/MS PMETS assays by the α1-recept...

Background: Enzalutamide is a next-generation androgen receptor (AR) antagonist, used as a daily oral agent, in the treatment of castration-resistant prostate cancer. Its suppression of 11β-hydroxysteroid dehydrogenase-2 enzyme has been reported in the literature, leading to hypertension through a relative increase in cortisol concentration at the level of the mineralocorticoid receptors. Enzalutamide is also known to be a potent inducer of drug metabolising enzymes (cyto...

Background: Diagnostic work-up for Cushing ’s syndrome (CS) can be challenging, with variable performance characteristics on screening tests. We were recently referred a young female patient with Cushing’s disease (CD) due to a microadenoma. She presented with a seizure and initial biochemical work-up included a Synacthen stimulation test (SST). Her peak cortisol rose to over 1,000 nmol/l. Exaggerated response during SST is expected in hyperestrogenic states due to e...

Background: A range of laboratory tests are available for investigation of phaeochromocytoma/paraganglioma (PPGL) and there is scope for significant variation in practice between centres. Endocrine Society Clinical Practice Guidelines make recommendations concerning the laboratory investigation of PPGL. We performed a national audit using these recommendations as audit standards.Methodology: A questionnaire was distributed to all clinical biochemistry de...

Introduction: Copeptin is the C-terminal fragment of proAVP and secreted in equimolar amounts with AVP. While AVP is unstable in vitro and has proved difficult to measure in clinical practice, copeptin is relatively stable and can be measured using an automated immunoassay. Therefore copeptin measurement offers potential as a more practical alternative to the direct measurement of AVP in the investigation of polyuria/polydipsia.Methods: AVP, cop...

Introduction: Measurement of plasma metanephrines (PMETS) is widely regarded as one of the best screening tests for phaeochromocytoma/paraganglioma (P/PGL). Current Endocrine Society guidelines recommend that samples for PMETS are ideally collected in the supine position after 30 min rest and interpreted using supine reference ranges, in order to optimise the diagnostic performance of the test. Current practice in our centre is to collect samples for PMETS from seated patients...

Background: Many adolescents and young adults with DMD receive long-term glucocorticoids (GC), a well-recognised cause of hypogonadotrophic hypogonadism. Pubertal induction is routinely offered to DMD adolescents in our centre but few individuals remain on supplementation into adulthood and it is unclear whether these men have age-appropriate endogenous testosterone production. Salivary testosterone (SalT) measurement is available but has not been used to assess androgen statu...

Objective: The 250 µg short Synacthen stimulation test (SST) is the most commonly used dynamic assessment to diagnose adrenal insufficiency (AI). There are challenges to the use of the SST in routine clinical practice, including staff and resource limitation in the current COVID-19 pandemic and Synacthen cost. We aimed to investigate the value of basal cortisol level for predicting AI in our selected cohort of patients at risk of secondary adrenal insufficiency from pitui...

Introduction: Copeptin is the C-terminal fragment of proAVP and provides an alternative measure of AVP secretion. While direct measurement of AVP during hypertonic saline infusion has been recommended as a diagnostic test for diabetes insipidus (DI), the number of reports examining the utility of copeptin in this context is limited. Here we describe a series of cases where measurement of copeptin during saline infusion has contributed to ...