Endocrine Abstracts

Mrs IP is a 79 year old lady with a past medical history of spleenic marginal zone lymphoma, diagnosed in 2007 and treated with chemotherapy. She has suffered two relapses but despite her diagnosis had remained generally quite fit and healthy until the recent issues. An IgM paraprotein was identified in the patient’s serum an December 2014.In April 2015 Mrs IP presented to her GP complaining of cramping symptoms overnight, especially marked in her h...

Heterophilic antibodies are human immunoglobulins with antigenic determinants directed against non-human species. These antibodies can interfere with the measurement of analytes in routine clinical laboratories, in particular in 2-site immunoassays. Skybio heterophilic blocking tubes-50 (HBT-50) are one way of overcoming this interference but, it has been reported (Sturgeon and Viljoen, Annals Clin Biochem, 2011, 48, 418), some samples may require two treatments to completely ...

Aims: To discover if the addition of DHEAS (dehydroepiandrosterone sulphate) and androstenedione aids diagnosis in GP patients with PCOS (polycystic ovary syndrome) as part of their differential diagnosis.Methods: Over two months our laboratory received seventy-nine female General Practice patients whose symptoms / signs led to a differential diagnosis including PCOS. Of these, nine had a raised total testosterone and twenty-seven had a raised free andro...

Introduction: Measurement of bloodspot 17-OHP is the current method of assessing hydrocortisone replacement in patients with congenital adrenal hyperplasia (CAH). Bloodspot 17-OHP has been measured in Southampton by LC–MS/MS since August 2011. Clinical observations of signs and symptoms of under- and over-treatment are equally as important.The aim of this audit was to assess whether the 17-OHP profile results are being appropriately used for adjustm...

Primary hyperaldosteronism ('Conn's syndrome') may have a prevalence as high as 10% in hypertensive patients, and in some cases there may not be obvious hypokalaemia. Recently the use of a single aldosterone/ renin ('A/R') ratio has been advocated as a screening test for Conn's, and less influence by anti-hypertensive drug therapy has been claimed.We have established a cut-off for ambulant A/R ratios of 25 ng/mU using the DPC'Coat-a-Count' aldosterone method and the Nichols 'A...

Background: Accurate measurement of serum cortisol is essential in the investigation of the HPA axis. It has been documented that routine immunoassays are liable to both under- and over-recovery leading to inaccurate results and subsequent inappropriate investigations. This study seeks to provide an up-to-date assessment of the accuracy of the major immunoassay platforms and compares results to a liquid chromatography–tandem mass spectrometry (LC–MS/MS) candidate ref...

Introduction: Adrenal insufficiency is rare in the neonatal period and if unrecognised may cause life-threatening circulatory collapse. The initial investigations taken at the time of presentation, and prior to the institution of hydrocortisone, are a key step in the diagnostic pathway, and aid the clinician to distinguish adrenal insufficiency from mineralocorticoid resistance or renal tubulopathy. A cortisol measurement at the time of illness is useful to evaluate the adrena...

Plasma and urine 18-hydroxycortisol ('18-OHF') measurements are helpful to discriminate primary hyperaldosteronism (Conn's syndrome) caused by adrenal hyperplasia (normal 18-OHF) from adrenal adenoma or glucocorticoid suppressible hyperaldosteronism ( raised 18-OHF). We have developed DELFIA time-resolved fluorescence assays for 18-OHF as a second-line biochemical investigation for patients with raised plasma aldosterone/ renin ratios. Following ether extraction, test samples ...

Background: NEQAS data demonstrate a divergence in bias of cortisol immunoassays over the last 10 years. Despite this, a serum cortisol of 50 nmol/l has been universally applied as the cut-off for the overnight dexamethasone suppression test (ONDST), the commonest screening test for Cushing’s syndrome.Aims: To assess the effect of assay bias on interpretation of the ONDST and determine the necessity for a method-specific cut-off.<p class="abstex...

Introduction and aims: The short Synacthen test (SST) is used to diagnose underactivity of the HPA axis, with a cortisol response <550 nmol/l at 30 min widely accepted as diagnostic of adrenal insufficiency. Earlier studies of the SST have shown variation in cortisol concentrations measured by different immunoassays, suggesting the need for method-specific cut-offs. We sought to define the cortisol response to Synacthen in healthy volunteers (HV) and establish method-speci...