ACBI and ACB-NI Scientific Meeting - Belfast.
Friday, 30 April 2010 Radisson SAS Hotel, The Gasworks, Belfast
By Dr Brona Roberts Belfast Health and Social Care Trust.
The ACB (Northern Ireland Region) and the Association of Clinical Biochemists in Ireland recently held their joint annual spring meeting in the Radisson Hotel, Belfast. As usual there was a good turnout from laboratories both North and South, and we also welcomed a few visitors from across the water. The event was generously sponsored primarily by Roche but also by Abbott, Biomedical Systems, Fannin, Medicon, MSD, Randox, Siemens, Takeda, ThermoFisher and Ulster Anaesthetics.
First speaker of the day was Dr Peter Sharpe, on the enormous public health problem that is Type 2 diabetes. He emphasised the importance of optimal control particularly in the early years of this disease, which appears to carry a long-term benefit even if intensive treatment cannot be maintained indefinitely. He described some of the new agents that have been added to our antidiabetic armoury in the last decade, notably the GLP-1 receptor agonists (exenatide and liraglutide) and the DPP-IV inhibitors (sitagliptin, vildagliptin and saxagliptin), and directed us to the NICE guidelines of 2009 for how these might be incorporated into clinical practice.
Dr Sharpe was followed by Professor Garry John, who continued the diabetic theme discussing the pros and cons of using of HbA1c to diagnose Type 2 diabetes, as has already been endorsed “in principle” by the American Diabetes Association. The advantages are that HbA1c has less intra-individual biological variability than fasting glucose, does not require a fasting sample and is unaffected by delay in sample separation. The disadvantages are that HBA1c has worse analytical variability than glucose and that the relationship between plasma glucose and HbA1c may be altered by a number of factors such as age, ethnicity, iron deficiency and the presence of haemoglobin variants. According to Professor John, many people who meet the WHO glucose criteria for diabetes will be missed if the proposed cut-off of 6.5% is used to rule out diabetes. His conclusion seemed to be that HbA1c is useful for diagnosis when used in addition to, not instead of, glucose.
Next was Dr Maria Fitzgibbon, who outlined some biochemical tests that may be undertaken in suspected endocrine hypertension, using a case history of a young man with hypertension and an adrenal mass. She recommended the use of the aldosterone/renin ratio for primary aldosteronism, with the appropriate assay-specific units, and warned against the use of serum potassium as an indicator of the presence or absence of hyperaldosteronism. For suspected phaeochromocytoma, plasma or urinary metanephrines are better than urinary catecholamines, if available, and a “hypertensive” range rather than a “normal” range of values should be used for reference.
The final speaker before lunch was Ms Vicki Barwick from the laboratory services company LGC, discussing the measurement of uncertainty. This topic surely lies close to the heart of any clinical biochemist, though, as she pointed out, it would be helpful if more reference materials were available in order for us to quantify the uncertainty of our results.
After an excellent lunch in honour of our retiring members Professor Denis Alexander, Dr Paul Boreland, Professor Terry Lappin, Dr Hugh O’Neill, Mr Brian Sheridan, and Dr Tim Wyatt, Professor Peter Maxwell took us through the history of erythropoietin prescribing. This drug revolutionised the management of anaemia in people with end-stage kidney disease, and more recently has found other uses in the management of less severe anaemias associated with chronic disease of any sort, including earlier stages of kidney disease. However, the evidence for benefit in these conditions is surprisingly lacking and indeed there is some evidence that erythropoietin may actually reduce survival in cancer patients. Erythropoietin is so well established in the management of dialysis patients, and so obviously improves their quality of life, that it seems unlikely that any placebo-controlled trial will ever take place. However, the recent TREAT study which compared darbepoetin with placebo in the management of moderate anaemia associated with Stage 3-4 kidney disease showed no survival benefit but an increased risk of stroke in the active treatment arm. The message was clear: evidence-based medicine is the order of the day, especially when using new, expensive drugs with potentially huge markets. Dr Jack Barr then stimulated a different area of our brains with reflections on art and microbiology, beginning with Canaletto and Holbein and moving on to the beauty that can be found in micro-organisms. Late on a Friday afternoon, the Venetian landscapes and colourful Streptomyces made a pleasant visual change from Powerpoint.
Just in case anybody was tempted to slip off before the final session, however, the organisers had given this slot to renowned local endocrinologist Professor Brew Atkinson. Professor Atkinson discussed the cyclical form of Cushing’s syndrome, which may occur with pituitary, adrenal or ectopic causes of cortisol excess and demands a high degree of clinical suspicion in the face of apparently normal results. Obviously, multiple 24-hr urine collections are impractical; he suggested instead 28 days of early-morning urine cortisol/creatinine ratios or salivary cortisols as a means of investigating a suspected intermittent Cushing’s. He ended by paying tribute to Brian Sheridan, now-retired head of the biochemistry service in Belfast, who devoted many years of work to the regional endocrine laboratory. He spoke of Brian as being “affable, available, astute and able” – a standard against which perhaps any biochemist could be measured.
The day over, we went our separate ways, educated, fed and perhaps inspired. Thank you and congratulations to our meetings secretary Derek McKillop on a job well done.