IFCC EuroMedLab 2017

Educational Seminars

active B12
 

The Value of Active b12

June 12, 2017
Speaker

Dr Dominic Harrington
Head of the Nutristasis Unit, Scientific Director for Viapath (Guy’s and St. Thomas’ Hospitals), and Reader in Diagnostic Haematology at King’s College London

Abstract

Vitamin B12 (B12) deficiency is common. Risk factors include restricted dietary intake of animal products, impaired gastric absorption, loss or inactivity of Intrinsic factor (Addisonian perniciousanaemia), pancreatic insufficiency, impaired intestinal absorption (e.g. ileal resection in Crohn disease), multiple congenital factors and acquired drug effects. The prompt detection and correction of B12-deficient states prevents megaloblastic anaemia and potentially irreversible neuropathy and neuro-psychiatric changes.

B12 status is typically assessed by measuring the total abundance of B12 in serum. However this test has low sensitivity, and when used in isolation, up to 45% of deficient patients may be overlooked. Moreover, the National Health Service Atlas of Variation in Diagnostic Services (Nov 2013) shows that the number of serum B12 tests ordered is five times greater in some parts of England compared with others. This degree of variation appears to be greater than can be explained in the prevalence of B12 deficiency, and in part may relate to local protocols, e.g. some may stipulate that B12 status is only to be evaluated when haematological indices indicate megaloblastic change. Crucially, ~20% of B12-deficient patients show no discernable haematological diathesis. Existing strategies may delay the diagnosis of B12 deficiency. In a recent survey of 889 members of the Pernicious Anaemia Society, 304 individuals experienced symptoms of the disorder for up to a year before a diagnosis; 193 for two years; 173 for five years; and 40 patients for ten years or more.

Serum B12 assays measure the sum of haptocorrin- and transcobalamin-bound (known as holotranscobalamin) yet it is only holotranscobalamin that is taken up by cells to meet metabolic demand (Active B12). Receiver operator characteristic curves show Active B12 measurement to be a moderately more reliable marker of B12 status than serum. Diagnostic utility is enhanced further when Active B12 is used in combination with a laboratory B12 status marker, such as methylmalonic acid or total homocysteine, that reflect the cellular utilisation of adenosylcobalamin and methylcobalamin respectively. Sequential assay selection algorithms or the combination of multiple markers into a single diagnostic indicator are both approaches that can be used to mitigate inherent limitations of each marker when used independently.

 

 
Learning Objectives 

The laboratory has a central role in the health care system, and often provides critically important information to the health care professional. In this symposium, Dr. Harrington will discuss Active B12 (holotranscobalamin) which is increasingly recognized as an improved marker for B12 deficiency. B12 deficiency is a relatively common but poorly characterized and often difficult to diagnose condition. Currently the typical first test used to look for deficiency is Total B12. There is growing evidence that a relatively new marker, Active B12, may be a better test and can aid in the diagnosis of B12 deficiency. Dr. Harrington  will look at how the selection of the most relevant assay and the performance of those assays can have an impact on the ability of health care professionals to assess patients and hence on patient care.

 
Who Should Attend 

Clinicians

Laboratorians

Metabolic Specialists

HbA1c Method
 

Approaches to Achieve Measurably Better Health Care Performance

What is the impact of analytical performance of an HbA1c Method on Clinical Practice?

June 12, 2017
Speaker

Dr. Erna Lenters-Westra, Isala, The Netherlands
European Reference Laboratory for Glycohemoglobin

Abstract

The central importance of HbA1c in monitoring glycemic control was highlighted by the Diabetes Control and Complications Trial (DCCT) and the UK Prospective Diabetes Study (UKPDS). These trials showed that improved glycemic control, as monitored by HbA1c, delayed the onset of diabetic complications. The publication of these trials has resulted in a large increase in the number of HbA1c requests received by clinical laboratories, and high quality methods for HbA1c measurement were required to ensure accurate assessment of the glycemic status. The lack of international standardization resulted in the development of National Standardization Programs in several countries and the effect of these standardization programs was that the inter laboratory precision (CV) decreased from 30% before 2003 to ± 3.5% in 2017. A few years ago, HbA1c was advocated as a diagnostic marker for diabetes, as a result of global standardization of the HbA1c assay, and major improvements in analytical performance of different HbA1c methods were made by manufacturers. But how good should an HbA1c method be? And what is the impact of precision and bias on clinical practice? 

In general, it is assumed that when an HbA1c method has a manufacturer National Glycohemoglobin Standardization Program (NGSP) certification, the analytical performance is adequate. Given the fact that even HbA1c assays with poor analytical performance seen in external quality schemes are certified, such an assumption should be challenged. 

The laboratory has a central role in the health care system, and often provides critically important information to the health care professional. In this symposium Dr. Erna Lenters-Westra will discuss HbA1c test analytical performance and its impact on clinical practice.

 

 

 

 
Learning Objectives

Diabetes is a chronic disease affecting an increasing proportion of the population. A cornerstone of the diagnosis and management of diabetes is the HbA1c assay. The accuracy and precision of the HbA1c assay can now be assessed compared to a reference method measurement. Some HbA1c assays have improved precision and accuracy compared to other assays; it has become clear that these differences can impact decisions made in the care of the patient. 

In our reference laboratory, the analytical performance of different HbA1c methods, including point-of-care and laboratory methods, were investigated using certified CLSI protocols. Furthermore, the interpretation of HbA1c values among different health care professionals was investigated which produced, in combination with the outcome of the evaluation studies, remarkable results.

Dr. Erna Lenters-Westra looks at how the performance of HbA1c can have an impact on the ability of health care professionals to assess patients, and hence, on patient care.

Who Should Attend

Laboratorians

Endocrinologists

Clinicians

Metabolic Specialists

You are about to exit the Abbott family of websites for a 3rd party website

Links which take you out of Abbott worldwide websites are not under the control of Abbott, and Abbott is not responsible for the contents of any such site or any further links from such site. Abbott is providing these links to you only as a convenience, and the inclusion of any link does not imply endorsement of the linked site by Abbott. The website that you have requested also may not be optimised for your screen size.

Do you wish to continue and exit this website?

Yes No

You are about to enter an Abbott country or region specific website.

Please be aware that the website you have requested is intended for the residents of a particular country or countries, as noted on that site. As a result, the site may contain information on pharmaceuticals, medical devices and other products or uses of those products that are not approved in other countries or regions.

Do you wish to continue and enter this website?

Yes No

You are about to enter an Abbott country or region specific website.

Please be aware that the website you have requested is intended for the residents of a particular country or countries, as noted on that site. As a result, the site may contain information on pharmaceuticals, medical devices and other products or uses of those products that are not approved in other countries or regions.

Do you wish to continue and enter this website?

Yes No

DO YOU WISH TO CONTINUE AND EXIT THE CORE LABORATORY WEBSITE?

Content is not under the control of corelaboratory.abbott.

Yes No