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New test may help detect vitamin D deficiency earlier
By Nathan Gray, 27-Jan-2011

A new diagnostic vitamin D assay to be released in Europe may help to detect early deficiency, and could help to provide more accurate data for dieticians and researchers.

Developed by the diagnostic lab technology company Abbott to detect the amount of 25-hydroxy vitamin D, the ARCHITECT 25-OH Vitamin D is a new diagnostic test to measure levels of vitamin D in blood using an automated instrument system.

Abbot announced Conformité Européenne (CE) marking for the assay, which is intended for the assessment of 25-hydroxy vitamin D in human serum and plasma to determine vitamin D status, but added that currently the test is not approved for use in the US.

Abbot said the assay will provide a quick and accurate gauge of vitamin D status in blood samples – which may provide greater opportunities for preventive and therapeutic interventions in at risk populations.

D deficiency
“Vitamin D deficiency is recognized as a global health problem, and vitamin D supplementation should be considered for all people at risk of vitamin D deficiency,” said Dr Jean-Claude Souberbielle, of the Université Paris.

He added that determination of the serum vitamin D concentration and supplementation according to the measured deficiency level is important for patients with osteoporosis, chronic kidney disease, abnormalities in absorbing food nutrients, and more generally, in those with a disease or a treatment that may impair bone health.

The UK National Institute of Health (NiH) said that whilst testing for levels of 25-hydroxy vitamin D is currently the most accurate way to determine vitamin D levels, many assays that are used can be notoriously inaccurate.
“As a major diagnostic lab, serum 25-OH vitamin D has become an increasingly important diagnostic marker to us,” said Dr. Frans AL van der Horst, from the Reinier de Graaf Group, Netherlands.

Brian Blaser, senior vice president, diagnostic operations for Abbott said that the new vitamin D assay is “a valuable and convenient addition” which provides an automated test for samples that may previously have been sent to outside reference labs.

http://www.nutraingredients.com/Industr ... cy-earlier

Abbott Cleared to Sell Automated Vitamin D Assay in EU as Controversy Continues to Simmer
Abbott can now sell its Architect 25-OH vitamin D immunoassay in the EU.

The fully automated test is designed to quantitatively determine 25-hydroxy vitamin D in human serum and plasma.

Ubiquitous and controversial, vitamin-D testing will continue to grow in coming years if researchers continue to tie vitamin-D deficiency to new health threats.
Worldwide demand for vitamin D testing has seen a "dramatic surge" in recent years, in the words of Washington G-2 Reports, and is believed to be growing by half each year, even in developed nations such as those in the EU.

For instance, vitamin D is required for calcium metabolism, which is essential for ageing Baby Boomers to maintain bone density. And as the number of Boomers continues to grow, so, too will orders for vitamin D testing.

In addition, recent studies have linked vitamin D deficiency to increased risk of breast and colon cancers; heart attacks in men; multiple sclerosis; psoriasis and other autoimmune disorders; diabetes; hypertension; depression; schizophrenia; and Parkinson’s disease.

As a result, "laboratories are seeing a surge in the number of vitamin D tests that are ordered as well as the variety of physicians ordering the test," said G-2 Reports.

Abbott is therefore betting that labs that see this trend will be lured to its automated Architect platform. The platform's throughput could also cut the need for send-outs, which, as I wrote last month, have been on the rise in recent years.

Serum 25-OH vitamin D testing "has become an increasingly important diagnostic marker to us," Frans AL van der Horst, manager of the Diagnostic Center SSDZ in Delft, The Netherlands, said in an Abbott press release announcing the CE Mark.

"There has been a great need for a reliable and cost effective assay," he added. Abbott's assay "can fulfill these needs and significantly improve the efficiency of the workflow in our routine lab."

But the increasing list of disorders and diseases tied to vitamin D deficiency — G-2 Reports has called it "hype" — has also spawned controversy over monitoring protocols.

A number of assays have been developed for 25-hydroxy vitamin D testing, including those based on high-pressure liquid chromatography, mass spectrometry, and, like Abbott's test, immunoassays.

The result is that "many general practitioners and internal medicine physicians are confused by which vitamin D test to order," said G-2 Reports. "While no one is certain if or when this market will peak or if this trend will endure, vitamin D is certainly the test du jour until a new test comes along."

Abbott's 25-OH vitamin D assay is not available in the US, but a 510(k) submission "should be done in the coming weeks," a company spokesperson told me this morning

http://www.genomeweb.com/blog/abbott-cl ... ues-simmer

Genetic factors affecting serum 25(OH)D concentrations
Healthcare News | January 24, 2011

Researchers recently identified two genes, CYP2R1 and GC, that appear to play an important role in regulating serum 25(OH)D (25-hydroxy vitamin D) concentration, which is an indicator of vitamin D status, in healthy white individuals.

The investigators explained that vitamin D deficiency is related to a number of bone diseases, such as osteoporosis. They noted that genetic factors have been shown to affect serum 25(OH)D levels, but the genes that contribute to the wide variation in these levels have not been elucidated.

To examine the association between genes and variations in 25(OH)D concentration, the researchers conducted a cross-sectional discovery study in which they evaluated nine prominent gene candidates, and then they performed a replication study in a separate cohort to confirm the results.

The discovery cohort included 156 healthy, unrelated, non-Hispanic white adults. Nine candidate genes were selected for assessment, all of which have demonstrated in prior studies involvement with synthesizing, transporting or degrading vitamin D or activating downstream signaling pathways for vitamin D. The candidate genes were screened using 49 SNP (single nucleotide polymorphism) markers, and 46 were successfully genotyped and used for the analysis.

After adjusting for potential confounding factors, including age, sex, body mass index, vitamin D supplementation and the time of year blood was collected, the analysis revealed that six SNPs—four in the CYP2R1 gene (cytochrome P450, family 2, subfamily R, polypeptide 1) and two in the GC gene (vitamin D binding protein)—were significantly associated with serum 25(OH)D levels.

For the replication study, a separate cohort of 340 healthy, unrelated, non-Hispanic white adults was used to evaluate the six SNPs identified in the discovery study. Using the same statistical methodology as in the discovery study, the researchers reported that the findings of the replication study's association analyses showed that two of the SNPs in the CYP2R1 gene were confirmed as being significantly associated with serum 25(OH)D levels, while one of the SNPs in the GC gene was confirmed to be marginally, although still statistically significantly, associated with these levels.

A pooled analysis using participants from both the discovery and replication cohorts (n=496) revealed that several of the SNPs of the CYP2R1 and GC genes remained significantly associated with serum 25(OH)D concentration.

Regarding the study findings, the investigators emphasized the importance of confirming them in other healthy populations and other races.

The data were published in the November issue of the journal Human Genetics

http://www.medical.siemens.com/webapp/w ... _10001.htm

Siemens to Offer Fully Automated Total Vitamin D Assay on ADVIA Centaur® Systems
Laboratories can meet the increased demand for Vitamin D testing with precise, consistent results in as little as 18 minutes

Deerfield, Ill., January 27, 2011– Siemens Healthcare Diagnostics ADVIA Centaur Vitamin D Total assay* has been CE-marked for use on the ADVIA Centaur/XP Immunoassay Systems. The company is offering a fully automated Vitamin D total assay that is traceable to LC-MS/MS (liquid chromatography-mass spectrometry), considered the gold standard in vitamin D testing. In addition, the assay measures the total 25-hydroxyvitamin D [25(OH)D] level (~100% D2 and D3) to ensure patients are correctly evaluated for deficiency, sufficiency or toxicity.

Vitamin D deficiency has long been associated with rickets in children and osteomalacia in adults, and long-term insufficiency of calcium and vitamin D leads to osteoporosis. More recently, studies are linking vitamin D deficiency to several other disease states such as cancer, cardiovascular, diabetes and autoimmune diseases1. At the same time, deficiency rates are increasing with over 1 billion people being vitamin D deficient worldwide2 as people limit their sun exposure due to the risk of skin cancer. As deficiency rates continue to rise – and support continues to build for vitamin D sufficiency as a general health indicator – so too has the demand for vitamin D testing.

A number of studies have reported discrepancies between assays used to measure vitamin D. This variability calls into question the assay’s ability to accurately identify individuals affected by vitamin D deficiency3. Siemens Vitamin D Total assay measures a patient’s total 25(OH) vitamin D level—~100% of D2 and D3, the two major forms of vitamin D. The most widely used indicator of vitamin D status is the measurement of the metabolite 25-hydroxyvitamin D in either serum or plasma. Because circulating 25(OH) D can arise from hydroxylation of either vitamin D2 or D3, measurement of total 25(OH) D (both D2 and D3) is essential for accurate assessment of vitamin D status3.

“As testing volumes continue to increase, laboratories need to feel confident they can meet that demand with an accurate, reliable Vitamin D assay,” said David Hickey, CEO, Chemistry, Immunoassay, Automation & Diagnostics IT Business Unit, Siemens Healthcare Diagnostics. “The ADVIA Centaur Vitamin D Total assay enables laboratories to have it all—precise, consistent results with a turnaround time in as little as 18 minutes.”

http://www.medical.siemens.com/webapp/w ... _10001.htm

Measuring Vitamin D Total
http://webcast.streamlogics.com/custom_ ... 300&lh=900

ADVIA Centaur® Vitamin D Total Assay
Sample Type Serum / Plasma (EDTA, lithium-heparin, sodium heparin)
Sample Volume 20 µL
Assay Range 3.7 - 150 ng/mL
Limit of Detection 3.20 ng/mL
Functional Sensitivity 3.33 ng/mL

http://www.medical.siemens.com/webapp/w ... Id=1038516