First 25-hydroxyvitamin D assay for general chemistry analyzers

Abstract

25-Hydroxyvitamin D [25(OH)D], the predominant circulating form of vitamin D, is an accurate indicator of the general vitamin D status of an individual. Because vitamin D deficiencies have been linked to several pathologies (including osteoporosis and rickets), accurate monitoring of 25(OH)D levels is becoming increasingly important in clinical settings. Current 25(OH)D assays are either chromatographic or immunoassay-based assays. These assays include HPLC, liquid chromatography-tandem mass spectrometry (LC-MS/MS), enzyme-immunosorbent, immunochemiluminescence, immunofluorescence and radioimmunoassay. All these assays use heterogeneous formats that require phase separation and special instrumentations. In this article, we present an overview of these assays and introduce the first homogeneous assay of 25(OH)D for use on general chemistry analyzers. A special emphasis is put on the unique challenges posed by the 25(OH)D analyte. These challenges include a low detection limit, the dissociation of the analyte from its serum transporter and the inactivation of various binding proteins without phase separation steps.

Circulating 25-hydroxycholecalciferol in Relationship to Central Dual-Energy X-Ray Absorptiometry Assesses. A clinical study

“…The levels of total/ionic calcium and phosphorus were similar between the groups. The levels of bone turnover Blood levels of 25OHD represent a major tool for assessment of vitamin D status in humans and current assays are for total 25OHD (meaning free 25OHD and molecules attached to transporter binding proteins, both albumin and globulin called vitamin D binding protein or VDBP) [16][17][18]. New data point the importance of switching to free component assessment (based on a immunoassay method) but this did not become a routine test yet [19][20][21].…”

Comparison of two different methods for routine 25(OH)D measurement in paediatric serum samples

“…Currently, a wide spectrum of different methods used for evaluation of vitamin D status is available. There are manual and automated immunoassays, methods of direct detection such as HPLC and LC-MS/MS, and recently a new developed enzyme-immunosorbent assay was adapted on general chemistry analysers [11]. Most commercially available automated immunoassays for 25(OH)D measurement use immunochemiluminescence technology.…”

“…The growing need for 25(OH)D testing forced most of the laboratories to implement fast and accurate tests for routine evaluation of vitamin D status. The Federal Drug Administration from early the 2000s approved the first fully automated immunoassay method for 25(OH) D measurement [11]. Lately a new homogenous assay measuring 25(OH)D was adapted on general chemistry analysers.…”

“…Lately a new homogenous assay measuring 25(OH)D was adapted on general chemistry analysers. This new approach is based on the principle of a-complementation of the b-galactosidase enzyme and reaction of the competition between an enzyme donor-25(OH)D conjugate, an anti-vitamin D antibody www.journals.viamedica.pl/medical_research_journal and the 25(OH)D in the blood [11]. This method was fully validated for the use on several chemistry analysers [11].…”

“…This new approach is based on the principle of a-complementation of the b-galactosidase enzyme and reaction of the competition between an enzyme donor-25(OH)D conjugate, an anti-vitamin D antibody www.journals.viamedica.pl/medical_research_journal and the 25(OH)D in the blood [11]. This method was fully validated for the use on several chemistry analysers [11]. Our study aimed to assess the performance of two different methods, one available on an immunoassay automated system and the other on a general chemistry system, for measurement of 25(OH)D in children.…”