Release reagent for vitamin d compounds

Abstract

A reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein and an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition as well as the reagent mixture obtained in this manner. Also disclosed is the use of the reagent compositions to release vitamin D compounds as well as a kit for detecting a vitamin D compound.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 14 / 277,359 filed May 14, 2014, which is a continuation of International Application No. PCT / EP2012 / 072569 filed Nov. 14, 2012, which claims the benefit of European Patent Application No. 11189736.9 filed Nov. 18, 2011, the disclosures of which are hereby incorporated by reference in their entirety.BACKGROUND INFORMATION[0002]The present invention concerns a reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein, an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition and the reagent mixture obtained in this manner. It also concerns the use of the disclosed reagent composition to release vitamin D compounds as well as a kit for detecting a vitamin D compound which contains the reagent composition for releasing vitamin D...

AI Technical Summary

Benefits of technology

The patent describes a method for detecting vitamin D compounds using a special reagent. The reagent contains a hydrogen carbonate salt and a substance that releases hydrogen carbonate ions when it comes into contact with water. When the reagent is mixed with the vitamin D compound, the pH of the mixture increases, causing a reaction that destroys the vitamin D compound. The detecting reagent also contains a reducing agent that helps produce a colored compound when it comes into contact with the vitamin D compound. To prevent the reducing agent from causing other reactions, the mixture is further incubated with unspecific proteins to remove any remaining reducing power. This method allows for a non-compromised detection of vitamin D compounds using a specific binding agent.

Problems solved by technology

Measuring the vitamin D level itself is of little benefit when determining the vitamin D status of a patient, because concentrations of vitamin D (vitamin D2 and vitamin D3) fluctuate greatly depending on food uptake or exposure to sunlight.

In addition vitamin D has a relatively short biological half-life in the circulation (24 hours) and it is therefore also for this reason not a suitable parameter for determining the vitamin D status of a patient.

The binding of 25-hydroxyvitamin D or other vitamin D compounds to the vitamin D-binding protein enormously complicates the determination of vitamin D compounds.

Despite immense efforts in recent years, all available methods for determining vitamin D have disadvantages such as laborious sample preparation, poor standardization, poor agreement between test procedures or bad recovery of spiked vitamin D (see for this in particular Zerwekh, J. E., supra).

It is particularly difficult to automate a test for a vitamin D compound.

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