Functional vitamin D derivatives and method of determining 25-hydroxy- and 1α, 25-dihydroxy vitamin D
AssigneesImmundiagnostik AG, Biomedica GmbH
InventorsFranz Paul Armbruster, Wolfgang Voelter, Jens Tampe, Christian Birkmayer
Life of this patent
Estimating the term…
Abstract
The preparation of vitamin D compounds of formula (I) with a label attached to a spacer group in the 3 position is disclosed. In the above formula (I), O represents the oxygen atom of an ether group; Y represents hydrogen or hydroxy; A represents a label such as biotin, digoxigenin, or another vitamin D group; R represents a substituted hydrocarbon side-group of vitamin D or a vitamin D metabolite. Also disclosed is a method of measuring 25-hydroxy vitamin D metabolite and a 1α,25-dihydroxy vitamin D metabolite in a sample.
Claims11
A method of measuring the amount of 1α,25-dihydroxy vitamin D in human serum using a competitive protein binding assay, comprising:
- i) separating 25-hydroxy vitamin D from 1α,25-dihydroxy vitamin D by binding 1α,25-dihydroxy vitamin D in a sample of the human serum to a material that binds 1α,25-dihydroxy vitamin D and eluting 1α,25-dihydroxy vitamin D from said material to provide a measurement sample,
- ii) measuring the displacement of a vitamin D derivative of formula (I) from an antibody that specifically binds 1α,25-dihydroxy vitamin D by adding an amount of the measurement sample to an amount of the antibody having the vitamin D derivative of formula (I) bound thereto,
- wherein:
- R represents a 25-hydroxylated side-group of vitamin D2 or of vitamin D3, and Y represents hydroxy;
- and
- iii) correlating the measurement of displacement of the vitamin D derivative of formula (I) from said antibody by 1α,25 dihydroxy-vitamin D present in the measurement sample to a measurement of displacement of the vitamin D derivative of formula (I) from the antibody by a known quantity of the 1α,25-dihydroxy vitamin D to determine the amount of 1α,25-dihydroxy vitamin D in the sample.
A kit for determining the concentration of 1α,25-dihydroxy vitamin D in a sample of human serum by an immune-based competitive protein binding assay, comprising a standardized quantity of a solid vitamin D derivative of formula (I) or a standardized solution of a vitamin D derivative of formula (I),
- wherein R represents a 25-hydroxylated side-group of vitamin D2 or of vitamin D3, and Y represents hydroxy;
- a standardized quantity of an antibody that specifically binds 1α,25-dihydroxy vitamin D;
- and a known quantity of 1α,25-dihydroxy vitamin D,
- so that the displacement of the vitamin D derivative of formula (I) from said antibody as effected by the 1α,25-dihydroxy vitamin D present in the measurement sample can be correlated to the displacement of the vitamin D derivative of formula (I) from said antibody as effected by the addition of a known quantity of the 1α,25-dihydroxy vitamin D to determine the amount of 1α,25-dihydroxy vitamin D present in human serum.
Dependencies are inferred from the claim text.