Use of 1,25-dihydroxyvitamin D values in ratio with PTH as a prognostic biomarker
The present invention relates to the use of 1,25-dihydroxyvitamin D values in ratio with PTH as a prognostic biomarker. More particularly, the present invention relates to a method for predicting or stratifying the risk of worsening renal function (WRF) in a patient at risk of renal injury or affected by renal injury. Levels of 1,25-dihydroxyvitamin D (1,25(OH) 2 D) are measured in a biological sample and taken together with parathyroid hormone (PTH) levels to provide a ratio indicative of the risk of worsening renal function.
1. A kit, being an article of manufacture, that comprises:
(A) a first container that contains:
(1) a Ligand Binding Domain of Vitamin D Receptor composed of residues 116-423 of the Ligand Binding Domain of Vitamin D Receptor from Rattus norvegicus with deletion of a 47 amino acid internal loop (165-211) (rVDR-LBD); and
(2) a monoclonal antibody, or epitope-binding fragment thereof, that specifically binds to a conformational epitope of rVDR-LBD when said rVDR-LBD is complexed with 1,25-dihydroxyvitamin D in serum or plasma or blood, and does not specifically bind to VDR-LBD or to 1,25-dihydroxyvitamin D that are not complexed with one another, wherein said monoclonal antibody, or said epitope-binding fragment thereof, comprise Heavy Chain CDR1, CDR2 and CDR3 Domains having, respectively, the sequences of SEQ ID NOs:1, 2 and 3, and Light Chain CDR1, CDR2 and CDR3 Domains having, respectively, the sequences of SEQ ID NOs:4, 5 and 6; and
(B) a second container that contains a detectably-labeled reagent capable of binding to parathyroid hormone (PTH).
2. The kit according to claim 1 , wherein said monoclonal antibody, or epitope-binding fragment thereof, that specifically binds to said conformational epitope of rVDR-LBD is immobilized to a solid support in said first container.
3. The kit according to claim 2 , wherein said solid support is a magnetic or paramagnetic bead.
4. The kit according to claim 1 , wherein said rVDR-LBD is detectably labeled with a fluorescent label, a chemiluminescent label, a radioactive label, an enzyme label, or a colorimetric label.
5. The kit according to claim 1 , wherein said monoclonal antibody, or said epitope-binding fragment thereof comprises a heavy chain variable domain that comprises the sequence of SEQ ID NO:7 and a light chain variable domain that comprises the sequence of SEQ ID NO:9.
6. The kit according to claim 1 , wherein said kit is a Reagent Integral that is a multi-chambered cartridge specially adapted for use in an automated analyzing device, wherein said first and second containers of said kit are Reagent Chambers of said Reagent Integral.
7. The kit according to claim 6 , wherein said monoclonal antibody, or said epitope-binding fragment thereof, of said Reagent Integral that specifically binds to said conformational epitope of rVDR-LBD is immobilized to a solid support in said first container.
8. The kit according to claim 7 , wherein said solid support is a magnetic or paramagnetic bead.
9. The kit according to claim 6 , wherein said rVDR-LBD of said Reagent Integral is detectably labeled with a fluorescent label, a chemiluminescent label, a radioactive label, an enzyme label, or a colorimetric label.
10. The kit according to claim 6 , wherein said Reagent Integral additionally comprises one or more Calibrator Chambers.
11. The kit according to claim 6 , wherein said monoclonal antibody, or said epitope-binding fragment thereof comprises a heavy chain variable domain that comprises the sequence of SEQ ID NO:7 and a light chain variable domain that comprises the sequence of SEQ ID NO:9.