Combination of CRP and D-dimer for in vitro diagnosis of deep venous thrombosis (DVT)
View Patent ↗The present invention relates to an in vitro diagnostic method for patients with suspected deep venous thrombosis wherein by combined testing of patients' samples for D-dimer and CRP both the sensitivity and the negative predictive value of DVT diagnostics can be increased up to 100%.
1. A method for the diagnostic exclusion of the presence of deep venous thrombosis (DVT) in a patient at risk, comprising:
(a) testing of a liquid sample from said patient with a reagent for the detection of D-dimer;
(b) evaluating the test result:
(i) if the D-dimer concentration is found to be equal to or above a predefined cut-off value, DVT is not excluded with said patient;
(ii) if the D-dimer concentration is found to be below the said cut-off value, performing further testing according to (c):
(c) testing of a liquid sample from said patient with a reagent for the detection of C-reactive protein (CRP);
(d) evaluating the test result: if the CRP-concentration is found below a predefined cut-off value, DVT is excluded with said patient.
2. The method according to claim 1 , wherein the liquid sample is serum, plasma or whole blood.
3. The method according to claim 1 , wherein the reagents for the detection of D-dimer and for the detection of CRP are immunoassays.
4. The method according to claim 3 , wherein the reagents for the detection of D-dimer and for the detection of CRP independently of each other are based on test principles chosen from: ELISA, turbidimetry, nephelometry, particle enhanced turbidimetry, particle enhanced nephelometry, and latex agglutination.
5. The method according to claim 1 , wherein the predetermined cut-off value for D-dimer concentration is approximately 0.5 mg/I, and wherein the detection of D-dimer comprises a particle enhanced turbidimetric assay.
6. The method according to claim 1 , wherein the predetermined cut-off value for CRP concentration is approximately 4 mg/I, and wherein the detection of CRP comprises a particle enhanced nephelometric assay.
7. The method according to claim 1 , wherein the predetermined cut-off value for D-dimer concentration is approximately 0.5 mg/I, and wherein the detection of D-dimer comprises a particle enhanced turbidimetric assay, and further, wherein the predetermined cut-off value for CRP concentration is approximately 4 mg/I, and wherein the detection of CRP comprises a particle enhanced nephelometric assay.