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CN-122011192-A - Abnormal prothrombin antibody or conjugate thereof and application thereof

CN122011192ACN 122011192 ACN122011192 ACN 122011192ACN-122011192-A

Abstract

The invention relates to the technical field of antibodies, in particular to an abnormal prothrombin (PIVKA-II) antibody or a conjugate thereof and application thereof. The antibody or the conjugate thereof comprises a heavy chain variable region VH and a light chain variable region VL, wherein the amino acid sequences of HCDR1, HCDR2 and HCDR3 of the heavy chain variable region VH are respectively shown as SEQ ID No. 1-3, the amino acid sequences of LCDR1, LCDR2 and LCDR3 of the light chain variable region VL are respectively shown as SEQ ID No. 4-5, and the antibody conjugate is coupled with a marker or a solid phase carrier by the antibody. The antibody provided by the invention has high binding activity and affinity to PIVKA-II, and can be used for detecting the specificity, sensitivity, reliability and accuracy of trace PIVKA-II in a sample in a double-antibody sandwich mode.

Inventors

  • YANG QIWEN
  • CHU XIAOBING
  • SONG WANYING
  • ZHU YING
  • CHEN YAO
  • LIU YUWEI

Assignees

  • 中国医学科学院北京协和医院
  • 中元汇吉生物技术股份有限公司

Dates

Publication Date
20260512
Application Date
20260108

Claims (10)

  1. 1. A monoclonal antibody of PIVKA-II or a conjugate thereof, the antibody or conjugate thereof comprising a heavy chain variable region VH comprising: HCDR1 with the amino acid sequence shown as SEQ ID No. 1; HCDR2 with the amino acid sequence shown in SEQ ID No. 2; HCDR3 with the amino acid sequence shown in SEQ ID No. 3; the light chain variable region VL comprises: LCDR1 with the amino acid sequence shown in SEQ ID No. 4; LCDR2 with the amino acid sequence shown in SEQ ID No. 5; LCDR3 with the amino acid sequence shown in SEQ ID No. 6; the antibody conjugate is coupled by the antibody to a label or a solid support.
  2. 2. The monoclonal antibody or conjugate thereof of claim 1, wherein the heavy chain variable region VH of said antibody or conjugate thereof is an amino acid sequence having at least 90% identity to SEQ ID NO.7 and the light chain variable region VL of said antibody or conjugate thereof is an amino acid sequence having at least 90% identity to SEQ ID NO. 8.
  3. 3. The monoclonal antibody or conjugate thereof according to claim 1 or 2, wherein the antibody is a full-length antibody or an antigen-binding fragment thereof, and wherein the antigen-binding fragment is at least one member selected from the group consisting of a Fab fragment, a F (ab') 2 fragment, an Fv fragment, a dsFv fragment, an scFv fragment and an sc (Fv) 2 fragment and a Diabody (Diabody).
  4. 4. The monoclonal antibody or conjugate thereof according to claim 1 or 2, wherein the antibody is a full-length antibody, the heavy chain amino acid sequence of which is shown in SEQ ID NO.9, and the light chain amino acid sequence of which is shown in SEQ ID NO. 10.
  5. 5. The monoclonal antibody or conjugate thereof according to claim 1 or 2, wherein the label is selected from one or more of an enzyme label, a biotin label, a fluorescent dye label, a chemiluminescent dye label, a nanoparticle label, and a radiolabel, and the solid support is selected from one or more of a microsphere, a plate, and a membrane.
  6. 6. A PIVKA-II detection reagent or kit comprising an antibody or conjugate thereof according to any one of claims 1-5.
  7. 7. The assay kit according to claim 6, wherein the reagent or kit comprises a capture reagent and an assay reagent, wherein each of the capture reagent and the assay reagent comprises an antibody or conjugate thereof to PIVKA-II of a different sequence, and wherein the antibody or conjugate thereof to PIVKA-II is selected from the antibody or conjugate thereof according to any one of claims 1 to 5.
  8. 8. The use of an antibody or conjugate thereof according to any one of claims 1-5 for the preparation of a PIVKA-II product.
  9. 9. A method for detecting PIVKA-II for non-diagnostic purposes, comprising the steps of forming an immune complex with an antigen in a sample using the antibody or conjugate thereof according to any one of claims 1-5, and detecting the presence or amount of the immune complex.
  10. 10. A nucleic acid molecule expressing the antibody of any one of claims 1-5, or a vector or host cell comprising said nucleic acid molecule.

Description

Abnormal prothrombin antibody or conjugate thereof and application thereof Technical Field The invention relates to the technical field of antibodies, in particular to an antibody of abnormal prothrombin or a conjugate thereof and application thereof. Background Abnormal prothrombin, also known as vitamin K deficiency or antagonist-induced protein-II (PIVKA-II) or desgamma-carboxyprothrombin (DCP). This is an abnormal protein without coagulation function which is produced in the case of vitamin K deficiency, malabsorption or hepatocellular carcinoma. In 1984, liebman et al reported for the first time in New England medical journal that abnormal prothrombin was detected in 91% of the serum of hepatocellular carcinoma (HCC) patients, with average concentrations as high as 900 ng/mL, but very low or undetectable levels in chronic active hepatitis, metastatic liver cancer and healthy people. This finding lays the foundation of using it as liver cancer marker. Under normal conditions, the liver carboxylates the prothrombin precursor with gamma-glutamyl carboxylase in the presence of vitamin K to produce normal prothrombin with clotting functions. When vitamin K is deficient, malabsorption or hepatocellular carcinoma, the carboxylation process is hindered, resulting in the release of abnormal prothrombin without coagulation function into the blood. The clinical significance of PIVKA-II is (1) that the sensitivity of single detection and diagnosis of hepatocellular carcinoma (HCC) is about 60-74%, the specificity is 89-90%, the PIVKA-II positive rate can reach 50% for small liver cancer with the diameter of less than 20 mm, the 20-30 mm focus positive rate is about 60%, the value in early screening is shown, the sensitivity of AFP early liver cancer is only 10-20%, and the PIVKA-II sensitivity can reach 90%. The combined detection of the two can improve the diagnosis sensitivity to 78-84%, the specificity reaches 98.5%, the diagnosis sensitivity is obviously superior to that of a single marker, and (2) the curative effect evaluation and recurrence monitoring are that the PIVKA-II level of an effective person is rapidly reduced after surgical excision, intervention or targeted treatment, and the recurrence or transfer is increased again. The continuous monitoring can find the recurrence sign at early stage, the serum half-life is only 40-72 hours, is far shorter than 5-7 days of AFP, and can reflect the treatment change more quickly, and (3) the prognosis judgment is that the pre-PIVKA-II level is obviously related to the postoperative survival rate and the tumor-free survival period. The higher the level, the worse the prognosis, the higher the risk of intrahepatic metastasis and portal vein invasion frequently associated with PIVKA-II positive patients, and (4) liver function assessment, in benign liver diseases such as hepatitis, cirrhosis, etc., PIVKA-II can be slightly elevated due to impaired hepatocyte synthesis function, assisting in assessing liver reserve function. PIVKA-II is used as an important serum marker with high specificity and rapid response in liver cancer diagnosis and treatment, has the value of overcoming the defect of insufficient AFP sensitivity, performing overlay diagnosis, evaluating curative effect, prognosis judgment and accurate complementation of recurrence monitoring, and can maximize diagnosis efficiency by being applied in combination with AFP and AFP-L3%. However, the performance of the current detection antibodies against PIVKA-II does not meet the clinical detection reagent requirements well. Disclosure of Invention In order to solve the technical problems, the monoclonal antibody for PIVKA-II detection, the kit and the application thereof are provided, the antibody has high binding activity and affinity to PIVKA-II, and the specificity, sensitivity, reliability and accuracy detection of trace PIVKA-II in a sample can be realized in a double-antibody sandwich mode. The invention is realized by the following technical scheme: In a first aspect the invention provides a monoclonal antibody to PIVKA-II or a conjugate thereof, the antibody or conjugate thereof comprising a heavy chain variable region VH comprising: HCDR1 with the amino acid sequence shown as SEQ ID No. 1; HCDR2 with the amino acid sequence shown in SEQ ID No. 2; HCDR3 with the amino acid sequence shown in SEQ ID No. 3; the light chain variable region VL comprises: LCDR1 with the amino acid sequence shown in SEQ ID No. 4; LCDR2 with the amino acid sequence shown in SEQ ID No. 5; LCDR3 with the amino acid sequence shown in SEQ ID No. 6; the antibody conjugate is coupled by the antibody to a label or a solid support. In a specific embodiment of the invention, the heavy chain variable region VH of the antibody or conjugate thereof is an amino acid sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identity to SEQ ID No. 7. In a specific embodiment of the invention, the light chain variable regio