Immunoassay for C-reactive protein

• US 6,838,250 B2
• Filed: 03/29/2001
• Issued: 01/04/2005
• Est. Priority Date: 03/31/2000
• Status: Expired due to Term

• Current Assignee: Ortho-Clinical Diagnostics Incorporated (The Carlyle Group LP (Corporate Private Equity))
• Original Assignee: Ortho-Clinical Diagnostics Incorporated (The Carlyle Group LP (Corporate Private Equity))
• Inventors: Daiss, John L., Scalice, Edward R.
• Primary Examiner(s): Chin, Christopher L.
• Assistant Examiner(s): GRUN, JAMES LESLIE
• Application Number:
  US09/821,227
• Publication Number:
  US 20020142356A1
• Time in Patent Office: 1,377 Days
• Field of Search: 435/7.1, 435/7.92, 435/7.93, 435/70.21, 435/452, 435/327, 435/337, 435/965, 435/975, 436/518, 436/528, 436/548, 530/387.2, 530/388.25, 530/391.1
• US Class Current: 435/7.93
• CPC Class Codes: C07K 16/18 against material from animals or humans
• CPC Class Codes: C07K 16/4241 against anti-human or anti-animal Ig
• CPC Class Codes: G01N 2333/4737 C-reactive protein
• CPC Class Codes: G01N 33/68 involving proteins, peptides or amino acids involving lipoproteins G01N33/92
• CPC Class Codes: G01N 33/686 Anti-idiotype
• CPC Class Codes: Y10S 435/965 involving idiotype or anti-idiotype antibody
• CPC Class Codes: Y10S 435/975 Kit

Abstract

The present invention relates to new CRP immunoassay compositions. The compositions include a low affinity anti-human CRP monoclonal antibody, and an antiidiotypic antibody raised against it. The invention further provides a method for obtaining antiidiotypic monoclonal antibody populations directed to an antibody that is specific for a high concentration, high molecular weight target antigen.

Claims

1. A method for performing a competitive immunoassay for detecting C-reactive protein in a sample containing an amount of C-reactive protein comprising:

contacting the sample with an immobilized, a low affinity anti-human C-reactive protein antibody and a labeled antiidiotypic antibody, wherein the labeled antiidiotypic antibody binds to the anti-human C-reactive protein antibody and inhibits binding to the C-reactive protein.

ii. detecting the label, and

iii. correlating the detection of the label with the amount of C-reactive protein in the sample.

3. The method of claim 1 wherein the low affinity anti-human C-reactive protein antibody is CRP5-23 monoclonal antibody produced by a hybridoma deposited as PTA-1354.

2. A method for performing a competitive immunoassay for detecting C-reactive protein in a sample containing an amount of C-reactive protein comprising:

i. contacting the sample with an immobilized antiidiotypic antibody and a labeled low affinity anti-human C-reactive protein antibody, wherein the antiidiotypic antibody binds to the labeled anti-human C-reactive protein antibody and inhibits binding to the C-reactive protein,

ii. detecting the label, and

iii. correlating the detection of the label with the amount of C-reactive protein in the sample.

4. The method of claim 2 wherein the antiidiotypic antibody binds CRP5-23 monoclonal antibody produced by a hybridoma deposited as PTA-1354.

5. A kit for a competitive immunoassay comprising:

a first antibody wherein said first antibody is a low affinity anti-human C-reactive protein antibody and a second antibody wherein said second antibody is an antiidiotypic antibody which binds to said first antibody and inhibits binding of C-reactive protein to said first antibody.

6. A hybridoma cell line, identified as CRP5-23 and deposited as PTA-1354, capable of producing a low affinity anti-human C-reactive protein monoclonal antibody.

7. An antibody produced by the hybridoma of claim 6.

8. The antibody of claim 7 wherein said antibody is insensitive to ionized calcium.

9. A purified, isolated antiidiotypic antibody raised against a low affinity anti-human C-reactive protein antibody, which is capable of binding to CRP5-23 with relatively high affinity (Kd <

10<sup>−

8</sup>M), and its binding to CRP5-23 is mutually exclusive with binding of C-reactive protein.

10. A hybridoma cell line, identified as C23id2-6.3 and deposited as PTA-1353, capable of producing an antiidiotypic monoclonal antibody.