Immunoassay of analytes in samples containing endogenous anti-analyte antibodies

• US 8,357,495 B2
• Filed: 04/24/2009
• Issued: 01/22/2013
• Est. Priority Date: 10/26/2006
• Status: Expired due to Fees

• Current Assignee: Abbott Laboratories Incorporated
• Original Assignee: Abbott Laboratories Incorporated
• Inventors: Mattingly, Phillip G., Adamczyk, Maciej, Brashear, Roy Jeffrey
• Primary Examiner(s): Cheu, Jacob
• Application Number:
  US12/429,592
• Publication Number:
  US 20090246800A1
• Time in Patent Office: 1,369 Days
• Field of Search: None
• US Class Current: 435/7.1
• CPC Class Codes: G01N 2800/24 Immunology or allergic disorders SLE G01N2800/104
• CPC Class Codes: G01N 33/54326 Magnetic particles
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding

Abstract

The disclosure provides among other things an assay method that compensates for the presence of endogenous antibodies, e.g., autoantibodies, which might otherwise compromise the measurement of an analyte in a biological sample. In one embodiment, this method entails the use of a two labeled entities: a labeled detection agent and a labeled species-specific antibody, wherein the labeled species-specific antibody is specific for the species from which the biological sample was obtained. Sample analyte is bound by the detection agent and any anti-analyte autoantibodies present in the sample. Analyte bound by autoantibodies is detected via the species-specific antibody, optionally labeled.

Claims

1. An immunoassay method for an analyte of interest in a biological sample that may contain endogenous anti-analyte antibodies, said method comprising:

(a) contacting a biological sample being tested for analyte with a capture agent affixed to a solid phase, wherein the capture agent binds analyte, under conditions sufficient for binding of the capture agent to analyte to form a solid phase-affixed capture agent/analyte complex, and;

(i) a detection agent that binds the analyte, under conditions sufficient for binding of the detection agent to any analyte present in the capture agent/analyte complex so as to form a solid phase-affixed detection agent/analyte/capture agent complex; and

(ii) a species-specific antibody, wherein the species-specific antibody is specific for the species from which the biological sample was obtained and specifically binds endogenous anti-analyte antibody, under conditions sufficient for specific binding of the species-specific antibody to any endogenous anti-analyte antibody present in the sample and bound to the capture agent/analyte complex so as to form a solid phase-affixed species-specific antibody/endogenous anti-analyte antibody/analyte/capture agent complex; and

(b) detecting analyte by detecting a signal from the solid phase-affixed complex(es) set forth in (a),

wherein the signal is positively correlated with the concentration of analyte present in the sample.

2. The immunoassay method of claim 1, wherein the detection agent and the capture agent bind to different sites on the analyte.

3. The immunoassay method of claim 1, wherein the detection agent and the species-specific antibody are labeled with the same label.

4. The immunoassay method of claim 1, wherein the biological sample is contacted with the detection agent and the species-specific antibody simultaneously.

5. The immunoassay method of claim 1, wherein the biological sample is contacted with the detection agent and the species-specific antibody sequentially.

6. The immunoassay method of claim 1, wherein the contacting of (a)(i) and/or (a)(ii) is carried out simultaneously with the contacting of the biological sample with the capture agent.

7. The immunoassay method of claim 1, wherein the contacting (a)(i) and/or (a)(ii) is carried out sequentially with the contacting of the biological sample with the capture agent.

8. An immunoassay method for an analyte of interest in a biological sample that may contain anti-analyte autoantibodies, said method comprising:

(a) contacting a biological sample being tested for the analyte with a capture agent affixed to a solid phase wherein the capture agent binds analyte, under conditions sufficient for binding of the capture agent to analyte to form a solid phase-affixed capture agent/analyte complex;

(b) contacting the biological sample with;

(i) a detection agent that binds the analyte under conditions sufficient for binding of the detection agent to any analyte present in the capture agent/analyte complex so as to form a solid phase-affixed detection agent/analyte/capture agent complex; and

(ii) a species-specific antibody, wherein the species-specific antibody is specific for the species from which the biological sample was obtained and specifically binds anti-analyte autoantibody, under conditions sufficient for specific binding of the species-specific antibody to any anti-analyte autoantibody bound to the capture agent/analyte complex so as to form a solid phase-affixed species-specific antibody/anti-analyte autoantibody/analyte/capture agent complex; and

(c) detecting analyte by detecting a signal from the solid phase-affixed complex(es) set forth in (b),

wherein the signal is positively correlated with the concentration of analyte present in the sample.

9. An immunoassay method for an analyte of interest in a biological sample that may contain anti-analyte autoantibodies, said method comprising:

(a) contacting a biological sample being tested for the analyte with an anti-analyte capture antibody affixed to a solid phase wherein the capture antibody specifically binds analyte, under conditions sufficient for specific binding of the capture antibody to analyte to form a solid phase-affixed capture antibody/analyte complex;

(b) contacting the biological sample with;

(i) an anti-analyte antibody that binds the analyte under conditions sufficient for specific binding of the anti-analyte antibody to any analyte present in the capture antibody/analyte complex so as to form a solid phase-affixed anti-analyte antibody/analyte/capture antibody complex; and

(ii) a species-specific antibody, wherein the species-specific antibody is specific for the species from which the biological sample was obtained and specifically binds anti-analyte autoantibody, under conditions sufficient for specific binding of the species-specific antibody to any anti-analyte autoantibody bound to the capture antibody/analyte complex so as to form a solid phase-affixed species-specific antibody/anti-analyte autoantibody/analyte/capture antibody complex; and

(c) detecting analyte by detecting a signal from the solid phase-affixed complex(es) set forth in (b),

wherein the signal is positively correlated with the concentration of analyte present in the sample.

10. The immunoassay method of claim 9, wherein the anti-analyte antibody and the species-specific antibody are labeled with the same label.

11. The immunoassay method of claim 9, wherein the contacting of (a) and the contacting of (b)(i) and/or (b)(ii) is carried out simultaneously.

12. The immunoassay method of claim 9, wherein the contacting of (a) and the contacting of (b)(i) and/or (b)(ii) is carried out sequentially.

13. The immunoassay method of claim 9, wherein the biological sample is contacted with the anti-analyte antibody and the species-specific antibody simultaneously.

14. The immunoassay method of claim 9, wherein the biological sample is contacted with the anti-analyte antibody and the species-specific antibody sequentially.

15. The immunoassay method of claim 9, wherein the biological sample is obtained from a human.

16. The immunoassay method of claim 9, wherein at least one label comprises a direct label.

17. The immunoassay method of claim 16, wherein the direct label comprises an acridinium-9-carboxamide.

18. The immunoassay method of claim 9, wherein at least one label comprises an indirect label.

19. The immunoassay method of claim 9, wherein the detecting of (c) comprises contacting at least one label with an indicator reagent.

20. The immunoassay method of claim 9, wherein the solid phase comprises a microparticle.

21. The immunoassay method of claim 20, wherein the microparticle is magnetic or paramagnetic.

22. The immunoassay method of claim 9, wherein the solid phase comprises a microplate.

23. The immunoassay method of claim 9, wherein the solid phase comprises an electrode.

24. The immunoassay method of claim 9, wherein the solid phase comprises a plurality of anti-analyte capture antibodies that are specific for a plurality of different analytes.

25. The immunoassay method of claim 24, wherein the biological sample is contacted with a plurality of different anti-analyte antibodies that are specific for said plurality of different analytes, wherein each different anti-analyte antibody is labeled with a distinct label.

26. The immunoassay method of claim 24, wherein the solid phase comprises a plurality of electrodes, each electrode bearing a different anti-analyte capture antibody.