IMMUNOASSAY OF ANALYTES IN SAMPLES CONTAINING ENDOGENOUS ANTI-ANALYTE ANTIBODIES

• US 20090246800A1
• Filed: 04/24/2009
• Published: 10/01/2009
• Est. Priority Date: 10/26/2006
• Status: Active Grant

• Current Assignee: Abbott Laboratories Incorporated
• Original Assignee: Abbott Laboratories Incorporated
• Inventors: Adamczyk, Maciej, Mattingly, Phillip G., Brashear, Roy Jeffrey
• Granted Patent: US 8,357,495 B2
• Time in Patent Office: Days
• US Class Current: 435/7.100
• 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, said method comprising:

(a) contacting a biological sample being tested for analyte with;

(i) a detection agent that binds the analyte, under conditions sufficient for binding of the detection agent to any analyte present in the sample so as to form a detection agent/analyte 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 detection agent/analyte complex so as to form a species-specific antibody/endogenous anti-analyte antibody/analyte/detection agent complex; and

(b) detecting one or more complex(es) comprising the detection agent/analyte and/or the species-specific antibody/anti-analyte antibody;

wherein the amount of the one or more complex(es) is positively correlated with the concentration of analyte present in the sample.

2. The immunoassay method of claim 1, wherein the contacting step (a) additionally comprises contacting the biological sample with a capture agent affixed to a solid phase wherein the capture agent binds analyte, and the detecting step (b) additionally comprises detecting said complex(es), which are affixed to the solid phase.

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

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

5. The immunoassay method of claim 1, wherein the detection agent and the species-specific antibody are labeled with different labels, and the signal attributable to the labeled species-specific antibody is positively correlated with the concentration of endogenous anti-analyte antibody present in the sample.

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

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

8. The immunoassay method of claim 2, 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.

9. The immunoassay method of claim 2, wherein the contacting (a)(i) and/or (a)(ii) is carried out sequentially with the contacting of the biological sample with the capture agent.

10. The method of claim 1, wherein the endogenous anti-analyte antibody comprises an anti-analyte autoantibody.

11. An immunoassay method for an analyte of interest, 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 endogenous anti-analyte antibody, 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 the one or more solid phase-affixed complex(es) set forth in (b),

wherein the amount of the one or more solid phase-affixed complex(es) is positively correlated with the concentration of analyte present in the sample.

12. An immunoassay method for an analyte of interest, 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 agent/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 endogenous anti-analyte antibody, 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 the one or more solid phase-affixed complex(es) set forth in (b),

wherein the amount of the one or more solid phase-affixed complex(es) is positively correlated with the concentration of analyte present in the sample.

13. The immunoassay method of claim 12, wherein the anti-analyte antibody and the species-specific antibody are labeled with the same label.

14. The immunoassay method of claim 12, wherein the anti-analyte antibody and the species-specific antibody are labeled with different labels, and the signal attributable to the labeled species-specific antibody is positively correlated with the concentration of anti-analyte autoantibody present in the sample.

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

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

17. The immunoassay method of claim 12, wherein the biological sample is contacted with the anti-analyte antibody and the species-specific antibody simultaneously.

18. The immunoassay method of claim 12, wherein the biological sample is contacted with the anti-analyte antibody and the species-specific antibody sequentially.

19. The immunoassay method of claim 12, wherein the biological sample is obtained from a human.

20. The immunoassay method of claim 12, wherein at least one label comprises a direct label.

21. The immunoassay method of claim 20, wherein the direct label comprises an acridinium-9-carboxamide.

22. The immunoassay method of claim 12, wherein at least one label comprises an indirect label.

23. The immunoassay method of claim 12, wherein the detecting of (c) comprises contacting at least one label with an indicator reagent.

24. The immunoassay method of claim 12, wherein the solid phase comprises a microparticle.

25. The immunoassay method of claim 24, wherein the microparticle is magnetic or paramagnetic.

26. The immunoassay method of claim 12, wherein the solid phase comprises a microplate.

27. The immunoassay method of claim 12, wherein the solid phase comprises an electrode.

28. The immunoassay method of claim 12, wherein the solid phase comprises a plurality of anti-analyte capture antibodies that are specific for a plurality of different analytes.

29. The immunoassay method of claim 28, 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.

30. The immunoassay method of claim 28, wherein the solid phase comprises a plurality of electrodes, each electrode bearing a different anti-analyte capture antibody.

31. A test kit comprising:

(a) a detection agent specific for an analyte; and

(b) a species-specific antibody, wherein the species-specific antibody is specific for the species from which the biological sample is to be obtained and specifically binds endogenous anti-analyte antibody.

32. The test kit of claim 31, additionally comprising a solid phase and a capture agent affixed to the solid phase.

33. The test kit of claim 32, wherein the capture agent comprises an anti-analyte capture antibody.

34. The test kit of claim 31, wherein the detection agent and the species-specific antibody are labeled.

35. The test kit of claim 34, wherein the detection agent and the species-specific antibody are labeled with the same label.

36. The test kit of claim 34, wherein the detection agent and the species-specific antibody are labeled with different labels.

37. The test kit of claim 34, wherein the detection agent comprises an anti-analyte antibody.

38. The test kit of claim 37, wherein the anti-analyte antibody and the species-specific antibody are present in the same container.

39. The test kit of claim 37, wherein the anti-analyte antibody and the species-specific antibody are present in different containers.

40. The test kit of claim 37, wherein the species-specific antibody comprises a human-specific antibody.

41. The test kit of claim 37, wherein at least one label comprises a direct label.

42. The test kit of claim 41, wherein the direct label comprises an acridinium-9-carboxamide.

43. The test kit of claim 37, wherein at least one label comprises an indirect label.

44. The test kit of claim 37, additionally comprising an indicator reagent that interacts with at least one label to produce a detectable signal.

45. The test kit of claim 32, wherein the solid phase comprises a microparticle.

46. The test kit of claim 45, wherein the microparticle is magnetic or paramagnetic.

47. The test kit of claim 32, wherein the solid phase comprises a microplate.

48. The test kit of claim 32, wherein the solid phase comprises an electrode.

49. The test kit of claim 32, wherein the solid phase comprises a plurality of anti-analyte capture antibodies that are specific for a plurality of different analytes.

50. The test kit of claim 49, wherein the test kit comprises 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.

51. The test kit of claim 49, wherein the solid phase comprises a plurality of electrodes, each electrode bearing a different anti-analyte capture antibody.