Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
  • G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
  • G01N33/54306—Solid-phase reaction mechanisms

Definitions

• the invention relates to an immunoassay for the simultaneous immunochemical determination of an analyte (antigen) and of a therapeutic antibody directed against the analyte.
• Areas of application of the invention are medical diagnostics, therapy control and pharmacological research.
• Immunoassay is a very common technique for the determination of unknown concentrations of analytically or diagnostically relevant substances (analyte) in sample materials such as serum, plasma, tissue samples, residue preparations, cell culture supernatants and the like.
• Immunoassays Radioimmunoassays (RIA), Enzyme immunoassays (EIA),
• Luminescence immunoassays are based on specifying an analyte concentration as standard and for this, after reaction with an antibody including a labeled compound (a labeled antigen or antibody), the response of the bound labeled antigen or antibody (pulse rate, Extinction, Relative Light Units) is determined.
• the relationship between response and analyte concentration of the standard is described in the form of a standard curve by means of mathematical calibration function or graphically.
• the analyte concentration of unknown samples is calculated from the response of the unknown sample using the calibration function converted to the analyte concentration, or is read from the graphically generated standard curve.
• a number of therapeutic antibodies have been developed or are still in development in recent years. These are primarily focused on the treatment of inflammation, autoimmune diseases and cancer. Although many of these therapeutic antibodies are originally produced as monoclonal antibodies, most of them have been genetically engineered into human antibodies to prevent the patient's immune response to the therapeutic antibody. Some of them are chimeras of human and monoclonal antibodies or even just monoclonal antibodies.
• Table 1 shows a selection of therapeutic antibodies that are already approved as drugs or are in the approval:
• therapeutic antibodies are directed against disease-specific human proteins.
• disease-specific human proteins concerned can be determined as antigens on the basis of sandwich immunoassays, this determination is falsified by the therapeutic antibodies and are specific
• the invention has for its object to develop a simple and fast to be performed method with which an antigen and a directed against it
• Therapeutic antibodies can be determined simultaneously in a solution. It should preferably be usable for a therapy control.
• the object is achieved according to the claims with a special immunoassay and a method for using this immunoassay.
• the immunoassay according to the invention comprises: an optionally labeled capture antibody bound to a surface, a labeled therapeutic antibody, or a labeled antibody having the same binding epitope as the therapeutic antibody - an antigen that binds to different epitopes with the capture antibody and the therapeutic antibody, thereby forming an immunochemical sandwich forms a solution of the unlabeled therapeutic antibody of known concentration and - an antigen solution to replenish the samples.
• the assay is based on a standard sandwich immunoassay. In a properly determined sandwich immunoassay in which the
• Therapeutic antibody or an antibody that binds to the same binding epitope is used in labeled form as a detection antibody or capture antibody, the presence of the therapeutic antibody in samples causes a systematic reduction in the recovery of the antigen to be determined, which correlates with the concentration of the therapeutic antibody. This correlation can be used to determine the unknown concentration of the therapeutic antibody and to determine the free and total antigen concentration. For this reason, this immunoassay can also be called short recovery immunoassay or recovery immunoassay.
• This sandwich immunoassay has the following structure: a) A capture antibody immobilized on the microtiter plate or biochip surface. b) The analyte is a protein or other biopolymer that binds to a binding epitope on the capture antibody, which is measured as a standard or sample in the immunoassay. c) The detection antibody is the therapeutic antibody that is radioactively or nonradioactivly labeled and has a binding epitope other than the one
• Capture antibody binds the analyte.
• nonradioactive markers all methods customary in immunoassay (with peroxidase, with alkaline phosphatase, with luminescent or fluorescent labels) can be used.
• Sandwich immunoassays are now carried out with and without addition of 2 to 5 different antibody concentrations of the unlabelled humanized therapeutic antibody. It is essential for the sandwich immunoassay without the unlabeled humanized therapeutic antibody that the assay in the samples to be tested correctly reflects the antigen concentrations.
• the measured values of the 2 to 6 immunoassays are then analyzed to which extent the addition of the humanized therapeutic antibodies causes a reduction of the measured values and thus the recovery of the antigen concentration in standard curves.
• the relationship between the reduction of the measured values reduction of the recalculated antigen concentration (standard concentration) and the addition of the humanized therapeutic antibodies is summarized by means of a statistical evaluation in a suitable mathematical function.
• This function establishes a connection between the recovery of the antigen in the immunoassay and the concentration of the therapeutic antibody.
• the relationship between the reciprocal of antigen recovery in the immunoassay is and the concentration of the therapeutic antibody a simple linear function.
• Prerequisite for the validity of this function is that distortions of the measured values due to matrix effects in the samples are excluded. For this reason, the reaction media of the standard solutions and the samples must be comparable.
• Table 2 shows the experimental setup on the microtiter plate and in Table 3 the result of the experiment.
• Figure 1 shows the IgE ELISA depending on the E-25 addition.
• the immunoassay is intended for the determination of unknown antigen concentrations.
• the measured values are determined by immunoassay as standard curve for standard dilutions of known antigen concentrations.
• the correlation between the known antigen concentrations and the measured values is recorded for the immunoassay usual mathematical functions with the help of the regression and used for the calculation of the Antigenkonzentrationen of unknown samples from their measured values in the immunoassay.
• NSB non-specific binding
• the coefficient of determination for the linear relationship was 99.292%.
• the evaluation function gives the correlation between measured values and hedgehog concentration to 99.3% correctly; only 0.7% of readings deviate randomly.
• In (IgE) (5,30775 + Logit (E)) / 0,892 (formula 4) can be used with very little error to calculate unknown samples from the measured values (here extinctions).
• IgE-lime IgE concentrations determined by the inverse function of the evaluation function.
• Example 1 only the basic principle of determining the concentrations of the therapeutic antibody E-25- (xoiair) in known samples should be shown. Also, the immunoassays were performed only in buffer solutions.
• Example 2 will now also be shown that the same method in unknown serum samples, the determination of the E-25 content by simple Heightening experiments in immunoassay is possible.
• IgE-free sera were generated by immunoaffinity chromatography and the IgE standards were set in these in the immunoassay.
• IgE standard IgE from OEM 13.
• POD-labeled detection antibody PD 08/110501 from Hum., MAb E25 labeled with POD, Novartis;
• Humanized monoclonal therapeutic antibody omalizumab (Xolair) E-25 from
• Reaction Medium Standard curves (1:10 diluted IgE-free serum in PBS / 0.33% casein + 0.0125% TWEEN 20 )
• Table 6 and 7 show the experimental setup on the microtiter plate, (1st and 2nd half) and in Table 8 the result of the immunoassay.
• Table 6 Experimental setup on the microtiter plate, 1st half
• H Serum 7 1 10 diluted in buffer + 0.25 Increased with 0 / 6.25 / 25 ng / ml IgE ⁇ g / ml E-25
• Serum 3 had been supplemented with 6.25 and 25 ng / ml IgE. Without addition of E-25, the recovery of added IgE concentrations at a baseline serum level of 12 ng / ml (1:10 diluted) was 108%. This did not deviate significantly from an expected recovery of 100%.
• Serum 5 had been supplemented with 6.25 and 25 ng / ml IgE. Without the addition of E-25, the recovery of added IgE concentrations at a serum starting level of 15.9 ng / ml (1:10 diluted) was 102%. This did not deviate significantly from an expected recovery of 100%.
• Serum 6 had been supplemented with 6.25 and 25 ng / ml IgE. Without addition of E-25, the recovery of added IgE concentrations at a baseline serum level of 3.9 ng / ml (1:10 diluted) was 96%. This gave way to an expected
• Serum 7 had been supplemented with 6.25 and 25 ng / ml IgE. Without addition of E-25, the recovery of added IgE levels at a baseline serum 2.7 ng / ml (1:10 diluted) was 95%. This did not deviate significantly from an expected recovery of 100%.

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• Medicines Containing Antibodies Or Antigens For Use As Internal Diagnostic Agents (AREA)

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• 2005
  • 2005-12-02 DE DE102005057920A patent/DE102005057920A1/de not_active Withdrawn
• 2006
  • 2006-11-29 WO PCT/DE2006/002107 patent/WO2007062628A2/de not_active Ceased
  • 2006-11-29 JP JP2008542594A patent/JP4918556B2/ja not_active Expired - Fee Related
  • 2006-11-29 DE DE502006005889T patent/DE502006005889D1/de active Active
  • 2006-11-29 US US12/095,776 patent/US20080280311A1/en not_active Abandoned
  • 2006-11-29 AT AT06828568T patent/ATE454629T1/de active
  • 2006-11-29 CA CA2640835A patent/CA2640835C/en not_active Expired - Fee Related
  • 2006-11-29 EP EP06828568A patent/EP1957980B1/de not_active Not-in-force

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