Method for assay of antibodies and antibody assay device

Abstract

The invention relates to a technology by which antibodies directed to sources of infection in body fluids can be assayed with high accuracy, expediency and specificity. More particularly, the invention provides an antibody immunoassay method in which the antigen-antibody reaction between a target antibody in a sample and an assay antigen is conducted in the presence of an E. coli component and an antibody assay method which comprises using a reagent having a specific affinity for the Fc region of an antibody IgG as the antibody assay reagent. The invention further provides an antibody assay device comprising a solid-phase support having at least (a) a first region to which a sample is applied and (b) a second region where the antibody in the sample is reacted as disposed in such an arrangement that the sample is wicked from the first region to the second region and a labeling means for detection of the result of the reaction in the second region, characterized in that the (b) second region is provided with (i) a test site in which a ligand for capturing the target antibody to be assayed is immobilized and (ii) a control site in which a ligand for capturing an arbitrary antibody occurring in the sample is immobilized.

1 . A method for assaying an antibody comprising detecting a target antibody in a sample by utilizing an antigen-antibody reaction, characterized in that said antigen-antibody reaction is carried out between said antibody and an assay antigen in the presence of an  E. coli  component.  
     
     
         2 . The antibody assay method according to  claim 1  wherein said  E. coli  component is at least one member selected from the group consisting of the soluble fraction and lipopolysaccharide fraction of  E. coli.    
     
     
         3 . The antibody assay method according to  claim 1  wherein said  E. coli  component is used in a proportion of about 0.1˜100 μg per μg of the assay antigen.  
     
     
         4 . A method for assaying an antibody comprising detecting a target antibody in a sample by the sandwich technique, characterized in that a substance having a specific affinity for the Fc region of the target antibody IgG is used as an antibody assay reagent.  
     
     
         5 . The antibody assay method according to  claim 4  wherein the antibody assay reagent is an Fc-specific anti-IgG antibody.  
     
     
         6 . The antibody assay method according to  claim 4  which comprises an antigen-antibody reaction step in which the target antibody in the sample is coupled to an immobilized form of an antigen to said antibody as immobilized on a support and a reaction step in which the target antibody captured by said immobilized antigen is reacted with an antibody assay reagent having a specific affinity for the Fc region of the antibody IgG.  
     
     
         7 . The antibody assay method according to  claim 6  wherein the antigen-antibody reaction is carried out in the presence of an  E. coli  component.  
     
     
         8 . The antibody assay method according to  claim 1  or  4  wherein the sample is a urine sample.  
     
     
         9 . The antibody assay method according to  claim 1  or  4  wherein the target antibody is the antibody against a source of infection.  
     
     
         10 . The antibody assay method according to  claim 1  or  4  wherein the source of infection is a member selected from the group consisting of human immunodeficiency virus, hepatitis viruses, rubella virus, influenza virus, measles virus, herpes virus, cytomegalovirus, Clamydia spp., gonococci,  Helicobacter pylori  and  Toxoplasma gondii.    
     
     
         11 . The antibody assay method according to  claim 1  or  4  wherein the antigen is a member selected from the group consisting of bacteria, viruses, protozoae and components of bacteria, viruses or protozoae which contain at least the antigenic determinant groups of said bacteria, viruses or protozoae.  
     
     
         12 . The antibody assay method according to  claim 1  or  4  wherein the antigen is the microorganism  Helicobacter pylori  or a component thereof which contains at least the antigenic determinant group of said microorganism.  
     
     
         13 . An antibody assay device comprising a solid phase support having at least (a) a first region to which a sample is applied and (b) a second region in which the antibody in the test sample is reacted as arranged in such a sequence that the sample is transported from the first region to the second region by capillary action, and a labeling means for detecting the result of reaction in the second region, said (b) second region having (i) a test site where a ligand for capturing the target antibody to be detected has been immobilized and (ii) a control site where a ligand for capturing an arbitrary antibody in the sample has been immobilized.  
     
     
         14 . The antibody assay device according to  claim 13  wherein the ligand immobilized in the test site is an antigen to the target antibody occurring in the sample.  
     
     
         15 . The antibody assay device according to  claim 13  wherein the ligand immobilized in the control site is an anti-human immunoglobulin antibody capable of capturing an arbitrary antibody in the sample.  
     
     
         16 . The antibody assay device according to  claim 13  comprising a labeled ligand to be bound by both the target antibody and arbitrary antibody as said labeling means.  
     
     
         17 . The antibody assay device according to  claim 13  wherein the labeling means is a labeled ligand to be bound by both the target antibody and arbitrary antibody as removably supported upstreams of the second region of the solid phase support in such a manner that, upon contact with a sample, it reacts with the target antibody and arbitrary antibody to form a target antibody/labeled ligand complex and an arbitrary antibody/labeled ligand complex, respectively, which are then transported by capillary action to the second region where they are fixed in the test site and control site, respectively.  
     
     
         18 . The antibody assay device according to  claim 17  wherein the labeled ligand is supported in a region (tracer region) intermediate between the first region and second region of the solid phase support.  
     
     
         19 . The antibody assay device according to  claim 17  wherein the labeled ligand to be bound by both the target antibody and arbitrary antibody is a labeled anti-human immonoglobulin antibody.  
     
     
         20 . The antibody assay device according to  claim 19  wherein the anti-human immunoglobulin antibody is an anti-IgG antibody having a specific affinity for the Fc region of immunoglobulin G.  
     
     
         21 . The antibody assay device according to  claim 13  wherein the solid phase support is further provided with an absorption region downstreams of the first and second regions so that the sample transported from the first region to the second region is further transported by capillary action to the absorption region.  
     
     
         22 . The antibody assay device according to  claim 13  wherein the coupling reaction of the target antibody at the test site in the second region takes place in the presence of an  E. coli  component.  
     
     
         23 . The antibody assay device according to  claim 13  wherein the sample is a urine sample.  
     
     
         24 . Use of the antibody assay device claimed in any of claims  13  through  22  for assay of a target antibody directed to a source of infection as occurring in a sample.  
     
     
         25 . The use according to  claim 24  wherein the sample is a urine sample.  
     
     
         26 . A method for solid phase assay of a target antibody in a sample which comprises applying the sample to the first region of the antibody assay device claimed in  claim 13  and detecting the development of a color at the test site in the second region under the condition of the control site in the second region developing a color.  
     
     
         27 . A method for solid phase assay of a target antibody in a sample which comprises applying the sample to the first region of the antibody assay device claimed in  claim 20  and detecting the development of a color at the test site in the second region under the condition of the control site in the second region developing a color.  
     
     
         28 . The method for solid phase assay of a target antibody according to  claim 26  or  27  wherein the coupling reaction of the target antibody at the test site in the second region of the antibody assay device takes place in the presence of an  E. coli  component.  
     
     
         29 . The method for solid phase assay of a target antibody according to  claim 26  wherein the sample is a urine sample.  
     
     
         30 . An antibody assay reagent kit for use in assaying an antibody in a sample by utilizing an antigen-antibody reaction, characterized in that said antibody assay reagent kit contains an  E. coli  component.  
     
     
         31 . An antibody assay reagent kit characterized by its containing a substance having a specific affinity for the Fc region of the target antibody IgG as an antibody assay reagent.  
     
     
         32 . An antibody assay reagent kit containing the antibody assay device claimed in claim  13 .