Assays for igfbp7 having improved performance in biological samples

Abstract

The invention provides IGFBP7 immunoassays with improved clinical performance, particularly when used in the evaluation of renal injuries. The immunoassays rely on the selection and use of antibodies and antibody pairs that exhibit improved assay performance when used in complex clinical specimens such as biological fluids, and particularly when used in rapid assay formats such as lateral flow test devices.

1 .- 14 . (canceled) 
     
     
         15 . A monoclonal antibody that binds to a human IGFBP7 protein, wherein the antibody binds to an epitope of human IGFBP7 comprising residues within an amino acid sequence set forth as LIWNKVKRGHYGVQRT (SEQ ID NO: 7). 
     
     
         16 . The antibody of  claim 15 , wherein the antibody is conjugated to a signal development element. 
     
     
         17 . The antibody of  claim 15 , wherein the antibody is conjugated to a solid support. 
     
     
         18 . A nucleic acid encoding the antibody of  claim 15 . 
     
     
         19 . An antibody-expressing cell line, wherein the cell line expresses the antibody of  claim 15 . 
     
     
         20 . An immunoassay method for detecting a presence or amount of human IGFBP7, comprising:
 contacting a sample with an antibody that binds to a human IGFBP7 protein, wherein the antibody binds to an epitope of human IGFBP7 comprising residues within an amino acid sequence set forth as LIWNKVKRGHYGVQRT (SEQ ID NO: 7);   detecting binding of the human IGFBP7 in the sample to the antibody; and   relating the detected binding to the presence or amount of the human IGFBP7.   
     
     
         21 . The immunoassay method of  claim 20 , wherein the antibody is a monoclonal antibody. 
     
     
         22 . The immunoassay method of  claim 20 , wherein the antibody is conjugated to a signal development element. 
     
     
         23 . The immunoassay method of  claim 20 , wherein the antibody is conjugated to a solid support. 
     
     
         24 . The immunoassay method of  claim 22 , wherein the method comprises applying a human patient sample to a disposable test device,
 forming an immobilized sandwich complex comprising the antibody and a second antibody,   inserting the disposable test device into an analytical instrument, and   detecting the immobilized sandwich complex to provide a signal.   
     
     
         25 . The immunoassay method of  claim 23 , wherein the method comprises applying a human patient sample to a disposable test device,
 forming an immobilized sandwich complex comprising the antibody and a second antibody,   inserting the disposable test device into an analytical instrument, and   detecting the immobilized sandwich complex to provide a signal.   
     
     
         26 . The immunoassay method of  claim 22 , wherein the minimum detectable amount of human IGFBP7 is 20 ng/mL or less. 
     
     
         27 . The immunoassay method of  claim 23 , wherein the minimum detectable amount of human IGFBP7 is 20 ng/mL or less. 
     
     
         28 . The immunoassay method of  claim 24 , wherein the minimum detectable amount of human IGFBP7 is 20 ng/mL or less. 
     
     
         29 . The immunoassay method of  claim 25 , wherein the minimum detectable amount of human IGFBP7 is 20 ng/mL or less. 
     
     
         30 . The immunoassay method of  claim 22 , wherein the immunoassay method is performed in a lateral flow device. 
     
     
         31 . The immunoassay method of  claim 23 , wherein the immunoassay method is performed in a lateral flow device. 
     
     
         32 . The immunoassay method of  claim 24 , wherein the immunoassay method is performed in a lateral flow device. 
     
     
         33 . The immunoassay method of  claim 25 , wherein the immunoassay method is performed in a lateral flow device. 
     
     
         34 . A monoclonal antibody that binds to a human IGFBP7 protein, wherein the antibody binds to an epitope of human IGFBP7, wherein mutating at least one amino acid of LIWNKVKRGHYGVQRT (SEQ ID NO: 7) in the IGFBP7 protein shows loss of binding of the antibody to the IGFBP7 protein.