Method for diagnosing acute coronary syndrome

Abstract

This invention concerns a bioaffinity assay for quantitative determination in a sample of free PAPP-A, defined as the pregnancy associated plasma protein A (PAPP-A) that is not complexed to the proform of major basic protein (proMBP), wherein free PAPP-A is determined either i) as a calculated difference between measured total PAPP-A and measured PAPP-A complexed to proMBP, or ii) by a direct bioaffinity assay measuring only free PAPP-A. Furthermore, the invention concerns a method for diagnosing an acute coronary syndrome in a person by using as marker either free PAPP-A as such or a ratio free PAPP-A/total PAPP-A, free PAPP-A/PAPP-A complexed to proMBP, or PAPP-A complexed to proMBP/total PAPP-A.

1 - 16 . (canceled) 
     
     
         17 . A method for diagnosing in vitro an acute coronary syndrome in a person by using as marker either free PAPP-A, defined as the pregnancy associated plasma protein A (PAPP-A) that is not complexed to the proform of major basic protein (proMBP), as such, or as a ratio
 free PAPP-A/total PAPP-A,   free PAPP-A/PAPP-A complexed to proMBP, or   PAPP-A complexed to proMBP/total PAPP-A.   
     
     
         18 . The method according to  claim 17 , wherein free PAPP-A is determined by a bioaffinity assay method for quantitative determination in a sample of free PAPP-A, either
 i) as a calculated difference between measured total PAPP-A and measured PAPP-A complexed to proMBP, or   ii) by a direct bioaffinity assay method measuring only free PAPP-A.   
     
     
         19 . The method according to  claim 18 , wherein free PAPP-A is determined according to alternative i) and two assays methods are performed, in which one aliquot of the sample is exposed to an antibody or antibody fragment which binds total PAPP-A and the antibody or antibody fragment is detected, and another aliquot of said sample is exposed to an antibody or antibody fragment which binds only PAPP-A complexed to proMBP and the antibody or antibody fragment is detected, and the amount of free PAPP-A is calculated as a difference between determined total PAPP-A and PAPP-A complexed to proMBP. 
     
     
         20 . The method according to  claim 19 , wherein the assay methods are non-competitive sandwich assays. 
     
     
         21 . The method according to  claim 20 , wherein the antibodies or antibody fragments are either capture antibodies or antibody fragments or labelled antibodies or antibody fragments. 
     
     
         22 . The method according to  claim 18 , wherein free PAPP-A is determined according to alternative i) as one single dual analyte assay method where the sample is exposed to a capture antibody or antibody fragment, which binds total PAPP-A, and to two detecting antibodies or antibody fragments labelled with different labels, so that the first detecting antibody or antibody fragment labelled with the first label is directed to an epitope present in any PAPP-A molecule, where the signal of the first label is used to give total PAPP-A, and the second detecting antibody or antibody fragment labelled with the second label is directed to an epitope in the proMBP subunit of the molecule, where the signal of the second label is used to give PAPP-A complexed to proMBP. 
     
     
         23 . The method according to  claim 18 , wherein free PAPP-A is determined according to alternative ii) by exposing the sample to an antibody or antibody fragment which binds the free PAPP-A but not the PAPP-A complexed to proMBP, and the free PAPP-A bound by said antibody or antibody fragment is detected. 
     
     
         24 . The method according to  claim 18 , wherein free PAPP-A is determined according to alternative ii) by making PAPP-A complexed to proMBP non-capable of participating in the bioaffinity reaction in which the sample is exposed to a antibody or antibody fragment binding total PAPP-A. 
     
     
         25 . The method according to  claim 24 , wherein PAPP-A complexed to proMBP is blocked or pre-adsorbed. 
     
     
         26 . A bioaffinity assay method for quantitative determination in a sample of free PAPP-A, defined as the pregnancy associated plasma protein A (PAPP-A) that is not complexed to the proform of major basic protein (proMBP), wherein free PAPP-A is determined either
 i) as a calculated difference between measured total PAPP-A and measured PAPP-A complexed to proMBP, or   ii) by a direct bioaffinity assay method measuring only free PAPP-A, by making PAPP-A complexed to proMBP non-capable of participating in the bioaffinity reaction in which the sample is exposed to an antibody or antibody fragment binding total PAPP-A.   
     
     
         27 . The assay method according to  claim 26 , wherein free PAPP-A is determined according to alternative i) and two assay methods are performed, in which one aliquot of the sample is exposed to an antibody or antibody fragment which binds total PAPP-A and the antibody or antibody fragment is detected, and another aliquot of said sample is exposed to an antibody or antibody fragment which binds only PAPP-A complexed to proMBP and the antibody or antibody fragment is detected, and the amount of free PAPP-A is calculated as a difference between determined total PAPP-A and PAPP-A complexed to proMBP. 
     
     
         28 . The method according to  claim 27 , wherein the methods are non-competitive sandwich methods. 
     
     
         29 . The method according to  claim 28 , wherein the antibodies or antibody fragments are either capture antibodies or antibody fragments or labelled antibodies or antibody fragments. 
     
     
         30 . The method according to  claim 26 , wherein free PAPP-A is determined according to alternative i) as one single dual analyte assay method where the sample is exposed to a capture antibody or antibody fragment, which binds total PAPP-A, and to two detecting antibodies or antibody fragments labelled with different labels, so that the first detecting antibody or antibody fragment labelled with the first label is directed to an epitope present in any PAPP-A molecule, where the signal of the first label is used to give total PAPP-A, and the second detecting antibody or antibody fragment labelled with the second label is directed to an epitope in the proMBP subunit of the molecule, where the signal of the second label is used to give PAPP-A complexed to proMBP. 
     
     
         31 . The method according to  claim 26 , alternative ii) wherein PAPP-A complexed to proMBP is blocked or pre-adsorbed.