Cytoplasmic antigens for detection of Candida

Abstract

The present invention relates to a method and a means of diagnosing Candida infection. In particular the present invention relates to a method of diagnosing Candida infection by measuring the levels of antibody to Candida cytoplasmic antigen present in a biological sample taken from a subject at risk of, or suspected to be suffering from a Candida infection.

1 . A method for monitoring the treatment of a subject with a  Candida  infection comprising the steps of: 
 (a) determining levels of antibody to a soluble cytoplasmic antigen preparation consisting essentially of  Candida  antigens of molecular weights 55 kDa, 30 kDa and 20 kDa in a subject infected with  Candida;      (b) administering a pharmaceutical composition for treating  Candida  infection to the subject; and    (c) re-determining said levels of antibody, wherein said levels of antibody decrease over time if the treatment is successful.    
     
     
         2 . The method of  claim 1 , wherein the antigen preparation further comprises one or more antigens selected from the group consisting of cell wall and enolase antigen.  
     
     
         3 . The method according to  claim 1 , wherein step of determining levels of antibody comprises the steps of: 
 a). obtaining a biological sample from a subject with a  Candida  infection;    b). contacting said biological sample with said soluble cytoplasmic antigen preparation; and    c). using a detection system to determine levels of bound antibody.    
     
     
         4 . The method according to  claim 3 , wherein the detection system is selected from the group consisting of enzyme-linked immunoassay, biligand binding, fluorometric assay, chemiluminescent assay, radialimmunodiffusion and radioimmunoassay.  
     
     
         5 . The method of  claim 3 , wherein the immunoassay is ELISA.  
     
     
         6 . A method according to  claim 1 , wherein the soluble cytoplasmic antigen preparation is bound to a solid phase either by adsorptive binding, covalent binding, or via a ligand already bound to the solid phase.  
     
     
         7 . A method according to  claim 3 , further comprising the step of using secondary labelled antibodies to detect the antibodies to  Candida  present in the biological samples.  
     
     
         8 . A method according to  claim 7 , further comprising the step of labelling the secondary antibodies with a label selected from the group consisting of fluorescent dye, radioisotope, enzyme, or combinations thereof.  
     
     
         9 . A method according to  claim 7 , wherein the secondary antibody is labelled via bound ligands.  
     
     
         10 . A method according to  claim 3 , wherein detection in the detection system is selected from the group consisting of colour development, chemiluminescence, fluorescence, radioactivity, or combinations thereof.  
     
     
         11 . A method according to  claim 3 , further comprising the step of performing the detection of antibodies by a method selected from the group consisting of qualitative detection, quantitative detection, or combination thereof.  
     
     
         12 . A method according to  claim 8 , further comprising the step of directly labelling the secondary antibody.  
     
     
         13 . A method according to  claim 8 , further comprising the step of indirectly labelling the secondary antibody.  
     
     
         14 . A method according to  claim 3 , wherein the antigen composition is either immobilized on an inert surface, embedded in a gel, or conjugated to a molecule.  
     
     
         15 . A method according to  claim 14 , wherein the molecule imparts colour, fluorescence or radioactivity to the antigen.  
     
     
         16 . A method according to  claim 3 , wherein the biological sample is selected from the group consisting of bone marrow, plasma, spinal fluid, lymph fluid, skin, tears, saliva, milk, blood, serum, blood cells, tumors and organs.  
     
     
         17 . A method according to  claim 16 , wherein the skin consists of external sections selected from the group consisting of respiratory, intestinal, and genitourinary tracts.  
     
     
         18 . A method according to  claim 17 , wherein the biological sample is serum.  
     
     
         19 . A lateral flow device for the detection of  Candida  antibody in a biological sample comprising a membrane having a detection zone and a control zone, and a wicking pad wherein said detection zone includes a soluble cytoplasmic antigen preparation consisting essentially of  Candida  antigens of molecular weights 55 kDa, 30 kDa and 20 kDa.  
     
     
         20 . The lateral flow device of  claim 19 , further comprising a sample pad.  
     
     
         21 . The lateral flow device of  claim 19 , wherein the biological sample deposited on an end of said detection zone is wicked into said detection zone by capillary action.  
     
     
         22 . A method for detecting the presence or absence of  Candida  antibodies comprising the step collecting a biological sample from a subject at risk of, or suspected to be suffering from,  Candida  infection and applying said sample onto a lateral flow device of  claim 19 .  
     
     
         23 . The method of  claim 3 , wherein in the immunoassay is an immunoblot.  
     
     
         24 . The method of  claim 3 , wherein the immunoassay is a protein array.