Method for diagnosing and treating crohn's disease

Abstract

The present invention relates to an in vitro method for diagnosing Crohn's disease or for determining predisposition in a person to develop Crohn's disease, by detecting an overexpression of the CD66c receptor in subjects suffering from said disease or at risk of developing the disease. The invention also relates to preventive or curative treatment for Crohn's disease.

What is claimed is: 
     
         1 . An in vitro method for the diagnosis of Crohn's disease, or for the determination of a predisposition of a person to develop Crohn's disease, comprising determining whether the level of expression of the CD66c receptor in a biological sample from a subject to be tested is higher than the level of expression in a control sample, which is indicative of Crohn's disease, or of a predisposition of the subject tested to develop Crohn's disease. 
     
     
         2 . The method as claimed in  claim 1 , in which the biological sample is an ileal biopsy or a preparation of enterocytes isolated from an ileal biopsy. 
     
     
         3 . The method as claimed in  claim 1 , in which the biological sample is a blood or stool sample. 
     
     
         4 . The method as claimed in  claim 1 , in which the level of expression of the CD66c receptor is determined by measuring the quantity of CD66c receptor glycoprotein. 
     
     
         5 . The method as claimed in  claim 4 , in which the quantity of CD66c receptor protein is measured by an immunological test comprising bringing the biological sample into contact with an optionally labeled anti-CD66c antibody which specifically recognizes CD66c, and revealing the antibody-CD66c receptor complexes formed. 
     
     
         6 . The method as claimed in  claim 5 , in which the anti-CD66c antibody is a monoclonal antibody. 
     
     
         7 . The method as claimed in  claim 6 , in which the biological sample is an ileal biopsy, and the immunological test is an immunohistochemical test. 
     
     
         8 . The method as claimed in  claim 6 , in which the biological sample is a blood or stool sample, and the immunological test is an ELISA test. 
     
     
         9 . The method as claimed in  claim 2 , in which the level of expression of the CD66c receptor is determined indirectly by the quantitative detection of the mannose units present at the level of the brush border of the enterocytes. 
     
     
         10 . The method as claimed in  claim 9 , in which the quantitative detection of the mannose units is carried out by bringing the biological sample into contact with detectably labeled concanavalin A, and revealing the complexes formed by the concanavalin A bound to the mannose units. 
     
     
         11 . The method as claimed in  claim 1 , in which the level of expression of the CD66c receptor is determined by measuring the quantity of mRNA for CD66c in the biological sample. 
     
     
         12 . The method as claimed in  claim 11 , in which the biological sample is an ileal biopsy and the quantity of mRNA for CD66c is measured by real-time RT-PCR. 
     
     
         13 . The method as claimed in  claim 3 , in which the level of expression of the CD66c receptor is determined by measuring the level of production of anti-CD66c antibodies. 
     
     
         14 . The method as claimed in  claim 13 , comprising bringing a blood or stool sample to be tested into contact with an optionally attached CD66c antibody, or an epitope fragment thereof, and revealing the antibody-CD66c receptor complexes formed.