title: Effect of inflammatory bowel disease therapies on immunogenicity of Mycobacterium paratuberculosis proteins.
abstract: OBJECTIVE
  The link between Mycobacterium avium subsp. paratuberculosis (MAP) and Crohn's disease (CD) is supported by several studies that have reported the detection and isolation of MAP from human tissues, but causation has not yet been proven. Preliminary studies have shown higher levels of antibodies in sera from CD patients against secreted protein from MAP within human macrophages when compared to healthy controls. The immunogenicity of this protein in CD patients under different treatment regimes was evaluated.
  
  
  METHODS
  Sera of 110 CD patients, 82 ulcerative colitis (UC), and 150 healthy controls were collected and the presence of antibodies against the mycobacterial protein tyrosine phosphatase PtpA was assayed using ELISA.
  
  
  RESULTS
  A statistically significant difference in the level of antibodies against PtpA was measured in untreated CD patients versus healthy controls, but variation in the antibody levels was observed when patients were subjected to different treatment regimens. UC patients showed no differences in the levels of antibodies against PtpA when compared to healthy controls.
  
  
  CONCLUSIONS
  CD patients under different drug treatments show a clear difference in the levels of antibodies against a protein secreted by MAP, suggesting that if MAP is active in the progress of CD, some treatments can be detrimental to its survival.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, University of British Columbia , Vancouver, BC , Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Xia
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Stempak
authors.forename: Jesse
authors.initials: J
authors.lastname: Grist
authors.forename: Brian
authors.initials: B
authors.lastname: Bressler
authors.forename: Mark S
authors.initials: MS
authors.lastname: Silverberg
authors.forename: Horacio
authors.initials: H
authors.lastname: Bach
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000907:Antibodies, Bacterial / Q000097:blood*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D001379:Azathioprine / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000276:immunology*; D019819:Budesonide / Q000627:therapeutic use; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000188:drug therapy* / Q000276:immunology*; D003424:Crohn Disease / Q000188:drug therapy* / Q000276:immunology*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D000069285:Infliximab; D008297:Male; D019804:Mesalamine / Q000627:therapeutic use; D008875:Middle Aged; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology*; D011241:Prednisone / Q000627:therapeutic use; D017027:Protein Tyrosine Phosphatases / Q000276:immunology*; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D007166:Immunosuppressive Agents; D019804:Mesalamine; D019819:Budesonide; D000069285:Infliximab; D017027:Protein Tyrosine Phosphatases; D001379:Azathioprine; D011241:Prednisone