title: Specific antibodies against recombinant protein of insertion element 900 of Mycobacterium avium subspecies paratuberculosis in Japanese patients with Crohn's disease.
abstract: BACKGROUND
  Mycobacterial avium subspecies paratuberculosis (MAP) infection has been hypothesized as an etiological factor of Crohn's disease (CD). However, the involvement of MAP in the pathophysiology of CD is controversial. The aim of this study is to investigate whether MAP is involved in the pathogenesis of CD with the glutathione S-transferase fusion recombinant protein encoding a portion of insertion element (IS) 900 (IS900-GST), which is specific for MAP.
  
  
  METHODS
  Serum samples from the patients with CD (n = 50), ulcerative colitis (n = 40), colonic tuberculosis (n = 20), and non-IBD controls (n = 44), were applied for solid-phase enzyme-linked immunosorbent assay (ELISA) to detect antibodies against MAP and Saccharomyces cerevisiae. IS900-GST, which was made by the pGST-4T-2 vector inserted with polymerase chain reaction-amplified IS900DNA, was used as an antigen of MAP. Moreover, we studied the relationship between antibodies against IS900-GST and clinical characteristics.
  
  
  RESULTS
  ELISA showed that the serum level of immunoglobulin G and immunoglobulin A antibodies against IS900-GST (anti-IS900) in patients with CD were significantly higher than those with ulcerative colitis, colonic tuberculosis, and control subjects. The levels of anti-IS900 tended to be higher in CD patients with small intestinal involvement than with colonic involvement alone. Anti-IS900 in patients with penetrating- and stricture-type CD was significantly higher than with inflammatory-type CD. Furthermore, a negative correlation was found between the titer of anti-IS900 and disease duration. Anti-IS900 was not associated with surgical treatment nor was it associated with the use of immunosuppressants. No significant correlation was observed between the serum levels of anti-IS900 and anti-S cerevisiae antibody.
  
  
  CONCLUSIONS
  This is the first demonstration of the ELISA system of detecting antibodies against IS900 in IBD patients. MAP could be involved in the pathophysiology of Japanese patients with CD.
authors.affiliation: Department of Gastroenterology & Endoscopic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakase
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Nishio
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tamaki
authors.forename: Minoru
authors.initials: M
authors.lastname: Matsuura
authors.forename: Masanori
authors.initials: M
authors.lastname: Asada
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Chiba
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Okazaki
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D003424:Crohn Disease / Q000382:microbiology*; D004269:DNA, Bacterial; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D050939:Gene Fusion; D005982:Glutathione Transferase; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007420:Intestine, Large / Q000276:immunology; D007421:Intestine, Small / Q000276:immunology; D007564:Japan; D008297:Male; D008875:Middle Aged; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology* / Q000472:pathogenicity; D010283:Paratuberculosis / Q000150:complications*; D011993:Recombinant Fusion Proteins / Q000276:immunology* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D004269:DNA, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase