title: Correlation between the immune responses to collagens type I, III, IV and V and Klebsiella pneumoniae in patients with Crohn's disease and ankylosing spondylitis.
abstract: BACKGROUND
  Increased levels of collagen types I, III and V are found in strictures of patients with Crohn's disease (CD) compared with normal gut tissue. Type IV collagen is present in the basement membranes, basal lamina, retina and cornea. Elevated levels of antibody to Klebsiella pneumoniae are found in both active CD and active ankylosing spondylitis (AS) patients compared with healthy controls.
  
  
  METHODS
  Reactivities for immunoglobulin class-specific antibodies (IgM, IgG and IgA) against collagen types I, III, IV, V and whole K. pneumoniae were measured by ELISA in nine patients with early CD and 10 with late CD from King's College Hospital and 12 late CD patients and 36 HLA-B27-positive AS patients from Middlesex Hospital and was compared with values for 26 healthy controls from the Blood Transfusion Service in London.
  
  
  RESULTS
  Levels of class-specific IgM, IgG and IgA antibodies to collagen types I, III, IV, V and K. pneumoniae were significantly elevated in early and late CD patients compared with healthy controls (P<0.001). Levels of IgM, IgG antibody to the four collagen types and K. pneumoniae were also significantly elevated (P<0.001) in AS patients compared with healthy controls. In addition, the level of IgA antibody to K. pneumoniae was elevated in AS patients (P<0.001). Furthermore, a positive correlation between antibody levels to collagen types I, III, IV and K. pneumoniae was demonstrated in both early and late CD patients and in those with AS, whilst a positive correlation to type V was found in early CD.
  
  
  CONCLUSIONS
  The role of K. pneumoniae and anti-collagen antibodies in the aetiopathogenesis of CD and AS requires further study.
authors.affiliation: Division of Life Sciences, Infection and Immunity Group, King's College London, Stamford Street, London, UK.
authors.forename: H
authors.initials: H
authors.lastname: Tiwana
authors.forename: R S
authors.initials: RS
authors.lastname: Natt
authors.forename: R
authors.initials: R
authors.lastname: Benitez-Brito
authors.forename: S
authors.initials: S
authors.lastname: Shah
authors.forename: C
authors.initials: C
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Bridger
authors.forename: M
authors.initials: M
authors.lastname: Harbord
authors.forename: M
authors.initials: M
authors.lastname: Sarner
authors.forename: A
authors.initials: A
authors.lastname: Ebringer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis*; D003094:Collagen / Q000276:immunology* / Q000378:metabolism; D003424:Crohn Disease / Q000276:immunology*; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis / Q000145:classification; D007711:Klebsiella pneumoniae / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013167:Spondylitis, Ankylosing / Q000276:immunology*; D013223:Statistics as Topic
chemical_list: D000907:Antibodies, Bacterial; D007136:Immunoglobulins; D003094:Collagen