title: Infliximab treatment influences the serological expression of matrix metalloproteinase (MMP)-2 and -9 in Crohn's disease.
abstract: BACKGROUND
  Matrix metalloproteinases (MMPs) are actively involved in the pathogenesis of Crohn's disease (CD). We assessed the effect of the anti-tumor necrosis factor-alpha (TNF-alpha) monoclonal antibody infliximab on the in vitro and in vivo expression of MMP-2 and MMP-9 in CD.
  
  
  METHODS
  Infliximab-treated fistulizing (n = 10) or active disease (n = 7) CD patients, from an in-house study, and fistulizing CD patients (n = 42) and active CD patients (n = 24) from 2 placebo controlled studies were evaluated for serum MMP levels and clinical response. Biopsies were evaluated immunohistochemically for the MMPs. Whole blood cultures stimulated with lipopolysaccharide (LPS)/infliximab were evaluated for MMP mRNA and protein levels.
  
  
  RESULTS
  Serum MMP-2 levels in CD patients increased during follow-up, similarly in responders and nonresponders, by infliximab. Immunohistochemistry showed no clear MMP-2 change in biopsies. Serum MMP-9 levels, however, showed a consistent pattern of decrease in most CD patients, particularly in those responding, and MMP-9-positive polymorphonuclear leukocytes in biopsies also decreased by infliximab. LPS stimulation of whole blood increased the MMP-9 levels in plasma significantly in CD patients and controls, but infliximab had no effect on the secretion. Long-term LPS stimulation raised leukocyte MMP-9 mRNA levels 16-fold and infliximab inhibited this induction by 80%.
  
  
  CONCLUSIONS
  Infliximab treatment increases MMP-2 and decreases MMP-9 in serum of patients with CD, the latter also in the intestine, which extends and confirms our previous ex vivo explants observations. However, these changes were not strictly associated with the response to treatment. The enhanced leukocyte MMP-9 expression in CD seems to be regulated by TNF-alpha.
authors.affiliation: Department of Gastroenterology and Hepatology, Leiden University Medical Center, The Netherlands.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gao
authors.forename: Martin J W
authors.initials: MJ
authors.lastname: Meijer
authors.forename: Ulrike G
authors.initials: UG
authors.lastname: Schlüter
authors.forename: Ruud A
authors.initials: RA
authors.lastname: van Hogezand
authors.forename: Johanna M
authors.initials: JM
authors.lastname: van der Zon
authors.forename: Marlies
authors.initials: M
authors.lastname: van den Berg
authors.forename: Wim
authors.initials: W
authors.lastname: van Duijn
authors.forename: Cornelis B H W
authors.initials: CB
authors.lastname: Lamers
authors.forename: Hein W
authors.initials: HW
authors.lastname: Verspaget
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D003424:Crohn Disease / Q000097:blood / Q000188:drug therapy / Q000201:enzymology; D004797:Enzyme-Linked Immunosorbent Assay; D005500:Follow-Up Studies; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007150:Immunohistochemistry; D000069285:Infliximab; D020778:Matrix Metalloproteinase 2 / Q000097:blood / Q000235:genetics*; D020780:Matrix Metalloproteinase 9 / Q000097:blood / Q000235:genetics*; D008875:Middle Aged; D009504:Neutrophils / Q000201:enzymology; D012333:RNA, Messenger / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D000911:Antibodies, Monoclonal; D015415:Biomarkers; D012333:RNA, Messenger; D000069285:Infliximab; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9