title: Acute inflammatory intestinal vascular lesions and in situ abnormalities of the plasminogen activation system in Crohn's disease.
abstract: OBJECTIVE
  The distribution of the intestinal vascular lesions and their relation with the fibrinolysis process are poorly known in Crohn's disease (CD). The mediators of the plasminogen activator system, namely urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1), are a key complex involved in fibrinolysis. The aims of this study were: (1) to further define vascular lesions and their distribution in the intestine; and (2) to study concomitantly the qualitative in situ expression and the levels of u-PA, t-PA and PAI-1 in the ileum of patients with CD.
  
  
  METHODS
  Histological, immunohistochemical and ultrastructural studies of vascular lesions in the resected ileum of 27 patients with CD were performed and compared with 36 control patients. Levels of u-PA, t-PA and PAI-1 measured by ELISA methods were compared in healthy and inflamed ileal tissues of 17 patients with CD.
  
  
  RESULTS
  Acute vascular lesions involving mainly serosal venules and capillaries were present in 63% of patients with CD vs 3/36 controls and were associated with PAI-1 expression. They were prominent on the mesenteric border beneath macroscopically normal mucosa. In contrast, chronic vascular lesions were present in all layers beneath mucosal ulcerations, where a significant increase of PAI-1 levels was found.
  
  
  CONCLUSIONS
  These results suggest that vascular involvement associated with abnormalities of PAI-1 expression is an early and widespread event in CD. Their prominence on the mesenteric border might explain the characteristic location of CD ulceration along the mesenteric margin.
authors.affiliation: Laboratoire de Recherche sur les Maladies Inflammatoires Intestinales (CRI4U004B), Centre Hospitalier Régional Universitaire, Lille, France.
authors.forename: P
authors.initials: P
authors.lastname: Desreumaux
authors.forename: G
authors.initials: G
authors.lastname: Huet
authors.forename: F
authors.initials: F
authors.lastname: Zerimech
authors.forename: L
authors.initials: L
authors.lastname: Gambiez
authors.forename: M
authors.initials: M
authors.lastname: Balduyck
authors.forename: P
authors.initials: P
authors.lastname: Baron
authors.forename: P
authors.initials: P
authors.lastname: Degand
authors.forename: A
authors.initials: A
authors.lastname: Cortot
authors.forename: J F
authors.initials: JF
authors.lastname: Colombel
authors.forename: A
authors.initials: A
authors.lastname: Janin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D002196:Capillaries / Q000201:enzymology / Q000473:pathology / Q000648:ultrastructure; D002648:Child; D003424:Crohn Disease / Q000201:enzymology / Q000473:pathology*; D005260:Female; D006801:Humans; D007082:Ileum / Q000098:blood supply / Q000201:enzymology* / Q000473:pathology*; D007150:Immunohistochemistry; D007249:Inflammation / Q000201:enzymology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis; D010960:Plasminogen Activators / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000096:biosynthesis; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis; D014699:Venules / Q000201:enzymology / Q000473:pathology / Q000648:ultrastructure
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator