title: Temporal relationships between acute cellular rejection features and increased mucosal fibrosis in the early posttransplant period of human small intestinal allografts.
abstract: BACKGROUND
  Intestinal allograft biopsies limit histopathological analysis to the superficial layers of the bowel. These biopsies allow a reasonable assessment of the histological features of acute rejection, but characteristics of chronic injury in mucosal layers remain poorly defined because of the limitations posed by endoscopic sampling. Experimental work has inferred that intestinal mucosal fibrosis may be indicative of chronic rejection; however, a temporal, graded study of mucosal fibrosis has not been performed.
  
  
  METHODS
  A total of 79 endoscopic intestinal allograft biopsies from 12 patients obtained at 3 to 120 days posttransplantation were evaluated. Fibrosis and individual parameters of acute cellular rejection were graded according to a semiquantitative scoring system and were evaluated for potential relationships with each other.
  
  
  RESULTS
  We found that while acute rejection tends to occur early in the posttransplant period, fibrosis of the lamina propria increases at a later time, particularly in the third and fourth month. Several individual graded parameters of acute rejection had an association with fibrosis at the same time points.
  
  
  CONCLUSIONS
  Fibrous replacement of the lamina propria in human endoscopic allograft biopsies occurs with advancing time after transplantation. Acute rejection precedes and may have some eventual impact upon the amount of fibrosis present. A measurement of the connective tissue component of bowel transplant tissue may serve as a harbinger of long-term enteral allograft dysfunction.
authors.affiliation: Department of Pathology, Division of Immunopathology, University of Miami, Miami, FL 33136, USA.
authors.forename: Maria T
authors.initials: MT
authors.lastname: Perez
authors.forename: Monica
authors.initials: M
authors.lastname: Garcia
authors.forename: Debbie
authors.initials: D
authors.lastname: Weppler
authors.forename: Tamaoki
authors.initials: T
authors.lastname: Kato
authors.forename: Spiros
authors.initials: S
authors.lastname: Delis
authors.forename: Seigo
authors.initials: S
authors.lastname: Nishida
authors.forename: Naveen
authors.initials: N
authors.lastname: Mittal
authors.forename: Andreas
authors.initials: A
authors.lastname: Tzakis
authors.forename: Phillip
authors.initials: P
authors.lastname: Ruiz
mesh_terms: D000208:Acute Disease; D000328:Adult; D002648:Child; D004487:Edema / Q000473:pathology; D004724:Endoscopy; D005355:Fibrosis; D006084:Graft Rejection / Q000473:pathology*; D006801:Humans; D007249:Inflammation / Q000473:pathology; D007413:Intestinal Mucosa / Q000473:pathology*; D007421:Intestine, Small / Q000473:pathology* / Q000637:transplantation*; D013997:Time Factors; D014184:Transplantation, Homologous / Q000473:pathology*