title: Clinicopathologic Threshold of Acute Colorectal Graft-versus-Host Disease.
abstract: BACKGROUND
  -Colon biopsies are often used to determine the presence and severity of acute gastrointestinal graft-versus-host disease following bone marrow transplant.
  
  
  OBJECTIVE
  -To establish a threshold consensus within our institution on the number of crypt apoptotic bodies (CAB) indicative of grade 1 acute colorectal graft-versus-host disease, we retrospectively reviewed colon biopsies from posttransplant patients and incorporated clinical and endoscopic findings to validate recently proposed minimum criteria for grade 1 graft-versus-host disease as 7 or more CAB per 10 contiguous crypts.
  
  
  METHODS
  -Eighty-one biopsies performed for suspected graft-versus-host disease from 74 individual patients were initially stratified based on their prior (prestudy) diagnoses: no significant abnormality, grade 1 graft-versus-host disease, and descriptive diagnoses mentioning increased apoptosis. A chart review was performed to assess the clinical and endoscopic impression at the time of biopsy and to determine the subsequent management and outcome.
  
  
  RESULTS
  -Twenty-six biopsies with an average of 3 CAB were considered true-negative cases, and 32 biopsies with an average of 9.75 CAB were considered true-positive cases (t = 3.95999, P < .001). True-negative cases had an average density of 1.36 CAB per crypt, and true-positive cases had an average density of 2.97 CAB per crypt (t = 3.950178, P < .001).
  
  
  CONCLUSIONS
  -A threshold of 7 or more CAB per 10 contiguous crypts promotes appropriate treatment of grade 1 acute graft-versus-host disease after other diagnostic entities are excluded. Although this threshold is 100% specific to grade 1 acute colorectal graft-versus-host disease after other histologic mimics are excluded, this threshold has a low sensitivity (59.4%) as patients with less than 7 CAB per 10 contiguous crypts constitute a heterogeneous group.
authors.affiliation: From the Division of Blood & Marrow Transplantation in the Department of Medicine (Dr Arai) and the Department of Pathology (Drs Gomez, Higgins, and Kambham), Stanford University, Stanford, California.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Gomez
authors.forename: Sally
authors.initials: S
authors.lastname: Arai
authors.forename: John P
authors.initials: JP
authors.lastname: Higgins
authors.forename: Neeraja
authors.initials: N
authors.lastname: Kambham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016026:Bone Marrow Transplantation / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D003106:Colon / Q000473:pathology*; D003108:Colonic Diseases / Q000473:pathology*; D016208:Databases, Factual; D006086:Graft vs Host Disease / Q000209:etiology / Q000473:pathology*; D006801:Humans; D007223:Infant; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult