[746] Small Bowel Allograft Explant Mucosal Alterations Correlate with Vascular Arteriopathy

BJ Swanson, WJ Grant, SJ Radio. University of Nebraska Medical Center, Omaha, NE

Background: Chronic allograft rejection (CR) is a significant barrier to small bowel allograft survival. Although CR primarily involves the submucosa, serosa and mesentery, some mucosal alterations have been suggested. The aim of this study was to correlate mucosal alterations of long-term small bowel allograft explants with vascular arteriopathic changes.
Design: Archived long-term (minimum 88 days) small bowel allograft explants were retrospectively analyzed (n=26). Common causes for explant included: graft rejection/failure(n= 12), Obstruction (n=5), and Sepsis/Necrotic Bowel (n=5), and perforation (n=4). Specimens were semi-quantitatively assessed for mucosal alterations (gland loss/distortion, villous blunting, cryptitis, epitheliitis, apoptosis, mucin loss, paneth cell loss), neural hyperplasia, submucosal/serosal fibrosis as well as vascular changes (location, size of vessel, amount of luminal narrowing and extent of involvement). Due to total mucosal atrophy/ulceration, 27% of cases could not be evaluated for mucosal alterations.
Results: The study included 20 children and 6 adults (age >18 years) with average time to explant of 1113 days (range 88-4457 days). Moderate (<25%) arteriopathy was present in 42% of cases, and severe (>75%) in 35%. Mucosal ulceration was present in 77% of cases. Mild to severe (>25%) mucin loss within the villi was present in 33% of cases when villi were present to evaluate. Moderate villous branching was present in 6% of cases when villi were present to evaluate. Minimal to mild villous blunting was present in 32% of cases while moderate to severe blunting was present in 53% of cases. Paneth cell loss was present in 21% of cases. Submucosal neural hyperplasia was present in 8% of cases. Explants with no vascular arteriopathy were removed on average at 645 days. Mucin loss (>25% villi without goblet cells) was associated with mild (<25%) vascular arteriopathy (p<0.05). Although Paneth cell loss (<76% of crypts) and submucosal hyperplasia were associated with vascular arteriopathy, these associations were not statistically significant (p = 0.11, p = 0.16, respectively).
Conclusions: Arteriopathy is common in chronic rejection of small bowel transplantation. Mucin loss is statistically associated with vascular arteriopathy. Furthermore, villous blunting and Paneth cell loss are associated with vascular arteriopathy. These findings may be useful for evaluating endoscopic intestinal mucosal biopsies for chronic rejection.
Category: Gastrointestinal

Monday, March 22, 2010 1:00 PM

Poster Session II # 86, Monday Afternoon


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