[660] Autoimmune-Associated Pouchitis (AAP): A Histologic Evaluation and Comparison to Antibiotic-Responsive Pouchitis (ARP) and Normal Pouches

W Jiang, B Shen, JR Goldblum. Cleveland Clinic, Cleveland, OH

Background: Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the treatment of choice in patients with presumed ulcerative colitis/indeterminate colitis who require surgical excision. Autoimmune disorders frequently coexist with inflammatory bowel disease, and they appear to be associated with an increased risk for chronic antibiotic-refractory pouchitis (CARP). The aim of this study was to determine whether histologic features could reliably distinguish patients with a clinical diagnosis of AAP from ARP.
Design: 16 patients were identified from our Pouchitis Clinic with the clinical diagnosis of AAP. Clinical diagnostic criteria for AAP included (1) CARP with response to corticosteroids, immunomodulators or biologics, (2) positive serum autoantibodies (ANA, RF, anti-microsomal, etc.), but negative anti-endomysial or tissue transglutaminase antibodies, and (3) concurrent autoimmune disorders (RA, asthma, SLE, etc.). The control groups included 39 patients with ARP and 19 patients with normal pouches. Each pouch biopsy was examined, and various histologic features were evaluated (Table 1).
Results: When compared with the ARP group, the AAP group showed significant increase in deep crypt apoptosis and pyloric gland metaplasia (PGM; Table 1). No difference was seen in other histopathologic parameters between these two groups. When compared to the normal group, AAP group also showed significantly more villous blunting, architectural distortion, ulceration, LP mononuclear cellularity and neutrophilic activity.

Conclusions: AAP has distinctive histologic features (increased crypt apoptosis and PGM) when compared with ARP, and this can aid in the diagnosis of this group of patients in the setting of CARP, which in turn would prompt appropriate treatment. Some of the histologic features of AAP have also been described in adult autoimmune enteropathy. Further studies are warranted to study these autoimmune-associated entities.
Category: Gastrointestinal

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 51, Wednesday Morning


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