[690] Gastrointestinal Biopsy Findings of Autoimmune Enteropathy – A Review of 20 Cases

Ricard Masia, Stephen Peyton, Gregory Y Lauwers, Ian Brown. Massachusetts General Hospital, Boston, MA; Pathology Queensland, Herston, Queensland, Australia

Background: Autoimmune enteropathy (AIE) is a rare condition characterised by malabsorption, intractable diarrhea, and small intestinal inflammation. Most cases present in early childhood, often as an inherited disorder of immune regulation. Adult cases are increasingly recognised, although missed or delayed diagnosis remains common. Small intestinal biopsies in AIE reportedly show crypt apoptosis, intraepithelial lymphocytosis, and neutrophilic crypt abscesses. Similar changes are described in the colon. This study aims to better define the histological patterns of AIE and to characterise changes in extra-enteric biopsies.
Design: AIE cases from 2 institutions (Royal Brisbane Hospital and Massachusetts General Hospital) were reviewed. Biopsies were classified on the predominant small intestinal histological pattern as 1) active chronic duodenitis (ACD) – villus blunting, lamina propria chronic inflammation, neutrophilic cryptitis and crypt abscesses. 2) celiac-like – villus blunting and intraepithelial lymphocytosis. 3) Graft versus Host Disease- like (GvHD-like) – increased crypt apoptosis ± crypt dropout but minimal inflammation. 4) No predominant pattern – admixture of ≥2 patterns or mild chronic inflammation only. Biopsies from other gastrointestinal sites were reviewed.
Results: 20 AIE patients were identified (13 males, age range 1-80 years). 5 were adults (≥ 18 years); 11 were ≥ 10 years. The predominant pattern was ACD - 9 cases (45%), celiac-like - 5 cases (25%), GvHD-like - 2 cases (10%), and no predominant pattern - 4 cases (20%). Other gastrointestinal sites showed eosinophil infiltration > 20/HPF in 3/15 esophageal biopsies (20%); inflammation in 14/19 gastric biopsies (74%, including active chronic gastritis - 3 cases, atrophic gastritis - 1 case, and GvHD-like pattern - 1 case); and abnormalities in 9/17 colon biopsies (53%, consisting of active colitis - 2 cases, GvHD-like pattern - 2 cases, lymphocytosis - 1 case, and mixed pattern - 4 cases). Inflammation was present outside the small intestine in all 19 cases with extraintestinal biopsies (100%).
Conclusions: AIE is characterised by a broader spectrum of pathological changes than previously recognised, and traditionally described features such as crypt apoptosis may be inconspicuous. The most common pattern on small intestinal biopsy is active chronic duodenitis, often with crypt abscesses. Histological changes are frequent outside the small intestine and AIE may be better regarded as a pan-gastrointestinal autoimmune disorder.
Category: Gastrointestinal

Wednesday, March 6, 2013 1:00 PM

Poster Session VI # 102, Wednesday Afternoon

 

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