Tuesday, December 12, 2006
Celiac and gluten sensitivity: Duodenal intraepithelial lymphocytes significantly increased compared with esophagitis and gastritis
Intraepithelial lymphocytes (IEL’s), are increased in number in the intestinal villi in celiac disease. Though not specific for celiac disease (CD), increased IEL’s are accepted as the earliest sign of gluten intolerance in the gut. Most pathologists either report the number of IEL’s per 20 intestinal lining cells (enterocytes) or per 100 enterocytes.
For more than 30 years >40 IEL’s/100 enterocytes was considered the diagnostic threshold for CD. That number has been reduced to >30/100. More recent studies have indicated it may need to be lowered to >20-25/100.
Helicobacter pylori bacteria infection, giardia parasite infection, cow’s milk protein sensitivity, and viral infections have all been reported to be associated with increased duodenal IEL’s. Though not well established, it is believed that the number of IEL’s in these conditions may not be as high as in CD.
A recent study of biopsies of the esophagus, stomach, and duodenum of 46 people without evidence of CD reached several conclusions. Though there may be a slight increase IEL’s in esophagitis and gastritis, the difference in IEL numbers is not significantly different in normal biopsies of the esophagus and stomach. Though general ranges of duodenal IEL's found in active esophagitis (2-13, average 8.8), active gastritis with Helicobacter pylori infection (2-13, average 7.2) and chronic gastritis without H. pylori infection (4-20, average 10.2) was very similar to those with negative esophagus, stomach and duodenal biopsies (2-18, average 6.7) the average number of IEL's was slightly higher, though not statistically significant.
I believe this study is important because it argues against attributing more than 20-25 IEL’s/ 100 enterocytes to other inflammatory processes in the esophagus or stomach. It also supports the findings of other studies that have found that >20-25 IEL’s/100 is a sign of gluten sensitivity and possibly early CD.
In the context of elevated gliadin antibody levels I believe that >25 IEL’s more likely than not indicates gluten sensitivity though not necessarily CD. Strict criteria for diagnosing CD require a positive specific CD blood test such as endomysial antibody or tissue transglutaminase antibody and >30 IEL’s/100 enterocytes and/or evidence of villous atrophy on small intestinal biopsy.
For more information about IEL’s, including illustrative biopsy photos, see my website www.thefooddoc.com and earlier posts on this blog.
Yousef MM, Yantiss RK, Baker SP and Banner BF. Duodenal Intraepithelial Lymphocytes in Inflammatory Disorders of the Esophagus and Stomach. Clinical Gastroenterology and Hepatology 2006;4:631-634.
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