Intraepithelial lymphocyte count distinguishes celiac disease from normal mucosa

Last Updated: 2017-09-25

By Will Boggs MD

NEW YORK (Reuters Health) - The intraepithelial lymphocyte (IEL) count in duodenal mucosa can be used to distinguish celiac disease from normal mucosa, with an optimal cutoff of 25 IEL/100 enterocytes, according to a case-control study.

"We achieved the confidence that IEL counts performed on cheap and conventional H and E-stained material provide optimal results in routine histological examinations and that using more-sophisticated CD3/gamma-delta immunostained sections would be recommended only in more-complex cases that require using specific markers," Dr. Kamran Rostami from Milton Keynes University Hospital, in the UK, told Reuters Health by email. "We hope this reassures busy histopathologists that simple is best - especially those working in difficult or under-resourced settings worldwide."

An increased population of IEL has been recognized as a hallmark of celiac disease for more than 50 years, but the literature lacks a definitive cutoff point to confirm the diagnosis.

Dr. Rostami and colleagues from 19 laboratories in 8 countries used H and E-stained biopsy specimens to determine IEL counts on 198 patients with celiac disease and 203 controls without celiac disease.

The mean IEL count was 54/100 enterocytes in celiac disease and 13/100 enterocytes in specimens from controls, according to the September 11 Gut online report.

IEL counts overlapped in 56 biopsies, representing 14% of the total specimens.

"The existence of a significant IEL numerical overlap between individuals with healthy small bowels and celiac disease was the most surprising finding," Dr. Rostami said. "This is because no definitive definition of a 'normal' IEL count has ever been published in the existing literature so far. As a result, and in contrast to previous belief, the IEL were shown to be not different (so called bimodal) in disease and individuals with healthy bowel. This has never been demonstrated before."

ROC curve analysis identified 25 IEL/100 enterocytes as the optimal cutoff for diagnosing celiac disease. This yielded 99.0% sensitivity, 93.1% specificity, and an overall accuracy of 99.5% (area under the curve).

With this cutoff, 3 women with celiac disease in this sample would have been false negatives and 12 controls would have been false positives.

IEL populations did not differ significantly among celiac disease biopsies graded as IIIa, IIIb, or IIIc.

"These data provide evidence for the lack of the validity of this sub-classification, whose abandonment would provide less work for pathologists concerned with celiac disease diagnosis," Dr. Rostami said.

"We were very excited with the outcome of our analysis when we were able to conclude this study would make the diagnostic process of celiac disease easier and less expensive," he said.

SOURCE: http://bit.ly/2hoEu6Q

Gut 2017.