Quantification of the duodenal eosinophil content in adults: a necessary step for an evidence‐based diagnosis of duodenal eosinophilia

Abstract

Summary Background The normal content of eosinophils in the adult duodenum remains undefined. Therefore, there is no foundation for evidence‐based criteria to diagnose eosinophilic duodenitis. Aim This study aimed at: (1) establishing the range of the eosinophil density in the mucosa of the duodenum of normal adults, and (2) determining the biopsy‐based prevalence of isolated eosinophilic duodenitis in a large population of adults. Methods We counted intact eosinophils in three separate high‐power fields (hpf area = 0.237 mm2 each) with the highest densities of eosinophils from the duodenal biopsy specimens of 370 consecutive adults (60% women) with no history of small intestinal disease and a normal duodenal histology. From a large database we also extracted patients with a diagnosis of elevated duodenal eosinophilia and reviewed their biopsies and clinical history. Results The mean eosinophil count for the 370 patients was 8.2 eos/hpf with a standard deviation of ± 6.3. Twenty‐seven of the 370 had eosinophil counts outside the 95% range, which was calculated as: mean + 1.96 × SD = 20.4 eos/hpf. In a database of 458 668 adult subjects, 31 patients (6.8/100 000) had elevated duodenal eosinophilia; 21 of these had other gastrointestinal organs involved by eosinophilia, suggesting eosinophilic gastroenteritis. No significant association between duodenal eosinophilia and any specific symptom was observed. Conclusions This study suggests that in this diverse US population, a cut‐off count of 20 eos/hpf would be useful to separate patients with normal from those with elevated duodenal eosinophilic infiltrations. The clinical implications of duodenal eosinophilia, particularly when it is not an expression of eosinophilic gastroenteritis, remain to be established.

Editorial: isolated duodenal eosinophilia—clinical condition or just seeing spots?

“…In addition, using a large database of 458 668 individuals, authors concluded that isolated duodenal eosinophilia is rare (only 10 cases) . However, we would like to argue against this using their own data.…”

“…We read with interest the article by Genta et al which aimed to establish the normal duodenal eosinophil content in adults …”

“…Based on evaluation of histopathologically normal duodenal biopsies of 370 adults, Genta et al suggested 20 eosinophils per high power field (hpf) as the upper limit of normal . They also found that 27 individuals with high duodenal eosinophil count were clinically no different from those with normal eosinophil count . Specifically, the frequency of dyspepsia was similar in the two groups.…”

“…However, there is a possibility of type II error due to absence of a true control group. Significant proportion of the patients including those with “incidental biopsies” were symptomatic with gastrointestinal symptoms such as dyspepsia . Moreover, clinicians might not include dyspepsia as the indication for upper endoscopy especially in the presence of other symptoms.…”

“…Moreover, clinicians might not include dyspepsia as the indication for upper endoscopy especially in the presence of other symptoms. The authors did not have access to detailed clinical history of all patients and standardised questionnaires (such as Rome) were not used . It is also unclear if symptoms such as epigastric pain were considered as “dyspepsia.” Their findings are in contrast to the previous studies that have reported an increased number of duodenal eosinophils/hpf in patients with FD compared with control population .…”