S1405 Endoscopy and Systematic Biopsy of Patients With Moderate-Severe Unexplained Gastrointestinal Symptoms Compared With Healthy Controls: High Discovery Rate of Eosinophilic Gastritis and/or Eosinophilic Duodenitis

Abstract

Introduction: We recently reported findings from a prospective study of over 500 patients with moderate–severe GI symptoms, demonstrating a high discovery rate of eosinophilic gastritis and/or eosinophilic duodenitis (EG and/or EoD) when using a systematic biopsy protocol. Normal mean and peak gastric and duodenal eosinophil counts have not been established using the same systematic biopsy regimen. We aimed to better define normal eosinophil counts to use as a comparator group to the patients we identified with gastroduodenal eosinophilia. Methods: We recruited 556 patients with chronic (≥6 months) GI symptoms unresponsive to pharmacologic/dietary interventions and/or a historical diagnosis of irritable bowel syndrome or functional dyspepsia. Those who met symptom-severity criteria were evaluated by esophagogastroduodenoscopy (EGD), with standardized collection of biopsies (8 gastric and 4 duodenal) for histopathology evaluation. Asymptomatic volunteers (controls, n=33) verified to be symptom-free using the same symptom questionnaire underwent identical biopsy procedures. Blinded GI pathologists systematically counted eosinophils; EG was defined as ≥30 eosinophils per high-power field (eos/hpf) in 5 gastric hpfs and EoD was defined as ≥30 eos/hpf in 3 duodenal hpfs. Results: Of the 405 patients who underwent EGD, 181 (45%) met histologic criteria for EG and/or EoD vs 6% (2/33) of controls (odds ratio, 12.5; 95% CI, 3.0–53.0; P< 0.001). Mean and peak eosinophil counts in stomach and duodenum were significantly higher in patients with EG/EoD compared to controls (all P< 0.001; Table 1). Conclusion: In a prospective study with standardized symptom assessment and biopsy protocols, we found gastroduodenal eosinophilia meeting criteria for EG and/or EoD in 45% of patients with chronic moderate–severe GI symptoms compared with 6% of controls. Mean and peak gastric and duodenal eosinophil counts are significantly higher in this population compared to an asymptomatic control population. EG and/or EoD might therefore be underdiagnosed, and endoscopy, systematic biopsy, and evaluation for tissue eosinophilia should be considered in patients with chronic moderate–severe symptoms.Table 1.: Mean and Peak Eosinophil Counts in Gastric and Duodenal Biopsies From Patients vs Controls.