Geographic Distribution of Eosinophilic Esophagitis in the United States: An Analysis of 6,724 Unique Patients.
Jennifer M Hurrell, Robert M Genta. Caris Life Sciences, Irving, TX; UTSW and Dallas VAMC, TX
Background: Eosinophilic esophagitis (EoE) is characterized by dysphagia, odynophagia, and marked eosinophilic infiltrates in the esophageal mucosa. The etiology is unknown; leading hypotheses involve antigenic exposure to airborne or ingested antigens. Previous studies have shown geographic variations in the numbers of constitutive eosinophils in the gastrointestinal mucosa. We hypothesized that geographic factors may influence the epidemiology of EoE and designed a study to estimate its prevalence in different U.S. regions.
Design: Demographic, clinical, endoscopic, and histopathologic data from all patients with esophageal biopsies submitted to a national pathology laboratory from 1/2008 through 8/2010 were analyzed and all unique patients with a histopathologic diagnosis of EoE (>15 eosinophils per high-power field) were selected. We then calculated the relative prevalence of EoE within Koppen-Geiger Zones (a widely used climate classification system that categorizes regions based on temperature, precipitation, and aridity) and further analyzed areas of high and low prevalence.
Results: There were 207,496 patients with esophageal biopsies (47% male); 6,724 unique patients had a histopathologic diagnosis of EoE (65% male; OR 2.07; p<0.0001). Main indications for endoscopy were dysphagia (55%), odynophagia (8.8%) and GERD (36%). Biopsy specimens were available from upper esophagus (7%); mid-esophagus (72%); lower esophagus (62%). The percentage of patients with EoE varied from 2.08% in Climate Zone A (Tropical) to 3.42% in Zone D (Snow) (OR 1.67; p<0.001).The highest prevalence rates (6.7%) were found in the northern Great Basin Desert (UT, ID), whereas the lowest (<1.9%) were in PR, HI, and southern FL (OR 3.39; p<0.001).
Conclusions: The wide variations in the prevalence of histopathologic EoE in different regions of the U.S. were inversely correlated with previously reported constitutive eosinophil gradients. Climates with cool summers and abundant snow had significantly higher prevalence than humid tropical regions. Practice patterns, patient populations, and living conditions may affect our findings and need to be explored. However, since the distribution of vegetation is an expression of climate, our results support the possibility that exposure to airborne plant antigens may play a role in the etiology of EoE. Geographic patterns identified in our large patient population may help identify candidate antigens characteristic to high-prevalence areas to be targeted for investigation.
Monday, February 28, 2011 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 90, Monday Morning