[560] H. pylori-Negative Gastritis: Effect of Proton Pump Inhibitors

SW Carmack, RM Genta. Dallas VA Medical Center, Dallas, TX; UT Southwestern Medical Center, Dallas, TX; Caris Diagnostics, Irving, TX

Background: An increasing proportion of gastric biopsies in our veteran population have active or chronic active gastritis (CAG) with no obvious etiology, suggesting that a decrease in detection of Helicobacter pylori (Hp) organisms may be responsible for this trend. Proton pump inhibitors (PPIs) have limited antimicrobial and anti-inflammatory activity and they alter the gastric distribution of Hp populations. This study was designed to test the hypothesis that the increased PPI usage over the past 15 years correlates with the increase in Hp-negative CAG.
Design: Patients with gastric biopsies at the Dallas VAMC (1993-2007) were extracted from the surgical pathology database. Diagnoses were tabulated and relevant demographic, clinical, and histopathologic data were collected. Only data from the first gastroscopy were used for patients who had a repeat biopsy during a given year. Patients were stratified in three categories: 1) Hp ; 2) CAG without Hp; and 3) all remaining patients (normal stomach, inactive, or reactive gastritis). To rule out underdetection due to suboptimal staining or interpretation, we performed IHC on biopsies from all patients with Hp-neg CAG and positive Hp serology. PPIs, available with restrictions in the VA system since 1993, became widely prescribed since 1998, when electronic records of usage also became available.
Results: Gastric biopsies from 4420 patients were collected and reviewed. Of these, 1112 had Hp CAG, including 3 of the 66 Hp-seropositive CAG cases (4.5%) found to have Hp by IHC. The percentage of Hp-negative CAG showed a consistent increasing trend during the study period (Fig. 1), which strongly correlated with the surge in PPI usage (r = 0.966; p< 0.0001).


Conclusions: In our population, the histoprevalence of Hp CAG has sharply declined over the past 15 years, likely due to a combination of a true decrease in the prevalence of Hp infection and the masking influence of PPI use on histologic detection. An estimated two thirds of US patients undergoing endoscopy are using PPIs; therefore, the role of histology as the gold standard for the diagnosis of Hp ought to be reevaluated.
Category: Gastrointestinal

Monday, March 9, 2009 8:00 AM

Platform Session: Section C, Monday Morning