Chronic proton pump inhibition therapy in the diagnostic accuracy of serum pepsinogen I and gastrin concentrations to identify pernicious anaemia

Abstract

Background: Chronic use of proton pump inhibitors (PPIs) leads to increases in gastrin and pepsinogen-I serum concentrations.

Aim: To asses if chronic treatment with PPIs has an effect on serum gastrin and pepsinogen-I concentrations for the diagnosis of pernicious anaemia (PA).

Materials and methods: Serum gastrin and pepsinogen-I were measured in 38 patients with PA and 74 without PA (controls); 17/38 PA patients and 36/74 controls were treated with PPIs. Receiver Operating Curves (ROC) were used to compare diagnostic accuracy of gastrin and pepsinogen-I for PA in patients under chronic treatment with PPIs and in untreated patients.

Results: PPI treatment increased pepsinogen-I in patients and in controls, while gastrin increased only in controls. In untreated patients, a pepsinogen-I <8.3ng/mL had 95.2% sensitivity and 100% specificity, whereas a gastrin >115pg/mL had 100% sensitivity and 92.11% specificity for PA diagnosis. In PPI-treated patients, a pepsinogen I<24.1ng/mL had a lower sensitivity (82.4%) but retained 100% specificity, however the best cut-off point for gastrin, 610pg/mL, had a very low sensitivity (58%).

Conclusions: PPI chronic treatment decreased the diagnostic accuracy for the studied biomarkers, particularly of gastrin. In PPI-treated patients, serum pepsinogen-I concentrations >24.1ng/mL allowed rejecting a PA diagnosis with 100% specificity.

Keywords: Autoimmune gastritis; Biomarkers; Gastrin; Pepsinogen-I; Pernicious anaemia; Proton pump inhibitors.