Lansoprazole elevates the ratio of serum pepsinogen I v.s. pepsinogen II

In order to investigate the mechanism by which proton pump inhibitor increases serum pepsinogen levels, we evaluated the effects of ulcer location and IgG antibody against Helicobacter pylori on lansoprazole-induced elevations. Patients with endoscopically proven peptic ulcer received lansoprazole 30 mg/day for 6 or 8 weeks; pepsinogen I and II levels, along with antibody to H. pylori, were measured in fasting blood samples. We found that whether or not antibody to H. pylori was present, pepsinogen I and II levels and the I/II ratio rose significantly in lansoprazole-treated patients. Patients with stomach-body ulcers showed smaller increases in both pepsinogens than did those with ulcers in the gastric angle/antrum or in the duodenum. In conclusion, lansoprazole increases serum levels of both pepsinogens I and II, although a larger increase in pepsinogen I elevates the pepsinogen I/II ratio. The relatively small increases seen in patients with stomach-body ulcers suggest atrophic changes in the gastric mucosa in patients with stomach-body ulcer.