The Relationship of Gastrinoma in MEN 1 to Helicobacter pylori infection

Context: Helicobacter pylori and Multiple Endocrine Neoplasia Type 1 (MEN 1) are risk factors for hypergastrinemia. Gastrin-secreting neoplasms of the foregut mucosa are both a source of, and potentially stimulated by, hypergastrinemia. Objective: To determine the relationship between H pylori exposure and the prevalence and severity of hypergastrinemia in patients with MEN 1. Design, setting & patients: Cross-sectional analysis of patients with a common MEN1 gene mutation managed at a tertiary referral hospital that underwent fasting serum gastrin and H pylori serum IgG measurement. Intervention: H pylori IgG and serum gastrin concentration, determined via immunoassay. Main outcome measures: The prevalence and severity of hypergastrinemia and its relationship to past H pylori exposure. Results: Thirty-four of 95 (36%) patients were H pylori IgG seropositive. H pylori seropositive patients were significantly more likely to exhibit hypergastrinemia compared with seronegative patients (relative risk [RR] 1.72, P=.023). H pylori exposure also predicted severe hypergastrinemia (RR 3.52, P=.026 and RR 9.37, P=.031 for patients with gastrin >= x4 and >= x8 the upper limit of normal [ULN], respectively). Gastrin concentrations >= x10 ULN occurred exclusively in H pylori seropositive patients (0/61 vs 6/34, P=.001). Serum gastrin and alpha subunit were positively associated in H pylori-exposed (beta = 0.69, P=.001), but not in H pylori-unexposed patients. Conclusion: Past H pylori exposure was associated with increased prevalence and severity of hypergastrinemia in MEN 1 patients. Past H pylori-related hypergastrinemia may contribute to the pathogenesis of ongoing gastrin hypersecretion by susceptible foregut neuroendocrine tissues.