Background & aims: The effect of chronic hypergastrinemia alone on gastric enterochromaffin-like (ECL) cells in humans is largely unknown because in the common chronic hypergastrinemic states (atrophic gastritis, chronic proton pump inhibitor use), it is not possible to separate the effect of hypergastrinemia and other factors, such as gastritis or atrophy. Studies of patients with sporadic Zollinger-Ellison syndrome (ZES) allow this separation.
Methods: In 106 patients with ZES, gastric biopsies were taken, and the qualitative ECL cell pattern/grade and the alpha-subunit of human chorionic gonadotropin (alpha-hCG) expression were determined.
Results: In patients with active disease, 99% had ECL hyperplasia and abnormal alpha-hCG staining. Fifty percent had advanced changes in both of these, with 7% having dysplasia and 0% having carcinoids. Advanced ECL cell and alpha-hCG changes were most affected by the level of hypergastrinemia. For ECL cell changes, even mild hypergastrinemia had an effect. Advanced ECL change was also affected by the duration of drug treatment, cure status, and presence of atrophic gastritis, but not by sex or previous vagotomy. The alpha-hCG expression independently predicted dysplasia.
Conclusions: In humans, chronic hypergastrinemia alone causes advanced ECL cell change and abnormal expression of mucosal alpha-hCG. No threshold for this effect was detected, as reported by some, and in contrast to animal studies, sex and vagal tone did not play a major role. The long-term risk of developing gastric carcinoids with chronic hypergastrinemia is low in patients with sporadic gastrinomas (at least 100 times less than in patients with multiple endocrine neoplasia type 1 with ZES) for at least 15-20 years.