Background: Chromogranin has been proposed as a marker for gastrin-dependent enterochromaffin-like cell proliferation.
Aim: To examine this question in three populations: acid hypersecretors with gastrinoma (Zollinger-Ellison), or without gastrinoma (non-Zollinger-Ellison), and also in pernicious anaemia with achlorhydria-caused hypergastrinaemia.
Methods: We measured serum chromogranin, gastrin, gastric secretion and counted and quantified hyperplasia of enterochromaffin-like cells in gastric biopsies from 38 Zollinger-Ellison and 13 non-Zollinger-Ellison patients being treated with lansoprazole, for 5 years (median) and again 2.5 years later. We also studied 12 patients with pernicious anaemia, half with gastric enterochromaffin-like cell carcinoids.
Results: Serum chromogranin was elevated in patients with gastrinoma, even without any enterochromaffin-like cell proliferation, but not in non-Zollinger-Ellison acid hypersecretors with normal gastrin (P < 0.001). In the hypersecretors chromogranin correlated well with serum gastrin (r = 0.82), but not with enterochromaffin-like cell proliferation. Moreover, chromogranin was normal or near normal (<75 ng/mL) despite very high serum gastrin in five of six patients with pernicious anaemia and enterochromaffin-like cell carcinoids.
Conclusions: Chromogranin is not a reliable marker for enterochromaffin-like cell activity or proliferation up to and including carcinoid; chromogranin originates in the gastrinoma and, like gastrin, is a marker for gastrinoma in acid hypersecretors.
Trial registration: ClinicalTrials.gov NCT00204373.