Hypergastrinemia as a cause of chromogranin a increase in blood in patients suspected to have neuroendocrine tumor.

Background: Chromogranin A (CgA) is a sensitive marker for neuroendocrine neoplasia. Enterochromaffin-like cell hyperplasia secondary to hypergastrinemia also leads to CgA increase in blood. Treatment with inhibitors of acid secretion, atrophic gastritis and infection with Helicobacter pylori are prevalent conditions leading to hypergastrinemia. We therefore wanted to study whether concomitant determination of gastrin could increase the utility of CgA as a marker of neuroendocrine neoplasia.
Methods: CgA and gastrin concentrations were determined by radioimmunoassay methods, while pepsinogen I (used to diagnose severe atrophic gastritis) was determined by a commercial immunoenzymatic assay.
Results: Among 100 patients with elevated CgA, we found that 29% had hypergastrinemia. Vice versa, CgA was elevated in 23 out of 26 (88.5%) in a population of patients with hypergastrinemia. By determining pepsinogen I in blood in patients with hypergastrinemia, a proportion of them was diagnosed as having severe atrophic gastritis.
Conclusion: We conclude that determination of gastrin in blood in patients with CgA elevation will increase the utility of CgA in the diagnosis of neuroendocrine tumors.
(Copyright 2001 S. Karger AG, Basel)