Basal chromogranin A and gastrin concentrations in circulation correlate to endocrine cell proliferation in type-A gastritis

Background: It is not known whether plasma chromogranin analysis could be a complement to histology for detection and grading of gastric fundic mucosal endocrine cell proliferation in hypergastrinemic (type-A) atrophic gastritis. Methods: Gastric biopsy sections (body and antrum) from 43 patients with type-A gastritis (9 with gastric carcinoid) were examined for density and micronodules of argyrophil endocrine cells. Fasting blood samples were analyzed for chromogranin A and B, gastrin, and somatostatin. Results: All patients with carcinoid and 17 of the 34 without carcinoid had micronodules in the gastric fundic mucosa. The median plasma chromogranin A concentration was 5.7 (3.5-40.0) nmol/l in patients with carcinoid, 4.5 (3.0-9.5) nmol/l in patients with micronodules, and 3.7 (0.8-6.0) nmol/l in patients without micronodules. Overall, chromogranin A concentrations correlated to endocrine cell densities in the fundic mucosa (r = 0.64, P < 0.001) and to gastrin concentrations (r = 0.71, P < 0.001). Plasma somatostatin and chromogranin B concentrations did not differ significantly between the groups. Conclusion: In type-A gastritis, analysis of plasma chromogranin A may be a useful complement to histology in estimating the endocrine cell mass. Moreover, subclinical type-A gastritis may be a source of error when chromogranin A analysis is used in the search for neuroendocrine neoplasia.