Serum chromogranin A as a screening test for gastric enterochromaffin-likecell hyperplasia during acid-suppressive therapy

Background Serum chromogranin A (CgA), a marker of neuroendocrine neoplasia , increases during profound gastric acid inhibition, possibly reflecting th e trophic effect of gastrin on the enterochromaffin-like (ECL) cells. Aims This study investigated the clinical value of serum CgA as a screening test for gastric fundic enterochromaffin-like (ECL) cell hyperplasia durin g acid-suppressive therapy. Method A consecutive series of 230 dyspeptic patients referred for upper ga strointestinal endoscopy was investigated in a cross-sectional design. They were 154 patients on continuous medium-term (6 weeks to one year) or long- term (longer than one year) acid inhibition with either proton pump inhibit ors (PPIs, n = 117) or histamine(2)-receptor antagonists (H2RAs, n = 37) fo r gastro-esophageal reflux disease, and 76 nontreated subjects, with normal endoscopic findings (control group). Fasting blood samples were analysed f or gastrin and CgA. Gastric biopsy specimens (oxyntic mucosa) were examined for histological evaluation of gastritis (Sydney classification) and of EC L cell hyperplasia (Solcia classification). Results Serum CgA levels correlated positively with serum gastrin, followin g a quadratic function (r = 0.78, P < 0.0001). Elevated serum CgA values du ring long-term acid inhibition correlated with the presence and severity of fundic ECL cell hyperplasia. Multivariate analysis identified hypergastrin aemia (P < 0.0001), duration of acid inhibition (P < 0.0001), H. pylori inf ection (P = 0.008), ECL cell hyperplasia (P = 0.012), and body gland atroph y (P = 0.043) as independent predictors of elevated serum CgA. In subjects on long-term acid inhibition (n = 123), serum CgA was equally sensitive but more specific than serum gastrin for the detection of ECL cell hyperplasia . (sensitivity, 91.3% for both; specificity, 73% vs. 43%, P < 0.0001). Conclusions During long-term gastric acid inhibition, serum CgA levels refl ect the presence and severity of fundic ECL cell hyperplasia. Serum CgA is therefore a useful screening test for gastric ECL cell proliferative change s within this context.