title: Hypergastrinemia as a cause of chromogranin a increase in blood in patients suspected to have neuroendocrine tumor.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Norwegian University of Science and Technology, Faculty of Medicine, Trondheim, Norway.
authors.forename: O
authors.initials: O
authors.lastname: Kleveland
authors.forename: U
authors.initials: U
authors.lastname: Syversen
authors.forename: K
authors.initials: K
authors.lastname: Slørdahl
authors.forename: H L
authors.initials: HL
authors.lastname: Waldum
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D053379:Chromogranin A; D002864:Chromogranins / Q000097:blood*; D019861:Enterochromaffin-like Cells / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D015408:Gastrinoma / Q000097:blood* / Q000473:pathology*; D005755:Gastrins / Q000097:blood*; D005757:Gastritis, Atrophic / Q000097:blood; D006801:Humans; D006965:Hyperplasia / Q000097:blood; D007124:Immunoenzyme Techniques; D018358:Neuroendocrine Tumors / Q000097:blood* / Q000473:pathology*; D020116:Pepsinogen A / Q000097:blood; D011863:Radioimmunoassay; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000097:blood* / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; C506150:CHGA protein, human; D053379:Chromogranin A; D002864:Chromogranins; D005755:Gastrins; D020116:Pepsinogen A