Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (943 page)

   Gastrin: 0–100 pg/mL

   Gastrin stimulation test (after secretin): no response or slight suppression

   Gastrin stimulation test (after calcium infusion): little or no increase over baseline

   Use

   Diagnosis of Z-E syndrome: The gastrin test after secretin (2–3 U/kg injected over 30 seconds) is preferred provocative test for patients suspected of having Z-E syndrome.

   Diagnosis of gastrinoma: Basal and secretin-stimulated serum gastrin measurements are the best laboratory tests for gastrinoma.

   Investigation of patients with achlorhydria or pernicious anemia.

   Interpretation

Increased In

   Increased serum gastrin without gastric acid hypersecretion

   Atrophic gastritis, especially when associated with circulating parietal cell antibodies

   PA in approximately 75% of patients

   Some cases of carcinoma of the body of the stomach, a reflection of the atrophic gastritis that is present

   Gastric acid inhibitor therapy