Laboratory: Clinical Biochemistry
Test Name:
GASTRIN - (S)
Test Code: GAST
Clinical Information:
Gastrin is a peptide hormone produced by the gastric mucosa. It promotes gastric cell proliferation, direct acid secretion, and indirect acid secretion through histamine release. It also stimulates gastric motility and release of pepsin and intrinsic factor. Stomach pH is the main factor controlling gastrin production and release. Gastrin testing is useful in the investigation of achlorhydria (absence of HCl in the stomach) as well as for the diagnosis of gastrinoma.

Patient Preparation Instructions:
1. For 12 hours before specimen collection, do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
2. If medically feasible, proton pump inhibitor (omeprazole, lansoprazole, dexlansoprazole, esomeprazole, pantoprazole, and rabeprazole) therapy should be discontinued 1 week before measurement of serum gastrin levels.
3. Drugs that interfere with gastrointestinal motility should be discontinued for at least 2 weeks before serum gastrin testing.
Collection Devices:
Collect after a 14 hr fast or prior to next feeding in infants. Place immediately on ice and send to lab as soon as possible.
Specimen Required:


Serum: 2.0 mL
Referral:
Requisition:
Reference Values:
1. Ellison EC, Johnson JA: The Zollinger-Ellison syndrome: a comprehensive review of historical, scientific, and clinical considerations. Curr Probl Surg. 2009 Jan;46:13-106.
2. Kuiper P, Biemond I, Masclee AA, Jansen JB, Verspaget HW, Lamers CB, Diagnostic efficacy of the secretin stimulation test for the Zollinger-Ellison syndrome: an intra-individual comparison using different dosages in patients and controls. Pancreatology. 2010;10(1):14-8. Epub 2010 Mar 19.
3. Metz DC, Cadiot G, Poitras P, Ito T, Jensen RT , Diagnosis of Zollinger-Ellison syndrome in the era of PPIs, faulty gastrin assays, sensitive imaging and limited access to acid secretory testing. Int J Endocr Oncol. 2017;4(4):167. Epub 2017 Oct 11. 
Availability:
Within 2 Weeks
See Also:
More Information:
Freeze serum within 4 hours of separation.  Avoid repeat freeze/thaw.  Stability:  Frozen - 1 month.  Store and ship frozen to In-Common Laboratories.