Laboratory Services

Gastrin, Serum

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Updated Test Information:

Test Description
Gastrin, Serum
Test ID
GAST
General Information

Useful for:



  • Investigation of patients with achlorhydria or pernicious anemia

  • Investigation of patients suspected of having Zollinger-Ellison syndrome

  • Diagnosis of gastrinoma

Specimen Type

Serum

Specimen Requirements

  • Preferred: Serum Gel

  • Acceptable: Red Top

Specimen Collection / Processing Instructions

  • Fasting (8 hours) required

  • 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

  • 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

  • Drugs that interfere with gastrointestinal motility (eg, opioids) should be discontinued for at least 2 weeks before serum gastrin testing

Additional Processing Details

  • If multiple specimens are collected, submit each vial under a separate order

  • Label specimens with corresponding collection time

  • Centrifuge at refrigerated temperature within 2 hours of collection and immediately aliquot serum into plastic vial.

Stability

  • Frozen (preferred): 30 days

  • Refrigerated: 24 hours

Unacceptable Specimen Conditions

Gross hemolysis

Limitations

  • Isolated serum gastrin levels can only be interpreted in fasting patients; nonfasting specimens are uninterpretable

  • Artifactual hypergastrinemia may be observed in fasting patients who have undergone procedures that result in temporary gastric distention or dysmotility (eg, after gastroscopy)

  • Renal failure prolongs the serum half-life of gastrin and is associated with increased serum gastrin levels

  • Drugs that interfere with gastric acid secretion, in particular proton pump inhibitors (eg, omeprazole, pantoprazole, dexlansoprazole, lansoprazole, rabeprazole), can lead to significant elevations of serum gastrin levels often above the normal range. These drugs can be discontinued, if feasible, for at least 1 week before serum gastrin measurement in order to avoid gastrin elevation

  • Drugs that interfere with gastrointestinal motility (eg, opioids) may also interfere with serum gastrin testing

Methodology

Automated Chemiluminescent Immunometric Assay

Estimated TAT

1-3 days

Testing Schedule

Monday-Saturday

Retention

3 months

CPT Code(s)

82941

Additional Information
Minimum Sample Volume

0.5 mL

Reference Range

Fasting Specimen: < 100 pg/mL

Performing Lab

Mayo

LOINC Code(s)

2333-3