Test Directory

Diagnose Zollinger-Ellison (Z-E) syndrome; diagnose gastrinoma. Gastrin >1000 pg/mL with gastric acid hypersecretion (basal acid secretion >15 mmol/hour in a patient with peptic ulcer who has not had surgery) establishes unequivocally the diagnosis of the Zollinger-Ellison syndrome. Antral G-cell hyperplasia may relate to high gastrin levels and duodenal ulcer.

Specimen Type: Serum 

Collection Container: Gold Top, Serum Separator 

Alternate Collection Container: Red Top, Plain

Desired Specimen Volume: 0.5 mL

1. Collect a gold top, serum separator tube via venipuncture.

1. Separate serum from cells.
2. Transfer 0.5 mL of serum to a LabCorp PP Transpak frozen purple tube.
3. Freeze immediately and maintain frozen until tested.
4. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

• The patient must be fasting overnight, 12 to 14 hours
• This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.

Transport to the laboratory frozen.

• Gross hemolysis
• Patient not fasting
• Specimen not received frozen
• Gross lipemia
• Plasma specimen

See patient report.

Gastric hyperacidity must be documented. Gastric ulcer, chronic renal failure, hyperparathyroidism, pyloric obstruction, carcinoma of stomach, vagotomy without gastric resection, retained gastric antrum and short bowel syndrome have been reported with moderate elevations of gastrin levels. Gastrin levels are increased with pernicious anemia. H₂-receptor blockers (cimetidine) may result in elevated levels. Overlap of serum gastrin values between gastrinoma and other states occurs. Up to 40% of Z-E patients have fasting gastrin values between 100 and 500 pg/mL, while a few patients with gastric or duodenal ulcer without gastrinoma, have results in this range. At least half of patients with the Z-E syndrome lack diagnostic serum gastrin levels, although in nearly all, fasting serum gastrin levels are increased. One report describes a patient with Z-E syndrome with a normal initial gastrin level.