Vasoactive Intestinal Peptide (Sendout)

Useful For: Detecting vasoactive intestinal polypeptide-producing tumors in patients with chronic diarrheal diseases.

Ordering Restrictions: This test should not be ordered on patients who have recently received radioactive material.

Interpretation:

An elevated vasoactive intestinal polypeptide (VIP) may indicate the presence of an enteropancreatic tumor causing hypersecretion of VIP.

Vasoactive intestinal polypeptide-producing tumors are unlikely with a 24-hour stool volume below 700 mL.

Cautions:

Test results cannot be interpreted as absolute evidence for the presence or absence of malignant disease. Use vasoactive intestinal polypeptide (VIP) results in conjunction with information from the clinical evaluation of the patient and other diagnostic procedures. This test should not be used for cancer screening or cancer diagnosis.

Assay sensitivity may be lower than the previous VIP radioimmunoassay. The absence of elevated VIP does not rule out the presence of malignancy.

In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies [HAMA] or heterophile antibodies), which may cause interference in some immunoassays. Caution should be used in interpretation of results and the laboratory should be alerted if the result does not correlate with the clinical presentation.

Vasoactive intestinal polypeptide concentration determinations are method dependent. Values obtained with different assay methods or kits may differ and cannot be used interchangeably.

3 mL blood in LAVENDER TOP (EDTA) tube

Note: Fasting samples are preferred. The patient should fast for 10 to 12 hours prior to collection of specimen.

Outside Laboratories: Promptly centrifuge sample and transfer plasma to a separate plastic vial. Freeze plasma immediately at -20°C while awaiting transport. Ship on dry ice.

Stability: Frozen: 90 days; Refrigerated: Unacceptable; Ambient: Unacceptable.

Unacceptable Conditions: Gross hemolysis or lipemia. Gross icterus: acceptable.

Promptly centrifuge sample and transfer plasma to a separate plastic vial. Freeze plasma immediately at -20°C.

Sendouts:

• Order Mayo Test: VIP
• Interfaced: Yes [Interface: 601; Worksheet: MAFZ]

Stability: Frozen: 90 days; Refrigerated: Unacceptable; Ambient: Unacceptable.

Unacceptable Conditions: Gross hemolysis or lipemia. Gross icterus: acceptable.