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HelpTest Code HPP Pancreatic Polypeptide, Plasma
Reporting Name
Pancreatic Polypeptide, PUseful For
Detecting pancreatic endocrine tumors
Assessing vagal nerve function after meal or sham feeding
Method Name
Radioimmunoassay (RIA)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Plasma EDTAOrdering Guidance
This test should not be requested on patients who have recently received radioactive materials.
Necessary Information
Patient's age must be provided.
Specimen Required
Patient Preparation: Fasting (8 hours)
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 3 mL
Collection Instructions:
1. Place specimen on wet ice and keep cold at all times following collection.
2. Centrifuge (refrigerated centrifuge is not required) and aliquot plasma into plastic vial. Freeze immediately.
Specimen Minimum Volume
0.35 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma EDTA | Frozen | 90 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
Reference Values
0-19 years: Not established
20-29 years: <228 pg/mL
30-39 years: <249 pg/mL
40-49 years: <270 pg/mL
50-59 years: <291 pg/mL
60-69 years: <312 pg/mL
70-79 years: <332 pg/mL
≥80 years: Not established
Day(s) Performed
Monday, Wednesday
CPT Code Information
83519
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HPP | Pancreatic Polypeptide, P | 2721-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8014 | Pancreatic Polypeptide, P | 2721-9 |
Clinical Information
Pancreatic polypeptide (PP) is secreted by the pancreas in response to hypoglycemia, ingestion of food, or "sham" feeding (food is chewed, but not swallowed) secondary to vagal nerve stimulation. Secretion is blocked by vagotomy or atropine.
The exact physiologic role of PP is undetermined, although the hormone is thought to be involved in exocrine pancreatic secretion and gallbladder emptying.
Markedly elevated levels are often associated with endocrine tumors of the pancreas (eg, insulinoma, glucagonoma, pancreatic polypeptide-secreting tumor of the pancreas). Patients with diabetes may also have elevated PP levels.
A lack of response to sham feeding may indicate vagal nerve damage (eg, surgery-related nerve damage, autonomic nerve disorders). Extensive pancreatic destruction (eg, chronic pancreatitis, pancreatic cancer) may also result in low basal PP levels and a lack of response to sham feeding.
Interpretation
High levels of pancreatic polypeptide may be seen in pancreatic endocrine tumors, diabetes, and a nonfasting state. Markedly elevated levels may be seen in some pancreatic exocrine tumors.
A normal response to a sham feeding consists of a rapid pancreatic polypeptide rise over baseline followed by a return to baseline. With vagal damage, no increase over baseline is seen.
Cautions
Pancreatic polypeptide (PP) normal values increase with age (approximately 20 pg/mL per decade).
Nonfasting state results in falsely elevated values.
The sham feeding test is invalid if food is swallowed. Ingestion of food typically results in a significant and prolonged PP increase over baseline (typically >200 pg/mL).
This test should not be requested in patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference. A recommended time period before collection cannot be made because it will depend on the isotope administered, the dose given, and the clearance rate in the individual patient. Specimens will be screened for radioactivity prior to analysis. Radioactive specimens received in the laboratory will be held and assayed after the radioactivity has sufficiently decayed. This will result in a test delay.
Method Description
A radioimmunoassay technique is used. The assay system utilizes rabbit-antihuman pancreatic polypeptide (PP) antiserum, a standard or patient plasma specimen, and radiolabeled human PP that has been iodinated by a modified Hunter-Greenwood technique.(Unpublished Mayo method)