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HelpTest Code LAB7547 Glucagon, Plasma
Additional Codes
GLP
Useful For
Diagnosis and follow-up of glucagonomas and other glucagon-producing tumors
Assessing diabetic patients with problematic hyper- or hypoglycemic episodes (extremely limited utility)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Plasma EDTASpecimen Required
Patient Preparation: Patient should fast for 8 hours before specimen collection.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions:
1. Pre-chill lavender top (EDTA) tube at 4° C before drawing the specimen.
2. Draw blood into the pre-chilled tube and process as follows:
a. Chill filled tube in wet ice for 10 minutes.
b. Centrifuge in a refrigerated centrifuge or in a pre-chilled centrifuge carrier.
c. Immediately after centrifugation, aliquot plasma into a plastic vial and freeze.
Specimen Minimum Volume
0.45 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma EDTA | Frozen | 90 days |
Reference Values
≥1 year of age: ≤159 pg/mL
<1 year of age: No reference interval established.
For International System of Units (SI) for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
Day(s) Performed
Tuesday, Friday
CPT Code Information
82943
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| GLP | Glucagon, P | 2338-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 9358 | Glucagon, P | 2338-2 |
Interpretation
Elevated glucagon concentrations in the absence of hypoglycemia may indicate the presence of a glucagon-secreting tumor. Successful treatment of a glucagon-secreting tumor is associated with normalization of glucagon levels.
Inappropriate elevations in glucagon concentrations in patients who are hyperglycemic and have type I diabetes indicate that paradoxical glucagon release may contribute to disease severity. This can be observed if insulin treatment is inadequate and patients are ketotic. However, glucagon measurement plays little, if any, role in the diagnostic workup of diabetic ketoacidosis.
In patients with diabetes, low glucagon concentrations (undetectable or in the lower quartile of the normal range) in the presence of hypoglycemia indicate impairment of hypoglycemic counter regulation. These patients may be particularly prone to recurrent hypoglycemia. This can be a permanent problem due to islet alpha-cell destruction or other, less well understood processes (eg, autonomous neuropathy). It can also be functional, most often due to over-tight blood glucose control and may be reversible after decreasing insulin doses.
Method Description
The glucagon enzyme-linked immunosorbent assay (ELISA) is a quantitative two-step sandwich type immunoassay. In the first step, calibrators, controls, and unknown samples are added to glucagon antibody-coated microtiter wells and incubated with biotinylated glucagon antibody. After the first incubation and washing, the wells are incubated with streptavidin horseradish peroxidase conjugate (SHRP). After the second incubation and washing step, the wells are incubated with substrate solution (tetramethylbenzidine: TMB). After TMB incubation, an acidic stopping solution is added. In principle, the antibody-biotin conjugate binds to the solid phase antibody-antigen complex, which in turn binds to the streptavidin-enzyme conjugate. The antibody-antigen-biotin conjugate-SHRP complex bound to the well is detected by enzyme-substrate reaction. The degree of enzymatic turnover of the substrate is determined by dual wavelength absorbance measurement at 450 nm as primary test filter and 630 nm as reference filter. The absorbance measured is directly proportional to the concentration of glucagon in the samples and calibrators.(Package insert: Glucagon ELISA IFU. Ansh Labs, Revision 09, 01/2023)
Report Available
3 to 7 daysSpecimen Retention Time
2 weeksReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Method Name
Enzyme-Linked Immunosorbent Assay (ELISA)
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.