Test Details
Methodology
Radioimmunoassay (RIA)
Result Turnaround Time
4 - 9 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Determination of cAMP is useful in the clinical assessment of parathyroid function.
Custom Additional Information
Cyclic adenosine-3'-5'-monophosphate (cAMP) serves as a second messenger in signal transduction of various hormones, like adrenaline, ACTH, LH, FSH, glucagon, and calcitonin. The hormone itself is the first messenger, binding to specific membrane receptors of hormone-responsive cells. This leads to the activation of an enzyme located at the inner side of the cell membrane, called adenylate cyclase, which catalyzes the synthesis of cAMP from ATP. The increased cellular level of cAMP initiates the activation of protein kinases. The determination of cAMP in urine or plasma has become more and more important in the clinical assessment of parathyroid functions. The parathyroid hormone (PTH) stimulates the synthesis of cAMP in the renal cortex and an increased secretion of cAMP. Cyclic AMP is a specific marker of circulating PTH: 90% of patients with hyperparathyroidism show increased levels of nephrogenic cAMP. The determination of cAMP is also significant for the differential diagnosis of hypercalcemia
Specimen Requirements
Specimen
Plasma, frozen
Volume
0.5 mL
Minimum Volume
0.2 mL (Note: this volume does not allow for repeat testing.)
Container
Lavender-top (EDTA) tube
Collection Instructions
Keep blood samples on ice and centrifuge as soon as possible. Separate plasma from cells and transfer to a plastic transport tube. Freeze immediately. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Stability Requirements
Temperature | Period |
|---|---|
Frozen | 9 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
13.9–25.1 pmol/L
Reference interval was developed through Labcorp in-house study.
Storage Instructions
Freeze.
Patient Preparation
Patient should have no radioactive isotopes administered within 48 hours prior to venipuncture.
Causes for Rejection
Gross hemolysis; gross lipemia; nonfrozen specimen received; non-EDTA plasma specimen received
References
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 004984 | Cyclic AMP, Plasma | 25498-7 | 004985 | Cyclic AMP, Plasma | pmol/mL | 25498-7 |
| Order Code | 004984 | |||||
| Order Code Name | Cyclic AMP, Plasma | |||||
| Order Loinc | 25498-7 | |||||
| Result Code | 004985 | |||||
| Result Code Name | Cyclic AMP, Plasma | |||||
| UofM | pmol/mL | |||||
| Result LOINC | 25498-7 |