Test Id : CARU
Cyclic Adenosine Monophosphate (cAMP), Urinary Excretion, Serum and Urine
Useful For
Suggests clinical disorders or settings where the test may be helpful
Differential diagnosis of hypercalcemia
As an adjunct to serum parathyroid hormone measurements, especially in the diagnosis of parathyroid hormone resistance states, such as pseudohypoparathyroidism
Profile Information
A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.
| Test Id | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| ACREA | Creatinine, S | Yes, (order CRTS1) | Yes |
| CAMP | Cyclic Amp, Urinary Excretion | No | Yes |
| CRETR | Creatinine, Random, U | Yes, (order RCTUR) | Yes |
Method Name
A short description of the method used to perform the test
ACREA, CRETR: Enzymatic Colorimetric Assay
CAMP: Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Adenosine, 5' Monophosphate, Cyclic AMP
AMP
C AMP
cAMP
Cyclic AMP Excretion
Urinary Cyclic AMP
abc
Specimen Type
Describes the specimen type validated for testing
Serum
Urine
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Both serum and urine are required. Serum must be collected at the time of the urine collection.
Specimen Type: Serum
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Within 2 hours of collection serum gel tubes should be centrifuged.
2. Within 2 hours of collection red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial.
3. Label specimen as serum.
Specimen Type: Urine
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube: Plastic vial
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a random urine specimen.
2. Label specimen as urine.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
Serum: 0.5 mL
Urine: 1 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 7 days | |
| Frozen | 90 days | ||
| Urine | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Differential diagnosis of hypercalcemia
As an adjunct to serum parathyroid hormone measurements, especially in the diagnosis of parathyroid hormone resistance states, such as pseudohypoparathyroidism
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
3'-5'-cyclic adenosine monophosphate (cAMP) functions as an intracellular "second messenger" playing a key role in cellular functions such as transcription, metabolism, mitochondrial homeostasis, cell division, and cell death. Several hormones such as calcitonin, dopamine, glucagon, glucagon like peptide-1, vasoactive intestinal peptide and parathyroid hormone (PTH) have been shown to increase the formation of cAMP in the kidney by the action of adenylate cyclase. It has been shown that a significant portion of the urinary cAMP is generated in response to parathyroid hormone. As a result, urinary cAMP measurements can be used for distinguishing between PTH or non-PTH mediated hypercalcemia and aid in the differential diagnosis of hypercalcemia. Additionally, measurements of urinary cAMP levels following PTH stimulation are useful for the differential diagnosis of hypoparathyroid disorders. Urinary cAMP is elevated in about 85% of patients with hyperparathyroidism.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
CYCLIC AMP
1.3-3.7 nmol/dL of glomerular filtrate
CREATININE, SERUM
Males
0-11 months: 0.17-0.42 mg/dL
1-5 years: 0.19-0.49 mg/dL
6-10 years: 0.26-0.61 mg/dL
11-14 years: 0.35-0.86 mg/dL
> or =15 years: 0.74-1.35 mg/dL
Females
0-11 months: 0.17-0.42 mg/dL
1-5 years: 0.19-0.49 mg/dL
6-10 years: 0.26-0.61 mg/dL
11-15 years: 0.35-0.86 mg/dL
> or =16 years: 0.59-1.04 mg/dL
CREATININE, URINE
No reference values apply. Interpret with other clinical data.
Interpretation
Provides information to assist in interpretation of the test results
3'-5' -cyclic adenosine monophosphate (cAMP) is elevated in about 85% of patients with hyperparathyroidism and in about 50% of patients with humoral hypercalcemia of malignancy.
Minimal to no increase in cAMP levels following parathyroid hormone stimulation suggests type I pseudohypoparathyroidism.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Parathyroid suppression (hypoparathyroidism) does not lower urinary 3'-5'-cyclic adenosine monophosphate (cAMP) excretion to definitively subnormal values.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Shaw JW, Oldham SB, Rosoff L, Bethune JE, Fichman MP. Urinary cyclic AMP analyzed as a function of the serum calcium and parathyroid hormone in the idfferential diagnosis of hypercalcemia. J Clin Invest. 1977;59(1):14-21. doi:10.1172/JCI108611
2. Babka JC, Bower RH, Sode J. Nephrogenous cyclic AMP levels in primary hyperparathyroidism. Arch Intern Med. 1976;136(10):1140-1144
3. Dohan PH, Yamashita K, Larsen PR, Davis B, Deftos L, Field JB. Evaluation of urinary cyclic 3'5'-adenosine monophosphate excretion in the differential diagnosis of hypercalcemia. J Clin Endocrinol Metab. 1972;35(6):775-784. doi:10.1210/jcem-35-6-775
4. Pak CY, Kaplan R, Bone H, Townsend J, Waters O. A simple test for the diagnosis of absorptive, resorptive and renal hypercalciurias. N Engl J Med. 1975;292(10):497-500. doi:10.1056/NEJM197503062921002
5. Neelon FA, Birch BM, Drezner M, Lebovitz HE. Urinary cyclic adenosine monophosphate as an aid in the diagnosis of hyperparathyroidism. Lancet. 1973;1(7804):631-633. doi:10.1016/s0140-6736(73)92199-5
6. Drezner MK, Neelon FA, Curtis HB, Lebovitz HE. Renal cyclic adenosine monophosphate: an accurate index of parathyroid function. Metabolism. 1976;25(10):1103-1112. doi:10.1016/0026-0495(76)90018-4
7. Delrue C, Speeckaert R, Moresco RN, Speeckaert MM. Cyclic Adenosine Monophosphate Signaling in Chronic Kidney Disease: Molecular Targets and Therapeutic Potentials. Int J Mol Sci. 2024;25(17):9441. doi:10.3390/ijms25179441
8. Kaminsky NI, Broadus AE, Hardman JG, et al. Effects of parathyroid hormone on plasma and urinary adenosine 3',5'-monophosphate in man. J Clin Invest. 1970;49(12):2387-95. doi:10.1172/JCI106458
9. Tze WJ, Saunders J, Drummond GI. Urinary 3'5' cyclic AMP. Diagnostic test in pseudohypoparathyroidism. Arch Dis Child. 1975;50(8):656-658. doi:10.1136/adc.50.8.656
10. Ishida M, Seino Y, Simotsuji T, et al. Differential diagnosis of hypoparathyroid disorders during childhood. Calcif Tissue Int. 1980;31(3):203-207. doi:10.1007/BF02407182
11. Mantovani G. Clinical review: Pseudohypoparathyroidism: diagnosis and treatment. J Clin Endocrinol Metab. 2011;96(10):3020-3030. doi:10.1210/jc.2011-1048
Method Description
Describes how the test is performed and provides a method-specific reference
Acetonitrile is added to urine samples to dilute and precipitate proteins in proteinaceous samples. Next, the sample is further diluted with buffer followed by the addition of internal standard (8-methyl amino cyclic AMP). The resulting supernatant is then injected on the liquid chromatography tandem mass spectrometry instrument, which performs chromatographic separation and target measurement of 3'-5'-cyclic adenosine monophosphate (cAMP). Urine and serum creatinine levels are used to determine the clearance of cAMP from the kidneys.(Unpublished Mayo method)
Creatinine:
The enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically.(Package insert: Creatinine plus v2. Roche Diagnostics; V15.0, 03/2019)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Wednesday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
82030
82570
82565
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| CARU | Cyclic Amp, Urinary Excretion | 21052-6 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 179 | Cyclic Amp, Urinary Excretion | 22712-4 |
| ACREA | Creatinine, S | 2160-0 |
| CRETR | Creatinine, Random, U | 2161-8 |