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Geisinger Medical Laboratories Test Catalog
CORTICOTROPIN RELEASING FACTOR(PLASMA) |
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Geisinger Epic Procedure Code: LAB2079
Geisinger Epic ID: 43807
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SPECIMEN COLLECTION |
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Specimen type: |
Plasma | |
Preferred collection container: |
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Specimen required: |
3 mL EDTA plasma | |
Special notes: |
An AM specimen is preferred. | |
Patient preparation: |
Patient should be fasting 10 - 12 hours and should not be on any corticosteroid, ACTH, or estrogen medications, if possible, for at least 48 hours prior to collection of specimen. | |
| SPECIMEN PROCESSING |
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Specimen processing instructions: |
Plasma should be frozen immediately after separation. | |
Transport temperature: |
Frozen. | |
Specimen stability: |
Room temperature: NOT ACCEPTABLE. Refrigerated: 1 day. Frozen: 6 months. | |
Rejection criteria: |
Serum is not acceptable. | |
TEST DETAILS |
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Reference interval: |
Up to 10 pg/mL. | |
Additional information: |
Report available in 7-10 days. | |
CPT code(s): |
83519 | |
| Note: The billing party has sole responsibility for CPT coding. Any questions regarding coding should be directed to the payer being billed. The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only. | ||
Methodology: |
Radioimmunoassay (RIA) |
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Synonyms: |
CRF, CRH, quest code 92100 CRF
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Clinical significance: |
Corticotropin Releasing Factor is a 41 amino acid peptide produced in the hypothalamus. It stimulates the release of ACTH from the pituitary which in turn releases Cortisol from the adrenal gland. The Cortisol produced rapidly shuts off CRF secretion acting as a negative feedback control. CRF also releases b-Endorphin, b-Lipotropin and other related proopiomelanocortin peptides. Ectopic tumors producing ACTH also frequently produce CRF. In these patients ACTH usually does not respond to Dexamethasone suppression. CRF is markedly elevated in third trimester pregnancy. Most of it is produced by the placenta and is bound to CRF-Binding Protein and is biologically inactive. The CRF stimulation test is the most effective method of differentiating primary from secondary adrenal insufficiency and in differentiating hypothalamic from pituitary causes. | |