Quantitative Chemiluminescent Immunoassay
Plasma separator tube or serum separator tube. Collect one tube per timed specimen. Also acceptable: Green (sodium or lithium heparin) or lavender (EDTA), or pink (K2EDTA).
Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma per timed specimen to individual ARUP Standard Transport Tubes. (Min: 0.4 mL per timed specimen)
Frozen. Also acceptable: Refrigerated.
Tissue or urine. Grossly hemolyzed or lipemic specimens.
Ambient: 24 hours; Refrigerated: 1 week; Frozen: 2 months
For pediatric patients, very low peak growth hormone (GH) concentrations on stimulation testing are consistent with severe GH deficiency (GHD). Thresholds distinguishing normal from partial GHD have not been well established. Inadequate response to two different provocative tests is required for diagnosis of GHD. (Grimberg et al. Horm Res Paediatr 2016;86:361-397).
In adults, expected peak GH concentrations depend on the stimulation test performed, as described in Endocrine Society guidelines for the evaluation and treatment of adults with GHD (Yuen KCJ et al. Endocr Pract. 2019;25(11):1191-1232).
For suppression testing, healthy subjects have GH concentrations of less than 1 ng/mL within 2 hours of ingestion of a 75 or 100 gram glucose dose. Patients with acromegaly fail to show normal suppression. (Katznelson et al. J Clin Endocrinol Metab, 2014, 99(11):3933-3951).
This Growth Hormone assay is now standardized to the Recombinant Second International Standard (IS): 98/574. Growth hormone results read approximately 25 percent lower than with the previous standards (First IS: 80/505). Reference ranges have also been modified according to the assay manufacturer.
|Component Test Code*||Component Chart Name||LOINC|
|0070084||Growth Hormone 90 Minutes||14147-3|
- GH testing
- Growth Hormone Provocative Test
- Growth Hormone Stimulation
- growth hormone, Serum
- Human Growth Hormone
- Somatotrophic Hormone