Growth Hormone Antibody

Test Code

37072

CPT Codes
86277

Preferred Specimen

0.5 mL serum

Minimum Volume

0.2 mL

Transport Temperature

Refrigerated (cold packs)

Specimen Stability

Room temperature: 7 days
Refrigerated: 14 days
Frozen: 28 days

Methodology
Radiobinding Assay (RBA)

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Tues; Report available: 4-11 days

Clinical Significance

This test helps identify growth hormone (GH) antibodies and is useful in assessing patients who fail to respond to human GH replacement therapy, especially those with isolated growth hormone deficiency type 1A [1,2].

Recombinant human growth hormone (rhGH) has been approved by the US Food and Drug Administration (FDA) to treat children with GH deficiency and idiopathic short stature (ie, non-GH-deficient short stature) [3] and adults with growth hormone deficiency [4] and AIDS-associated wasting or cachexia [5]. Because rhGH is exogenous, an immunogenic response can be induced with the development of GH antibodies. Approximately 2% to 22% of children receiving rhGH treatment have detectable GH antibodies, although the biological significance of these antibodies differs [6]. Treatment efficacy of rhGH can be diminished when those antibodies neutralize rhGH and consequently inhibit the growth promoting effect, particularly in patients with isolated growth hormone deficiency type 1A who completely lack endogenous GH [1]. Therefore, measurement of GH antibodies may help identify the cause of suboptimal response of rhGH therapy.

In addition to GH neutralizing antibodies, other causes may be associated with inadequate treatment response to rhGH, such as patient compliance, hypothyroidism, under-nutrition, and advanced bone age [2].

The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.

References
1. Collett-Solberg PF, et al. Horm Res Paediatr. 2019;92(1):1-14.
2. SKYTROFA. Package insert. Ascendis Pharma; 2021.
3. Grimberg A, et al. Horm Res Paediatr. 2016;86(6):361-397.
4. FDA approves weekly therapy for adult growth hormone deficiency. The US Food and Drug Administration. Accessed March 9, 2023. https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-weekly-therapy-adult-growth-hormone-deficiency
5. Windisch PA, et al. Ann Pharmacother. 1998;32(4):437-445.
6. Binder G, et al. Horm Res Paediatr. 2019;91(1):17-24

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.