IGF Binding Protein-3 (IGFBP-3) : 34458

Test Code

IGFP3Q or 34458

Alias/See Also

Insulin-Like Growth Factor Binding Protiein

CPT Codes
83520

Instructions

Serum separator tube or plain red tube.

Transport Container

Centrifuge serum separator tube and transport. If plain red, centrifuge and aliquot 1 mL serum (Min: 0.5 mL) into a standard transport tube.

Transport Temperature

Refrigerated.

Specimen Stability

Ambient: 7 days; Refrigerated: 14 days; Frozen: 1 year

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis; Gross lipemia.

Methodology
Immunoassay (IA)

Setup Schedule

Tuesday - Saturday

Report Available

1-2 days (From receipt at performing laboratory)

Reference Range

IGF-Binding Protein-3 (mg/L)
Age           Range
1-7 days    less than 0.7
8-15 days    0.5-1.4
16 days-1 year 0.7-3.6
2 years 0.8-3.9
3 years 0.9-4.3
4 years             1.0-4.7
5 years 1.1-5.2
6 years             1.3-5.6
7 years             1.4-6.1
8 years             1.6-6.5
9 years             1.8-7.1
10 years 2.1-7.7
11 years 2.4-8.4
12 years 2.7-8.9
13 years 3.1-9.5
14 years    3.3-10.0
15 years 3.5-10.0
16 years           3.4-9.5
17 years 3.2-8.7
18 years 3.1-7.9
19 years    2.9-7.3
20 years 2.9-7.2
21-30 years      3.4-7.8
31-40 years      3.4-7.0
41-50 years      3.3-6.7
51-60 years    3.4-6.9
61-70 years 3.0-6.6
71-80 years      2.5-5.7
81-85 years      2.2-4.5
greater than 85 years No primary data

Protein-3 (IGFBP-3) by Pubertal (Tanner) Stage (mg/L):
Females
Tanner I    1.2-6.4
Tanner II 2.8-6.9
Tanner III    3.9-9.4
Tanner IV    3.3-8.1
Tanner V    2.7-9.1
Males
Tanner I    1.4-5.2
Tanner II 2.3-6.3
Tanner III 3.1-8.9
Tanner IV    3.7-8.7

Clinical Significance

Insulin-like growth factor binding proteins bind IGF-I and IGF-II with high affinity but do not bind insulin. Of the six distinct IGF binding proteins structurally characterized at this time, IGFBP-3 has been shown to be the major carrier of the IGFs, transporting approximately 95% of circulating IGF-I and IGF-II.
IGFBP-3 is growth hormone (GH) responsive. Thus, levels are high in cromegaly and low in hypopituitarism, and levels increase in GH-deficient children after GH administration. Thus, both assays and the ratios of IGF-I/IGFBP-2 and IGFBP-2/IGFBP-3 are useful as markers of GH action and for discriminating between growth hormone deficiency and short stature due to other etiologies in children. Other causes of short stature that result in reduced IGFBP-3 levels include poorly controlled diabetes.

The IGFBP-3 assay is useful in assessing nutritional status, since IGFBP-3 decreases during both caloric and protein restriction.

Performing Laboratory
Quest Diagnostics

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.