Insulin-like growth factor binding protein-3 (IGFBP-3)
- Description
- IGFBP-3 measured by chemiluminescent immunoassay using the Immulite XPi
- Clinical details
IGFBP-3 is produced largely by the liver but to a lesser extent in fibroblasts, the ovaries, and the placenta. The Insulin like growth factor binding proteins bind IGF-I and IGF-II with high affinity and control the ability of IGF-1 and IGF-II to bind to their receptors. The major functions of the IGF-binding proteins in circulation are:
a) to transport IGFs in the vascular system,
b) to regulate their half-lives, and
c) to control transcapillary transport into the extravascular fluid compartments.IGFBP-3 is the predominant IGF carrier of six distinct IGF binding proteins structurally characterised. It is responsible for complexing and transporting approximately 95% of circulating IGF-I and IGF-II.
Similarly to age-related changes for IGF-I, serum IGFBP-3 concentrations vary with age. In growth hormone deficient children, IGFBP-3 concentrations increase following GH administration whilst in contrast IGFBP-2 decreases following administration. Measurement of the binding proteins is useful in discriminating between growth hormone deficiency and short stature due to other aetiologies in children. IGFBP-3 may also be low in patients with short stature due to poorly controlled diabetes. In addition, IGFBP-3 decreases in calorific and protein restriction therefore IGFBP-3 measurement offers a useful tool in assessing nutritional status.
- Reference range
*Paediatric references ranges by age (Age & Ref range mg/L)* 1 yr; 0.7 – 3.6 2 yrs; 0.8 – 3.9 3 yrs; 0.9 – 4.3 4 yrs; 1.0 – 4.7 5 yrs; 1.1 – 5.2 6 yrs; 1.3 – 5.6 7 yrs; 1.4 – 6.1 8 yrs; 1.6 – 6.5 9 yrs; 1.8 – 7.1 10 yrs; 2.1 – 7.7 11 yrs; 2.4 – 8.4 12 yrs; 2.7 – 8.9 13 yrs; 3.1 – 9.5 14 yrs; 3.3 – 10.0 15 yrs; 3.5 – 10.0 16 yrs; 3.4 – 9.5 17 yrs; 3.2 – 8.7 18 yrs; 3.1 – 7.9 19 yrs; 2.9 – 7.3 20 yrs; 2.9 – 7.2 *Adult references ranges by age (Age & Ref range mg/L)* 21 – 25 yrs; 3.4 – 7.8 26 – 30 yrs; 3.5 – 7.6 31 – 35 yrs; 3.5 – 7.0 36 – 40 yrs; 3.4 – 6.7 41 – 45 yrs; 3.3 – 6.6 46 – 50 yrs; 3.3 – 6.7 51 – 55 yrs; 3.4 – 6.8 56 – 60 yrs; 3.4 – 6.9 61 – 65 yrs; 3.2 – 6.6 66 – 70 yrs; 3.0 – 6.2 71 – 75 yrs; 2.8 – 5.7 76 – 80 yrs; 2.5 – 5.1 81 – 85 yrs; 2.2 – 4.5
- Units
mg/L
- Testing site
- Synnovis : Reference Services : Blackfriars Hub
- Laboratory
- Immunochemistry
- Sample type and volume required
Serum or heparinized plasma (250 µL). EDTA plasma unsuitable
- Storage and transport
Must be sent frozen by courier.
- Turnaround time
1 week
- Contacts
Immunochemistry Laboratory at Blackfriars Hub
Phone: 020 8078 8984
Immunochemistry Laboratory
Floor 1, Synnovis hub
Friars Bridge Court
41-43 Blackfriars Road
London, SE1 8NZ