IGF-1, LC/MS

Test Code
16293

CPT Codes
84305

Preferred Specimen
0.5 mL serum

Minimum Volume
0.3 mL

Instructions
For red-top tubes, allow blood to clot 10-15 minutes at room temperature. Separate serum from cells and refrigerate. If sample collected in glass collection tube, transfer to plastic container.

Transport Container
Plastic screw-cap vial

Transport Temperature
Refrigerated (cold packs)

Specimen Stability
Room temperature: 48 hours
Refrigerated: 5 days
Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemia • Received in glass tube • Grossly icteric

Methodology
Liquid Chromatography/Mass Spectrometry (LC/MS)

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 FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: Daily; Report available: 2-5 days

Reference Range
 Pediatric Male (ng/mL) Female (ng/mL)
<1 Years 16-142 17-185
1-1.9 Years 16-134 16-175
2-2.9 Years 16-135 16-178
3-3.9 Years 30-155 38-214
4-4.9 Years 28-181 34-238
5-5.9 Years 31-214 37-272
6-6.9 Years 38-253 45-316
7-7.9 Years 48-298 58-367
8-8.9 Years 62-347 76-424
9-9.9 Years 80-398 99-483
10-10.9 Years 100-449 125-541
11-11.9 Years 123-497 152-593
12-12.9 Years 146-541 178-636
13-13.9 Years 168-576 200-664
14-14.9 Years 187-599 214-673
15-15.9 Years 201-609 218-659
16-16.9 Years 209-602 208-619
17-17.9 Years 207-576 185-551

Adult (ng/mL)
18-19.9 Years 108-548
20-24.9 Years 83-456
25-29.9 Years 63-373
30-39.9 Years 53-331
40-49.9 Years 52-328
50-59.9 Years 50-317
60-69.9 Years 41-279
70-79.9 Years 34-245
>80 Years 34-246

Z-Score (Male) -2.0 - +2.0 SD
Z-Score (Female) -2.0 - +2.0 SD


Clinical Significance
Insulin-like Growth Factor 1 (IGF-1, or Somatomedin C), a protein involved in stimulating somatic growth, is regulated principally by Growth Hormone (GH) and nutritional intake. IGF-1 is transported in serum by several proteins; this helps maintain relatively high IGF-1 plasma levels and minimizes fluctuations in serum IGF-1 concentrations.
Measuring IGF-1 is useful in several growth-related disorders. Dwarfism caused by deficiency of growth hormone (Hypopituitarism) results in decreased serum levels of IGF-1, while acromegaly (growth hormone excess) results in elevated levels of IGF-1. IGF-1 measurements are also helpful in assessing nutritional status; levels are reduced in undernutrition and restored with a proper diet



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.