IGF-1

Diagnostic Use

Acromegaly: IGF-1 levels are elevated in active acromegaly and provide a good guide to activity of the disorder after treatment. Diagnosis of acromegaly also requires demonstration of autonomous growth hormone secretion.

Growth hormone deficiency: IGF-1 measurements are a relatively insensitive test for growth hormone deficiency. Levels are low in normal children aged <3 years, children with Laron dwarfism and some patients with classical growth hormone deficiency. IGF-1 levels may also be reduced in panhypopituitarism, panhypothyroidism and malnutrition.

Department

Endocrinology Lab

Delphic Registration Code

IGF

Laboratory Handling

Separating

Sample should be separated as soon as possible and sent to Endolab same day. If not in Endolab same day, then separate and freeze.

Synonyms

Insulin-like growth factor 1

Turnaround Time

10 days

Test Code

8381

Specimen Type

• Serum
• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Preferred if West Coast

• SST II (Gold Cap)

Acceptable

• SST II (Gold Cap)
• Lithium Heparin - Non-gel (Green Cap)
• Lithium Heparin - Gel (Light Green Cap)
• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

2

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Acceptable

• SST II (Gold Cap)
• Lithium Heparin - Non-gel (Green Cap)
• Lithium Heparin - Gel (Light Green Cap)
• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1

Pre-testing Requirements

Pre-Testing Requirements:
If patient is on high dose Biotin therapy (>5 mg/day), wait until at least 8 hours after last dose to take blood sample

Additional Specimen Information

Sample should be separated as soon as possible and sent to Endolab same day. If not in Endolab same day, then separate and freeze.

Aliquot Instructions

Sample Type

• Serum
• Plasma

Minimum Volume (ml)

0.15

Transport to Lab

Chilled (2 - 8 degrees Celsius)
If overnight - Frozen

Additional Referral/Aliquot Information

Preferably 0.5ml serum or plasma. Minimum 0.15ml serum or plasma. Heat-inactivated samples are not acceptable.

West Coast: If specimen is unable to be separated, take blood on SST, centrifuge as soon as possible, and send chilled to Greymouth Lab. At Greymouth lab freeze serum/plasma for transport to CHL.

Interpretation

Elevated level indicates probable acromegaly

Reference Intervals

Specific age and gender-related intervals are issued with each result as well as a calculated SDS (standard deviation score)

Test Method

Automated ICMA on an IDS iSYS analyser (since June 2014)

Non-Funded Test Cost

$41.97 (Exclusive of GST)

Billing Code

8381

This automated method replaced a manual "in-house" radioimmunoassay in June 2014 and the registration code changed from IGF1 to IGF. The reference intervals for the two methods are not interchangeable.

This method is not validated for animal IGF-1 measurements.

Contact Information

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