Growth Disorder Management Immunoassays

The Immunodiagnostic Systems Limited growth panel currently offers three fully automated, non-radioactive, chemiluminescent immunoassays which measure:

• IDS human Growth Hormone (hGH)
• IDS Insulin-like Growth Factor-I (IGF-I)
• IDS Insulin-like Growth Factor Binding Protein-3 (IGFBP-3)

This portfolio of assays provides laboratories with a growth disorder management solution which is:

Unique

• Conformance to Consensus Statement on the Standardisation and Evaluation of GH and IGF-I Assays¹
• Full adherence to the World Health Organisation Standard and Reference Material

Comprehensive

• Complete panel for growth disorder management
• Total automated testing solution available for use on the IDS-iSYS Multi-Discipline Automated System

Efficient

• Only 1 patient serum or plasma sample required
• Precise and accurate first-pass measurement

There are two main types of growth disorders: excessive growth and growth-hormone deficiency.

Excessive growth
Acromegaly is the most common disorder of excess growth hormone secretion, caused by hyper secretion of IGF-I. In contrast to gigantism in children, it occurs in adolescence and adults after their epiphyseal growth plates have fused.

The symptoms of acromegaly vary and can develop gradually over time. Early detection of acromegaly is key, as the pathological effects of increased growth hormone production are progressive. IGF-I provides the most sensitive lab test for the diagnosis of acromegaly.

Gigantism is a very rare disorder which affects both children and adolescents and is also an excessive action of IGF-I, but occurring whilst epiphyseal growth plates are open. Those with gigantism stand >2 standard deviations above the mean height for their gender and age.

Growth Hormone Deficiency
Growth hormone deficiency means the pituitary gland does not make enough growth hormone. The cause of growth hormone deficiency is mainly unknown. It may be present at birth or develop later as a result of an injury or medical condition. Severe brain injury may also cause growth hormone deficiency. Slow growth may first be noticed in infancy and continue through childhood. Although uncommon, growth hormone deficiency may also be diagnosed in adults. Possible causes include tumours involving the pituitary gland or hypothalamus, or brain radiation treatments for cancer.

The IDS Growth panel can be used to:

• Identify diseases and conditions caused by either a deficiency, or overproduction of growth hormone (GH)
• Evaluate pituitary function
• Monitor the effectiveness of growth hormone (GH) treatment

The IDS Insulin-like Growth Factor-I (IGF-I) assay can be used to achieve faster diagnosis of growth disorders and for growth hormone treatment monitoring. IDS human Growth Hormone (hGH) tests are primarily requested on those with symptoms of growth hormone abnormalities, as a follow-up to other abnormal hormone test results, or to help understand pituitary gland function. IDS Insulin-like Growth Factor Binding Protein-3 (IGFBP-3) is particularly useful for diagnosing paediatric growth hormone disorders as patients with GHD have sub-normal IGFBP-3 levels.

The IDS growth portfolio provides a comprehensive, unique and efficient tool to assist laboratories and clinicians in the diagnosis and treatment monitoring of growth hormone disorders.

1. Clemmons, D. Consensus Statement on the Standardization and Evaluation of Growth Hormone and Insulin-like Growth Factor Assays.Clinical Chemistry 57:4 (2011).

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