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Free Androgen Index (LCMS)
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General
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Clinical Use:
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The relationship between the circulating concentrations of SHBG and testosterone is important in the evaluation of possible androgen excess in women who have hirsutism, acne or virilization, which may originate from excessive adrenal (eg Cushings syndrome) or ovarian (eg polycystic ovarian syndrome, PCOS, or ovarian tumour) androgen production. However, the total testosterone may be within normal limits but the SHBG may be abnormal. In females, the ratio of testosterone to SHBG (Free Androgen Index, FAI) approximately determines the "biologically available" fraction of testosterone in the blood. Thus the FAI is superior to the measurement of serum androgen concentrations alone as an indicator of androgen excess. Also, changes in the FAI during therapy generally parallel the clinical outcome. In males, the FAI is not a good index of the "biologically available" fraction of testosterone in the blood and is therefore not reported. |
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Availability:
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Samples are batched and tested twice a week. |
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Aliases/Synonyms:
| FAI (LCMS), |
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Code:
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TXX |
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Handling Instructions (to laboratory):
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Send sample chilled. |
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Hyperlink:
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Reference Interval:
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Calculated measure
FAI: <6.0
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Collection Requirements
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Container:
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Serum, no gel (RED), |
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Sample Type:
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See container |
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Minimum Collection Volume:
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1mL |
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Collection Instructions:
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If a dexamethasone suppression test is requested at the same time, collect the free androgen index on day one and schedule the dexamethasone suppression test for day 2. |
Processing Requirements
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Alternate Containers:
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Processing Instructions:
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If a sample other than serum non-gel is received, please forward sample to the testing department to determine sample suitability. |
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Minimum Assay Volume:
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150uL |
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Stability:
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7 days chilled; 2 months frozen |
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Transport Instructions (to testing laboratory):
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Send sample chilled. |
Testing Locations
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Performed at:
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Section
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Department
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Site
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Contact Phone
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| HPLC/LCMS |
Biochemistry |
Fiona Stanley Hospital |
6152 2396 |
| Special Chemistry |
Biochemistry |
QEII Medical Centre |
6383 4114 |
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Last Updated : 07-10-2020 11:13 |