Laboratory Medicine
Test Directory / Sex Hormone Binding Globulin
Sex Hormone Binding Globulin
Brown clotted serum, gel barrier
| Test | Sex Hormone Binding Globulin |
|---|---|
| Common Abbreviations | SHBG |
| Profile | Consists of testosterone and SHBG |
| Tube type | Brown clotted serum, gel barrier |
| Clinical Indication | Measurement of SHBG and testosterone levels enables the concentration of biologically active testosterone to be estimated. Testosterone circulates mainly in protein bound form, principally to SHBG, but also to albumin & cortisol binding globulin. Since variations in the carrier protein levels may affect the concentration of testosterone in circulation, SHBG levels are commonly measured as a supplement to total testosterone determinations. The Free Androgen Index (FAI), calculated as the ratio of total testosterone to SHBG in women, has proved a useful indicator of abnormal androgen status in conditions such as hirsutism. |
| Specimen Type | Blood |
| Sample type | Serum |
| Minimum Volume | 0.5mL If requesting more than 10 tests please send an additional brown clotted serum sample. |
| Special Precautions | No special requirements |
| Stability | 5 days at 20 - 25°C, 7 days at 2 - 8°C and 12 months at -20°C |
| Turnaround Time | Inpatient: 48 hours Outpatient/ GP: 48 hours |
| Laboratory | York |
| Reference Interval | Male 20 - 49 years: 18.3 - 54.1 nmol/L Male ?50 years: 20.6 - 76.7 nmol/L Female 20 - 49 years: 32.4 - 128 nmol/L Female ? 50 years: 27.1 - 128 nmol/L (Quoted by the manufacturer) |
| Limitations | Analysis should not be performed on haemolysed, icteric or lipaemic samples. No interference was observed from rheumatoid factors up to a concentration of 1200 IU/mL. The assay is unaffected by biotin < 287 nmol/L or < 70 ng/mL. In rare cases, high titres of antibodies to analyte specific antibodies, streptavidin or ruthenium can occur. Samples should not be taken from patients receiving therapy with high biotin doses (i.e. > 5 mg/day) until at least 8 hours following the last biotin administration. In vitro tests were performed on 16 commonly used pharmaceuticals. No interference with the assay was found |
| Notes |
