Category
SPECIAL CHEMISTRY.
Sub Category
ENDOCRINE.
Synonyms/Aliases
SEX STEROID BINDING PROTEIN; TESTOSTERONE-OESTRADIOL BINDING GLOBULIN; TESTOSTERONE-ESTRADIOL BINDING GLOBULIN.
Abbreviations
SHBG; SBP; ToBG; TeBG.
Type
INDIVIDUAL TEST.
7 DAYS
RESULTS READY/ REPORTED IN 7 WORKING DAYS.
Method
IMMUNOASSAY.
Temp
AMBIENT, REFRIGERATED OR FROZEN.
Setup
BATCHED.
Components Parameters
N/A.
PRE-ANALYTIC CONSIDERATIONS
Test Ordering Instructions
FILL OUT TEST REQUEST FORM FULLY & LEGIBLY.
Patient preparation
NOT APPLICABLE.
Sample type
SERUM. HEPARIN PLASMA IS AN ACCEPTABLE ALTERNATE SPECIMEN.
Container/ preservative
SERUM SEPARATOR TUBE (SST/ GEL) OR PLAIN (RED TOP) VACUTAINER.
Sample volume
AT LEAST 2 ML.
Rejection criteria
LABELING ISSUE (UNLABELED/ MISLABELED); MISSING REQUEST FORM; MISMATCH BETWEEN REQUEST FORM & SAMPLE DETAILS; MISSING AGE/ GENDER; WRONG SAMPLE TYPE; INSUFFICIENT SAMPLE.
Other Instructions
CENTRIFUGE SST (SERUM GEL TUBES) WITHIN 1-2 HOURS OF COLLECTION. CENTRIFUGE RED TOP VACUTAINERS AND ALIQUOT SERUM WITHIN 1-2 HOURS OF COLLECTION. THE SEPARATION VIAL MUST BE LABELED WITH AT LEAST 2 PATIENT IDENTIFIERS AND THE SAMPLE TYPE.
Reference intervals
DEPENDENT ON AGE, GENDER & TANNER STAGE.
Clinical Utility
SHBG IS THE MAJOR SEX STEROID BINDING PROTEIN & INFLUENCES BIOAVAILABLE LEVELS OF TESTOSTERONE. FURTHER TESTING WHEN TOTAL TESTOSTERONE LEVELS ARE DISCORDANT WITH SIGNS & SYMPTOMS E.G. CALCULATION OF FREE ANDROGEN INDEX FROM TOTAL TESTOSTERONE & SHBG LEVELS. ALSO USED IN EVALUATION OF PATIENTS WITH FEATURES OF ANDROGEN EXCESS (HIRSUTISM, PCOS ETC.).
Test Limitations/ Confounders
LEVELS ARE INCREASED BY THYROID HORMONES, ESTROGENS AND DECREASED BY ANDROGENS. IMMUNOASSAY INTERFERENCE CAN GIVE RISE TO SPURIOUS RESULTS. SUCH INTERFERENCE CAN ARISE FROM PRESENCE OF HETEROPHILE ANTIBODIES, ANTI-ANIMAL ANTIBODIES, AUTOANTIBODIES, PARAPROTEINS, BIOTIN ETC. RESULTS SHOULD ALWAYS BE CORRELATED WITH CLINICAL FINDINGS.